RT Fails to Improve on Chemo in Resected Gastric Cancer

Adding radiotherapy to adjuvant chemotherapy in the ARTIST trial yielded similar results to chemo alone in patients with D2 lymph node-resected gastric cancer.

The addition of radiotherapy to adjuvant chemotherapy yielded similar results to chemotherapy alone in patients with D2 lymph node–resected gastric cancer, according to final results of the ARTIST trial. Certain subgroups did see improvement with radiotherapy, leading to further work on this regimen.

A previous trial (Intergroup 0116) established adjuvant radiotherapy as part of the standard of care for gastric cancer. “Controversy remains, however, because the Intergroup 0116 trial has been criticized for suboptimal surgery, with only 10% of patients receiving D2 lymph node dissection,” wrote study authors led by Won Ki Kang, MD, of Samsung Medical Center in Seoul, South Korea. D2 dissection is the most widely recommended surgical procedure for resectable gastric cancer.

The ARTIST trial thus included only patients who had undergone such resection. A total of 458 patients were included, and randomized to either 6 cycles of adjuvant chemotherapy with capecitabine and cisplatin (228 patients) or 2 cycles of that regimen followed by chemoradiotherapy, and then 2 more cycles of capecitabine and cisplatin (230 patients). Results were published online ahead of print on January 5 in the Journal of Clinical Oncology.

After a median follow-up of 7 years, the probability for survival at 5 years was 73% for chemotherapy alone patients and 75% in the radiotherapy group (P = .484). The hazard ratio for overall survival was 1.13 (95% CI, 0.775-1.647; P = .5272), and for disease-free survival (DFS) was 0.74 (95% CI, 0.52-1.05; P = .0922). There were 141 patients who relapsed, and the median time from relapse to death was 9.7 months with chemotherapy and 7.2 months with chemoradiotherapy (P = .076).

In the 396 patients with node-positive disease, the 3-year DFS rate was significantly better with chemoradiotherapy, at 76% vs 72% with chemotherapy alone (P = .04). Another subgroup also showed benefit with the radiotherapy addition: in the 163 patients with intestinal-type gastric cancer, the 3-year DFS was 94% with radiotherapy and 83% without (P = .01).

Those subgroup benefits are similar to findings from the Intergroup 0116 trial. “At the moment, in making treatment decisions for individual patients, we suggest that advanced stage, lymph node status, and the Lauren classification be the factors taken into account when chemoradiotherapy is being considered,” the authors wrote. The subgroup benefits are under further investigation in the phase III ARTIST 2 trial, which will eventually include about 1,000 gastric cancer patients.