Spees et al.Page 882

Urban–rural disparities in treatment are often attributed to the longer distances rural patients must travel to receive care. However, recent evidence suggests that distance to care has a differential effect on urban and rural patients. Spees and colleagues examined the influence of distance on the timely treatment initiation and completion in women with cervical cancer. In urban areas, living further away from care was associated with a lower likelihood of initiating treatment. However, rural women with advanced cervical cancer residing farther from care were more likely to complete timely treatment. Distance was not associated with timely treatment completion among urban women. Distance is an access barrier for cervical cancer patients in urban areas whereas rural patients may require more intensive support, even among those living closer to treatment.

Heath et al.Page 900

The role of vitamin D in cancer risk is contentious and data on associations with tumor subtypes are limited. Heath and colleagues investigated the association between prediagnostic 25-hydroxyvitamin D (25(OH)D) concentration and risk of incident colorectal, breast, and prostate cancers and subtypes of these cancers in a cohort of middle-aged Australians. Circulating 25(OH)D was not associated with risk of breast cancer or prostate cancer, whereas higher 25(OH)D was associated with a lower risk of colorectal cancer in women and BRAF V600E-mutant colorectal cancer. Vitamin D might be important for preventing some colorectal cancer in women and specifically BRAF-mutant tumors.

Ascha et al.Page 917

Ascha and colleagues describe incidence proportions (IP) of both synchronous (SBM) and lifetime brain metastases (LBM) for primary lung, breast, and skin cancers, validating their Medicare-derived estimates of lifetime incidence by comparison with cancer registry data. The SBM IP was highest in lung (specifically for non–small cell lung cancer) followed by breast and melanoma cancers; the LBM IP was also highest in lung (specifically for small-cell lung cancer), followed by breast and melanoma cancers. Large population-based datasets such as SEER-Medicare allow for accurate estimates of both SBM and LBM for an elderly U.S. population.

Palazzo et al.Page 926

Palazzo and colleagues analyzed cancer registry data to identify patient factors associated with the utilization of genetic testing and treatment with erlotinib, a targeted therapy drug for metastatic non–small cell lung cancer, and to examine how these associations changed over time. Patient age was found to be associated with genetic testing; race, gender, and income level were associated with erlotinib treatment. Some of these disparities decreased in magnitude over time, while others remained stable or grew. This study highlights the need to reduce disparities as precision cancer treatments continue to be developed.