Combined adjuvant radiochemotherapy with IMRT/XELOX improves outcome with low renal toxicity in gastric cancer.

OBJECTIVES: Adjuvant radiochemotherapy improves survival of patients with advanced gastric cancer. We assessed in two sequential cohorts whether improved radiotherapy technique (IMRT) together with intensified chemotherapy improves outcome vs. conventional three-dimensional conformal radiotherapy (3D-CRT) and standard chemotherapy in these patients while maintaining or reducing renal toxicity.
MATERIALS AND METHODS: Sixty consecutive patients treated for gastric cancer either with 3D-CRT (n = 27) and IMRT (n = 33) were evaluated. More than 70% had undergone D2 resection. Although there was a slight imbalance in R0 status between cohorts, N+ status was balanced. Chemotherapy consisted predominantly of 5-fluorouracil/folinic acid (n = 36) in the earlier cohort and mostly of oxaliplatin/capecitabine (XELOX, n = 24) in the later cohort. Primary end points were overall survival (OS), disease-free survival (DFS), and renal toxicity based on creatinine levels.
RESULTS: Median follow-up (FU) of all patients in the 3D-CRT group was 18 months and in the IMRT group 22 months (median FU of surviving patients 67 months in the 3D-CRT group and 25 months in the IMRT group). Overall median survival (and DFS) were 18 (13) months in the 3D-CRT group and both not reached in the IMRT group (p = 0.0492 and 0.0216). Actuarial 2-year survival was 37% and 67% in the 3D-CRT and IMRT groups, respectively. No late renal toxicity >Grade 2 (LENT-SOMA scale) was observed in either cohort.
CONCLUSION: When comparing sequentially treated patient cohorts with similar characteristics, OS and DFS improved with the use of IMRT and intensified chemotherapy without signs of increased renal toxicity.