Purpose : For early stage non-small-cell lung cancer, surgical resection is the treatment of choice. But when the patients are not able to tolerate it because of medical problem and when refuse surgery, radiation therapy is considered an acceptable alternative. We report on the treatment results and the effect of achieving local control of primary tumors on survival end points, and analyze factors that may influence survival and local control.
Materials and Method : We reviewed the medical records of 32 patients with medically inoperable non-small cell lung cancer treated at our institution from June, 1987 through June, 1997. All patients had a pathologic diagnosis of non-small cell lung cancer and were not candidate for surgical resection because of either patients refusal (4), old age (2), lung problem (21), chest wall invasion (3) and heart problems (3). In 8 patients, there were more than 2 problems. The median age of the patients was 68 years (ranging from 60 to 86 years). Histologic cell type included squamous (24), adenocarcinoma (6) and unclassified squamous cell (2). The clinical stages of the patients were T1 in 5, T2 in 25, T3 in 2 patients. Initial tumor size was ≤3.0 cm in 11, between 3.0 cm and 5.0 cm in 13 and more than 5.0 cm in 8 patients. All patients had taken chest x-rays, chest CT, abdomen USG and bone scan. Radiotherapy was delivered using 6 MV or 10 MV linear accelerators. The doses of primary tumor were the ranging from 54.0 Gy to 68.8 Gy (median; 61.2 Gy). The duration of treatment was from 37 days through 64 days (median; 48.5 days) and there was no treatment interruption except 1 patient due to poor general status. In 12 patients, concomitant boost technique was used. There were no neoadjuvant or adjuvant treatments such as surgery or chemotherapy. The period of follow-up was ranging from 2 months through 93 months (median; 23 months). Survival was measured from the date radiation therapy was initiated.
Results : The overall survival rate was 44.6% at 2 years and 24.5% at 5 years, with the median survival time of 23 months. Of the 25 deaths, 7 patients died of intercurrent illness, and cause-specific survival rate was 61.0% at 2 years and 33.5% at 5 years. The disease-free survival rate was 38.9% at 2 years and 28.3 % at 5 years. The local-relapse-free survival rate was 35.1%, 28.1%, respectively. On univariate analysis, tumor size was significant variable of overall survival ( p=0.0015, 95% C.I.; 1.4814-5.2815), disease-free survival ( p=0.0022, 95% C.I.; 1.4707-5.7780) and local-relapse-free survival ( p=0.0048, 95% C.I.; 1.2910- 4.1197). T stage was significant variable of overall survival ( p=0.0395, 95% C.I.; 1.1084-65.9112) and had borderline significance on disease-free survival ( p=0.0649, 95% C.I.; 0.8888-50.7123) and local-relapse-free survival (p= 0.0582, 95% C.I.; 0.9342-52.7755). On multivariate analysis, tumor size had borderline significance on overall survival (p=0.6919, 955 C.I.; 0.9610-5.1277) and local-relapse-free survival ( p=0.0585, 95% C.I.; 0.9720- 4.9657). Tumor size was also significant variable of disease-free survival ( p=0.0317, 95% C.I.; 1.1028-8.4968).
Conclusion : Radical radiotherapy is an effective treatment for small (T1 or ≤3 cm) tumors and can be offered as alternative to surgery in elderly or infirmed patients. But when the size of tumor is larger than 5 cm, there were few long-term survivors treated with radiotherapy alone. The use of hyperfractionated radiotherapy, endobronchial boost, radisensitizer and conformal or IMRT should be consider to improve the local control rate and disease-specific survival rate.
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