The objective of this study was to investigate the efficacy of first-line chemotherapy containing irinotecan and/or oxaliplatin in patients with advanced mucinous colorectal cancer. Prognostic factors associated with response rate and survival were identified using univariate and multivariate logistic and/or Cox proportional hazards analyses. The population included 255 patients, of whom 49 (19%) had mucinous and 206 (81%) had non-mucinous colorectal cancer. The overall response rates for mucinous and non-mucinous tumours were 18.4 (95% CI, 7.5 -29.2%) and 49% (95% CI, 42.2 -55.8%), respectively (P ¼ 0.0002). After a median follow-up of 45 months, median overall survival for the mucinous patients was 14.0 months compared with 23.4 months for the nonmucinous group (hazard ratio (HR), 1.74; CI 95%, 1.27 -3.31; P ¼ 0.0034). After adjustment for significant features by multivariate Cox regression analysis, mucinous histology was associated with poor overall survival (HR, 1.593, 95% CI, 1.05 -2.40; P ¼ 0.0267), together with performance status ECOG 2, number of metastatic sites X2, and peritoneal metastases. This retrospective analysis shows that patients with mucinous colorectal cancer have poor responsiveness to oxaliplatin/irinotecan-based first-line combination chemotherapy and an unfavourable prognosis compared with non-mucinous colorectal cancer patients.

For patients with stage II and III colon cancer who underwent curative surgery, mucinous histology has no significant correlation with prognosis compared with NMC. This retrospective analysis suggests a comparable benefit from adjuvant chemotherapy for MC compared with NMC.

Specific polymorphisms may influence clinical outcomes of AGC patients. Selecting palliative chemotherapy on the basis of pretreatment genotyping may represent an innovative strategy that warrants prospective studies.

The primary end point of the study was the analysis of associations between polymorphisms with putative influence on 5-fluorouracil/irinotecan activity and progression-free survival (PFS) of patients with advanced colorectal cancer treated with first-line FOLFIRI chemotherapy. Peripheral blood samples from 146 prospectively enrolled patients were used for genotyping polymorphisms in thymidylate synthase (TS), methylenetetrahydrofolate reductase (MTHFR), excision repair cross-complementation group-1 (ERCC 1) xeroderma pigmentosum group-D (XPD), X-ray cross-complementing-1 (XRCC 1), X-ray cross-complementing-3 (XRCC 3) and uridine diphosphate-glucuronosyltransferases-A1 (UGT1 A1). TS 3 0 -UTR 6 þ /6 þ and XRCC3-241 C/C genotypes were associated with adverse PFS. Hazard ratio for PFS achieved 2.89 (95% confidence interval ¼ 1.56-5.80; P ¼ 0.002) in 30 patients (20%) with both risk genotypes. Risk for Grade III-IV neutropenia was significantly associated with UGT1A1*28 7/7 genotype. These promising findings deserve further investigations and their validation in independent prospective studies.

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