The lymph node ratio (LNR) could be used to guide the use of adjuvant chemotherapy in patients with locally advanced gastric cancer (LAGC), according to a retrospective study published in JAMA Network Open.

Researchers found that patients with LNRs of 9% or higher had better overall survival (OS) when they received adjuvant chemotherapy, but patients with LNRs less than 9% derived no benefit from adjuvant chemotherapy.

Researchers compared outcomes with and without adjuvant chemotherapy in 462 patients with LAGC who underwent neoadjuvant chemotherapy and curative-intent gastrectomy. The study included an Eastern cohort of 353 patients from China and a Western cohort of 109 patients from the United States and Italy.


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In the Eastern cohort, 78.1% of patients were men, the mean age was 58 years, and 74.1% of patients received postoperative adjuvant chemotherapy. In the Western cohort, 67.9% of patients were men, the mean age was 61 years, and 67.9% of patients received adjuvant chemotherapy.

In the Eastern cohort, before matching, the 3-year OS was not significantly different for patients who received adjuvant chemotherapy and those who did not — 55.2% and 49.3%, respectively (P =.17). After matching, the 3-year OS was significantly higher in patients who received adjuvant chemotherapy than in those who did not — 60.1% and 49.3%, respectively (P =.02).

The opposite results were observed in the Western cohort. Before matching, there was a significant difference in 3-year OS between the adjuvant chemotherapy and non-adjuvant chemotherapy groups — 64.8% and 39.5%, respectively (P =.004). After matching, there was no significant difference in 3-year OS between the groups — 57.3% and 39.5%, respectively (P =.11).

A subgroup analysis revealed a significant improvement in the 3-year OS rate with adjuvant chemotherapy among patients with an LNR of 9% or higher but not in patients with LNRs less than 9%.

In the Eastern cohort, among patients with an LNR of 9% or higher, the 3-year OS rate was 46.6% with adjuvant chemotherapy and 21.7% without adjuvant chemotherapy (P <.001). Among patients with an LNR less than 9%, the 3-year OS rate was 73.9% and 71.3%, respectively (P =.30). 

In the Western cohort, among patients with an LNR of 9% or higher, the 3-year OS rate was 53.0% in the adjuvant chemotherapy group and 26.3% in the non-adjuvant chemotherapy group (P =.04). Among patients with an LNR less than 9%, the 3-year OS rate was 62.6% and 54.5%, respectively (P =.92). 

“These findings suggest that the lymph node ratio could be useful in adjuvant chemotherapy selection for locally advanced gastric cancer after neoadjuvant chemotherapy in future decision-making processes,” the researchers concluded.

Reference

Lin JX, Tang YH, Lin GJ, et al. Association of adjuvant chemotherapy with overall survival among patients with locally advanced gastric cancer after neoadjuvant chemotherapy. JAMA Netw Open. 2022;5(4):e225557. doi:10.1001/jamanetworkopen.2022.5557

This article originally appeared on Cancer Therapy Advisor