Outcome and prognostic factors in localized primitive neuroectodermal tumors with uniform chemotherapy protocol: A single center experience of 224 cases.

Abstract

10527 Background: Data on localized PNET with uniform protocol is minimal. Methods: This is single institutional patient review treated between June 2003-Nov 2011, and evaluated on intent-to-treat analysis. All patients received uniform chemotherapy (VAC/IE) as follows: neo-adjuvant chemotherapy (NACT), surgery and/or radiotherapy as local treatment followed by ACT. Results: 224/374 (60%) PNET patients were localized with median age 15 years (range: 0.1–55), tumor diameter 8 cm (range: 1.6-25) and symptom duration 4 months (range: 0.5-30). Regions were extremities 40%, thorax 25% and head & neck 14%. Post-NACT, CR was 32(14%); PR 152(68%) with ORR 82%. Ninety-nine patients underwent surgery (50/99 received adjuvant radiotherapy); 80 received radical radiotherapy as local therapy. There were no adverse tumor characteristics or poor NACT response in radical radiotherapy group versus surgery group. At median follow-up of 31.1 months (range: 1.3–113.4), 5-year EFS, OS and local control rate (LCR) were 34±3.5%, 52.5±4.7% and 59.5±4.8%, respectively. Multivariate analysis of prognostic factors is shown in the Table. Conclusions: This is largest data of localized PNET from Asia which identified unique prognostic factors. Localized PNET constituted 60% of entire cohort with delayed presentation. High WBC may be a marker of micrometastatic disease or an adverse paraneoplastic response. Skeletal primary and tumor diameter >8 cm predicted inferior OS and LCR; additionally radical radiotherapy predicted inferior LCR. All efforts should be made to resect primary tumor post-NACT as radical radiotherapy alone despite good NACT response results in inferior LCR. [Table: see text]