Introduction: Titanium dioxide has been classified by the International Agency for Research on Cancer (IARC) as a Group 2B carcinogen. As indispensable material for dental implant fixture, dental patients are exposed to its toxicological reactions. Objectives: The primary aim of this research is to prevent making nanoparticle titanium dioxide from the corrosion of dental implant fixture and gain possible osseointegration. Methods: The authors introduce two-layer coating system for controlling corrosional toxicity of TiO2 from the surface of two dental implant fixtures by medronic acid and teriparatide acetate. Results: The first layer coated with medronic acid will generate phosphate bridges, functioning as a corrosion-resistant sheath layer, and will be the only connector to Forteo (Teriparatide Acetate). The second layer encloses the essential elements of teriparatide like C, N, O and H with saving the functional radicals like CNO-, C2H3O-, CHO2-, C3H3O- and C2H3O2-, for and it will stimulate the coated implant fixture with PTH receptors, osteoblasts, and osteogenesis. The first layer covers Ti-O-P, acting as a titanium grade 4 antioxidant. Conclusion: The top surface radicals in the second layer of the fixture have pharmaceutically functioning parts of the chemical structure of Teriparatide (C181H291N55O51S2) activating osteoblasts more than osteoclasts, which leads to an overall increase in bone. Though the recommended duration of use for grade 4 implant fixtures is 3 years, but these new coated fixtures are expected to use longer than 3 years by containing the stimulating effect of new alveolar bone formation by increasing the mineral density of the alveolar bone around the fixture besides preventing corrosional toxicity from the surface of preexisting titanium fixtures. Cheaper producing cost of a coated implant fixture are also suggested.
{"title":"Schematic Suggestion and Results of Two-Layer Coating System for Controlling Corrosional Toxicity of Titanium Dioxide from Dental Implant Fixture","authors":"Bon-Suk Goo, T. Navrátil, I. Malbohan","doi":"10.2139/ssrn.3898489","DOIUrl":"https://doi.org/10.2139/ssrn.3898489","url":null,"abstract":"Introduction: Titanium dioxide has been classified by the International Agency for Research on Cancer (IARC) as a Group 2B carcinogen. As indispensable material for dental implant fixture, dental patients are exposed to its toxicological reactions. Objectives: The primary aim of this research is to prevent making nanoparticle titanium dioxide from the corrosion of dental implant fixture and gain possible osseointegration. Methods: The authors introduce two-layer coating system for controlling corrosional toxicity of TiO2 from the surface of two dental implant fixtures by medronic acid and teriparatide acetate. Results: The first layer coated with medronic acid will generate phosphate bridges, functioning as a corrosion-resistant sheath layer, and will be the only connector to Forteo (Teriparatide Acetate). The second layer encloses the essential elements of teriparatide like C, N, O and H with saving the functional radicals like CNO-, C2H3O-, CHO2-, C3H3O- and C2H3O2-, for and it will stimulate the coated implant fixture with PTH receptors, osteoblasts, and osteogenesis. The first layer covers Ti-O-P, acting as a titanium grade 4 antioxidant. Conclusion: The top surface radicals in the second layer of the fixture have pharmaceutically functioning parts of the chemical structure of Teriparatide (C181H291N55O51S2) activating osteoblasts more than osteoclasts, which leads to an overall increase in bone. Though the recommended duration of use for grade 4 implant fixtures is 3 years, but these new coated fixtures are expected to use longer than 3 years by containing the stimulating effect of new alveolar bone formation by increasing the mineral density of the alveolar bone around the fixture besides preventing corrosional toxicity from the surface of preexisting titanium fixtures. Cheaper producing cost of a coated implant fixture are also suggested.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89619418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In radiotherapy, uncertainties in tumor radioresistance and its progression can degrade the efficacy of deterministic treatments. While a robust methodology can overcome this, it often produces overly conservative or suboptimal decisions, especially when there are changes in time. We aim to develop an adaptive radiotherapy planning framework that can reduce over-conservatism yet remain robust to the uncertainties in radioresistance. Specifically, intermediate imaging is used to update the uncertainty at each stage and curb over-conservatism. While additional imaging reduces uncertainty, it accrues costs such as extra radiation to organs, which deters continuous imaging. We probe this trade-off in uncertainty and cost of observation by computing and comparing results from two-stage, three-stage, and four-stage robust models. The three robust models are also compared to two currently practiced deterministic methods, one that does not account for radioresistance and one that assumes a constant radioresistance. All five models are evaluated on a clinical prostate case. The three robust models improve control of the tumor compared to the deterministic model ignoring radioresistance, at comparable radiation dose to critical organs. The robust models also reduce tumor overdose and organ dose compared to the deterministic model assuming a constant radioresistance. Increasing the number of intermediate imaging leads to further improvements, especially on tumor dose criteria under best-case and nominal scenarios. Under the worst-case, intermediate images provide no additional benefit as robust optimization inherently protects against the worst-case. The proposed method is generic and can include additional sources of uncertainties that reduce the effect of radiation.
