Ductal carcinoma in situ (DCIS) is a category of early stage, non-invasive breast tumor defined by the intraductal proliferation of malignant breast epithelial cells. DCIS is a heterogeneous disease composed of multiple molecular subtypes including luminal, HER2 and basal-like types, which are characterized by immunohistochemical analyses and gene expression profiling. Following surgical and radiation therapies, patients with luminal-type, estrogen receptor-positive DCIS breast tumors can benefit from adjuvant endocrine-based treatment. However, there are no available targeted therapies for patients with basal-like DCIS (BL-DCIS) tumors due to their frequent lack of endocrine receptors and HER2 amplification, rendering them potentially susceptible to recurrence. Moreover, multiple lines of evidence suggest that DCIS is a non-obligate precursor of invasive breast carcinoma. This raises the possibility that targeting precursor BL-DCIS is a promising strategy to prevent BL-DCIS patients from the development of invasive basal-like breast cancer. An accumulating body of evidence demonstrates the existence of cancer stem-like cells (CSCs) in BL-DCIS, which potentially determine the features of BL-DCIS and their ability to progress into invasive cancer. This review encompasses the current knowledge in regard to the characteristics of BL-DCIS, identification of CSCs, and their biological properties in BL-DCIS. We summarize recently discovered relevant molecular signaling alterations that promote the generation of CSCs in BL-DCIS and the progression of BL-DCIS to invasive breast cancer, as well as the influence of the tissue microenvironment on CSCs and the invasive transition. Finally, we discuss the translational implications of these findings for the prognosis and prevention of BL-DCIS relapse and progression.
Aim: To examine the influence of gynecologic oncologists (GO) in the United States on surgical/chemotherapeutic standard of care (SOC), and how this translates into improved survival among women with ovarian cancer (OC).
Methods: Surveillance, Epidemiology, and End Result (SEER)-Medicare data were used to identify 11688 OC patients (1992-2006). Only Medicare recipients with an initial surgical procedure code (n = 6714) were included. Physician specialty was identified by linking SEER-Medicare to the American Medical Association Masterfile. SOC was defined by a panel of GOs. Multivariate logistic regression was used to determine predictors of receiving surgical/chemotherapeutic SOC and proportional hazards modeling to estimate the effect of SOC treatment and physician specialty on survival.
Results: About 34% received surgery from a GO and 25% received the overall SOC. One-third of women had a GO involved sometime during their care. Women receiving surgery from a GO vs non-GO had 2.35 times the odds of receiving the surgical SOC and 1.25 times the odds of receiving chemotherapeutic SOC (P < 0.01). Risk of mortality was greater among women not receiving surgical SOC compared to those who did [hazard ratio = 1.22 (95%CI: 1.12-1.33), P < 0.01], and also was higher among women seen by non-GOs vs GOs (for surgical treatment) after adjusting for covariates. Median survival time was 14 mo longer for women receiving combined SOC.
Conclusion: A survival advantage associated with receiving surgical SOC and overall treatment by a GO is supported. Persistent survival differences, particularly among those not receiving the SOC, require further investigation.
Aim: To determine the association between the distribution of gynecologic oncologist (GO) and population-based ovarian cancer death rates.
Materials and methods: Data on ovarian cancer incidence and mortality in the United States (U.S.) was supplemented with U.S. census data, and analyzed in relation to practicing GOs. GO locations were geocoded to link association between county variables and GO availability. Logistic regression was used to measure areas of high and low ovarian cancer mortality, adjusting for contextual variables.
Results: Practicing GOs were unevenly distributed in the United States, with the greatest numbers in metropolitan areas. Ovarian cancer incidence and death rates increased as distance to a practicing GO increased. A relatively small number (153) of counties within 24 miles of a GO had high ovarian cancer death rates compared to 577 counties located 50 or more miles away with high ovarian cancer death rates. Counties located 50 or more miles away from a GO practice had an almost 60% greater odds of high ovarian cancer mortality compared to those with closer practicing GOs (OR 1.59, 95% CI 1.18-2.15).
Conclusion: The distribution of GOs across the United States appears to be significantly associated with ovarian cancer mortality. Efforts that facilitate outreach of GOs to certain populations may increase geographic access. Future studies examining other factors associated with lack of GO access (e.g. insurance and other socioeconomic factors) at the individual level will assist with further defining barriers to quality ovarian cancer care in the United States.