Risk of Ocular Adverse Events With Taxane-Based Chemotherapy

IMPORTANCE Taxane-based chemotherapy agents, such as docetaxel and paclitaxel, are used for treating a wide range of cancers. Although much has been published on adverse events related to taxanes, data on ocular outcomes with these very important drugs are scant. OBJECTIVE To quantify the risk of 3 mutually exclusive ocular adverse events of epiphora, cystoid macular edema (CME), and optic neuropathy with taxane-based chemotherapy agents by undertaking a large pharmacoepidemiologic study. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study design used a private health-claims database from the US that captures health information of more than 150 million enrollees. The study team created a cohort of new users of women with cancer who were taking taxane-based chemotherapy (docetaxel or paclitaxel) and new users of tamoxifen as controls. Study members were observed to the first incidence of each of the 3 mutually exclusive outcomes. An analysis of taxane-only users was also undertaken. EXPOSURE Tamoxifen (unexposed) and taxanes (ie, paclitaxel and docetaxel) as the exposed. MAIN OUTCOMES AND MEASURES First diagnosis of (1) epiphora, (2) cystoid macular edema (CME), or (3) optic neuropathy ascertained using International Statistical Classification of Diseases and Related Health Problems, Ninth Revision or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. RESULTS Among the 18 219 users in the epiphora analysis and optic neuropathy analysis, there were 1824 taxane users (paclitaxel and docetaxel) (age, mean [SD], 62.1 [12,7] years) and 16 395 tamoxifen users (age, mean [SD], 54.6 [12.8] years), respectively. The crude hazard ratio (HR) for epiphora was 5.55 (95% CI, 2.99-10.29) and adjusted HR was 5.15 (95% CI, 2.79-9.54). For optic neuropathy, the crude HR was 4.43 (95% CI, 1.10-17.82) and the adjusted HR was 4.44 (95% CI, 1.04-18.87). Among the 18 433 users in the CME analysis, there were 1909 taxane users (paclitaxel and docetaxel) (age, mean [SD], 62.5 years) and 16 524 tamoxifen users (age, mean [SD], 54.6 years). The crude HR for CME comparing taxane users with tamoxifen users was 1.37 (95% CI, 0.72-2.60) and adjusted HR was 1.33 (95% CI, 0.70-2.53). The HRs for epiphora and CME in the taxane cohort during the time of exposure compared with the period prior to use of the drugs were 2.86 (95% CI, 1.11-7.39) and 2.27 (95% CI, 0.68-7.54), respectively. CONCLUSIONS AND RELEVANCE In a cohort of women who were using taxane chemotherapy agents, there was an association with elevated risk for epiphora, CME, and optic neuropathy. Ophthalmologists and oncologists should be aware of these adverse events in women with breast cancer who receive these drugs.