{"title":"Towards Adaptive Robust Radiotherapy to Manage Radioresistance","authors":"A. Roy, S. Dabadghao, Ahmadreza Marandi","doi":"10.2139/ssrn.3836102","DOIUrl":"https://doi.org/10.2139/ssrn.3836102","url":null,"abstract":"In radiotherapy, uncertainties in tumor radioresistance and its progression can degrade the efficacy of deterministic treatments. While a robust methodology can overcome this, it often produces overly conservative or suboptimal decisions, especially when there are changes in time. We aim to develop an adaptive radiotherapy planning framework that can reduce over-conservatism yet remain robust to the uncertainties in radioresistance. Specifically, intermediate imaging is used to update the uncertainty at each stage and curb over-conservatism. While additional imaging reduces uncertainty, it accrues costs such as extra radiation to organs, which deters continuous imaging. We probe this trade-off in uncertainty and cost of observation by computing and comparing results from two-stage, three-stage, and four-stage robust models. The three robust models are also compared to two currently practiced deterministic methods, one that does not account for radioresistance and one that assumes a constant radioresistance. All five models are evaluated on a clinical prostate case. The three robust models improve control of the tumor compared to the deterministic model ignoring radioresistance, at comparable radiation dose to critical organs. The robust models also reduce tumor overdose and organ dose compared to the deterministic model assuming a constant radioresistance. Increasing the number of intermediate imaging leads to further improvements, especially on tumor dose criteria under best-case and nominal scenarios. Under the worst-case, intermediate images provide no additional benefit as robust optimization inherently protects against the worst-case. The proposed method is generic and can include additional sources of uncertainties that reduce the effect of radiation.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75359486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
X. Kong, Qiang Liu, R. Coleman, Yi Fang, Jing Wang
Background Thorough population-based estimates of the epidemiological features of metastatic disease in newly diagnosed stage IV breast cancer are lacking.
Methods Target patients were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Logistic regression was used to estimate the odds ratios (ORs) for different metastasis patterns (bone, brain, liver and lung), stratified by sociodemographic and clinicopathological variables. Survival estimates were performed using the Kaplan-Meier method and the Cox regression.
Results A total of 356789 patients with breast cancer were included of which 18036 (5.06%) had stage IV disease. Bone metastasis had the highest composition ratio (42.6%). Patients with HR-/HER2+ subtype had the highest metastasis at diagnosis incidence proportions (1310/15062 [8.7%] of the entire cohort). Female breast cancer patients were more susceptible to bone metastasis, lung metastasis, and liver metastasis than male patients (all P<0.01). Hispanics were the most likely to have brain metastases (P<0.01). Compared with other subtypes, HR-/HER2- patients was the most likely to have lung metastases. Patients with bone metastasis displayed the longest median survival (27 months). Among patients with brain or liver metastases, Grade III patients had the worst prognosis (P<0.01). Among patients with lung metastasis, infiltrating duct mixed with other types of carcinoma (IDM) had a better prognosis than infiltrating duct carcinoma (IDC) (P<0.01). For liver metastases, TNM N0 stage patients had the highest risk of death, followed by N2 (P<0.01).
