Highlights of This Issue

Gilkey and colleagues sought to describe human papillomavirus (HPV) vaccine communication practices among primary care physicians. Physicians completed a national online survey and the quality of their HPV vaccine recommendations was assessed. A sizeable minority of physicians reported that they do not strongly endorse HPV vaccine (27%). Many physicians (59%) used a risk-based approach to recommending HPV vaccine and only half (51%) usually recommended same-day vaccination. In this national sample, many physicians reported recommending HPV vaccine inconsistently, behind schedule, or without urgency. Efforts to improve physician communication about HPV vaccine will be critical to address the persistent underuse of a powerful tool for cancer prevention.

African American and Hispanic women are both more likely to be diagnosed with aggressive forms of breast cancer, but disparities within each breast cancer subtype have not been well documented. Chen and Li used data from 18 SEER cancer registries and identified 102,064 women diagnosed with invasive breast cancer in 2010–2011 with known stage, hormone receptor, and HER2 status. African American and Hispanic women were 30–60% more likely to be diagnosed with stage II–IV breast cancer compared to non-Hispanic whites, and African American women had 40–70% higher risks of stage IV breast cancer across all four subtypes. American Indian/Alaska Native women had a 3.9-fold higher risk of stage IV triple-negative breast cancer. These findings provide important characterization of the subtypes of breast cancer racial/ethnic disparities.

A common variant (rs9790517) at chromosome position 4q24 has been reported to be associated with breast cancer risk. Guo and colleagues conducted fine-mapping analysis in 55,540 breast cancer cases and 51,168 controls from the Breast Cancer Association Consortium. Conditional analyses identified two independent association signals among women of European ancestry. Functional annotation revealed two putative functional variants in the promoter and enhancer of the gene, TET2. Both variants are located in DNase I hypersensitivity and transcription factor binding sites, suggesting that the observed association in this locus may be mediated through the regulation of TET2.

Existing literature suggests that metformin may lower colorectal cancer (CRC) risk. Because most CRC originates in precancerous adenomas, Marks and colleagues examined whether metformin use lowered colorectal adenoma risk after polypectomy in patients with type-2 diabetes. Compared to patients not receiving diabetes medications (n = 1,578), metformin-only use (n = 457) was associated with lower adenoma recurrence risk and the association was stronger with increasing total metformin dose. This study suggests a potential benefit of metformin use in lowering the risk of subsequent adenomas after polypectomy in patients with type-2 diabetes.