PROGNOSTIC FACTORS IN THE TREATMENT OF NODE-NEGATIVE NONSMALL CELL LUNG-CARCINOMA WITH RADIOTHERAPY ALONE

Purpose: For patients with early stage nonsmall cell lung carcinoma (N SCLC) but medically inoperable, aggressive radiation therapy might imp act on survival.Methods and Materials: Between 1980 and 1990, 71 patie nts treated at MDACC by radiation therapy alone for NSCLC because of m edical contradindications for surgery were analyzed. All patients had histologic or cytologic confirmation of NSCLC. The median total radiat ion dose was 63.23 Gy with 79% of patients receiving doses exceeding 6 0 Gy. The radiographic response was documented at completion of radiat ion therapy and 6 months after completion of radiation therapy. The me dian follow-up time was 36 months, ranging from 14-61 months. Results: Overall survival rates at 3 and 5 years were 19 and 12%, respectively . The disease-specific survival (DSS) rates at 3 and 5 years were 44 a nd 32%, respectively. The DSS rates at 3 years by T-stage were: 49% fo r T1, 47% for T2, 26% for T3, and 32% for T4. The local control rates at 3 and 5 years were 66 and 56%, respectively. The local control rate s at 3 years by T-stage were: 89% for T1, 61% for T2, 42% for T3, and 55% for T4. Univariately, the significant favorable prognostic factors for DSS were a KPS greater than or equal to 70, tumor size less than or equal to 5 cm, no chest-wall invasion, and a radiation dose greater than or equal to 50 Gy. The significant favorable prognostic factors for local control were tumor size less than or similar to 4 cm, no che st-wall invasion, a radiation dose >60 Gy, and a complete response con firmed by chest x-ray at 6 months after radiotherapy (p = 0.04). Cover age of nodal drainage areas did not affect survival or local control. No lethal complications were seen, and documented symptomatic radiatio n pneumonitis occurred in only 7% of cases. Hence, the significant fav orable prognostic factors for DSS were a KPS of greater than or equal to 70, tumor size less than or equal to 5 cm, no chest-wall invasion, and a radiation dose greater than or equal to 50 Gy. The significant f avorable prognostic factors for local control mere tumor size of less than or equal to 4 cm, no chest-wall invasion, a radiation dose >60 Gy , and a complete response confirmed by chest x-ray at 6 months after r adiotherapy. Multivariate analysis showed that the most important prog nostic factor for DSS was KPS, and the most important prognostic facto r for local control was radiation dose. Conclusions: Patients with a K PS of greater than or equal to 70, a tumor size <5 cm, and no chest-wa ll invasion would benefit most from treatment with radiation alone to doses exceeding 60 Gy. This patient group represents the best sample f or studying the benefit of conformal radiotherapy. Copyright (C) 1996 Elsevier Science Inc.