Background
Adjuvant radiotherapy (ART) is recognized as a pivotal therapeutic modality capable of augmenting the overall survival(OS) outcomes in patients afflicted with gastroesophageal junction cancer (GEJ) at the T3-4N+ stage. However, there remains a need for comprehensive investigations into the optimal timing of radiotherapy administration relative to surgery. Furthermore, the number of regional nodes examined(RNE) and the metastasis lymph node ratio (MLR) exert discernible impacts on the prognosis of such patients. Our study endeavors to delve deeper into elucidating the interplay between ART and surgical interventions, while assessing the prognostic significance of RNE and MLR, with the ultimate goal of developing a nomogram to accurately predict the 5-year survival rate for T3-4N+ gastric cancer patients.
Patients and Methods
7,709 patients with GEJ cancer were involved from the Surveillance, Epidemiology, and End Results (SEER) database, spanning 2010 to 2019. 335 gastric cancer patients were involved from the Henan Provincial People's Hospital (HPPH), spanning 2015 to 2019. OS was analyzed using the log-rank test and multivariate analysis. The Cox regression models were valuable in predicting outcomes for these cancers. Receiver operating characteristic curve (ROC) and Decision Curve Analysis (DCA) were used to validate predictive model. Restricted cubic splines (RCS) were employed to analyze the potential nonlinear relationship between RNE and prognosis. Additionally, the relationship between MLR and prognosis was examined using the same method.
RESULTS
We found that esophageal adenocarcinoma exhibited a superior response to preoperative radiotherapy(p<0.001). However, the timing of radiotherapy for gastric adenocarcinoma post-operation did not significantly affect outcomes (p=0.6). Age, tumor grade, lymph node stage, RNE, type of surgery, and timing of radiotherapyrelative to surgery emerged as crucial prognostic factors for T3-4N+ gastric cancers. Additionally, the analysis showed no significant nonlinear relationship between RNE (with a threshold of 15) and patient survival in esophageal and gastric adenocarcinomas (p>0.05), suggesting consistent findings across varying levels of lymph node removal.
CONCLUSIONS
Esophageal adenocarcinoma demonstrates a greater therapeutic response to preoperative radiotherapy. Our nomogram provides an effective tool for predicting the 5-year prognosis of T3-4N+ gastric adenocarcinoma. Moreover, our analysis suggests that the removal of 15 lymph nodes may not represent the optimal strategy for lymph node dissection. Additionally, MLR emerges as a significant prognostic factor influencing outcomes in patients with both esophageal and gastric cancer.
