Failure of T stage to predict survival in patients with non-small-cell lung cancer treated by radiotherapy with or without concomitant chemotherapy

Purpose: Because T stage does not consistently reflect tumor size in non-small-cell lung cancer (NSCLC), we hypothesized that T stage may be of limited prognostic value in patients with locoregional NSCLC treated by nonsurgical means. Methods and Materials: The study population consisted of 243 patients with histologically or cytologically proven NSCLC treated in three consecutive prospective trials between 1989 and 1998. The eligibility criteria for this analysis included planned for and began treatment at 60 Gy; Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1; weight loss:less than or equal to10%; no prior treatment; and no supraclavicular nodes, pleural effusion, or distant metastases. In the first study, 204 patients were randomized to receive conventional or accelerated radiotherapy (RT) with or without concomitant carboplatin. In the second, 15 patients were treated with concomitant cisplatin, etoposide, and RT in a single-arm study. In the third, 24 patients were treated with concomitant carboplatin, 5-fluorouracil, and RT in a dose-escalation study. Results: A total of 231 patients for whom the T and N stage were known met the eligibility criteria. The patient characteristics were 77% male, 64% squamous histologic features, 33% ECOG status of 0, and 69% no weight loss. The nodal status was 36% N0, 7 % N1, 52% N2, and 5% N3. The estimated median survival for all patients was 1.4 years (95% confidence interval 1.2-1.6), with an estimated 10% surviving 5 years (95% confidence interval 7-15). No significant difference was found in survival among the three trials (p = 0.16). The estimated median survival time and 5-year survival rate according to T stage were as follows: T1 (n = 29), 1.6 years and 16 %; T2 (n = 88), 1.3 years and 9 %; T3 (n = 59), 1.4 years and 9 %; and T4 (n = 55), 1.4 years and 9 %. No significant trend was found in overall survival according to T stage (p = 0.85, log-rank). To test whether a significant effect of T stage on overall survival existed after adjusting for N stage, trial, ECOG status, and weight loss, a multifactor analysis using Cox proportional hazards regression analysis was carried out. There was still no significant effect of T stage on survival (p = 0.66) when all factors were taken into account. Conclusion: Although there is some evidence that T stage is an independent prognostic factor in patients with NSCLC treated surgically, it did not appear to be of value in this series of patients treated with RT with and without concomitant chemotherapy. (C) 2002 Elsevier Science Inc.