Abstract
Background
BRCA 1/2 mutation carriers are encouraged to have their ovaries removed by age 40 to reduce cancer risk and prolong survival. Given the recency of genetic testing, it will be some years before robust estimates are available of the long term adverse effects. In the meantime data from the general population can help inform women and providers about potential adverse effects so that preventive strategies can be implemented. Bone loss accelerates following natural menopause and oophorectomy before age 45 is a known risk factor for osteoporosis. However there is limited data quantifying the effects of bilateral oophorectomy on bone mineral density (BMD), an early sensitive marker of osteoporosis.
Methods: We evaluated the associations of oophorectomy with arthritis and BMD in NHANES III, a nationally representative survey conducted 1988–1994. For analysis we included women aged 40 years and older with no history of cancer who reported a bilateral oophorectomy or intact ovaries. Women were asked if a doctor told them they had arthritis. Femoral neck BMD was measured by dual energy x-ray (DXA). Osteoporosis was defined as BMD (g/m2) more than 2.5 standard deviations below the mean of white women aged 20–29 years. Survey weights were used to account for the complex survey design. Odds Ratios (OR) for arthritis and osteoporosis were estimated using logistic regression. Oophorectomy status was categorized intact ovaries, oophorectomy <45 years, and oophorectomy ≥45 years. Multivariate models were adjusted for age at interview, race, income, smoking status, education, alcohol, and BMI. Analyses were repeated excluding women who reported using hormone replacement therapy (HRT).
Results: The sample size was 4039 for the arthritis analysis and 3660 for the BMD analysis. Women with oophorectomy were more likely to report arthritis than women with intact ovaries (45.4% vs. 32.1% p<0.001).The prevalence was even higher in women with oophorectomy <45 years (47.7%). The age-standardized mean femoral neck BMD was lower for women reporting oophorectomy at <45 years than women with intact ovaries (0.711 vs. 0.743 g/m2 p=0.017). In multivariate models women with oophorectomy had greater odds of arthritis than women with intact ovaries, particularly among women with oophorectomy <45 years (OR=1.78 95% CI 1.31−2.42). The odds of arthritis were even greater after excluding HRT users (OR=1.99 95% CI=1.25−3.18). Similarly, women who had a prior oophorectomy had greater odds of osteoporosis than women with intact ovaries, particularly among women with oophorectomy <45 years (OR=1.78 95% CI 1.07−2.97). The odds were increased further after excluding HRT users (OR=2.92 95% CI 1.32−6.44).
Conclusions: The prevalence of arthritis and osteoporosis were significantly greater in women who reported bilateral oophorectomy. Results were most profound among women whose oophorectomy was performed before age 45 and among women who never used HRT. These results suggest that women who undergo oophorectomy for cancer prevention should be closely monitored for osteoporosis over the long term.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-01.
Volume 71, Issue 24 Supplement
