CHICAGO — First results from the phase 3 CRITICS study found no significant difference in overall survival between postoperative chemotherapy and chemoradiotherapy in patients with resectable gastric cancer, according to a study presented at the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting.1
The study investigated whether chemoradiotherapy after neoadjuvant chemotherapy and adequate surgery leads to improved overall survival compared with postoperative chemotherapy, said Marcel Verheij, MD, PhD, Department of Radiation Oncology, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam, Netherlands.
Currently, long-term survival is approximately 25%, and local recurrences as part of treatment failure are observed in up to 80% of patients.
Between January 2007 and April 2015, the study randomly assigned 788 patients with stage Ib-IVa resectable gastric cancer after diagnosis; neoadjuvant chemotherapy, comprised of 3 courses of epirubicin, cisplatin/oxaliplatin, and capecitabine, was administered and the patients resected.
After resection, patients received another 3 courses of epirubicin, cisplatin/oxaliplatin, and capecitabine (n = 393) or chemoradiotherapy, 45 Gy in 25 fractions combined with weekly cisplatin and daily capecitabine (n = 395).
Median patient age was 62 years and 67% were male. A total of 84% of patients completed 3 cycles of preoperative chemotherapy before surgery and 47% in the chemotherapy arm and 52% in the chemoradiotherapy arm completed treatment. The primary reasons patients did not start postoperative treatment were patient refusal, progressive disease, preoperative toxicity, and surgical complications.
After a median follow-up of 4.2 years, no significant differences in rates of either 5-year overall survival, the primary end point, or progression-free survival were observed.
The 5-year overall survival rate was 40.8% for the chemotherapy arm and 40.9% for the chemoradiotherapy arm (P = .99); median overall survival was 3.5 years and 3.3 years, respectively. The 5-year progression-free survival rate was also similar between the two arms, 38.5% for chemotherapy and 39.5% for chemoradiotherapy (P = .99); median progression-free survival was 2.3 years and 2.5 years.
Postoperative toxicity was primarily hematologic; 34% of patients in the chemotherapy arm and 4% in the chemoradiotherapy arm reported grade 3/4 neutropenia, and 2% in each arm had febrile neutropenia. Grade 3 or higher gastrointestinal events included anorexia, nausea, fatigue, diarrhea, and vomiting.
“Based on the currently available data, no advice can be given on the preferred adjuvant strategy,” Dr. Verheij said. “Ongoing analyses may identify treatment benefits in specific subgroups.”
Finally, since less than half of patients could complete full treatment, “more emphasis on preoperative strategies should be considered,” he concluded.
1. Verheij M, Jansen EP, Cats A, et al. A multicenter randomized phase III trial of neo-adjuvant chemotherapy followed by surgery and chemotherapy or by surgery and chemoradiotherapy in resectable gastric cancer: First results from the CRITICS study. Oral presentation at: ASCO 2016 Annual Meeting; June 3-7, 2016; Chicago, IL.