In patients with resectable gastric cancer (RGC), neoadjuvant chemoradiation (nCRT) may be superior to alternative treatment modalities for achieving pathologic complete response (pCR), according to a comparative effectiveness study published in JAMA Network Open.

While treatment of RGC typically applies a multimodal approach that includes surgical treatment and chemotherapy with or without radiation, improving outcomes can be a challenge due to the aggressive nature of this disease. Due to a lack of data regarding the optimal treatment strategy for RGC, researchers retrospectively investigated the association of various neoadjuvant and adjuvant treatment modalities with rates of pCR, surgical margin status (SMS), and overall survival (OS).

Between 2004 and 2015, 183,204 patients with RGC were screened and 3064 were ultimately included in the analysis. Median patient age was 65 years and 57.6% were men. In total, 20.7% of patients were Black, 48.9% White, and 30.4% identified as “other”. The majority of tumors were located in the antrum (51.7%), with stage T3 being the most common (48.7%).


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Multivariable analyses among 1939 patients with RCG revealed nCRT was associated with increased odds of pCR compared with no perioperative therapy (NT) (P <.001), followed by radiation therapy with timing unknown (RTTU) (P=.004).

In multivariable analysis for OS among 3061 patients, chemotherapy with timing unknown (CTTU) was associated with decreased risk for death compared with NT (P <.001), as well as nCRT (P <.001). Median OS was greatest among patients treated with CTTU (53.9 months), followed by nCRT (39.1 months) and adjuvant chemotherapy only (aCT) (36.1 months); 2-year OS rates were 65.6% for CTTU, 63.6% for nCRT, and 59.7% for aCT.

Overall clinical stage was associated with increased odds for SMS (odds ratio [OR] for stage 3 vs stage 1, 1.81; P =.001), with higher stages exhibiting greater ORs for SMS, though this result was not statistically significant (P =.17).  

This study was limited by the presence of selection bias, as treatment regimens were chosen for patients based on certain demographic and clinical characteristics. Additionally, the retrospective nature of the study design may have led to incomplete treatment information and prevented standardization of treatment regimens. 

The authors stated, “These findings suggest that nCRT may be more effective than nCT in treating tumor burden and may be associated with improved OS. “Additionally, our study suggests the importance of chemotherapy (including neoadjuvant and adjuvant therapy) as the standard of treatment in the multimodal approach for RGC based on the association of chemotherapy with increased OS,” they concluded.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Anderson E, LeVee A, Kim S, et al. A comparison of clinicopathologic outcomes across neoadjuvant and adjuvant treatment modalities in resectable gastric cancer. JAMA Netw Open. 2021;4(12):e2138432. doi: 10.1001/jamanetworkopen.2021.38432