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.

Final Results of the Randomized Phase II NorCap-CA223 Trial Comparing First-Line All-Oral Versus Taxane-Based Chemotherapy for HER2-Negative Metastatic Breast Cancer.

BACKGROUND: The purpose of this study was to evaluate the efficacy of 3 first-line chemotherapy combination regimens for HER2-negative metastatic breast cancer (mBC). PATIENTS AND METHODS: In this open-label, 3-arm, randomized phase II trial, patients were randomized to all-oral NORCAP (vinorelbine/capecitabine), GEMPAC (gemcitabine/paclitaxel), or GEMDOC (gemcitabine/docetaxel) as first-line chemotherapy for HER2-negative mBC. Stratification factors were center, previous (neo)adjuvant anthracycline, and age. The primary end point was disease control rate (DCR; complete or partial response, or stable disease for ≥3 months). RESULTS: The DCR was 73% (95% confidence interval [CI], 59-85) with NORCAP (36 of 49 patients), 78% (95% CI, 64-88) with GEMPAC (39 of 50 patients), and 80% (95% CI, 66-90) with GEMDOC (40 of 50 patients). Objective response rates were 33% (16 of 49 patients), 24% (12 of 50 patients), and 50% (25 of 50 patients), respectively; median progression-free survival was 7.6, 9.0, and 11.4 months, respectively. Median overall survival was 30 to 31 months with all regimens. The most common Grade ≥3 adverse event with each regimen was neutropenia (24 patients [50%], 23 patients [46%], and 43 patients [86%], respectively). The most common nonhematological Grade ≥3 adverse event was fatigue. Grade 2 alopecia occurred in 36 patients (72%) who received GEMPAC and 38 patients (76%) who received GEMDOC, but only 4 patients (8%) who received NORCAP. There was no evidence of a detrimental effect of NORCAP on quality of life. CONCLUSION: All-oral NORCAP is an active first-line chemotherapy regimen and might be offered as an alternative to first-line taxane-based therapy for HER2-negative mBC, particularly if patients wish to avoid alopecia or frequent intravenous administrations.

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.