Aim To report the underlying causes and treatment outcome of lacrimal drainage obstruction in patients with cancer-associated epiphora.

Methods A single-centre retrospective review was performed for consecutive referrals to an oculoplastic surgeon for cancer-associated epiphora between 2010 and 2016. Charts were reviewed for underlying neoplastic conditions, pharmacy records, radiotherapy records, levels of obstruction of the lacrimal drainage apparatus and treatment methods and outcome.

Results Forty-three patients (70 eyes) were included in this study. The most common cause of epiphora was radiotherapy on the head and neck (35%), followed by oral S-1 (33%) and docetaxel (23%). The nasolacrimal duct was the most common obstruction site in patients who underwent radiotherapy (59%), whereas the punctum or canaliculus was mostly affected in patients treated with S-1 (94%) or docetaxel (100%). S-1-treated patients showed severe obstruction of the entire canaliculus (11/24 (46%)) with the lowest success rate at 58% (S-1 vs radiotherapy: p=0.012; S-1 vs docetaxel: p=0.002). Moreover, the patients treated within 1 year after the first symptom showed a significantly higher proportion of symptom improvement (85%) than did those treated after 1 year (27%) in the S-1 group (p=0.011).

Conclusions Cancer-associated epiphora can have various causes. The level of obstruction and treatment outcome vary according to underlying causes, and S-1-associated epiphora and delayed treatment are related to unsatisfactory results. Given the importance of early intervention, oncologists should be alert to tearing symptoms and cooperate with ophthalmologists in the early stages to improve patients’ quality of life.