Maspin, a member of the Serpin protease inhibitor family, is overexpressed in poorly differentiated colorectal tumors and more frequently found in tumors with microsatellite instability. Immunohistochemical nuclear Maspin staining is predominantly seen in tumor cells at the invasion front of such cancers, suggesting that this molecule is associated with local tumor cell infiltration and aggressiveness. In a retrospective study, we studied nuclear Maspin expression as a potential prognostic tool in a total of 172 primary stage III colon cancers by immunohistochemistry. Of those 172 patients, 76 were treated by surgery only, and 96 patients received additional adjuvant 5-fluorouracil (5-FU) based chemotherapy. Nuclear Maspin expression was an independent adverse prognostic factor for overall survival in our patient cohort (hazard ratio 2.08; 95% CI, 1.13-3.81; p 5 0.018). However, patients with primary tumors expressing Maspin in the nucleus showed a significant treatment benefit from 5-FU chemotherapy (hazard ratio 0.384; 95% CI, 0.188-0.784; p 5 0.009) compared to adjuvantly treated patients whose tumors did not express this molecule. Nuclear Maspin expression is highly predictive of 5-FU chemotherapy response in patients with advanced stage colon cancer. Patients with negative immunhistochemical Maspin expression do not benefit from 5-FU treatment and may be candidates for an alternative (non-5-FU based) adjuvant therapy regime. ' 2005 Wiley-Liss, Inc.Key words: colon cancer; Maspin; prediction; 5-flourouracil; chemotherapy Adjuvant 5-fluorouracil (5-FU) chemotherapy is the current standard therapy after surgical resection of stage III colon carcinoma, with an overall 5-year survival of only 50% in affected patients. It is estimated that up to 40% of patients would be cured by surgery alone, and only 10% of patients benefit from 5-FU chemotherapy.

The prevalence and development of microsatellite instability (MSI) and underlying mismatch repair (MMR) deficiency in the carcinogenesis of adenocarcinomas of the papilla of Vater and their precursor lesions are not well established. We analyzed 120 ampullary adenomas (31 pure adenomas and 89 carcinoma-associated adenomas) and 170 pure adenocarcinomas for MSI, immunohistochemical expression of MMR proteins and specific histopathologic features. The most common histologic subtype was intestinal (46.5%), followed by pancreatobiliary (23.5%), poorly differentiated adenocarcinomas (12.9%), intestinal-mucinous (8.2%), and invasive papillary carcinomas (5.3%). Eight of 89 adenomas (9%) and 15/144 carcinomas (10%) showed high microsatellite instability (MSI-H), 10/89 adenomas (11%) and 5/144 carcinomas (4%) showed low microsatellite instability (MSI-L), and 71/89 adenomas (80%) and 124/144 carcinomas (86%) were microsatellite stable (MSS). MSI analysis from carcinomas contiguous with an adenomatous component (n=54) exhibited concordant results in 6/8 (75%) MSI-H and 42/46 (91.3%) MSS tumors. Of 14 carcinomas with MSI-H, 7 showed loss of MLH1 and 5/6 (83%) MLH1 promoter methylation, and 2 carcinomas showed simultaneous loss of MSH2 and MSH6. Two carcinomas and 3 adenomas with MSI-H revealed exclusive loss of MSH6. MSI-H cancers were significantly associated with intestinal mucinous subtype (P<0.001), high tumor grade (P=0.003), expansive growth pattern (P=0.044), and marked lymphoid host response (P=0.004). Patients with MSI-H carcinoma had a significantly longer overall survival (P=0.0082) than those with MSI-L or MSS tumors. Our findings indicate that the MSI-phenotype is an early event, which develops at the stage of adenoma and is reliably detectable in the precursor lesion. The MMR deficient molecular pathway of carcinogenesis is associated with a histopathologic phenotype in ampullary cancer, similar to the one that has been well described in colon cancer.

BackgroundCurrent staging methods such as tumor thickness, ulceration and invasion of the sentinel node are known to be prognostic parameters in patients with malignant melanoma (MM). However, predictive molecular marker profiles for risk stratification and therapy optimization are not yet available for routine clinical assessment.Methods and FindingsUsing tissue microarrays, we retrospectively analyzed samples from 364 patients with primary MM. We investigated a panel of 70 immunohistochemical (IHC) antibodies for cell cycle, apoptosis, DNA mismatch repair, differentiation, proliferation, cell adhesion, signaling and metabolism. A marker selection procedure based on univariate Cox regression and multiple testing correction was employed to correlate the IHC expression data with the clinical follow-up (overall and recurrence-free survival). The model was thoroughly evaluated with two different cross validation experiments, a permutation test and a multivariate Cox regression analysis. In addition, the predictive power of the identified marker signature was validated on a second independent external test cohort (n = 225). A signature of seven biomarkers (Bax, Bcl-X, PTEN, COX-2, loss of β-Catenin, loss of MTAP, and presence of CD20 positive B-lymphocytes) was found to be an independent negative predictor for overall and recurrence-free survival in patients with MM. The seven-marker signature could also predict a high risk of disease recurrence in patients with localized primary MM stage pT1-2 (tumor thickness ≤2.00 mm). In particular, three of these markers (MTAP, COX-2, Bcl-X) were shown to offer direct therapeutic implications.ConclusionsThe seven-marker signature might serve as a prognostic tool enabling physicians to selectively triage, at the time of diagnosis, the subset of high recurrence risk stage I–II patients for adjuvant therapy. Selective treatment of those patients that are more likely to develop distant metastatic disease could potentially lower the burden of untreatable metastatic melanoma and revolutionize the therapeutic management of MM.

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