Cancer prevention research (Philadelphia, Pa.)最新文献

The study by Downs and colleagues targets patients with non-muscle-invasive bladder cancer (NMIBC) to explore secondary/tertiary cancer prevention strategies. Utilizing a "window-of-opportunity" design, erlotinib was evaluated for its effect on EGFR phosphorylation, although the unconventional dosing regimen failed to demonstrate efficacy. New opportunities in NMIBC prevention include targeting FGFR3 mutations with emerging FGFR inhibitors. A future trial design could focus on clinical outcomes such as tumor response and NMIBC recurrence while also evaluating FGFR3 inhibition in both tumor and adjacent normal bladder epithelia. See related article by Downs et al., p. 31.

Mammographic density is a strong risk factor for breast cancer and is reported clinically as part of Breast Imaging Reporting and Data System (BI-RADS) results issued by radiologists. Automated assessment of density is needed that can be used for both full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) as both types of exams are acquired in standard clinical practice. We trained a deep learning model to automate the estimation of BI-RADS density from a prospective Washington University clinic-based cohort of 9,714 women, entering into the cohort in 2013 with follow-up through October 31, 2020. The cohort included 27% non-Hispanic Black women. The trained algorithm was assessed in an external validation cohort that included 18,360 women screened at Emory from January 1, 2013, and followed up through December 31, 2020, that included 42% non-Hispanic Black women. Our model-estimated BI-RADS density demonstrated substantial agreement with the density as assessed by radiologists. In the external validation, the agreement with radiologists for category B 81% and C 77% for FFDM and B 83% and C 74% for DBT shows important distinction for separation of women with dense breast. We obtained a Cohen's κ of 0.72 (95% confidence interval, 0.71-0.73) in FFDM and 0.71 (95% confidence interval, 0.69-0.73) in DBT. We provided a consistent and fully automated BI-RADS estimation for both FFDM and DBT using a deep learning model. The software can be easily implemented anywhere for clinical use and risk prediction. Prevention Relevance: The proposed model can reduce interobserver variability in BI-RADS density assessment, thereby providing more standard and consistent density assessment for use in decisions about supplemental screening and risk assessment.

Women at increased risk for breast cancer may benefit from taking risk-reducing medication (RRM) with tamoxifen (tam). Historical uptake of tam in women who qualify has been low. Recent studies have shown low-dose tam to have similar efficacy to standard dosing, with lower risk for adverse events. In this study, we aimed to evaluate uptake, adherence, and tolerability of low-dose tam in women at increased risk for breast cancer and those with ductal carcinoma in situ (DCIS). In this two-site prospective study, women who qualified for breast cancer RRM were offered participation and received consultation with a breast specialist for discussion of RRM rationale, benefits, side effects, and risks. Patients received baseline and 1-year follow-up surveys. A total of 41 patients consented for participation, and 31 completed 1-year follow-up. After initial consultation, 90% (n = 37) reported good/complete understanding of breast cancer risk. Of patients included in 1-year follow-up, 5 had DCIS, 13 had high-risk intraepithelial lesion, and 13 qualified based on Breast Cancer Risk Assessment Tool/International Breast Intervention Study calculation. Furthermore, 74% (n = 23) of patients reported that they took low-dose tam after consultation, with 78.2% (n = 18) of those still taking medication at 1 year. Patients who continued medication had higher estimated breast cancer risk compared with those who discontinued (International Breast Intervention Study 10-year risk, 12.7% vs. 7.6%; P = 0.027). All patients with DCIS initiated low-dose tam, and only one patient with DCIS had discontinued at 1 year. Uptake of low-dose tam after informed discussion is high. Adherence and tolerability at 1-year follow-up improved compared with those with traditional dosing of tam. Prevention Relevance: tam has been used extensively for breast cancer prevention in high-risk women. Historical uptake has been low because of concern for side effects and poor tolerability. Herein, we demonstrate that in the clinical setting, effective patient education and offering of a low-dose option can improve uptake in this high-risk population. See related Spotlight, p. 545.

