Induction carboplatin/paclitaxel followed by concurrent carboplatin/paclitaxel and dose-escalating conformal thoracic radiation Therapy in unresectable Stage IIIA/B nonsmall cell lung carcinoma a modified Phase I trial

BACKGROUND A modified Phase I trial was conducted evaluating the incorporation of 3-dimensional conformal radiation therapy (3DCRT) into a strategy of sequential and concurrent carboplatin/paclitaxel in Stage III, unresectable nonsmall cell lung carcinoma (NSCLC). In addition, dose escalation of thoracic conformal radiation therapy (TCRT) from 60 to 74 gray (Gy) was performed. Endpoints included response rate, toxicity, and survival. METHODS Twenty-nine patients with unresectable Stage III NSCLC were included. Patients received 2 cycles of induction carboplatin (AUC 6) and paclitaxel (225 mg/m2/3 hours) every 21 days. On Day 43, concurrent TCRT and weekly (×6) carboplatin (AUC 2) and paclitaxel (45 mg/m2/3 hours) was initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts. RESULTS The response rate to induction carboplatin/paclitaxel was 52%. Three patients (10%) experienced disease progression during the induction phase. No dose-limiting toxicity was seen during the escalation of the TCRT dose from 60 to 74 Gy. The major toxicity was esophagitis, with 18% of patients developing Radiation Therapy Oncology Group Grade 3 esophagitis. The overall response rate was 70% (1 complete response and 18 partial responses). Survival rates at 1 and 2 years were 69% and 45%, with a median survival of 21 months. The 1-year progression free survival probability was 41% (95% confidence interval, 23–59%). CONCLUSIONS Incorporation of 3DCRT with sequential and concurrent carboplatin/paclitaxel is feasible, and dose escalation of TCRT to 74 Gy is possible with acceptable toxicity. Overall response and survival rates are encouraging. Accrual is continuing in a Phase II fashion at 74 Gy with sequential and concurrent carboplatin/paclitaxel. Cancer 2000;89:534–42. © 2000 American Cancer Society.