Do ovarian cancer patients using statins have better outcomes?

Background: There is evidence in breast, colorectal and prostate cancer that patients who use statins have better cancer outcomes. There is biological evidence of similar benefits in ovarian tumour cells. We investigated whether stain use was associated with survival in ovarian cancer patients in Ireland. Methods: Women diagnosed with invasive ovarian cancer (C56) between 2001-2011 were identified from the National Cancer Registry. Those with at least one year medical card history (means tested) pre-diagnosis were identified and linked to community prescription records. Any statin use (ATC code: C10AA,C10B) in the year prior to diagnosis was determined. Association between statin use and cause-specific survival (end of follow-up: 31/12/2012) was estimated using Cox regression (adjusted for: age, smoking, marital status, year of diagnosis, urban/rural, local area deprivation, stage, grade, surgery at diagnosis). Secondary analysis accounting for competing risk was conducted. Results: Of 3097 invasive ovarian cancers diagnosed 2001-2011, 1823 (59%) had had a medical card history for at least one year prior to diagnosis and, of these, 490 (27%) had some exposure to statin in the year prior to diagnosis. 78% of women in the cohort had died by 31/12/2012 (median follow-up=5.8years). Pre-diagnostic statin use was not associated with ovarian cancer-specific survival (HR=1.06, 95%CI 0.92, 1.23) but was associated with better survival for other causes (HR=0.57, 95%CI 0.36, 0.93). When adjusting for competing risks, statin use was significantly associated with increased risk of ovarian cancer-specific death (HR=1.20, 95%CI 1.03, 1.40, p=0.02). Conclusion: In this, the largest ever study of statin use in ovarian cancer, we observed an association between pre-diagnostic statin use and cancer survival when adjusting for competing risks. Further work is being conducted to verify these results in United Kingdom populations. Research is needed to better understand the mechanisms by which prediagnosis statin use might influence cancer survival.