Antihistamine use and risk of ovarian cancer: A population-based case-control study

Objective: Histamine is suggested to play a role in ovarian carcinogenesis. We examined the association between antihistamine use and ovarian cancer risk in a nationwide case-control study. Study design: Cases (n = 5 556) comprised all women in Denmark aged 30–84 years with a histologically verified first diagnosis of epithelial ovarian cancer during 2000-2015. Age-matched population controls (n = 83 340) were selected using risk-set sampling. Data on prescription use, patient and demographic characteristics were retrieved from nationwide registries. Main outcome measures: We used conditional logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for epithelial ovarian cancer associated with antihistamine use (≥2 prescriptions). The association was evaluated according to patterns of antihistamine use, menopausal status, and histological subtype of ovarian cancer. Results: Ever use of antihistamines was not associated with ovarian cancer overall (OR = 0.97, 95% CI = 0.90–1.05). The lack of association remained in subanalyses for patterns of antihistamine use. We observed an inverse association between antihistamine use and ovarian cancer among pre-menopausal women (<50 year: OR = 0.72, 95% CI = 0.57-0.90), but not post-menopausal women (≥50 year: OR = 1.02, 95%CI = 0.93–1.11). In analyses of histological subtypes, an inverse association emerged for mucinous ovarian cancer (OR = 0.74, 95% CI = 0.57-0.96), but not for other subtypes. Conclusion: Antihistamine use was not associated with overall ovarian cancer risk. Additional research is needed to confirm inverse associations between antihistamine use and mucinous ovarian cancer, and overall ovarian cancer among pre-menopausal women.