[Assessment the efficacy of postoperative radiotherapy in the patients with non-small cell lung cancer. Retrospective study].

Introduction: The basic method of therapy of non-small cell lung cancer is surgery. For a number of years a discussion has gone concerning the indications for postoperative radiotherapy in the case of non-radical surgical treatment. At present, in many centers, the postoperative radiotherapy is recommended for patients with confirmed metastases to mediastinal lymph nodes (pN2) and in case of microscopic or macroscopic features of incomplete surgical margins. The aim of this retrospective study was to assess the results of adjuvant radiotherapy after surgical treatment of non-small cell lung cancer.

Material And Methods: From December 1993 to October 2005 in the Department of Radiotherapy Centre of Oncology at Wawelska St. in Warsaw, 366 patients (pts) were radically irradiated after surgery. In 192 pts radiotherapy was performed due to incomplete surgical margins, in 174 pts - due to metastases to mediastinal lymph nodes - in 26 pts both indications coexisted. First and second clinical stage was found in 96 pts: (I - 9 pts: 2.4%; II - 87 pts: 24%). Stage IIIA was found in 252 pts (69%) and IIIB in 18 pts (5%). Performance status according to Zubrod scale was: 0 - in 302 pts (82.5%), 1 - in 54 pts (14.8%) and 2 - in 10 pts (2.7%). Retrospective analysis of the treatment results was carried out. Survival time and time of occurrence of a local progression were assessed. Survival probability was calculated with the Kaplan-Meier method. Multidimensional analysis of prognostic factors was carried out with the D.R. Cox proportional risk model.

Results: In the studied group, one year survival was 78.02 ± 2%, two years, survival was 54.14 ± 2%, an five years, survival was 31.03 ± 2%. The two years, local control was estimated as 45.62% ± 4% and the five years, local control was 27.37 ± 4%. Probability of survival was significantly higher in the pts with better performance status - median survival in the groups with Zubrod stage 0 and 1 + 2 were 3.2 and 1.3 years respectively). Patients who received 〉 50 Gy of irradiation had significantly better life expectancy than others - median survival in the groups 〉 50 Gy and ≤ 50 Gy were 4.42 and 2.25 years respectively). Frequency of local recurrence was lower in the group of pts who received 〉 50 Gy of irradiation, than in remaining pts. Local recurrences were not observed in the pts treated with 3D radiotherapy regimen, but this group of pts received also higher dose of irradiation than others. Multiple survival analysis revealed that dose of irradiation ≤ 50 Gy, worse performance status and older age of the patient were independent adverse prognostic indicators.

Conclusions: 1. The results of postoperative radiotherapy in his retrospective study were strongly influenced by the dose of irradiation, patients' age and performance status. Total radiotherapy dose ≤ 50 Gy, older age of the patients and worse performance status (1 + 2) were negative survival indicators. 2. 3D technique of irradiation was combined with the best regional control of the disease.