Incidence and risk factors related to ocular adverse effects caused by S-1 chemotherapy

This study aimed to identify the incidence and risk factors of corneal disorders (CDs) and lacrimal passage obstruction (LPO) caused by S-1 chemotherapy.

Multicenter prospective cohort study.

This study included patients who were administered S-1 for the first time and underwent ophthalmic evaluations for 1 year during the treatment. CD was defined as an increase of >2 points in the National Eye Institute classification. LPO was defined as an abnormality in lacrimal irrigation. Risk factors were identified via univariate and multivariate analyses.

This study enrolled 126 men and 49 women with a mean age of 68.1 (30-87) years. Over a mean follow-up of 169.6 ± 127.3 days, the incidence rates of CD and LPO were 24.6% and 14.0%, with 1-year cumulative incidence rates of 37.0% and 25.9%, respectively. The risk factors for CD were no previous use of eye drops (hazard ratio [HR] 3.45, p = 0.0955) and tear breakup time over 5 s prior to S-1 chemotherapy (HR 1.86, p = 0.0535). The risk factors for LPO were male sex (HR 5.00, p = 0.0311), primary tumor other than gastric cancer (HR 2.27, p = 0.0666), previous use of eye drops for dry eye (HR 21.16, p = 0.0035), and previous visual disturbance (HR 2.89, p = 0.0303).

The high incidence of CD and LPO among patients undergoing S-1 chemotherapy warrants close monitoring of those with identified risk factors, especially within the first six months of chemotherapy.