Randomized phase II chemotherapy and radiotherapy trial for patients with locally advanced inoperable non-small-cell lung cancer: long-term follow-up of RTOG 92-04.

PURPOSE: The standard treatment for patients with locally advanced inoperable non-small-cell lung cancer and good prognostic factors has become combined chemotherapy (ChT) and radiotherapy (RT). However, the sequencing of the two modalities, as well as fractionation of RT, has been controversial. The Radiation Therapy Oncology Group (RTOG) Study 92-04 was a randomized Phase II study designed to evaluate further the toxicity and efficacy of 2 different strategies of chemoradiation evaluated in 2 prior RTOG Phase II studies.

METHODS: Patients with Stage II or III medically inoperable or unresectable non-small-cell lung cancer, good performance status, and minimal weight loss were enrolled into a prospective randomized Phase II RTOG study. Arm 1 consisted of induction ChT (vinblastine 5 mg/m(2) i.v. bolus weekly for the first 5 weeks, and cisplatin, 100 mg/m(2) i.v. on Days 1 and 29) followed by concurrent ChT/RT (cisplatin 75 mg/m(2) i.v. on Days 50, 71, and 92) during thoracic radiotherapy (63 Gy in 34 fractions during 7 weeks starting on Day 50). Arm 2 was concurrent ChT and hyperfractionated RT starting on Day 1 with a total dose of 69.6 Gy in 58 fractions during 6 weeks, 1.2 Gy/fraction b.i.d. ChT consisted of cisplatin, 50 mg/m(2) i.v. on Days 1 and 8, and oral VP-16, 50 mg b.i.d. for 10 days only on the days of thoracic radiotherapy repeated on Day 29.

RESULTS: A total of 168 patients were entered between 1992 and 1994, and 163 patients were eligible for analysis. Eighty-one patients were treated in Arm 1 and 82 patients in Arm 2. Pretreatment characteristics, including age, gender, Karnofsky performance status, histologic features, and stage, were similar. The incidence of acute esophagitis was significantly higher among patients treated in Arm 2 than among those treated in Arm 1 (p <0.0001). The incidence of acute hematologic toxicity was significantly higher among patients treated in Arm 1 (p = 0.01 for anemia and p = 0.03 for other hematologic toxicities) than among those treated in Arm 2. Analysis of late toxicity showed that chronic esophageal toxicity was significantly more frequent in Arm 2 than in Arm 1 (p = 0.003). The time to in-field progression was significantly different (p = 0.009), favoring Arm 2 compared with Arm 1 (26% vs. 45% with failure in 2 years and 30% vs. 49% with failure in 4 years, respectively). The median 2-year and overall 5-year survival rates were similar between the two arms.

CONCLUSION: Concurrent ChT and hyperfractionated RT resulted in a significant prolongation of the time to in-field progression, but with higher acute and chronic esophagitis. No other significant differences were observed between the two groups. Investigation with a chemoradio-protector is under way.