Influence of survival in primary tumor volume for stage IV non-small cell lung cancer on survival-re-analysis of phase II multicenter prospective clinical findings

Abstract

Objective To investigate the effect of primary tumor volume on the survival in the three-dimensional radiotherapy of primary tumors of stage Ⅳ non-small cell lung cancer (NSCLC). Methods Clinical data of 428 patients in a multicenter prospective clinical study from December 2002 to January 2017 were reanalyzed, and 423 of them were subject to survival analyses. Platinum-based doublet chemotherapy was adopted. The median number of chemotherapy cycle was 4, and the critical value of planning target volume (PTV) of primary tumors was 63 Gy. The critical value of gross tumor volume (GTV) of primary tumors was 150 cm3. Results Single factor Cox regression analysis demonstrated that female, KPS score, single organ metastasis, N0-N1 staging, adenocarcinoma, radiotherapy dose ≥63 Gy, 4-6 cycles of chemotherapy, recent effectiveness, post-treatment progress in taking targeted drugs and GTV<150 cm3 were good prognostic factors for the patients with stage Ⅳ NSCLC (all P<0.05). According to the stratified analysis of different radiotherapy regimes, for the stage Ⅳ NSCLC patients with a GTV ≥150 cm3, the survival rate of the primary tumor radiotherapy dose ≥63 Gy on the basis of systemic chemotherapy was significantly better than that of the primary tumor radiotherapy dose <63 Gy (P<0.05). Conclusions Stage Ⅳ NSCLC patients with GTV≥150 cm3 in 4-6 cycles of chemotherapies combined with primary tumor radiotherapy dose ≥63 Gy and GTV<150 cm3 in 1-3 cycles of chemotherapies combined with primary tumor radiotherapy dose ≥63 Gy may prolong the overall survival of patients with stage Ⅳ NSCLC. Key words: Lung neoplasm/concurrent chemoradiotherapy; Three-dimensional radiotherapy; Prognosis