RESUMO
BACKGROUND: Neoadjuvant therapy enhances the possibility of achieving radical resection and improves the prognosis for locally advanced gastric cancer (GC). However, there is a lack of evidence regarding the optimal extent of resection for locally advanced proximal GC after neoadjuvant therapy. METHODS: In this study, 330 patients underwent resection in Peking University Cancer Hospital, with curative intent after neoadjuvant therapy for histologically confirmed proximal GC from January 2009 to December 2022. Among them, 45 patients underwent proximal gastrectomy (PG), while 285 underwent total gastrectomy (TG). RESULTS: In this study, 45 patients underwent proximal gastrectomy (PG), while 285 underwent total gastrectomy (TG). After propensity-score matching, 110 patients (71 TG and 39 PG) were included in the analysis. No significant differences between PG and TG regarding short-term outcomes and long-term prognosis were found. Specifically, PG demonstrated comparable overall survival to TG (P = 0.47). Subgroup analysis revealed that although not statistically significant, PG showed a potential advantage over TG in overall survival for patients with tumor-long diameters less than 4 cm (P = 0.31). However, for those with a long diameter larger than 4 cm, TG had a better survival probability (P = 0.81). No substantial differences were observed in baseline characteristics, surgical safety, postoperative recovery, and postoperative complications. CONCLUSION: For locally advanced proximal GC with objective response to neoadjuvant therapy (long diameter <4 cm), PG is an alternative surgical procedure. Further research and prospective studies are warranted to validate these findings and guide clinical decision-making.
RESUMO
Objective: Positive peritoneal lavege cytology (CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1 and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer. Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31 matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer. Results: Least absolute shrinkage and selection operator (LASSO) algorithm identified 43 cytology-positive marker genes, while MutSigCV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology (CY0). Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1 and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.