Bisphosphonate use after estrogen receptor-positive breast cancer and risk of contralateral breast cancer.

Abstract

BACKGROUND:

A growing body of evidence suggests that nitrogenous bisphosphonates may reduce the risk of developing a first breast cancer and may prevent metastases among breast cancer survivors. However, their impact on risk of second primary contralateral breast cancer is uncertain.

METHODS:

Within a nested case-control study among women diagnosed with a first primary estrogen receptor-positive invasive breast cancer at ages 40-79 years, we assessed the association between post-diagnostic bisphosphonate use and risk of second primary contralateral breast cancer. We used multivariable-adjusted conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) comparing 351 contralateral breast cancer case subjects with 662 control subjects (ie, breast cancer patients not diagnosed with contralateral breast cancer) who were incidence density-matched on county; race/ethnicity; and age at, year of, and stage at first breast cancer diagnosis. We performed sensitivity analyses with respect to bisphosphonate type and confounding by indication. All statistical tests were two-sided.

RESULTS:

Current use of any nitrogenous bisphosphonate and use specifically of alendronate were both associated with reduced risks of contralateral breast cancer compared with never use (OR = 0.41, 95% CI = 0.20 to 0.84 and OR = 0.39, 95% CI = 0.18 to 0.88, respectively). The risk of contralateral breast cancer further declined with longer durations of bisphosphonate use among current users (P(trend) = .03). Results were similar in analyses restricted to patients with a history of osteoporosis or osteopenia.

CONCLUSIONS:

Bisphosphonate use was associated with a substantial reduction in risk of contralateral breast cancer. If this finding is confirmed in additional studies, nitrogenous bisphosphonate therapy may be a feasible approach for contralateral breast cancer risk reduction.

• Authors: Genevieve M Monsees, Kathleen E Malone, Mei-Tzu C Tang, Polly A Newcomb, Christopher I Li
• Journal: Journal of the National Cancer Institute (J Natl Cancer Inst) Vol. 103 Issue 23 Pg. 1752-60 (Dec 07 2011) ISSN: 1460-2105 [Electronic] United States
• PMID: 22021667 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Biomarkers, Tumor
• Bone Density Conservation Agents
• Diphosphonates
• Nitrogen Compounds
• Receptors, Estrogen

Topics

• Adult
• Aged
• Biomarkers, Tumor (analysis)
• Bone Density Conservation Agents (therapeutic use)
• Breast Neoplasms (chemistry, diagnosis, epidemiology, prevention & control)
• Case-Control Studies
• Confidence Intervals
• Confounding Factors, Epidemiologic
• Diphosphonates (therapeutic use)
• Dose-Response Relationship, Drug
• Female
• Humans
• Incidence
• Logistic Models
• Middle Aged
• Multivariate Analysis
• Neoplasm Recurrence, Local (epidemiology, prevention & control)
• Neoplasms, Second Primary (epidemiology, prevention & control)
• Nitrogen Compounds (therapeutic use)
• Odds Ratio
• Receptors, Estrogen (analysis)
• Risk Assessment
• SEER Program
• Secondary Prevention (methods)
• Washington (epidemiology)