Gastric adenocarcinoma (GAC) is the fourth leading global cause of cancer mortality and leading infection-associated cancer. High-incidence regions of GAC include Latin America and Eastern Asia. Immigrants from high-incidence regions maintain their GAC risk. GAC is a major U.S. cancer disparity, and its incidence rates are 2 to 10 times higher in non-White populations. Emerging guidelines recommend 3-year surveillance endoscopy for patients with high-risk gastric premalignant conditions (GPMC). Clinical trials of GPMC chemoprevention agents are lacking. We conducted a NCI Division of Cancer Prevention-funded, phase II placebo-controlled chemoprevention trial in patients with GPMCs (atrophic gastritis and intestinal metaplasia) with a highly bioavailable preparation of curcuminoids (Meriva). The trial sites in Puerto Rico and rural Honduras had important characteristics: (i) representative Caribbean and Mesoamerican populations, linked to large U.S. immigrant populations; (ii) high prevalence of Helicobacter pylori infection and GPMCs; (iii) the absence of turmeric and curcuminoids in local diets; and (iv) proven bidirectional collaboration with U.S. academic institutions. H. pylori-negative patients with GPMCs were randomized to the study drug (500 mg po bid) or placebo for 180 days (NCT02782949), with primary outcomes based upon histologic parameters. Principal study challenges included (i) an international regulatory environment; (ii) research infrastructure strengthening, particularly in Central America; (iii) participant recruitment in Honduras, wherein only 10% to 15% are H. pylori negative; (iv) the COVID-19 pandemic; and (v) natural disasters (three hurricanes). There were no losses to follow-up related to the pandemic or natural disasters. In conclusion, the south-south partnership provides a model for chemoprevention and translational studies in Latino populations with prevalent cancers, such as GAC.

The uptake and adherence of preventive therapy of breast cancer in clinical practice are low because of fear of serious adverse events and menopausal symptoms. Low-dose tamoxifen has been shown to retain efficacy while reducing toxicity in high-risk women. In this issue of the journal, Cornell and colleagues evaluated uptake, adherence, and tolerability of low-dose tamoxifen in high-risk women. More than 70% of patients reported that they took low-dose tamoxifen after counseling and were still taking the medication at 1 year. This paradigm shift may move the field of breast cancer prevention forward and reduce breast cancer incidence and mortality. See related article by Cornell et al., p. 565.

Metformin administration has recently emerged as a candidate strategy for the prevention of head and neck squamous cell carcinoma (HNSCC). However, the intricate relationship between genetic alterations in HNSCC and metformin sensitivity is still poorly understood, which prevents the stratification of patients, harboring oral premalignant lesions that may benefit from the chemopreventive activity of metformin. In this study, we investigate the impact of prevalent mutations in HNSCC on response to metformin. Notably, we found that the expression of oncogenic HRAS mutants confers resistance to metformin in isogenic HNSCC cell systems, and that HNSCC cells harboring endogenous HRAS mutations display limited sensitivity to metformin. Remarkably, we found that metformin fails to reduce activation of the mTOR pathway in HRAS oncogene-expressing HNSCC cells in vitro and in vivo, correlating with reduced tumor suppressive activity. Mechanistically, we found that this process depends on the ability of HRAS to enhance glycolytic metabolism, thereby suppressing the requirement for oxidative phosphorylation to maintain the cellular energetic balance. Overall, our study revealed that HNSCC cells with oncogenic HRAS mutations exhibit diminished metformin sensitivity, thus shedding light on a potential mechanism of treatment resistance. This finding may also help explain the limited clinical responses to metformin in cancers with RAS mutations. Ultimately, our study underscores the importance of understanding the impact of the genetic landscape in tailoring precision cancer-preventive approaches in the context of HNSCC and other cancers that are characterized by the presence of a defined premalignant state, and therefore, are amenable to cancer interception strategies. Prevention Relevance: Our findings highlight the challenges of using metformin for cancer prevention in RAS-mutant cancers, where elevated glycolysis may reduce drug efficacy. This underscores the need to explore metformin's potential in early, premalignant stages, before metabolic shifts render it less effective.

