An ultrasonography-cytology protocol for the diagnostic management of regional nodes in a subset of patients with Merkel cell carcinoma of the skin.

BACKGROUND: The status of regional lymph nodes (LNs) is one of the most consistent predictors of survival in Merkel cell carcinoma (MCC). In cases of clinically localized disease, current practice involves sentinel lymph node (SLN) assessment. OBJECTIVES: To propose ultrasonography (US) followed by fine needle aspiration cytology (FNAC) and immunohistochemistry as a useful diagnostic tool in the pre-surgical management of patients with MCC. METHODS: US of LNs was performed in 75 patients with MCC (22 with stage III tumours; 53 with stage I-II). In patients with US suspected disease, US coupled with FNAC of the LN was performed. Smears were examined by routine cytological staining supplemented with immunohistochemical staining for cytokeratin 20. All patients underwent surgical removal of regional LNs. RESULTS: In all 22 patients with stage III tumours, US was indicative of tumour deposits and FNAC confirmed metastases to LNs. In 11 of 53 patients with localized MCC without clinical evidence of nodal disease, US revealed enlarged, equivocal nodes where FNAC was performed. Ten LNs were cytologically positive for metastases, and one was negative. Upon histological examination, the FNAC-negative case showed a metastasis 5 mm in diameter. In all the other 42 cases with no clinical or US evidence of LN involvement, only SLN biopsy was performed and in six cases small metastatic foci were detected. Ultimately, of the 53 stage I-II MCC, 17 had positive LN involvement. In 10 cases (59%) metastases were detected by FNAC, and in seven cases, were detected by SLN biopsy. CONCLUSIONS: In a selected subset (∼20%) of patients with MCC with clinically localized disease, US followed by FNAC in the suspect LN is a valid alternative to the classical protocol of SLN histological examination.

The natural history of colorectal adenomas and early cancer.

Adenomas represent the morphological precursors of the vast majority of colorectal cancers: although every adenoma has the capacity of malignant evolution, most adenomas stabilize their progression or even regress. Pathological factors are predictive of the natural history of adenomas in terms of potential and time interval for becoming malignant. Regression of adenomas is histologically well established, but it is thought to be a dynamic process, with cycling phases of regression and growth. Colorectal carcinoma invading the submucosa but not the muscular layer represents the earliest form of clinically relevant colorectal cancer. Grade of differentiation of carcinoma, lymphovascular invasion, and state of the resection margin predict the risk of metastasis. Microstaging of invasive cancer together with tumuor budding allow the metastatic risk to be further stratified into minimal, low, and high. Two distinct profiles are identifiable in the natural history of cancerous adenomas: blocking the growth of early cancer and allowing its progression towards advanced cancer. Thus, biomarkers to distinguish between progressive and non-progressive pT1 neoplasia are needed.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Quality assurance in pathology in colorectal cancer screening and diagnosis.

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in pathology in colorectal cancer screening and diagnosis includes 23 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of the screening process, including multi-disciplinary diagnosis and management of the disease.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Annotations of colorectal lesions.

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in pathology was supplemented by an annex describing in greater detail some issues raised in the chapter, particularly details of special interest to pathologists. The content of the annex is presented here to promote international discussion and collaboration by making the issues discussed in the guidelines known to a wider professional and scientific community.

CD31 and CD34 expression as immunohistochemical markers of endothelial transdifferentiation in human cutaneous melanoma.

INTRODUCTION: Vasculogenic mimicry, as previously described in aggressive melanoma, is characterized by the de novo generation of intratumoral patterned vascular channels, composed of PAS-positive basement membrane in the absence of endothelial cells, providing additional microcirculation, in support to the classic tumoral angiogenesis. METHODS: We investigated the immunohistochemical expression of two endothelial markers, CD31 and CD34, in tumoral cells of 60 melanomas (45 primary cutaneous and 15 metastatic) as possible evidence of vasculogenic mimicry. In addition we investigated the relationship between CD31 and CD34 expression and three pathological markers such as Clark's level, and skin ulceration, predictive of melanoma's aggressive behaviour, and mitotic index. RESULTS: No cases of common melanocytic nevi immunoreacted with CD31 or CD34. Random CD31 immunoreactivity was present in 6% of Clark's level I/II, 50% of Clark's level III and 80% Clark's level IV/V. CD34 was negative in Clark's level I/II but randomly stained the 20% and 55% of level III and IV/V respectively. 66% (10/15) of metastatic melanomas were CD31 positive showing a canalicular immunostaining pattern, conversely CD34 expression was never found. 7/8 cutaneous ulcerated melanomas immunostained for CD31 and 4/8 for CD34. CD31 immunostained 88% high/intermediate MI, and 53% of low MI melanomas. CD34 decorated the 29% of high/intermediate and 38% of low MI melanomas. CONCLUSIONS: CD31 and CD34 immunoreactivity closely parallel both the different morphologic steps of melanocytic tumor progression and the presence of histological parameters related to the aggressive behaviour. Their expression could be related to endothelial transdifferentiation of melanoma cells although a consequent functional role has not been demonstrated yet.

