Prognostic factors in limited-stage small cell lung cancer of patients treated with combined modality approach

To evaluate the combined modality treatment results of patients with limited-stage small cell lung cancer (SCLC), who were treated and followed by the DELCSG.

Sixty-three patients with limited-stage SCLC diagnosed between April 1991 and December 2002 were included. All patients were treated with combined chemotherapy and thoracic radiotherapy. Median age was 59 years (range 36-84), and all patients were male except 4. Surgery was performed for diagnosis in 3 patients. Four cycles of chemotherapy (median) were administered, composed of cisplatin-etoposide (CE) (26 patients), cyclophosphamide-vincristine-adriamycin (CAV) (10 patients) or alternated CE and CAV (18 patients). Nine patients received various chemotherapy regimes other than CE and/or CAV. A total dose of 5000 cGy with 180-200 cGy daily fractions was given to the primary tumor and mediastinum, excluding the spinal cord after 4500 cGy. Prophylactic cranial irradiation (PCI) was performed in 13 (20%) patients. Overall survival (OS) and progression-free survival (PFS) were calculated, beginning from the date of diagnosis and the end of radiotherapy, respectively. Kaplan-Meier method was used for obtaining survival rates. Log-rank test and Cox proportional hazards model were used for univariate and multivariate analyses, respectively.

Median follow-up time was 17 months (range 3-131). Median PFS and OS were 12 (range 1-131) and 17 (range 3-131) months, respectively. Two-years PFS and OS rates were 27 % and 38 %, respectively. During follow-up, 27 (43%) patients developed brain metastasis; among them only 3 had received PCI. Univariate analysis showed that addition of PCI significantly improved PFS (p=0.025) and advanced age was a favorable prognostic factor for OS (p=0.039). In the multivariate analysis, advanced age (p=0.034) and addition of PCI (p=0.004) were independent factors increasing PFS, however no significant prognostic factor influencing OS was found.

Our treatment results are in accordance with the relevant literature. It is also concluded that PCI should be given to all patients with complete response to chemotherapy. However, analysis of prognostic factors should be cautiously evaluated because of small number and heterogeneous distribution of patients in subgroups. Prospective studies are necessary for better determination of prognostic factors.