Renal Cell Carcinoma and Milk Consumption
Timpson et al., Page 1341
Milk consumption has been reported to be a potential risk factor for renal cell carcinoma (RCC). It is unclear if this represents a causal association or is due to confounding or bias. In this study, Timpson and colleagues use genetic variation in lactase persistence as a tool to interrogate these relationships. This hospital-based case-control study utilized observational and phenotypic data as well as the lactase persistence genotype at rs4988235 within the MCM6 gene. The study found no association between the MCM6 genotype and RCC, suggesting that observational associations between milk consumption and RCC may be due to confounding or bias.
Physical Activity and Endometrial Cancer
John et al., Page 1276
Despite increasing evidence that physical activity may reduce the risk of endometrial cancer, the role of moderate physical activity in reducing endometrial cancer risk remains uncertain. To help clarify this relationship, John and colleagues conducted a population-based case-control study involving 427 newly diagnosed endometrial cancer cases. Through in-person interviews, the study reports that reduced endometrial cancer risks were associated with greater lifetime physical activity. Interestingly, the relationship was reported for both total physical activity and for moderate intensity physical activity. These findings emphasize the importance of physical activity in lowering the risk of endometrial cancer.
Meat Mutagens and Breast Cancer
Wu et al., Page 1301
Mutagenic heterocyclic amines (HCA) are generated from cooking meats at high temperature and for long duration. Animal studies suggest that HCAs have a role in breast carcinogenesis, and there is epidemiological evidence that higher intake of well-done meat may raise breast cancer risk in humans. To explore the association of HCA intake and breast cancer, Wu and colleagues used data from a cooking method questionnaire administered in 1996 in the Nurses' Health Study. They report that higher intake of HCAs was not associated with elevated risk of breast cancer. In addition, they found that HCA intake was not associated with estrogen receptor-positive/progesterone-positive breast cancer risk.
VIA Use for Cervical Cancer Screening
Vedantham et al., Page 1373
Because of its simplicity, visual inspection of the cervix after acetic acid application (VIA) is widely recommended for cervical cancer screening in resource-limited settings. To evaluate the determinants of positive VIA tests, Vedantham and colleagues compared VIA against Pap cytology and human papillomavirus DNA testing in a peri-urban area in Andhra Pradesh, India. They report that of the 19 women that were diagnosed with cervical intraepithelial neoplasia grade 2 and worse (CIN2+), only 5 were positive by VIA. In addition, VIA positivity was found to be subjective and difficult to evaluate against objective standards. This study cautions against the use of VIA as the primary screening test in resource-limited regions.