Estrogen and colorectal cancer incidence and mortality.

BACKGROUND: The preponderance of observational studies describe an association between the use of estrogen alone and a lower incidence of colorectal cancer. In contrast, no difference in the incidence of colorectal cancer was seen in the Women's Health Initiative (WHI) randomized, placebo-controlled trial with estrogen alone after a mean intervention of 7.1 years and cumulative follow-up of 13.2 years. This study extends these findings by providing detailed analyses of the effects of estrogen alone on the histology, grade, and stage of colorectal cancer, relevant subgroups, and deaths from and after colorectal cancer. METHODS: The WHI study was a randomized, double-blind, placebo-controlled trial involving 10,739 postmenopausal women with prior hysterectomy. Participants were assigned to conjugated equine estrogen at 0.625 mg/d (n = 5279) or a matching placebo (n = 5409). Rates of colorectal cancer diagnoses and deaths from and after colorectal cancer were assessed throughout the study. RESULTS: Colorectal cancer rates in the estrogen-alone and placebo groups were comparable: 0.14% and 0.12% per year, respectively (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.83-1.58; P = .43). Bowel screening examinations were comparable between the 2 groups throughout the study. The grade, stage, and location of colorectal cancer did not differ between the randomization groups. There were more colorectal cancer deaths in the estrogen-alone group (34 [0.05%] vs 24 [0.03%]; HR, 1.46, 95% CI, 0.86-2.46; P = .16), but the difference was not statistically significant. The colorectal cancer incidence was higher for participants with a history of colon polyp removal in the estrogen-alone group (0.23% vs 0.02%; HR, 13.47; nominal 95% CI, 1.76-103.0; P < .001). CONCLUSIONS: The use of estrogen alone in postmenopausal women with prior hysterectomy does not influence the incidence of colorectal cancer or deaths from or after colorectal cancer. A possibly higher risk of colorectal cancer in women with prior colon polyp removal who use estrogen alone requires confirmation.

The Quality of Reporting Harms-Related Data in Clinical Trials of Adjuvant Trastuzumab in Early-Stage Breast Cancer Treatment.

Randomized controlled trials (RCTs) usually place less emphasis on the harmful effects than on the efficacy of interventions. The 10 CONSORT (Consolidated Standards of Reporting Trials) recommendations for harms reporting aim to improve harms data reporting of RCTs. The aim of this study was to assess the reporting of harms data in adjuvant trastuzumab studies in early-stage breast cancer. The resources PubMed, Cochrane Library, the American Society of Clinical Oncology, and the San Antonio Breast Cancer Symposium were searched for relevant RCTs that met the eligibility criteria. Each RCT was reviewed to determine whether the reporting of data complied with the 10 CONSORT recommendations for harms reporting, and the frequency of compliance with each CONSORT recommendation criterion was reviewed. Five RCTs met the eligibility criteria. Overall, selected RCTs failed to adhere to CONSORT recommendations in all sections of reporting. These results suggest that there is a need to standardize harms data reporting.