Associations between pre- and post-diagnostic use of beta-blockers and ovarian cancer survival

Background: There is evidence in breast, colorectal and prostate cancer that patients who use beta-blocker (BB) medication have better cancer outcomes. There is some evidence of similar benefits in ovarian tumours. We investigated whether BB use was associated with improved survival within Irish ovarian cancer patients.

Method: Women diagnosed with invasive ovarian cancer (ICD code: C56) between 2001–2011 were identified from the National Cancer Registry Ireland. Those with continuous eligibility for a (means-tested) medical card in the year immediately prior to diagnosis were identified and linked to community prescription records. Any BB exposure (WHO ATC: C07) in the year prior to diagnosis was determined. Associations between exposure and ovarian cause-specific survival (OvCSS) and other causes until follow-up 31/12/2012 was estimated using Cox regression adjusted for: age, smoking, marital status, diagnosis year, urban/rural residence,deprivation, stage, grade, and surgery at diagnosis. Secondary analysis accounting for competing risks was conducted. Time-varying regression with ever/never status (6 month lag) was used to evaluate post-diagnostic BB use.

Results: Of 3097 invasive ovarian cancers diagnosed 2001–2011, 1823 (59%) had a medical card for at least one year prior to diagnosis. Of these, 432 (24%) had some BB exposure in that year. 78% of women in the cohort had died by 31/12/2012 (median follow-up 5.8 years). Pre-diagnostic use was not associated with improved OvCCS (AHR = 1.08, 95% CI 0.93,1.23) or other-cause survival (AHR = 1.39, 95% CI 0.92,2.09). Results were similar adjusting for competing risks. Post-diagnostic BB use was associated improved OvCSS (AHR = 0.80, 95% CI 0.65, 0.99) but not other-cause survival(AHR = 1.61, 95% CI 0.85, 3.03).

Conclusions: In this, one of the largest ever studies of beta-blocker use in ovarian cancer, we observed a post- (but not pre-) diagnostic association between exposure and cancer-specific survival.This analysis is being replicated in Northern Ireland and English populations.

Acknowledgements: Project funding, Health Research Board; Registry funding, Department of Health.