Conclusion We believe this is the most comprehensive analysis of the distribution and prognosis of metastatic disease in newly diagnosed stage IV breast cancer. It lends support to consideration of further studies evaluating the utility of modern screening strategies of the bone, brain, liver and lung among patient subsets at high risk for metastasis.
{"title":"Distribution and Prognosis of Metastatic Disease in Newly Diagnosed Stage IV Breast Cancer","authors":"X. Kong, Qiang Liu, R. Coleman, Yi Fang, Jing Wang","doi":"10.2139/ssrn.3633992","DOIUrl":"https://doi.org/10.2139/ssrn.3633992","url":null,"abstract":"Background Thorough population-based estimates of the epidemiological features of metastatic disease in newly diagnosed stage IV breast cancer are lacking.<br><br>Methods Target patients were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Logistic regression was used to estimate the odds ratios (ORs) for different metastasis patterns (bone, brain, liver and lung), stratified by sociodemographic and clinicopathological variables. Survival estimates were performed using the Kaplan-Meier method and the Cox regression.<br><br>Results A total of 356789 patients with breast cancer were included of which 18036 (5.06%) had stage IV disease. Bone metastasis had the highest composition ratio (42.6%). Patients with HR-/HER2+ subtype had the highest metastasis at diagnosis incidence proportions (1310/15062 [8.7%] of the entire cohort). Female breast cancer patients were more susceptible to bone metastasis, lung metastasis, and liver metastasis than male patients (all P<0.01). Hispanics were the most likely to have brain metastases (P<0.01). Compared with other subtypes, HR-/HER2- patients was the most likely to have lung metastases. Patients with bone metastasis displayed the longest median survival (27 months). Among patients with brain or liver metastases, Grade III patients had the worst prognosis (P<0.01). Among patients with lung metastasis, infiltrating duct mixed with other types of carcinoma (IDM) had a better prognosis than infiltrating duct carcinoma (IDC) (P<0.01). For liver metastases, TNM N0 stage patients had the highest risk of death, followed by N2 (P<0.01).<br><br>Conclusion We believe this is the most comprehensive analysis of the distribution and prognosis of metastatic disease in newly diagnosed stage IV breast cancer. It lends support to consideration of further studies evaluating the utility of modern screening strategies of the bone, brain, liver and lung among patient subsets at high risk for metastasis.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85338117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The likelihood of cancer emergence is highly dependent on the underlying tissue structure. This article gives evolutionary explanations for why natural selection fails to select for tissue structures that would minimize the likelihood of cancer. In a second step, a mathematical framework is proposed, within which the risk of cancer emergence can be expressed and calculated dependent on a given tissue structure. This can be used to identify optimal structures and strategies for improvement. Lastly, the article explores both, ways to identify target areas for such intervention, as well as avenues towards developing treatment options.
