Evaluation of the TN sub-staging in patients with initially unresectable stage III non-small cell lung cancer treated by induction chemotherapy

PurPose: This study attempted to investigate, in a cohort of patients with clinical stage III initially unresectable non-small cell lung cancer (NSCLC ) treated by the same induction chemotherapy regimen, the prognostic value of clinical T and N sub-groupings in order to validate the current Internat ional Staging System (ISS). Patients ann methods: All the eligible patients with stage III NSCLC (428 patients) registered in a clinical trial were in cluded in the study investigating, after three courses of induction chemoth erapy, the role, in responders, of chest irradiation in comparison to furth er chemotherapy. The chemotherapy regimen consisted of mitomycin C, ifosfam ide and cisplatin. Results: Patients with ISS 1986 stage IIIA had a signifi cantly better survival than those with stage IIIB (median survival 47 vs 36 weeks; P = 0.01). A RECPAM analysis showed that patients with T1-T2 N3 and T4 N0-1-2 stage had a more similar prognosis to those with stage IIIA. Tha t result leads to define two new sub-groups: stage III alpha (T3-T4 N0-N1; any T N2; T1-T2 N3) and III beta (T3-T4 N3), with a highly significant diff erence in survival between them (median survival: 45 vs 29 weeks; P < 0.000 1). The superiority of that new classification on the ISS documented in our series of stage III patients for discriminating survival and tumour respon se has to be confirmed on another series in a multivariate context. Conclus ion: For unresectable NSCLC treated by induction chemotherapy, stage III su b-classification by moving T4 N0-1 and T1-2 N3 tumours from stage IIIB to s tage IIIA appeared to better correlate with prognosis. The usefulness of th is new sub-division has to be tested in validation studies. (C) 1998 Elsevi er Science Ireland Ltd. All rights reserved.