Role of chemotherapy in clinical T2N0M0 gastric cancer.

• DOI: 10.1200/jco.2023.41.4_suppl.308
• Publication Date: 2023-01-24T21:05:07Z
• Authors: Sawyer Bawek; Yeshwanth Vedire; Adrienne Groman; Sarbajit Mukherjee
• Keywords: 03 medical and health sciences; 0302 clinical medicine; 3. Good health

308 Background: The role of chemotherapy for patients with early stage, node-negative gastric adenocarcinoma (T2N0M0) remains unclear. Possible options are surgery alone, surgery followed by adjuvant chemotherapy, or perioperative chemotherapy. The objective of our study was to investigate the role and sequence of chemotherapy in T2N0M0 gastric adenocarcinoma. Methods: The National Cancer Data Base (2006-2017) was used to identify patients with T2N0M0 gastric adenocarcinoma. Patients were categorized into 3 groups, surgery alone (S), surgery followed by adjuvant chemotherapy (AC), and peri-operative chemotherapy (POC). Univariate and multivariable Cox proportional-hazards models were performed to evaluate treatment differences in overall survival (OS). Patients were further sub-categorized into two subgroups based on the number of regional nodes examined, less than 15 (RNE<15) and greater or equal to 15 (RNE>15). Univariate and multivariable Cox proportional-hazards models were performed on each subgroup to assess the treatment differences within two groups. Results: The retrospective study analyzed 3,142 patients between 2006 to 2017. Surgery alone represented 2,090 patients (66.5%), AC group had 360 patients (11.5%), and the POC group 692 patients (22.0%). The median age of the population was 70 yrs. Mean inpatient stay was 12.5 days in S, 9.2 days in AC and 10.1 days in the POC group (p<0.001). In the multivariable model, surgery followed by adjuvant chemotherapy (HR 0.75, p=0.003), RNE>15 (HR 0.73, p<0.001), patients treated at academic facilities (HR 0.84, p=0.005), female sex (HR 0.84, p=0.004), and Asian race (HR 0.69, p=0.002) had better outcomes. There were 1,526 (49.2%) patients with RNE<15 and 1,577 (50.8%) patients with RNE>15. Subgroup analysis showed that peri-operative chemotherapy for RNE<15 was beneficial (HR 0.74, p= 0.029). Patients with RNE>15 had an improved survival with surgery followed by adjuvant chemotherapy (HR 0.72, p= 0.017) in the multivariable model. Conclusions: Surgery followed by adjuvant chemotherapy was found to be beneficial in patients having a T2N0M0 Gastric Cancer. However, the number of lymph nodes examined during surgery influences this association. Perioperative chemotherapy maybe beneficial for patients who were under staged due to inadequate exploration of lymph nodes during surgery.