{"title":"Preventative Cancer Treatments Through Optimizing Tissue Structure","authors":"C. Graser","doi":"10.2139/ssrn.3542732","DOIUrl":"https://doi.org/10.2139/ssrn.3542732","url":null,"abstract":"The likelihood of cancer emergence is highly dependent on the underlying tissue structure. This article gives evolutionary explanations for why natural selection fails to select for tissue structures that would minimize the likelihood of cancer. In a second step, a mathematical framework is proposed, within which the risk of cancer emergence can be expressed and calculated dependent on a given tissue structure. This can be used to identify optimal structures and strategies for improvement. Lastly, the article explores both, ways to identify target areas for such intervention, as well as avenues towards developing treatment options.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74529758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaobei Luo, E. Fong, Chaojun Zhu, Quy Xiao Xuan Lin, Man Xiong, Aimin Li, Tingting Li, T. Benoukraf, Hanry Yu, Side Liu
The development of patient-derived organoid (PDO) technologies has greatly expanded the toolbox for drug discovery and personalized drug screening for several cancer types. While PDO models more closely represent the molecular characteristics and heterogeneity of patient tumors than traditional immortalized cancer cell lines, they are inherently limited in their ability to reflect the tumor microenvironment in vitro as they comprise exclusively of epithelial cells. The lack of stromal cells in PDO models, such as cancer-associated fibroblasts (CAFs), poses a major problem as these tumor microenvironmental components contribute to the various hallmarks of cancer and response to therapy. Particularly for colorectal cancer, CAFs comprise the majority of the tumor microenvironment and play important roles in cancer progression and drug resistance. In this study, we addressed this problem by establishing in vitro conditions that robustly enable the co-culture of CRC PDO with patient-derived CAFs. We report the development of an engineered tumor microenvironment consisting of CRC PDO encapsulated within a well-defined three-dimensional (3D) hyaluronan-gelatin hydrogel and co-cultured with patient-derived CAFs. Basement membrane extracts conventionally used for PDO culture exhibit batch-to-batch variability. Considering that the CRC extracellular matrix is high in hyaluronan and collagen I, and that hyaluronan-based matrices have been shown to be conducive for the culture of various human cancers, we hypothesized that hyaluronan-gelatin hydrogels may serve as a suitable alternative 3D matrix to support the co-culture of CRC PDO and CAFs. Through RNA- and whole-exome sequencing, we first show that these hydrogels are capable of maintaining key molecular characteristics of the original patient tumors in CRC PDO but not support the culture of CAFs. Further, based on our findings that CRC PDO culture medium poorly supports CAF viability, we developed a co-culture strategy that maintains the viability of both CRC PDO and CAFs. We found that in the absence of growth factors added to the co-culture, CAFs were able to maintain the proliferation of the cultured CRC PDO in the hydrogels and restore distinct biological pathways absent in the PDO culture alone but present in patient tissues. Lastly, we demonstrate that these CRC PDO-CAFs models are suitable for evaluating standard-of-care drugs, making them potentially very useful for realizing personalized cancer medicine.
{"title":"Bioengineered Cancer-Fibroblast Interactions in Patient-Derived Colorectal Cancer Organoid Models","authors":"Xiaobei Luo, E. Fong, Chaojun Zhu, Quy Xiao Xuan Lin, Man Xiong, Aimin Li, Tingting Li, T. Benoukraf, Hanry Yu, Side Liu","doi":"10.2139/ssrn.3687917","DOIUrl":"https://doi.org/10.2139/ssrn.3687917","url":null,"abstract":"The development of patient-derived organoid (PDO) technologies has greatly expanded the toolbox for drug discovery and personalized drug screening for several cancer types. While PDO models more closely represent the molecular characteristics and heterogeneity of patient tumors than traditional immortalized cancer cell lines, they are inherently limited in their ability to reflect the tumor microenvironment in vitro as they comprise exclusively of epithelial cells. The lack of stromal cells in PDO models, such as cancer-associated fibroblasts (CAFs), poses a major problem as these tumor microenvironmental components contribute to the various hallmarks of cancer and response to therapy. Particularly for colorectal cancer, CAFs comprise the majority of the tumor microenvironment and play important roles in cancer progression and drug resistance. In this study, we addressed this problem by establishing in vitro conditions that robustly enable the co-culture of CRC PDO with patient-derived CAFs. We report the development of an engineered tumor microenvironment consisting of CRC PDO encapsulated within a well-defined three-dimensional (3D) hyaluronan-gelatin hydrogel and co-cultured with patient-derived CAFs. Basement membrane extracts conventionally used for PDO culture exhibit batch-to-batch variability. Considering that the CRC extracellular matrix is high in hyaluronan and collagen I, and that hyaluronan-based matrices have been shown to be conducive for the culture of various human cancers, we hypothesized that hyaluronan-gelatin hydrogels may serve as a suitable alternative 3D matrix to support the co-culture of CRC PDO and CAFs. Through RNA- and whole-exome sequencing, we first show that these hydrogels are capable of maintaining key molecular characteristics of the original patient tumors in CRC PDO but not support the culture of CAFs. Further, based on our findings that CRC PDO culture medium poorly supports CAF viability, we developed a co-culture strategy that maintains the viability of both CRC PDO and CAFs. We found that in the absence of growth factors added to the co-culture, CAFs were able to maintain the proliferation of the cultured CRC PDO in the hydrogels and restore distinct biological pathways absent in the PDO culture alone but present in patient tissues. Lastly, we demonstrate that these CRC PDO-CAFs models are suitable for evaluating standard-of-care drugs, making them potentially very useful for realizing personalized cancer medicine.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81297883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We describe how the development of x-ray-based techniques and equipment (“mammography”) lead to widespread screening for breast cancer and enabled “minimally invasive” biopsies of breast tumors. Specifically, we chronicle how: 1) new protocols and equipment catalyzed the first widespread screening programs and minimally invasive biopsies in the 1960s and 1970s; 2) concerns about safety and accuracy spurred technological advance in the 1980s; and, 3) digitization further improved the safety and accuracy of mammography in the 1990s and 2000s.
