Neo-adjuvant radiation therapy provides a survival advantage in T3-T4 nodal positive gastric and gastroesophageal junction adenocarcinoma: a SEER database analysis

Abstract

Background Due to negative results in clinical trials of postoperative chemoradiation for gastric cancer, at present, there is a tendency to move chemoradiation therapy forward in gastric and gastroesophageal junction (GEJ) adenocarcinoma. Several randomized controlled trials (RCTs) are currently recruiting subjects to investigate the effect of neo-adjuvant radiotherapy (NRT) in gastric and GEJ cancer. Large retrospective studies may be beneficial in clarifying the potential benefit of NRT, providing implications for RCTs. Methods We retrieved the clinicopathological and treatment data of gastric and GEJ adenocarcinoma patients who underwent surgical resection and chemotherapy between 2004 and 2015 from Surveillance, Epidemiology, and End Results (SEER) database. We compared survival between NRT and non-NRT patients among four clinical subgroups (T1–2N−, T1–2N+, T3–4N−, and T3–4N+). Results Overall, 5272 patients were identified, among which 1984 patients received NRT. After adjusting confounding variables, significantly improved survival between patients with and without NRT was only observed in T3–4N+ subgroup [hazard ratio (HR) 0.79, 95% confidence interval (CI): 0.66–0.95; P = 0.01]. Besides, Kaplan-Meier plots showed significant cause-specific survival advantage of NRT in intestinal type (P < 0.001), but not in diffuse type (P = 0.11) for T3–4N+ patients. In the multivariate competing risk model, NRT still showed survival advantage only in T3–4 N+ patients (subdistribution HR: 0.77; 95% CI: 0.64–0.93; P = 0.006), but not in other subgroups. Conclusions NRT might benefit resectable gastric and GEJ cancer patients of T3–4 stages with positive lymph nodes, particularly for intestinal-type. Nevertheless, these results should be interpreted with caution, and more data from ongoing RCTs are warranted.

Survival benefit after neoadjuvant or adjuvant radiotherapy for stage II–III gastroesophageal junction adenocarcinoma: A large population-based cohort study

“…Moreover, patients exhibit better tolerance to the full course of NART than to ART. Based on the findings of our study, survival advantages afforded by NART could be noted in patients with T 3–4 N + and T 3–4 with intestinal type, which was similar to the findings of a previous study ( 14 ), which failed to consider the implications of ART in GEJA. According to Shridhar et al., NART could improve survival rates in patients with lymph node involvement; however, the authors failed to perform subgroup analysis by T stage stratification ( 19 ).…”

“…In summary, ART conferred significant survival benefits in patients with T 1-2 N + and T 3-4 N + , whereas survival advantages after NART were only noted in patients with T 3-4 N + . In a previous report (14), patients with Lauren's classification-intestinal type were found to exhibit a response to NART. Therefore, we proposed a new category based on the intestinal type of Lauren's classification in patients with T 3-4 .…”

Comparative Analysis of Adjuvant Radiotherapy, Lymph Node Dissection, and Metastatic Positive Rate on Prognosis in T3-4N+ Gastroesophageal Junction Cancer: A Study Based on SEER Database and External Validation in China

“…However, for patients who have undergone D2 resection, postoperative radiotherapy may not be necessary, especially considering treatment toxicity. (20) Currently, the majority of research conclusions on gastric cancer are more inclined toward RST rather than SRT (21,22).…”

Neoadjuvant versus adjuvant radiotherapy for resectable locally advanced gastric cancer: A SEER population analysis

“…All patients with resected LAGC were histologically classified as intestinal subtype and diffuse subtype according to Lauren classification and the codes of International Classification of Diseases for Oncology, Version 3 ( ICD-O-3 ) [ 18 ]. The intestinal type included 8144/3 (adenocarcinoma, intestinal type), 8140/3 (adenocarcinoma, not otherwise specified), 8010/3 (carcinoma, not otherwise specified), 8211/3 (tubular adenocarcinoma).…”