GSTM1 and Decreased total leukocyte count: Acute GI toxicities:Weight lose: 1.2% vs 5.8%*≥ 5% weight lose: 16% vs 64%*Grade 2 nausea/vomiting: 26% vs 71%*Esophagitis medical management: 5% vs 57%*Intravenous fluid support: 0 vs 14%Acute hematologic toxicities:WBC reduction: 46% vs 55%*Hb reduction: 88% vs 97%*Platelet reduction: 48% vs 65%*Grade ≥ 1 anemia: 17% vs 48%*Grade ≥ 1 leukopenia: 84% vs 77%Grade ≥ 1 thrombocytopenia: 12% vs 29%2y OS: 94% vs 90%PFS: 94% vs 85%