Impact of surgery on the development of duodenal cancer in patients with familial adenomatous polyposis.

PURPOSE: Precancerous duodenal lesions in patients with familial adenomatous polyposis can be detected with duodenoscopy and treatment may prevent the development of cancer. We proposed to determine the frequency, natural history, cumulative risk, and risk factors of the precancerous duodenal lesions in a series of patients diagnosed in northern Italy. METHODS: A prospective, endoscopic, follow-up protocol was performed in 50 patients examined by gastroduodenoscopy at two years of interval or less. The presence and severity of precancerous lesions of the duodenal mucosa were evaluated by Spigelman score. Twenty-five patients (50 percent) had proctocolectomy and ileoanal anastomosis, 15 (30 percent) had colectomy and ileorectal anastomosis, and 5 (10 percent) had proctocolectomy and definitive ileostomy from 0 to 3 years before the admission to the surveillance program. All patients showed more than a thousand adenomas in the colorectal mucosa. No patients with attenuated polyposis were found. RESULTS: At the first endoscopy, duodenal adenomas could be detected in 19 of 50 patients (38 percent), whereas at the end of the follow-up, 43 (86 percent) had duodenal lesions. The final mean Spigelman score increased during the follow-up period (P<0.001 respect to baseline values). No duodenal cancer could be detected. Eleven patients had or developed severe precancerous duodenal lesions (Stage IV) treated with endoscopic or surgical resection. The distribution of patients with Stage IV according to the surgery of the colon was: 2 of 25 treated with ileoanal anastomosis and 8 of 15 with ileorectal anastomosis (P=0.0024, Fisher's exact test). CONCLUSIONS: Patients with familial adenomatous polyposis are at risk of significant neoplasia. The natural history of precancerous lesions might be related to surgical treatment of colorectal neoplasms.

Serum bile acids, programmed cell death and cell proliferation in the mucosa of patients with colorectal adenomas.

BACKGROUND: Deoxycholic acid induced programmed cell death and an imbalance with cell proliferation may favour colorectal tumourigenesis according to 'in vitro' studies, but information is lacking on the relationships occurring 'in vivo' in humans. AIMS: To evaluate whether serum deoxycholic acid is associated with programmed cell death and cell proliferation in colonic mucosa. METHODS: In 10 patients with colorectal adenomas, we measured fasting serum levels of bile acids; and, in normal colonic mucosa, programmed cell death by the TUNEL technique and cell proliferation by immunohistochemical staining with anti-Ki67. Total and compartmental indices for both activities were calculated. RESULTS: Among serum bile acids, only total deoxycholic acid (median: 0.89 micromol/L +/- 0.54 95% CI), showed a significant positive correlation with the total and basal compartments PCD Index (r = 0.68, p < 0.05). Total proliferation index showed no correlation with either total PCD Index, or bile acids. Within the median compartment of the crypt, cell proliferation was negatively associated with all unconjugated bile acids. CONCLUSIONS: The positive association between deoxycholic acid and programmed cell death in the basal compartment of the crypt, and the negative association of cell proliferation and unconjugated bile acids in the median compartment, do not seem to support the co-carcinogenic effect of deoxycholic acid.

Malignant adenoma: diagnosis, staging, risk factors, lymph node involvement and problems of sampling.

Colorectal adenoma containing invasive carcinoma corresponds to a carcinoma invading the submucosa and represents the earliest form of clinically relevant colon cancer. Despite the generally favourable course after endoscopic removal, a limited risk of developing lymph node metastases still exists and the correct histologic assessment of malignant polyps can help in defining the evolutive potential. At present, histopathologic parameters alone determine whether a high (35%) or low (7%) risk of nodal metastases exists and the most relevant diagnostic criteria are the grade of differentiation of invasive adenocarcinoma, vascular invasion, the level of invasion of carcinomatous cells and the status of the resection margin.

Somatic alterations of the androgen receptor CAG repeat in human colon cancer delineate a novel mutation pathway independent of microsatellite instability.

The human androgen receptor gene contains a polymorphic CAG repeat region ranging from 8 to about 35 repeats in the normal human population. The repeat length is inversely related to the transactivation potential of the receptor. We have analyzed the repeat length in 50 sporadic colon cancer samples in comparison to surrounding healthy mucosa and have found somatic reductions of up to 10 repeats in 5 cases (10%), 3 of which were complex, probably involving both alleles. Alterations occurred in tumors with and without microsatellite instability indicating that they follow an independent mutation pathway. The similar repeat of the huntingtin gene did not show any somatic alterations in the same cases. No correlation to sex, tumor stage, location, or histology was evident. In the tumors that showed somatic reductions, the reduced allele was present in at least half of the cells and thus in most, if not all, of the tumor component of the sample. Somatic reductions of the androgen receptor CAG repeat thus occur frequently, through a pathway distinct from microsatellite instability and early during colon carcinogenesis. The receptor is expressed in most normal and neoplastic tissue samples analyzed. Apparent growth selection of cells bearing shortened AR alleles suggests that androgens contribute to colon carcinogenesis in a yet unknown way.

