Childhood long-term survivors now experience significant late effects from the primary cancer itself or from therapy. Cisplatin, an alkylating agent used in treatment for osteosarcoma, has been associated with irreversible high-frequency sensorineural hearing loss. There were 27 osteosarcoma patients treated at Department of Pediatrics, National University Hospital from 1997 to 2005. Twelve of these were long-term survivors, i.e. survived more than 2 years from initial diagnosis.

Pre-chemotherapy audiogram was performed in 50% (n=6) of patients and the audiogram results were not available in the remainder (n=6, 50%) as it was either not done or records were not available. Prior to year 2003, Cisplatin was administered at a dose of 100mg/ m2/course (EOI regimen) in 50% of cases, and after year 2003, 120mg/m2/course (T12 regimen) in 45%. Median cumulative dose of cisplatin was 550mg/m2 (cumulative dose range, 240 – 800 mg/m2). Out of 12 patients, 7 patients (58%) experienced cisplatin induced ototoxicity. According to NCI Toxicity Criteria, Grade I ototoxicty was observed in two cases (30%), grade 2 toxicity in five cases (70%), and bilateral sensorineural hearing loss was noted in six of the survivors. One long term survivor required a hearing aid. Six of them had and renal tubulopathy (NCI Toxicity Grade 2) was noted simultaneously in 35% of cases (n=4).

The incidence of cisplatin induced ototoxicity is high in our small series of long-term survivors of osteosarcoma. Baseline pre-chemotherapy testing, close monitoring during treatment and further follow-up are essential for this subset of patients receiving high doses of cisplatin.

The study was funded by Singapore Cancer Syndicate (POU-097)

Childhood cancer survival has increased dramatically over the last 30 years. Childhood Cancer Survivor Study- SG was established to evaluate the outcome and toxicities experienced by long term childhood cancer survivors in Singapore. There were 429 cases of hematological malignancies (HM) and 342 cases of solid tumors (ST) diagnosed and treated at National University Hospital (NUH) Singapore from May 1981 to December 2007.

There were seven long term survivors for Osteosarcoma (OS) out of 26 patients seen during the study period. Median age at diagnosis was 13.8 (range, 6.4–15.8 years) and median follow-up was 7.9 (range, 2.6 – 13.2 years). Cumulative doses of chemotherapy received included: cisplatin (240 – 800 mg/m2); doxorubicin 150 – 450 mg/m2); methotrexate (16 – 144 Grams/m2); ifosfamide (27–80 mg/m2); and etoposide (1000 – 3300 mg/ m2). According to the NCI Criteria for Toxicity (CTC version 2.0), three patients experiences grade 2 sensorineural hearing loss; three cases of grade 1 cardiomyopathy; three cases of grade 1 renal tubulopathy; and six cases of post surgical complications (infection-3, length discrepancy-3, poor fitting prosthesis-2).

Many of the patients did not have baseline pre-treatment evaluations such as audiograms, renal function, echocardiograms and similar proportion were not adequately followed-up post treatment. This is the first analysis and report in the country on treatment related outcome and toxicity in long-term survivors of childhood cancers such as osteosarcoma and other solid tumors. Authors recommend that future treatment protocols for childhood cancer in Singapore should incorporate pre- and post-treatment evaluations and close follow-up of young survivors with establishment of a multi-disciplinary late effects clinic.