Lung dose and the potential risk of death in postoperative radiation therapy for non-small cell lung cancer: A study using the method of stratified grouping.

PURPOSE: Postoperative radiation therapy may have a detrimental effect on survival in patients with non-small cell lung cancer. We investigated the association of the lung radiation dose with the risk of death in patients treated with postoperative radiation therapy. METHODS: We analyzed 178 patients with non-small cell lung cancer who received postoperative radiation therapy. The mean lung dose was calculated from dose-volume data, and we categorized patients into the high and low lung dose groups using 2 different methods; (1) simple grouping using the median lung dose of all patients, and (2) stratified grouping using the median lung dose of each subgroup sharing the same confounders. We compared clinical variables, and survival between the high and low lung dose groups. RESULTS: In the simple grouping, there were no significant differences in survivals between the high and low lung dose groups. After stratification, the overall survival of low lung dose group was significantly longer than that of high lung dose group (5-year survival, 60.1% vs. 35.3%, p = 0.039). On multivariable analyses, the lung dose remained a significant prognostic factor for overall survival (hazard ratio, HR = 2.08, p = 0.019). CONCLUSIONS: The lung dose was associated with the risk of death in patients with non-small cell lung cancer having the same confounders. Further studies evaluating the risk of death according to the lung dose will be helpful to administer more precise and individualized postoperative radiation therapy.

Comparison of concurrent chemoradiotherapy versus sequential radiochemotherapy in patients with completely resected non-small cell lung cancer.

PURPOSE: Our institution has implemented two different adjuvant protocols in treating patients with non-small cell lung cancer (NSCLC): chemotherapy followed by concurrent chemoradiotherapy (CT-CCRT) and sequential postoperative radiotherapy (PORT) followed by postoperative chemotherapy (POCT). We aimed to compare the clinical outcomes between the two adjuvant protocols. MATERIALS AND METHODS: From March 1997 to October 2012, 68 patients were treated with CT-CCRT (n = 25) and sequential PORT followed by POCT (RT-CT; n = 43). The CT-CCRT protocol consisted of 2 cycles of cisplatin-based POCT followed by PORT concurrently with 2 cycles of POCT. The RT-CT protocol consisted of PORT followed by 4 cycles of cisplatin-based POCT. PORT was administered using conventional fractionation with a dose of 50.4-60 Gy. We compared the outcomes between the two adjuvant protocols and analyzed the clinical factors affecting survivals. RESULTS: Median follow-up time was 43.9 months (range, 3.2 to 74.0 months), and the 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were 53.9%, 68.2%, and 51.0%, respectively. There were no significant differences in OS (p = 0.074), LRFS (p = 0.094), and DMFS (p = 0.490) between the two protocols. In multivariable analyses, adjuvant protocol remained as a significant prognostic factor for LRFS, favouring CT-CCRT (hazard ratio [HR] = 3.506, p = 0.046) over RT-CT, not for OS (HR = 0.647, p = 0.229). CONCLUSION: CT-CCRT protocol increased LRFS more than RT-CT protocol in patients with completely resected NSCLC, but not in OS. Further studies are warranted to evaluate the benefit of CCRT strategy compared with sequential strategy.

Radiation Therapy-First Strategy After Surgery With or Without Adjuvant Chemotherapy in Stage IIIA-N2 Non-Small Cell Lung Cancer.

PURPOSE: Postoperative radiation therapy (PORT) and postoperative chemotherapy (POCT) can be administered as adjuvant therapies in patients with non-small cell lung cancer (NSCLC). The aim of this study was to present the clinical outcomes in patients treated with PORT-first with or without subsequent POCT in stage IIIA-N2 NSCLC. METHODS AND MATERIALS: From January 2002 to November 2014, the conditions of 105 patients with stage IIIA-N2 NSCLC who received PORT-first with or without subsequent POCT were analyzed. PORT was initiated within 4 to 6 weeks after surgical resection. Platinum-based POCT was administered 3 to 4 weeks after the completion of PORT. We analyzed the outcomes and the clinical factors affecting survival. RESULTS: Of 105 patients, 43 (41.0%) received POCT with a median of 4 cycles (range, 2-6 cycles). The follow-up times ranged from 3 to 123 months (median, 30 months), and the 5-year overall survival (OS) was 40.2%. The 5-year OS of patients treated with PORT and POCT was significantly higher than that of patients with PORT (61.3% vs 29.2%, P<.001). The significant prognostic factors affecting OS were the use of POCT (hazard ratio [HR] = 0.453, P=.036) and type of surgery (pneumonectomy/lobectomy; HR = 2.845, P<.001). CONCLUSIONS: PORT-first strategy after surgery appeared not to compromise the clinical outcomes in the treatment of stage IIIA-N2 NSCLC. The benefit of POCT on OS was preserved even in the PORT-first setting. Further studies are warranted to compare the sequencing of PORT and POCT, guaranteeing the proper use of POCT.