Gastrectomy ‘Not Justified’ For Advanced Gastric Cancer With Single Incurable Metastatic Site

Chemotherapy alone offers best overall survival for patients with advanced gastric cancer with up to one non-curable factor

medwireNews: REGATTA results suggest that combining chemotherapy with gastrectomy does not extend the survival of advanced gastric cancer patients with one incurable site of metastases over that achieved by chemotherapy alone.

“[G]astrectomy plus chemotherapy cannot be justified to treat patients with advanced gastric cancer, even with a single non-curable factor”, the study authors emphasize in The Lancet Oncology.

“Chemotherapy alone remains the standard of care for these patients.”

The open-label, phase III trial conducted in Japan, South Korea and Singapore ended early after the first interim analysis showed there was only a small likelihood that overall survival (OS) would be longer in the patients given oral S-1 and cisplatin chemotherapy plus gastrectomy, without metastases resection, than in the patients given chemotherapy alone.

Indeed, 2-year OS was achieved by 25.1% of the 89 patients who were randomly assigned to undergo resection and chemotherapy versus 31.7% of the 86 patients given chemotherapy alone, with a comparable median OS of 14.3 versus 16.6 months, respectively.

And patients who underwent resection plus chemotherapy were more likely to discontinue treatment than those given chemotherapy alone, at 36% versus 28%. The gastrectomy group also had a higher rate of grade 3 or 4 drug-related adverse events than those who only received chemotherapy, including leukopenia (18 vs 3%), anorexia (29 vs 12%), nausea (15 vs 5%) and hyponatraemia (9 vs 5%).

Toshimasa Tsujinaka, from Kaizuka City Hospital in Osaka, Japan, and co-investigators highlight prespecified subgroup analysis indicating that use of surgery plus chemotherapy versus chemotherapy alone was particularly unfavourable in patients with up to one positive lymph node or upper-third tumours, with significant hazard ratios for death of 1.79 and 2.23, respectively.

They suggest that the poor OS in patients with upper-third disease who underwent surgery may be attributed to the impaired compliance with chemotherapy, with patients receiving half the number of cycles of those who did not undergo gastrectomy.

Noting that poor chemotherapy compliance after gastrectomy has also been reported in European patients, the REGATTA investigators believe that the “results of this trial are applicable to a broad population of patients with advanced gastric cancer worldwide.”

“Postoperative complications are less likely to cause lower compliance with chemotherapy because of the low incidence of surgical morbidity and mortality in this study”, they add.

Reference

Fujitani K, Yang H-K, Mizusawa J, et al. Gastrectomy plus chemotherapy versus chemotherapy alone for advanced gastric cancer with a single non-curable factor (REGATTA): a phase 3, randomised controlled trial. Lancet Oncol 2016; Advance online publication 25 January. DOI: http://dx.doi.org/10.1016/S1470-2045(15)00553-7

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