Second primary malignancies in retinoblastoma patients treated with intra-arterial chemotherapy: The first 10 years

Background/Aims Survivors of retinoblastoma carry a lifetime risk of secondary malignancies. It is well established that external beam radiation increases this risk; however, the risk with ophthalmic artery chemosurgery (OAC) remains unknown. We report on 10 years of experience with OAC and the rate of second primary malignancy (SPM) development. Methods This is a single-centre retrospective review approved by the Memorial Sloan Kettering Cancer Center Institutional Review Board of all patients who received OAC over a 10-year period, from May 2006 to November 2016. The second tumour incidence and survival in patients with germline disease (bilateral and unilateral with family history or confirmed germline mutation) was estimated using the Kaplan-Meier method. Patients who received external beam radiotherapy were excluded from analyses. Results Two hundred and thirty-three patients with heritable retinoblastoma who received OAC were analysed. Nineteen patients were excluded for having received external beam radiation. The Kaplan-Meier estimate of the likelihood for SPM development was 2.7% at 5 years (95% CI 0 to 25). All of the SPMs were pineoblastomas and all patients had bilateral disease in this cohort. Conclusions In our 10-year experience, we have found that SPM development in patients with germline retinoblastoma treated with OAC alone is comparable to previously published rates. In the first 10 years, OAC did not increase the known incidence of SPMs. This cohort will continue to be followed to establish the rate of development with extended follow-up.