Pathologic Response and Outcomes After Neoadjuvant Chemotherapy in Gastric Cancer: A NCDB Analysis

Area of Science:

• Oncology
• Gastrointestinal Oncology
• Clinical Research

Background:

• Pathologic complete response (pCR) is linked to better survival in many cancers, but its prognostic significance in gastric cancer is not well-established.
• Neoadjuvant chemotherapy followed by resection is a standard treatment for non-metastatic gastric adenocarcinoma.

Purpose of the Study:

• To evaluate the prognostic value of pCR on overall survival (OS) in gastric cancer patients.
• To analyze trends in pCR rates and identify factors associated with achieving pCR.

Main Methods:

• The National Cancer Database was used to identify patients diagnosed between 2004-2021 who received neoadjuvant chemotherapy and curative-intent resection.
• Generalized estimating equations, Kaplan-Meier, and Cox proportional hazards models were employed to analyze pCR rates and OS.
• Time-trend analysis assessed changes in pCR over time.

Main Results:

• Of 7258 patients, 9.3% achieved pCR, with significantly higher median OS (167.9 vs. 65.8 months; p<0.001).
• Patients with both tumor and nodal pCR (cT2N1 or higher) had the best survival (median OS 181.8 months).
• pCR rates increased after 2018, coinciding with FLOT regimen adoption (OR: 1.26; p=0.005).

Conclusions:

• pCR is a significant predictor of improved OS in gastric cancer, particularly when both tumor and nodal responses are complete.
• Increasing pCR rates highlight the success of contemporary neoadjuvant chemotherapy regimens.
• Neoadjuvant strategies are crucial for enhancing survival outcomes in gastric cancer.