{"title":"Mammography: Case Histories of Significant Medical Advances","authors":"A. Bhide, S. Datar, K. Stebbins","doi":"10.2139/SSRN.3424129","DOIUrl":"https://doi.org/10.2139/SSRN.3424129","url":null,"abstract":"We describe how the development of x-ray-based techniques and equipment (“mammography”) lead to widespread screening for breast cancer and enabled “minimally invasive” biopsies of breast tumors. Specifically, we chronicle how: 1) new protocols and equipment catalyzed the first widespread screening programs and minimally invasive biopsies in the 1960s and 1970s; 2) concerns about safety and accuracy spurred technological advance in the 1980s; and, 3) digitization further improved the safety and accuracy of mammography in the 1990s and 2000s.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74909252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-02DOI: 10.3844/ajeassp.2018.1310.1319
Avishek Choudhury
Malignant Pleural Mesothelioma (MPM) or malignant mesothelioma (MM) is an atypical, aggressive tumor that matures into cancer in the pleura, a stratum of tissue bordering the lungs. Diagnosis of MPM is difficult and it accounts for about seventy-five percent of all mesothelioma diagnosed yearly in the United States of America. Being a fatal disease, early identification of MPM is crucial for patient survival. Our study implements logistic regression and develops association rules to identify early stage symptoms of MM. We retrieved medical reports generated by Dicle University and implemented logistic regression to measure the model accuracy. We conducted (a) logistic correlation, (b) Omnibus test and (c) Hosmer and Lemeshow test for model evaluation. Moreover, we also developed association rules by confidence, rule support, lift, condition support and deployability. Categorical logistic regression increases the training accuracy from 72.30% to 81.40% with a testing accuracy of 63.46%. The study also shows the top 5 symptoms that is mostly likely indicates the presence in MM. This study concludes that using predictive modeling can enhance primary presentation and diagnosis of MM.
{"title":"Identification of Cancer: Mesothelioma’s Disease Using Logistic Regression and Association Rule","authors":"Avishek Choudhury","doi":"10.3844/ajeassp.2018.1310.1319","DOIUrl":"https://doi.org/10.3844/ajeassp.2018.1310.1319","url":null,"abstract":"Malignant Pleural Mesothelioma (MPM) or malignant mesothelioma (MM) is an atypical, aggressive tumor that matures into cancer in the pleura, a stratum of tissue bordering the lungs. Diagnosis of MPM is difficult and it accounts for about seventy-five percent of all mesothelioma diagnosed yearly in the United States of America. Being a fatal disease, early identification of MPM is crucial for patient survival. Our study implements logistic regression and develops association rules to identify early stage symptoms of MM. We retrieved medical reports generated by Dicle University and implemented logistic regression to measure the model accuracy. We conducted (a) logistic correlation, (b) Omnibus test and (c) Hosmer and Lemeshow test for model evaluation. Moreover, we also developed association rules by confidence, rule support, lift, condition support and deployability. Categorical logistic regression increases the training accuracy from 72.30% to 81.40% with a testing accuracy of 63.46%. The study also shows the top 5 symptoms that is mostly likely indicates the presence in MM. This study concludes that using predictive modeling can enhance primary presentation and diagnosis of MM.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83776763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Colorectal cancer is the second leading cause of cancer-related mortality, but the cost-sharing environment for colonoscopies, the preferred form of screening, is complex. This paper combines a machine learning-based double-selection algorithm to perform principled covariate selection with differential exposure to the Affordable Care Act’s requirement that insurers fully cover cancer screening services as an instrumental variable to estimate the effect of cost sharing on colonoscopy utilization and price-shopping. The reduced form results show that the ACA’s requirements increased the use of colonoscopies by 1.7% and the IV results imply a price elasticity of 0.09. I do not find a price shopping response.
