A subset of genetic susceptibility variants for colorectal cancer also has prognostic value.

We investigated the possible influence of 86 single-nucleotide polymorphisms (SNPs), known to associate with the risk of colorectal cancer (CRC), on overall survival and time to recurrence (TTR) in 733 Italian CRC patients followed up for up to 84 months after surgery. In the Cox multivariate analysis, adjusted for gender, age, pathological stage and adjuvant chemotherapy (yes/no), the risk of death significantly increased by rare allele count (P<0.05) for rs1801133 (MTHFR), rs4939827 (SMAD7), rs2306283 (SLCO1B1) and rs12898159 (BMP4), whereas for rs736775 (GPX3) the opposite was observed. Two additional SNPs associated with TTR, namely rs16892766 (downstream of EIF3H) and rs10749971 (COLCA2). Our findings show that some genetic variants previously found to associate with CRC risk are also associated with survival after treatment. The identification of alleles defining subgroups of patients with worse clinical outcome may have application in developing pharmacogenetic strategies aimed at personalizing CRC treatment.

Gene expression profiling reveals GC and CEACAM1 as new tools in the diagnosis of lung carcinoids.

BACKGROUND: Classification of lung carcinoids into typical and atypical is a diagnostic challenge since no immunohistochemical tools are available to support pathologists in distinguishing between the two subtypes. A differential diagnosis is essential for clinicians to correctly discuss therapy, prognosis and follow-up with patients. Indeed, the distinction between the two typical and atypical subtypes on biopsies/cytological specimens is still unfeasible and sometimes limited also after radical surgeries. By comparing the gene expression profile of typical (TC) and atypical carcinoids (AC), we intended to find genes specifically expressed in one of the two subtypes that could be used as diagnostic markers. METHODS: Expression profiling, with Affymetrix arrays, was performed on six typical and seven atypical samples. Data were validated on an independent cohort of 29 tumours, by means of quantitative PCR and immunohistochemistry (IHC). RESULTS: High-throughput gene expression profiling was successfully used to identify a gene signature specific for atypical lung carcinoids. Among the 273 upregulated genes in the atypical vs typical subtype, GC (vitamin D-binding protein) and CEACAM1 (carcinoembryonic antigen family member) emerged as potent diagnostic markers. Quantitative PCR and IHC on a validation set of 17 ACs and 12 TCs confirmed their reproducibility and feasibility. CONCLUSIONS: GC and CEACAM1 can distinguish between TC and AC, defining an IHC assay potentially useful for routine cytological and histochemical diagnostic procedures. The high sensitivity and reproducibility of this new diagnostic algorithm strongly support a further validation on a wider sample size.

Lack of Bax expression is associated with irinotecan-based treatment activity in advanced colorectal cancer patients.

BACKGROUND: Currently, first-line chemotherapy in advanced colorectal cancer is not tailored on predictive biomarkers. Bax proapoptotic protein may correlate to chemosensitivity and differential response to irinotecan or oxaliplatin-based combinations. METHODS: Bax expression was assessed by immunohistochemistry in 49 advanced colorectal cancer patients enrolled at our institution from 2002 to 2004 within a multicenter, phase II, randomized trial of first-line UFT/leucovorin/irinotecan (TEGAFIRI) versus UFT/leucovorin/oxaliplatin (TEGAFOX). RESULTS: Bax-positive and negative samples were 49 and 51 %. Response was significantly lower in Bax positive (25 %) as compared to Bax negative (56 %) (Odds ratio = 0.26; p = 0.03). No significant difference was noted in TEGAFOX subgroup; in TEGAFIRI arm, responses were lower in Bax positive (18 %) than Bax negative (67 %) (Odds ratio = 0.11; p = 0.03). No difference in terms of progression-free and overall survival was observed according to Bax. CONCLUSION: Bax-negative colorectal cancer may identify a specific phenotype of patients with significantly higher chance to respond to doublet irinotecan-based chemotherapy.

Papillary carcinoma of the thyroid: low expression of NCAM (CD56) is associated with downregulation of VEGF-D production by tumour cells.

The expression of NCAM was investigated in tissue sections of 61 cases of papillary carcinoma and in 14 lymph node metastases using immunohistochemistry. Tumour cells of 18 primary tumours were not stained, whereas in the remaining 43 cases, NCAM was expressed in less than 5% tumour cells. Similar results were obtained when NCAM expression was evaluated at the RNA level. Reduced expression of NCAM is an early event since 6/15 cases (40%) of micro-carcinoma were NCAM-negative. NCAM-positive tumour cells were more often located at the invasion front of the tumour. It has been reported that NCAM expression may affect lymphangiogenesis. In tissue sections immunostained for podoplanin, it was found that lymphatic vessels were extremely rare inside the body of the tumour, and were mostly associated with foci of chronic inflammation and/or of reparative fibrosis. Lymphangiogenesis is sustained by VEGF-C, VEGF-D, and FGF2. Analysis of micro-dissected samples of the tumour and of the paired normal thyroid tissue revealed that RNA transcripts for VEGF-D were significantly less numerous in the tumour tissue (p = 0.001). The potential role of NCAM in tumour cell biology was investigated by silencing the NCAM gene in the TPC1 thyroid papillary carcinoma cell line. It was found that NCAM down-regulation caused a significant reduction (p < 0.05) in the expression of both VEGF-C and VEGF-D mRNAs. In addition, NCAM-silenced TPC-1 cells were more adhesive to different extracellular matrix components, and were less efficient in cell migration (59% reduction; p < 0.05) and invasiveness (68% reduction). These latter results confirm that modifications of NCAM expression cause profound alterations in the adhesive and migratory properties of tumour cells, but are in apparent discrepancy with the observation that loss of NCAM is usually associated with increased tumour invasiveness in vivo.

Lack of Bax expression is associated with irinotecan-based treatment activity in advanced colorectal cancer patients

BACKGROUND: Currently, first-line chemotherapy in advanced colorectal cancer is not tailored on predictive biomarkers. Bax proapoptotic protein may correlate to chemosensitivity and differential response to irinotecan or oxaliplatin-based combinations. METHODS: Bax expression was assessed by immunohistochemistry in 49 advanced colorectal cancer patients enrolled at our institution from 2002 to 2004 within a multicenter, phase II, randomized trial of first-line UFT/leucovorin/irinotecan (TEGAFIRI) versus UFT/leucovorin/oxaliplatin (TEGAFOX). RESULTS: Bax-positive and negative samples were 49 and 51 %. Response was significantly lower in Bax positive (25 %) as compared to Bax negative (56 %) (Odds ratio = 0.26; p = 0.03). No significant difference was noted in TEGAFOX subgroup; in TEGAFIRI arm, responses were lower in Bax positive (18 %) than Bax negative (67 %) (Odds ratio = 0.11; p = 0.03). No difference in terms of progression-free and overall survival was observed according to Bax. CONCLUSION: Bax-negative colorectal cancer may identify a specific phenotype of patients with significantly higher chance to respond to doublet irinotecan-based chemotherapy (AU)