Clinical Outcome of paediatric ewing sarcoma and significance of pathological necrosis for mortality after neoadjuvant chemotherapy: Single institutional study.

ABSTRACT

OBJECTIVE: To determine the clinical outcome and significance of pathological necrosis after neoadjuvant chemotherapy. METHODS: The retrospective study was conducted in Shaukat Khanum Memorial Cancer Hospital and Research Center and comprised data from January 2010 to December 2015 related to young with newly diagnosed Ewing sarcoma on histopathology. Data was collected on patients aged <20 years of either gender along with primary tumour site, metastatic status, tumour volume, mode of local therapy, degree of necrosis post-surgery, tumour margins after resection, outcome at the end of treatment and at last follow-up visit. Tumours were categorised as grade I = little or no necrosis, grade II = 50-90% necrosis, grade III = 90-99% necrosis, and grade IV = 100% necrosis. Data was analysed using SPSS 20. RESULTS: Of the 124 patients, 89(72%) were non-metastatic; 35(28%) were metastatic; 37(29.8%) underwent surgery; 58(46%) received radiotherapy; 7(5.6%) received both surgery and radiotherapy; 22(17.7%) received no treatment. Histopathology report post-surgery showed little grade 1 necrosis in 10(8%) patients, grade II in 8(6.5%), grade III in 8(6.5%) and grade IV in 14(11%). Event-free survival in grade IV necrosis was 93% in 14 (11.3%) patients, EFS in grade III necrosis was 71% in 8(6.5%) patients , EFS in grade II necrosis was 22% seen in 9(7.3%) patients and EFS in grade- I necrosis was 35% seen in 14 (11.3%) patients. Overall survival in grade IV necrosis was 93% in 14 (11.3%) patients, OS in grade III 75% seen in 8(6.5%), OS in grade II 25% seen in 9(7.3%) and OS in grade I was 50% in 14(11.3%) patients. Event-free survival was 48 (38%) patients and overall survival of Ewing sarcoma patients was 52 (46.6%) patients respectively. CONCLUSION: Tumour necrosis and histopathological changes post-surgery were found to have great impact on survival outcome in Ewing Sarcoma.