A novel model may help to identify patients with stage II to III resectable gastric cancer likely to benefit from adjuvant chemotherapy after D2 gastrectomy, according to a study published in The Lancet Oncology.1
For this retrospective study, researchers identified 4 classifier genes relevant to gastric cancer (GZMB, WARS, SFRP4, and CDX1) in 307 patients in an internal cohort (193 received surgery plus chemotherapy vs 114 who received surgery alone). The model classified 8% of patients as low risk, 37% as intermediate risk, and 55% as high risk; 47% of patients were grouped into a predicted chemotherapy-benefit cohort vs 53% to a no-benefit cohort.
After a median follow up of 59 months, the 5-year overall survival (OS) rates were 83.3%, 71.8%, and 58.2% in the low-, intermediate-, and high-risk groups, respectively. A multivariate analysis showed an OS improvement among patients who received chemotherapy in the chemotherapy-benefit arm vs the no-benefit arm.
To validate these findings, investigators applied the model to an external cohort of 625 patients, of whom the model identified 13%, 47%, and 40% as low-, intermediate-, and high-risk patients, respectively. After a median-follow up of 61 months, 5-year OS rates were 83.2%, 74.8%, and 66.0%, respectively.
Forty-five percent of these patients were then assigned to a predicted chemotherapy-benefit arm and 55% to a no-benefit arm. The 5-year OS rates were 80% among patients in the chemotherapy-benefit arm who received adjuvant chemotherapy after surgery vs 64.5% among those who underwent surgery only (univariate hazard ratio [HR], 0.47; P = .0015; multivariate HR, 0.46; P = .0012).
No OS improvement was observed for patients who received chemotherapy in the no-benefit group (P = .71).
The authors concluded that “the single patient classifiers could complement…staging to [optimize] decision making in patients with resectable gastric cancer who are eligible for adjuvant chemotherapy after surgery. Further validation of these results in prospective studies is warranted.”
- Cheong JH, Yang HK, Kim H, et al. Predictive test for chemotherapy response in resectable gastric cancer: a multi-cohort, retrospective analysis. Lancet Oncol. 2018 Mar 19. doi: 10.1016/S1470-2045(18)30108-6 [Epub ahead of print]