Postoperative Combined Radiation and Chemotherapy Improves Disease-FreeSurvival (DFS) and Overall Survival (OS) in Resected Adenocarcinoma ofthe Stomach and G.E. Junction. Results of Intergroup Study INT-0116(SWOG 9008)
Presenter: John S. Macdonald
Affiliation: SWOG; ECOG; RTOG; CALGB; NCCTG
It is estimated that there will be 22,000 new cases and 13,500 deaths from gastric cancer in the US this year. The cure rate for gastric carcinoma treated with surgery alone ranges between 10% - 30% for node positive patients and 40% - 60% for node negative patients. The intergroup study reported here was designed to evaluate post-operative adjuvant chemotherapy and radiotherapy in patients who have their gastric cancers resected.
- 603 patients with adenocarcinoma of the stomach or gastroesophageal junction (GEJ), Stage IB - IV without evidence of metastatic disease and with SWOG performance status of 0 - 1 were entered onto study.
- All patients underwent gastric resection with curative intent (nodal metastases were present in 85% of cases)
- Patients were then randomized to one of two treatment arms: 1. postoperative followup with observation only 2. 5-FU plus leucovorin x 1 cycle followed by 45 Gy external beam radiation therapy combined with 5-FU plus leucovorin for 2 cycles 109 lines more (you've seen 39%) radiation therapy combined with 5-FU plus leucovorin for 2 cycles followed, after completion of radiation therapy, by 5-FU plus leucovorin for 2 cycles.
- The median followup was 2 years.
- 20% of patients had tumors in the GEJ
- The 3 year disease-free survival (DFS) was 49% for patients who received treatment, and 32% for the group that was observed (p = 0.001).
- The 3 year overall survival (OS) was 52% for patients who received treatment, and 41 for the group that was observed (P = 0.03).
- The median survival was 35 months for the patients who received postoperative treatment, and 28 months for the observed patients.
- The major toxicities (Grade II, IV) consisted primarily of myelosuppression and GI toxicity.
- Chemotherapy plus radiation after resection in this patient group significantly improves DFS and OS.
- Toxicity from this combined therapy is acceptable.
- Postoperative chemotherapy plus radiation should now be now the standard of care for resected gastric cancer in patiens with acceptable performance status.
- This is the report of a long awaited intergroup trial. Although many patients did not have a planned full-nodal dissection, and 54% had less than D1 resections, this is probably a good representation of the surgical standard in the US.
- This study clearly shows that the addition of postoperative chemo/radiotherapy results in improved survival for this patient group, and should now be considered the current standard of care.