Timing of Thoracic Radiotherapy in Limited Stage Small Cell Lung Cancer: Results of Early Versus Late Irradiation from a Single Institution in Turkey

Abstract

Background: It is standard treatment to combine chemotherapy (CT) and thoracic radiotherapy (TRT) in treating patients with limited stage small cell lung cancer (LS-SCLC). However, optimal timing of TRT is unclear. We here evaluated the survival impact of early versus late TRT in patients with LS-SCLC. Materials and Methods: Follow-up was retrospectively analyzed for seventy consecutive LS-SCLC patients who had successfully completed chemo-TRT between January 2006 and January 2012. Patients received TRT after either 1 to 2 cycles of CT (early TRT) or after 3 to 6 cycles of CT (late TRT). Survival and response rates were evaluated using the Kaplan-Meier method and comparisons were made using the multivariate Cox regression test. Results: Median follow-up was 24 (5 to 57) months. Carboplatin+etoposide was the most frequent induction CT (59%). Median overall, disease free, and metastasis free survivals in all patients were 15 (5 to 57), 5 (0 to 48) and 11 (3 to 57) months respectively. Late TRT was superior to early TRT group in terms of response rate (p=0.05). 3 year overall survival (OS) rates in late versus early TRT groups were 31% versus 17%, respectively (p=0.03). Early TRT (p=0.03), and incomplete response to TRT (p=0.004) were negative predictors of OS. Significant positive prognostic factors for distant metastasis free survival were late TRT (p=0.03), and use of PCI (p=0.01). Use of carboplatin versus cisplatin for induction CT had no significant impact on OS (p=0.634), DFS (p=0.727), and MFS (p=0.309). Conclusions: Late TRT appeared to be superior to early TRT in LS-SCLC treatment in terms of complete response, OS and DMFS. Carboplatin or cisplatin can be combined with etoposide in the induction CT owing to similar survival outcomes.

Importance of Performing Radiotherapy and Chemotherapy in the Same Clinic and Bad Prognostic Factors for Small-cell Lung Cancer Patients

“…These results suggest that RT is effective for the patients who do not shown a good response to CT despite the different reported results in the literature (5,31). The response rates to CT for SCLC were 60-95% in many studies (6,4,10,5). However, the total response rate to CT was 45% in our study because these patients were sent from other clinics after disease progression or bad results of CT.…”

“…The partial response rate increased to 53.7% post RT, while it was 25.92% pre RT. These results suggest that RT is effective for the patients who do not shown a good response to CT despite the different reported results in the literature (5,31). The response rates to CT for SCLC were 60-95% in many studies (6,4,10,5).…”

“…Prophylactic cranial RT should be considered for all patients to achieve complete remission. Extensive-stage disease should be treated by combination CT administered for 4-6 cycles (4,5).…”

“…This treatment results in a complete response rate of 80% or higher, a median survival in excess of 17 months, and a 5-year cancer-free survival rate of 12-25% in best series (6,4,10,5).…”

Sequential Versus Concurrent Thoracic Radiotherapy in Combination With Cisplatin and Etoposide for N3 Limited-Stage Small-Cell Lung Cancer

“…One study showed that late TRT appeared to be superior to early TRT in terms of complete response and OS in patients with LS-SCLC. 20 In our study, concurrent CRT showed a trend toward improving the complete response rate, PFS and OS, but there was no significant difference between sequential group and concurrent group. For N3 LS-SCLC patients, systemic therapy plays a more important role compared with N0-2 patients.…”