METHODS: We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics.
RESULTS: We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P(trend) = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P(trend) = 0.005) but not cases (P(trend) = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P(het) = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (OR(het) = 0.84, 95% CI 0.75, 0.94; OR(hom) = 0.81, 95% CI 0.51, 1.30; P(trend) = 0.002) but not for those who had their menarche age ≤11 years (OR(het) = 1.06, 95% CI 0.95, 1.19, OR(hom) = 1.07, 95% CI 0.67, 1.72; P(trend) = 0.29).
CONCLUSIONS: To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.
METHOD: A historical cohort of 986 premenopausal, and 1123 postmenopausal, parous breast cancer patients diagnosed from 2001 to 2012 in University Malaya Medical Centre were included in the analyses. Time since LCB was categorized into quintiles. Multivariable Cox regression was used to determine whether time since LCB was associated with survival following breast cancer, adjusting for demographic, tumor, and treatment characteristics.
RESULTS: Premenopausal breast cancer patients with the most recent childbirth (LCB quintile 1) were younger, more likely to present with unfavorable prognostic profiles and had the lowest 5-year overall survival (OS) (66.9; 95% CI 60.2-73.6%), compared to women with longer duration since LCB (quintile 2 thru 5). In univariable analysis, time since LCB was inversely associated with risk of mortality and the hazard ratio for LCB quintile 2, 3, 4, and 5 versus quintile 1 were 0.53 (95% CI 0.36-0.77), 0.49 (95% CI 0.33-0.75), 0.61 (95% CI 0.43-0.85), and 0.64 (95% CI 0.44-0.93), respectively; P trend = 0.016. However, this association was attenuated substantially following adjustment for age at diagnosis and other prognostic factors. Similarly, postmenopausal breast cancer patients with the most recent childbirth were also more likely to present with unfavorable disease profiles. Compared to postmenopausal breast cancer patients in LCB quintile 1, patients in quintile 5 had a higher risk of mortality. This association was not significant following multivariable adjustment.
CONCLUSION: Time since LCB is not independently associated with survival in premenopausal or postmenopausal breast cancers. The apparent increase in risks of mortality in premenopausal breast cancer patients with a recent childbirth, and postmenopausal patients with longer duration since LCB, appear to be largely explained by their age at diagnosis.
METHODS: A face-to-face interview using a validated questionnaire was conducted with 324 Sarawakian women aged 40-65 to determine the mean age of menopause and perceptions and experiences of menopause among these women.
RESULTS: The mean age ± standard deviation of the women was 51.37 ± 5.91 years. Ninety (27.8%) participants were premenopausal, 124 (38.5%) perimenopausal and 110 (33.7%) postmenopausal. The majority of these women (228; 70.4%) were local indigenous inhabitants of Sarawak. The findings show that 22.5% of the participants agreed that problems during menopause are a natural process. While 21.9% of the participants suggested that menopause should be treated medically, 32.3% argued that natural approaches for menopause symptoms are better than hormonal treatments. Seventy-five per cent of the women agreed that the absence of menses after menopause is a relief; meanwhile, 61.2% stated that menopause causes unpleasant symptoms. Notably, 51.7% were not sure whether women become less sexually attractive after menopause, and 51.1% were uncertain as to whether they feel less of a woman following menopause. Finally, 81.7% of participants were unsure if sexual activity is more enjoyable after menopause, and 71.9% were uncertain whether changes in life during menopause are more stressful. Among the different menopausal stages, the premenopausal group of women were noted to have more positive perceptions of menopause compared to the peri- and postmenopausal women. The study also observed that women with a better educational background generally had more positive perceptions of menopause.
CONCLUSIONS: The women's perceptions of menopause in this study were found to correspond to those in other studies on Asian women. Women with higher levels of education and premenopausal women comparatively expressed more positive opinions regarding menopause. Lastly, most of the women noted that menopausal symptoms are unpleasant, but that the absence of menses after menopause is a relief.