Sex-Related Differences in Impact on Safety of Pharmacogenetic Profile for Colon Cancer Patients Treated with FOLFOX-4 or XELOX Adjuvant Chemotherapy.

Polymorphisms contribute to inter-individual differences and show a promising predictive role for chemotherapy-related toxicity in colon cancer (CC). TOSCA is a multicentre, randomized, non-inferiority, phase III study conducted in high-risk stage II/stage III CC patients treated with 6 vs 3 months of FOLFOX-4 or XELOX adjuvant chemotherapy. During this post-hoc analysis, 218 women and 294 men were genotyped for 17 polymorphisms: TYMS (rs34743033, rs2853542, rs11280056), MTHFR (rs1801133, rs1801131), ERCC1 (rs11615), XRCC1 (rs25487), XRCC3 (rs861539), XPD (rs1799793, rs13181), GSTP1 (rs1695), GSTT1/GSTM1 (deletion +/-), ABCC1 (rs2074087), and ABCC2 (rs3740066, rs1885301, rs4148386). The aim was to assess the interaction between these polymorphisms and sex, on safety in terms of time to grade ≥3 haematological (TTH), grade ≥3 gastrointestinal (TTG) and grade ≥2 neurological (TTN) toxicity. Interactions were detected on TTH for rs1801133 and rs1799793, on TTG for rs13181 and on TTN for rs11615. Rs1799793 GA genotype (p = 0.006) and A allele (p = 0.009) shortened TTH in men. In women, the rs11615 CC genotype worsened TTN (co-dominant model p = 0.008, recessive model p = 0.003) and rs13181 G allele improved the TTG (p = 0.039). Differences between the two sexes in genotype distribution of rs1885301 (p = 0.020) and rs4148386 (p = 0.005) were found. We highlight that polymorphisms could be sex-specific biomarkers. These results, however, need to be confirmed in additional series.

Genetic markers for toxicity of adjuvant oxaliplatin and fluoropyrimidines in the phase III TOSCA trial in high-risk colon cancer patients.

We investigated 17 polymorphisms in 11 genes (TS, MTHFR, ERCC1, XRCC1, XRCC3, XPD, GSTT1, GSTP1, GSTM1, ABCC1, ABCC2) for their association with the toxicity of fluoropyrimidines and oxaliplatin in colorectal cancer patients enrolled in a prospective randomized trial of adjuvant chemotherapy. The TOSCA Italian adjuvant trial was conducted in high-risk stage II-III colorectal cancer patients treated with 6 or 3 months of either FOLFOX-4 or XELOX adjuvant chemotherapy. In the concomitant ancillary pharmacogenetic study, the primary endpoint was the association of polymorphisms with grade 3-4 CTCAE toxicity events (grade 2-4 for neurotoxicity). In 517 analyzed patients, grade ≥ 3 neutropenia and grade ≥ 2 neurotoxicity events occurred in 150 (29%) and in 132 patients (24.8%), respectively. Diarrhea grade ≥ 3 events occurred in 34 (6.5%) patients. None of the studied polymorphisms showed clinically relevant association with toxicity. Hopefully, genome-wide association studies will identify new and more promising genetic variants to be tested in future studies.

Adjuvant chemotherapy in completely resected gastric cancer: a randomized phase III trial conducted by GOIRC.

BACKGROUND: Complete surgical resection of gastric cancer is potentially curative, but long-term survival is poor. METHODS: Patients with histologically proven adenocarcinoma of the stomach of stages IB, II, IIIA and B, or IV (T4N2M0) and treated with potentially curative surgery were randomly assigned to follow-up alone or to intravenous treatment with four cycles (repeated every 21 days) of PELF (cisplatin [40 mg/m(2), on days 1 and 5], epirubicin [30 mg/m(2), days 1 and 5], L-leucovorin [100 mg/m(2), days 1-4], and 5-fluorouracil [300 mg/m(2), days 1-4] in a hospital setting. Frequencies and severity of adverse events were determined. Overall survival (OS) and disease-free survival (DFS) were compared between the treatment arms using Kaplan-Meier analysis and a Cox proportional hazards regression model. All statistical tests were two-sided. RESULTS: From January 1995 through September 2000, 258 patients were randomly assigned to chemotherapy (n = 130) or surgery alone (n = 128). Patient characteristics were well balanced between the two arms. Among those who received chemotherapy, grade 3 or 4 toxic effects including vomiting, mucositis, and diarrhea were experienced by 21.1%, 8.4%, and 11.8% of patients, respectively. Leucopenia, anemia, and thrombocytopenia of grade 3 or 4 were experienced by 20.3%, 3.3%, and 4.2% of patients, respectively. After a median follow-up of 72.8 months, 128 patients (49.6%) experienced recurrence and 139 (53.9%) deaths were observed, one toxicity-related. Relative to treatment with surgery alone, adjuvant chemotherapy did not increase disease-free survival (hazard ratio [HR] of recurrence = 0.92; 95% confidence interval [CI] = 0.66 to 1.27) or overall survival (HR of death = 0.90; 95% CI = 0.64 to 1.26). CONCLUSIONS: Our results failed to provide proof of an effect of adjuvant chemotherapy with PELF on overall survival or disease-free survival. The estimated effect of chemotherapy (10% reduction in the hazard of death or relapse) is modest and consistent with the results of meta-analyses of adjuvant chemotherapy without platinum agents.