[Morphological assessment of predictive factors in adenocarcinoma of the colon].

Immunohistochemical investigation of 15 different markers in colon adenocarcinoma was carried out. Prognostic significance showed chemokine receptor CXCR4 and Ki-67. Predictive significance was revealed for thymidylate synthase (TS) and thymidine phosphorylase (TP).

Assessment of thymidylate synthase expression in biopsy specimens and corresponding resection specimens of non-small-cell lung cancer.

AIMS: Pemetrexed (Pem) is a potent inhibitor of thymidylate synthase (TS), and has shown efficacy in the treatment of non-small-cell lung cancer (NSCLC). TS expression in NSCLC biopsy specimens may correlate with the tumour responses to TS-inhibiting agents. As TS is not homogeneously expressed, our aim was to test whether TS expression in biopsy specimens may be representative for the whole tumour and can be used for therapeutic assessment. METHODS AND RESULTS: We immunohistochemically analysed TS expression in biopsy and corresponding resection specimens of 100 consecutive NSCLCs. The samples were subgrouped according to TS expression levels, and the degree of agreement between the biopsy and the corresponding resection specimen was calculated. TS expression-based grouping according to one cut-off criterion (high or low expression) led to concordant results between biopsy and resection specimens. When more than one cut-off criterion was used, the results were significantly different. CONCLUSIONS: Thymidylate synthase expression levels in NSCLC biopsy specimens may correspond to TS expression of the whole tumour when robust scoring systems are applied. Further studies are needed to determine whether high or low TS expression in NSCLC biopsy specimens is of predictive value, and whether it may allow the selection of patients who will benefit from Pem treatment.

[Assessment of dihydropyrimidine dehydrogenase and thymidylate synthase expression in gastric carcinoma and colonic carcinoma].

We measured DPD activity and TS content in cancer and normal mucosa obtained from 23 patients with colorectal carcinoma and 7 patients with gastric carcinoma. DPD activity in colorectal carcinoma cases was significantly decreased in cancer tissues compared to those in adjacent normal mucosa (p<0.001), while TS content was significantly increased in cancer tissues (p<0.01). No significant correlation was found between cancer and adjacent normal mucosa in DPD activity and TS content of gastric carcinoma cases. Immunohistochemically, DPD and TS overexpression were found in 11 out of 23 patients (47.8%) and 3 out of 23 patients (13%) in colorectal carcinoma cases, respectively. In gastric carcinoma cases, DPD and TS overexpression were found in 3 out of 7 patients (42.9%) and 3 out of 7 patients (42.9%), respectively. No significant correlation was found between quantitative measurement and immunohistochemical overexpression in colorectal and gastric carcinoma cases. DPD and TS protein were partially overexpressed in some cases. Heterogeneity of the tumor is thought to be one of the reasons for the discrepancy between quantitative measurement and immunohistochemical overexpression.