Association between clinicopathological factors and postoperative radiotherapy in patients with completely resected pathological N2 non-small cell lung cancer

Abstract

Abstract. The function of postoperative radiotherapy (PORT) in patients with completely resected pathologically N2 (pN2) non-small cell lung cancer (NSCLC) remains controversial due to a lack of prospective studies. The present study aimed to evaluate the efficacy of PORT in completely resected pN2 NSCLC when using modern radiation techniques, and to determine the associations between clinicopathological factors and PORT and survival rates. Following patient selection, 246 out of 269 consecutive patients with pN2 NSCLC were enrolled in the present study, with 88 patients having received postoperative chemotherapy (POCT) and PORT, 90 having received adjuvant chemotherapy, 1 having received adjuvant radiotherapy and the remaining 67 having received no adjuvant therapy. Overall survival (OS), local recurrence-free survival (LRFS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. The median age of the patients was 59 years, overall, 175 (71.1%) of the patients were male and the median radiation dose was 50.4 Gy. The median follow-up duration was 38.3 months. The 1-, 3-and 5-year OS rates were 98.9, 71.3 and 54.9%, and 93.0, 58.4 and 36.7% (P=0.011) in the PORT and non-PORT group, respectively. The 1-, 3-and 5-year LRFS rates were 95.5, 84.6 and 78.0%, and 86.6, 70.6 and 52.8% (P<0.001) in the PORT and non-PORT groups, respectively. The 1-, 3-and 5-year DFS rates were 86.5, 55.2 and 37.9%, and 80.9, 40.3 and 26.8% (P=0.132) in the PORT and non-PORT groups, respectively. Univariate analysis revealed that the OS rate was significantly increased in patients with peripheral tumors (P=0.029), pT1-2 (P=0.015), one N2 lymph node (LN) metastasis (P=0.001), single N2 station metastasis (P=0.030), no bronchial involvement (P=0.025), use of PORT (P=0.011) and POCT (P=0.003). Multivariate analysis revealed that PORT (HR, 0.755; 95% CI, 0.498-0.986; P=0.047), POCT (HR, 0.645; 95% CI, 0.420-0.988; P=0.044), bronchial involvement (HR, 1.453; 95% CI, 1.002-2.107; P= 0.049) and ≥2 N2 metastases (HR, 1.969; 95% CI, 1.228-3.157; P= 0.005) were significant independent predictors of OS. Subgroup analysis demonstrated an increased OS rate with PORT only in the patients with positive bronchial involvement and ≥2 N2 LN metastases. The results revealed that PORT may improve the LRFS and OS rates in completely resected pN2 NSCLC, and that the patients with positive bronchial involvement and ≥2 N2 LN metastases may receive more benefit from PORT.

Mediastinal lymph node evaluation, especially at station 4L, in left upper lobe lung cancer

“…This information helps to determine the indications for adjuvant chemotherapy, which reportedly has therapeutic effects (28). As previously reported, N2 is a prognostic factor for survival in patients with lung cancer who have undergone radical resection (29). The pathological N factor was one of the clinical factors associated with DFS in left upper lobe lung cancer in this study.…”

The role of postoperative radiotherapy for completely resected pIIIA-N2 non-small cell lung cancer patients with different clinicopathological features: a systemic review and meta-analysis

“…Therefore, a number of studies investigated the efficacy of PORT for pIIIA-N2 NSCLC according to the N2 metastasis status. Several retrospective studies 14, 18, 19, including two population-based studies 16,17, demonstrated the benefit of PORT in terms of improving OS for patients with multiple N2 metastases or multiple N2 station involvement, but not for patients with single N2 station involvement. However, the subgroup analysis of a recent randomized phase II study 20 revealed that postoperative chemotherapy (POCT) alone was favored compared with POCRT in patients with multiple N2 station involvement.…”

Postoperative Radiotherapy Option Based on Mediastinal Lymph Node Reclassification for Patients with pN2 Non-small-Cell Lung Cancer

“…Currently, with the widespread use of X-ray linear accelerators and the emergence of technologies such as 3-dimensional conformal rt and intensity-modulated rt, the conformity index of the target volume, the dose distribution, and the organs at risk doses have all been improved, and radiation-related toxicity is also well controlled 6 . As a result, port has been validated in several studies to improve survival for patients classified pN2 5,7,8 . In the present study, port was implemented based on modern rt technologies (40 patients received 3-dimensional conformal rt, and 183 received intensity-modulated rt).…”

“…However, the meta-analysis was also disputable because of its inclusion of outdated studies, older radiotherapy (rt) techniques, and incomplete surgical information. Subsequently, some studies verified that, with modern rt techniques, port is sufficiently safe 6 and can improve the postoperative survival of patients with pN2 nsclc 5,7,8 . However, some scholars have held the opposite opinion 9,10 , making it crucially important to screen for patients who might benefit from port.…”