Steroidal contraceptive use update, United States, 1989-1994

Recent oral contraceptive use by formulation and breast cancer risk among women 20 to 49 years of age

Previous studies of oral contraceptives and breast cancer indicate that recent use slightly increases risk, but most studies relied on self-reported use and did not examine contemporary oral contraceptive formulations. This nested case-control study was among female enrollees in a large U.S. integrated health care delivery system. Cases were 1,102 women ages 20 to 49 years diagnosed with invasive breast cancer from 1990 to 2009. Controls were randomly sampled from enrollment records (n = 21,952) and matched to cases on age, year, enrollment length, and medical chart availability. Detailed oral contraceptive use information was ascertained from electronic pharmacy records and analyzed using conditional logistic regression, ORs, and 95% confidence intervals (CI). Recent oral contraceptive use (within the prior year) was associated with an increased breast cancer risk (OR, 1.5; 95% CI, 1.3-1.9) relative to never or former OC use. The association was stronger for estrogen receptor-positive (ER(+); OR, 1.7; 95% CI, 1.3-2.1) than estrogen receptor-negative (ER(-)) disease (OR, 1.2, 95% CI, 0.8-1.8), although not statistically significantly different (P = 0.15). Recent use of oral contraceptives involving high-dose estrogen (OR, 2.7; 95% CI, 1.1-6.2), ethynodiol diacetate (OR, 2.6; 95% CI, 1.4-4.7), or triphasic dosing with an average of 0.75 mg of norethindrone (OR, 3.1; 95% CI, 1.9-5.1; Pheterogeneity compared with using other oral contraceptives = 0.004) was associated with particularly elevated risks, whereas other types, including low-dose estrogen oral contraceptives, were not (OR, 1.0; 95% CI, 0.6-1.7). Our results suggest that recent use of contemporary oral contraceptives is associated with an increased breast cancer risk, which may vary by formulation. If confirmed, consideration of the breast cancer risk associated with different oral contraceptive types could impact discussions weighing recognized health benefits and potential risks.

Oral contraceptives and breast cancer risk overall and by molecular subtype among young women

BACKGROUND

Evidence suggests that recent oral contraceptive (OC) use is associated with a small increased breast cancer risk; yet risks associated with contemporary OC preparations and by molecular subtype are not well characterized.

METHODS

We conducted a population-based case-control study of invasive breast cancer among women ages 20 to 44 residing in the Seattle-Puget Sound area from 2004 to 2010 (985 cases and 882 controls). We collected information on contraceptive use and participant characteristics via an in-person interview. Multivariable-adjusted logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Lifetime duration of OC use for ≥ 15 years was associated with an increased breast cancer risk (OR, 1.5; 95% CI, 1.1-2.2). Current OC use (within 1 year of reference date) for ≥ 5 years was associated with an increased risk (OR, 1.6; 95% CI, 1.1-2.5) and there were no statistically significant differences in risk by OC preparation. Risk magnitudes were generally greater among women ages 20 to 39, and for estrogen receptor-negative (ER(-)) and triple-negative breast cancer (current use for ≥ 5 years among ages 20-39: ER(-) OR, 3.5; 95% CI, 1.3-9.0; triple-negative OR, 3.7; 95% CI, 1.2-11.8), although differences between groups were not statistically significant.

CONCLUSIONS

Long-term use of contemporary OCs and current use for ≥ 5 years was associated with an increased breast cancer risk among women ages 20 to 44. Risk may be greater among younger women and for ER(-) and triple-negative breast cancer, but these findings require confirmation.

IMPACT

Continued surveillance and pooled analyses of OC use and breast cancer risk by molecular subtype are needed as OC preparations evolve.

Polymorphisms in stromal genes and susceptibility to serous epithelial ovarian cancer: a report from the Ovarian Cancer Association Consortium

Alterations in stromal tissue components can inhibit or promote epithelial tumorigenesis. Decorin (DCN) and lumican (LUM) show reduced stromal expression in serous epithelial ovarian cancer (sEOC). We hypothesized that common variants in these genes associate with risk. Associations with sEOC among Caucasians were estimated with odds ratios (OR) among 397 cases and 920 controls in two U.S.-based studies (discovery set), 436 cases and 1,098 controls in Australia (replication set 1) and a consortium of 15 studies comprising 1,668 cases and 4,249 controls (replication set 2). The discovery set and replication set 1 (833 cases and 2,013 controls) showed statistically homogeneous (P(heterogeneity)≥0.48) decreased risks of sEOC at four variants: DCN rs3138165, rs13312816 and rs516115, and LUM rs17018765 (OR = 0.6 to 0.9; P(trend) = 0.001 to 0.03). Results from replication set 2 were statistically homogeneous (P(heterogeneity)≥0.13) and associated with increased risks at DCN rs3138165 and rs13312816, and LUM rs17018765: all ORs = 1.2; P(trend)≤0.02. The ORs at the four variants were statistically heterogeneous across all 18 studies (P(heterogeneity)≤0.03), which precluded combining. In post-hoc analyses, interactions were observed between each variant and recruitment period (P(interaction)≤0.003), age at diagnosis (P(interaction) = 0.04), and year of diagnosis (P(interaction) = 0.05) in the five studies with available information (1,044 cases, 2,469 controls). We conclude that variants in DCN and LUM are not directly associated with sEOC, and that confirmation of possible effect modification of the variants by non-genetic factors is required.

Survey of knowledge and practice on oral contraceptive and emergency contraceptive pills of drugstore personnel in Hat Yai, Thailand

In Thailand, oral contraceptive (OC) and emergency contraceptive pill (ECP) are available as over-the-counter (OTC) drugs, and drugstores share 30% of services. While the rate of dispensing contraceptive pills has increased, the knowledge and awareness of ECP use is limited among users and providers. The objective of this study was to assess knowledge and practice of drugstore personnel on providing OC and ECP, in order to improve the quality of services. Drugstores located in Hat Yai District, Songkhla Province, Southern Thailand, were the accessible population. There were 109 drugstores, half of them owned by pharmacists. The population was stratified by owner (pharmacist or non-pharmacist) and randomly selected to obtain a sample size of 30 drugstores for each class. Two study methods, questionnaire interview and secret shopping, were used to measure knowledge, and practice, respectively. History-taking, drug-choosing, and advice-giving were the domains measured. The results demonstrated that knowledge on OC was fair, but that on ECP was poor. Pharmacists had better knowledge of proper history taking and ECP indication than non-pharmacists. OC and ECP provision were inappropriately practised in drugstores in the study area. A majority of drugstores were mainly owned by non-pharmacists. For OC practice, drug-choosing was good, but history-taking and advice-giving were poor in both groups. Although both groups dispensed ECP poorly, pharmacists dispensed significantly better than non-pharmacists. Among non-pharmacist staff, the average scores of OC advice-giving, and ECP dispensing, were statistically significantly better among those working in pharmacist-owned drugstores. Both knowledge and practice on OC and ECP should be improved in both types of drugstores in the study area.