结直肠癌是癌症相关死亡的第二大原因，但结肠镜检查的费用分摊环境是复杂的，结肠镜检查是首选的筛查形式。本文结合了基于机器学习的双重选择算法来执行原则性的共变量选择，并对《平价医疗法案》(Affordable Care Act)的要求进行差异暴露，该法案要求保险公司完全覆盖癌症筛查服务，作为评估成本分摊对结肠镜检查使用率和价格购物的影响的工具变量。简化形式的结果表明，ACA的要求使结肠镜检查的使用增加了1.7%，IV结果意味着价格弹性为0.09。我没有发现价格购物的回应。
{"title":"The Effects of Cost Sharing on Cancer Screening and Price Shopping: Evidence from the Affordable Care Act","authors":"C. Whaley","doi":"10.2139/ssrn.3264607","DOIUrl":"https://doi.org/10.2139/ssrn.3264607","url":null,"abstract":"Colorectal cancer is the second leading cause of cancer-related mortality, but the cost-sharing environment for colonoscopies, the preferred form of screening, is complex. This paper combines a machine learning-based double-selection algorithm to perform principled covariate selection with differential exposure to the Affordable Care Act’s requirement that insurers fully cover cancer screening services as an instrumental variable to estimate the effect of cost sharing on colonoscopy utilization and price-shopping. The reduced form results show that the ACA’s requirements increased the use of colonoscopies by 1.7% and the IV results imply a price elasticity of 0.09. I do not find a price shopping response.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87000868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hepatocellular carcinoma (HCC) is the most common type of liver cancer and the fastest-growing cause of cancer-related deaths in the United States. Most HCC cases are attributed to chronic hepatitis C virus infection, which affects nearly 3 million Americans and 170 million globally. Although surveillance for HCC in hepatitis C patients can improve survival, the optimal surveillance policies remain unknown. In this study, we develop a mixed-integer programming (MIP)-based framework to systematically analyze a rich set of policies and determine the optimal HCC surveillance policies with the maximum societal net benefit. Our MIP-based framework captures two problem features that make dynamic programming-based formulation computationally intractable. In particular, our proposed framework allows to (1) explicitly formulate M-switch policies that are practical for implementation, and (2) tailor surveillance policies for each subpopulation by stratifying surveillance intervals based on the observable disease states. We theoretically analyze the HCC surveillance problem, characterize when the surveillance policies should be adapted to populations with different disease progression rates, and quantify the trade-off between decreasing HCC incidence and increasing treatment outcomes. We carefully parameterize our model using clinical trial data, a previously validated simulation model, and published clinical studies. Our numerical analyses lead to three main results with important policy implications. First, we find that, in addition to cirrhotic patients, expanding surveillance to patients in earlier stage of hepatitis C infection improves the cost-effectiveness of HCC surveillance. Second, compared with the one-size-fits-all type routine policies, we find that it is cost-effective to stratify surveillance strategies based on the stage of hepatitis C infection with less frequent cancer surveillance in earlier stages of infection. Lastly, we find that a little flexibility in the policy structure as captured by M-switch policies is sufficient to capture almost as much benefit as complex fully dynamic policies.
