Highlights of This Issue

Given current drug-policy reforms to decriminalize or legalize cannabis in numerous countries worldwide, it is critically important to understand the possible cancer risks associated with cannabis use. Callaghan and colleagues, using a retrospective cohort design with a 42-year follow-up period in the current study of Swedish conscripts (n = 49,343), found that “heavy” cannabis use (defined as usage of more than 50 times in lifetime, as measured at conscription) was associated with a 2.5-fold increased hazard of developing testicular cancer. These results suggest that emerging changes to cannabis drug policy should consider the potential role of cannabis use in the development of testicular cancer.

Hypertension affects most elderly breast cancer survivors. With various antihypertensive agents available, a better understanding of their safety on breast cancer progression will help women and their providers weigh the benefits and risks of different treatment options. In this retrospect cohort of 14,766 women with stage I/II breast cancer identified through SEER-Medicare, Chen and colleagues found most antihypertensive medications are not associated with increased risk, while postcancer use of diuretics and β-blockers may be associated with higher risks of recurrence and breast cancer death. More research is needed to clarify the positive associations with adverse outcomes observed for diuretics and β-blockers.

This study by Stanczuk and colleagues compares the performance of triage strategies of hrHPV+ women, including women who test hrHPV+ in self-taken vaginal samples. Results show that triage with p16/ki-67 cytoimmunochemistry is superior to cytology. Women who test HPV16/18- and have negative p16/ki-67 cytoimmunochemistry can be released to the normal screening schedule. The HPV16/18- women with negative p16/ki-67 cytoimmunochemistry and negative cytology have the lowest post-test probability of CIN2+ (0.6%). This strategy may require 3.5 colposcopies to identify one CIN2+ lesion. The increase of colposcopy will occur in the first round of screening only and should be further reduced by HPV vaccinations.

Vasectomy has been variably implicated as a risk factor for prostate cancer in epidemiologic studies spanning decades. Detection bias is a major concern, as men who choose to have vasectomies likely have distinct patterns of healthcare utilization, including having seen a urologist. Using data from a prostate cancer screening trial, Shoag and colleagues found no association between vasectomy and prostate cancer in men in the screening arm of the trial who had standardized prostate cancer screening, while there was an association in men in the control arm who had variable screening. This suggests that vasectomy is not a risk factor for prostate cancer development but rather its detection.