Fellow in Complex General Surgical Oncology Moffitt Cancer Institute Tampa, Florida, United States
Disclosure: Disclosure information not submitted.
Participants should be aware of the following financial/non-financial relationships:
Andrew J. Sinnamon, MD, MSCE: Disclosure information not submitted.
Introduction: Perioperative chemotherapy is the standard of care for locoregional gastric cancers in western populations. However, the impact of response to therapy as a biomarker of cancer survival has not been fully defined. This study focuses on the pathological response to neoadjuvant chemotherapy, as measured by tumor regression grade (TRG), for gastric cancer and its impact on patient outcomes.
Methods: Patients undergoing gastrectomy for nonmetastatic invasive gastric adenocarcinoma following perioperative chemotherapy (clinical T2+/N+cM0) were identified from an institutional database (2000-2021). Demographics, clinical and surgical factors, and survival outcomes were included. OS was estimated using the Kaplan Meier method with adjustment for covariates using Cox regression.
Results: One hundred seventeen patients were identified. Median age was 65 years. Sixty-four were male (55%). Seventy-six patients underwent total gastrectomy, 22 subtotal gastrectomy, and 19 distal gastrectomy. Six patients (5.1%) had a TRG of 0, 18 patients (15.4%) had a TRG of 1, 25 patients (21.4%) had a TRG of 2, and 68 patients (58.1%) had a TRG of 3. Median survival overall was 40.9 months (95% CI 28.7–66.4). TRG status was not significantly different between chemotherapy regimens (doublet vs triplet, p=0.96).Median survival was longest in the TRG 0 group (86.9 months), followed sequentially by TRG 1 (74.5 months), TRG 2 (51.5 months), and lastly, TRG 3 group with 27.0 months. Increased tumor regression (lower TRG) was significantly associated with prolonged survival (p < 0.01 by log-rank for trend). After adjustment for clinical patient factors and tumor factors, TRG remained significantly associated with overall survival (Table; TRG hazard ratio 1.62, p = 0.007). In addition to TRG status, clinical T4 tumors and diffuse histology were associated with poor survival (cT4 hazard ratio 2.09, p = 0.039, diffuse histology hazard ratio 1.82 (p = 0.071).
Conclusions: In patients receiving perioperative chemotherapy for treatment of gastric cancer, response to therapy as defined by TRG is independently prognostic of survival.
Learning Objectives:
Demonstrate the association between tumor regression grade and prognosis after preoperative chemotherapy for gastric cancer.
Interpret the effect of other clinical factors, such as histology and clinical T stage, on survival for gastric cancer patients.
Recognize favorable long term prognosis in patients with TRG 0.