{"title":"Optimal M-Switch Surveillance Policies for Liver Cancer in Hepatitis C-Infected Population","authors":"Qiushi Chen, T. Ayer, J. Chhatwal","doi":"10.2139/ssrn.2966381","DOIUrl":"https://doi.org/10.2139/ssrn.2966381","url":null,"abstract":"Hepatocellular carcinoma (HCC) is the most common type of liver cancer and the fastest-growing cause of cancer-related deaths in the United States. Most HCC cases are attributed to chronic hepatitis C virus infection, which affects nearly 3 million Americans and 170 million globally. Although surveillance for HCC in hepatitis C patients can improve survival, the optimal surveillance policies remain unknown. In this study, we develop a mixed-integer programming (MIP)-based framework to systematically analyze a rich set of policies and determine the optimal HCC surveillance policies with the maximum societal net benefit. Our MIP-based framework captures two problem features that make dynamic programming-based formulation computationally intractable. In particular, our proposed framework allows to (1) explicitly formulate M-switch policies that are practical for implementation, and (2) tailor surveillance policies for each subpopulation by stratifying surveillance intervals based on the observable disease states. We theoretically analyze the HCC surveillance problem, characterize when the surveillance policies should be adapted to populations with different disease progression rates, and quantify the trade-off between decreasing HCC incidence and increasing treatment outcomes. We carefully parameterize our model using clinical trial data, a previously validated simulation model, and published clinical studies. Our numerical analyses lead to three main results with important policy implications. First, we find that, in addition to cirrhotic patients, expanding surveillance to patients in earlier stage of hepatitis C infection improves the cost-effectiveness of HCC surveillance. Second, compared with the one-size-fits-all type routine policies, we find that it is cost-effective to stratify surveillance strategies based on the stage of hepatitis C infection with less frequent cancer surveillance in earlier stages of infection. Lastly, we find that a little flexibility in the policy structure as captured by M-switch policies is sufficient to capture almost as much benefit as complex fully dynamic policies.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79075444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Given the global, national, and local impact of skin cancer in terms of morbidity/mortality as well as direct economic cost to treat, and the fact that skin cancer development in adulthood is mediated by exposure to ultraviolet radiation in youth and adolescence, the development of a skin cancer prevention program is of primary public health importance. This program will build upon the success of a similar program developed by MD Anderson Cancer Centre, which focused on the day-care environment and which has been shown to raise the capacity of parents, caregivers and children to engage in preventative sun exposure behaviour. This prevention programme will utilize the Health Belief Model (HBM) to increase sunscreen and protective clothing usage among pre/school age children of the patients of a primary care paediatrics practice in Las Vegas, Nevada, by providing their caregivers the knowledge/capacity to recognize the risks of sun exposure and adopt healthy sun protection habits for their children.
{"title":"The Use of Community-Based Primary Care Clinics for the Prevention of Skin Cancers: A Model Proposal","authors":"Brian P. Mangum, Paul O. Dacanay, T. Mangum","doi":"10.2139/SSRN.3043054","DOIUrl":"https://doi.org/10.2139/SSRN.3043054","url":null,"abstract":"Given the global, national, and local impact of skin cancer in terms of morbidity/mortality as well as direct economic cost to treat, and the fact that skin cancer development in adulthood is mediated by exposure to ultraviolet radiation in youth and adolescence, the development of a skin cancer prevention program is of primary public health importance. This program will build upon the success of a similar program developed by MD Anderson Cancer Centre, which focused on the day-care environment and which has been shown to raise the capacity of parents, caregivers and children to engage in preventative sun exposure behaviour. This prevention programme will utilize the Health Belief Model (HBM) to increase sunscreen and protective clothing usage among pre/school age children of the patients of a primary care paediatrics practice in Las Vegas, Nevada, by providing their caregivers the knowledge/capacity to recognize the risks of sun exposure and adopt healthy sun protection habits for their children.","PeriodicalId":19714,"journal":{"name":"Oncology eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85513869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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