Oxysterols are metabolites of cholesterol that regulate the homeostasis of cholesterol, fatty acids, and glucose. These metabolites are generated throughout the body, either enzymatically or from oxidative stress, and are detectable in peripheral circulation. We previously reported that circulating 27-hydroxycholesterol (27-OHC), an endogenous selective estrogen receptor modulator, may be a risk factor for colorectal adenomas. Here, in addition to 27-OHC, we report on four other circulating oxysterols: 25-hydroxycholesterol, 24(S)-hydroxycholesterol, 7ɑ-hydroxycholesterol, and 4β-hydroxycholesterol. Oxysterol concentrations were measured using liquid chromatography/mass spectrometry from fasting plasma collected at baseline from 1,246 participants of the Vitamin D/Calcium Polyp Prevention Study, a multicenter adenoma chemoprevention trial. To evaluate multiple oxysterols simultaneously, we used both log-linear regression and Bayesian kernel machine regression models developed for analyses of complex mixtures adjusted for potential confounding factors. Higher circulating 7ɑ-hydroxycholesterol was associated with higher adenoma risk (Bayesian kernel machine regression-based multivariable-adjusted risk ratios (RR; for the 75th vs. 25th percentile, 1.22; 95% credible interval, CI, 1.04-1.42). In contrast, higher circulating 4β-hydroxycholesterol was associated with lower risk of these polyps (RR, 0.84; 95% CI, 0.71-0.99). The positive association with advanced adenoma risk that we previously reported for circulating 27-OHC persisted when controlling for other oxysterols (RR, 1.26; 95% CI, 0.98-1.62), including among those with advanced adenomas at baseline (RR, 1.75; 95% CI, 1.01-3.06). Prevention Relevance: Circulating concentrations of multiple oxysterols measured at the time of an initial colorectal adenoma diagnosis may be risk factors for subsequent incidence of these lesions. Novel colorectal cancer prevention strategies may target oxysterol formation.

Vaginal dysbiosis is implicated in persistent human papillomavirus (HPV) infection and cervical cancer. Yet, there is a paucity of data on the vaginal microbiome in Native American communities. Here, we aimed to elucidate the relationships between microbiome, HPV, sociodemographic, and behavioral risk factors to better understand an increased cervical cancer risk in Native American women. In this pilot study, we recruited 31 participants (16 Native American and 15 non-Native women) in Northern Arizona and examined vaginal microbiota composition, HPV status, and immune mediators. We also assessed individuals' sociodemographic information and physical, mental, sexual, and reproductive health. Overall, microbiota profiles were dominated by common Lactobacillus species (associated with vaginal health) or a mixture of bacterial vaginosis-associated bacteria. Only 44% of Native women exhibited Lactobacillus dominance, compared with 58% of non-Native women. Women with vaginal dysbiosis also had elevated vaginal pH and were more frequently infected with high-risk HPV. Furthermore, we observed associations of multiple people in a household, lower level of education, and high parity with vaginal dysbiosis and abundance of specific bacterial species. Finally, women with dysbiotic microbiota presented with elevated vaginal levels of proinflammatory cytokines. Altogether, these findings indicate an interplay between HPV, vaginal microbiota, and host defense, which may play a role in the cervical cancer disparity among Native American women. Future longitudinal studies are needed to determine the mechanistic role of vaginal microbiota in HPV persistence in the context of social determinants of health toward the long-term goal of reducing health disparities between non-Hispanic White and Native American populations. Prevention Relevance: Cervical cancer disproportionally affects Native American women. Sociodemographic and behavioral factors might contribute to this disparity via alteration of vaginal microbiota. Here, we show the association between these factors and vaginal dysbiosis and immune activation, which can be implicated in high-risk HPV infection among Native American and other racial/ethnic populations.