Programmed cell death, proliferating cell nuclear antigen and p53 expression in mouse colon mucosa during diet-induced tumorigenesis.

Western-style diets (WDs) trigger and sustain the early phases of tumorigenesis in mouse colon, and when continued throughout the life span lead to the development of dysplastic crypts. In order to evaluate the roles both of cell proliferation and programmed cell death (PCD) in WD-induced tumorigenesis, immunohistochemical detection of proliferating nuclear antigen (PCNA), in situ end labeling (TUNEL) of DNA breaks, and p53 protein were carried out in mouse colonic mucosa during prolonged feeding of two WDs. PCNA Labeling Index of colonic crypts was significantly higher in WD-treated animals than in controls only at the beginning of the nutritional study, the gap rapidly bridged by increased cell proliferation spontaneously occurring in the colonic mucosa during aging. A transient early homeostatic activation of PCD at the base of the crypt also was observed in WD groups. No changes in PCD were seen in the upper third of the crypt or in surface epithelium throughout the study, indicating that PCD in that colonic crypt segment produces a constant flux of cell loss, uninfluenced by homeostatic fluctuations. A major finding was an irreversible, progressive, age-related decline of PCD at the crypt base in both control and treated animals that occurred during the second half of the rodents' life span. p53 protein was not immunohistochemically detected, suggesting that neither overexpression of wild-type nor mutated forms of the protein are involved in the above mentioned changes.

Small bowel tumors and polyposis syndromes.

Tumors of the small bowel are uncommon and seldom suspected on a clinical basis. Together with the relative inaccessibility of the small bowel to endoscopic investigation, the rarity of these tumors undoubtedly delays the diagnosis. Small bowel tumors may be an interesting field of application for enteroscopy, which now can be readily performed with dedicated enteroscopic evaluation in patients with suspected small bowel neoplasia could improve prognosis and treatment. Enteroscopy may also play an important role in the surveillance of inherited polyposis syndromes, as in other precancerous condition of the small bowel. In Peutz-Jeghers syndrome it may reduce polyp-induced complications and improve planning for surgery; in familial adenomatous polyposis it may contribute to preventing upper gastrointestinal tract cancer.

K-ras2 activation and genome instability increase proliferation and size of FAP adenomas.

The possible role of K-ras2 mutations and aneuploidy toward increase of proliferation and adenoma size in Familial Adenomatous Polyposis (FAP) adenomas is not known. The present study addresses these issues by investigating 147 colorectal adenomas obtained from four FAP patients. The majority of adenomas had size lower than or equal to 10 mm (86%), low grade dysplasia (63%), and were preferentially located in the right colon (60%). Normal mucosa samples were obtained from 19 healthy donors. Three synchronous adenocarcinomas were also investigated. K-ras2 mutation spectrum was analysed by PCR and Sequence Specific Oligonucleotide (SSO) hybridization, while flow cytometry (FCM) was used for evaluating degree of DNA ploidy and S-phase fraction. Overall, incidences of K-ras2 mutations, DNA aneuploidy and high S-phase values (>7.2%) were 6.6%, 5.4% and 10.5%, respectively. In particular, among the adenomas with size lower than 5 mm, K-ras2 mutation and DNA aneuploidy frequencies were only slightly above 1%. Statistically significant correlations were found between K-ras2 and size, DNA ploidy and size and K-ras2 and S-phase (p < 0.001). In particular, among the wild type K-ras2 adenomas, high S-phase values were detected in 8% of the cases versus 57% among the K-ras2 mutated adenomas (p = 0.0005). The present series of FAP adenomas indicates that K-ras2 activation and gross genomic changes play a role toward a proliferative gain and tumour growth in size.

Preclinical mouse models for cancer chemoprevention studies.

To aid in identifying the ability of chemopreventive agents to inhibit tumor development, new preclinical in vivo rodent models have recently been developed. Some of the models contain targeted mutations capable of increasing the incidence and progression of neoplastic lesions, whereas in other models dietary nutrients induce preneoplastic lesions in normal mice. These new preclinical models are assisting the analysis of genetic and environmental factors leading to neoplasia, and clinical studies to evaluate the chemopreventive efficacy of specific nutrients and pharmacological agents.

Specific K-ras2 mutations in human sporadic colorectal adenomas are associated with DNA near-diploid aneuploidy and inhibition of proliferation.

Recent studies indicate that p21ras proteins mediate their multiple cell functions through interactions with multiple effectors and that the number of new effectors is growing. We recently reported that K-ras2 mutations in human colorectal adenomas were associated with chromosome instability and proliferation changes. In the present study, we extend these previous observations. Hereditary and multiple (n > or = 5) adenomas and adenomas with early cancer were excluded. Dysplasia was moderate in 91 cases and high in 25, and the median adenoma size was 1.5 cm. K-ras2 spectrum analysis was done by sequence-specific oligonucleotide hybridization using nuclear suspensions provided by analysis and sorting of multiparameter flow cytometry. In particular, tissue inflammatory cells were separated for DNA diploid tumors, whereas DNA aneuploid epithelial subclones were analyzed separately. K-ras2 mutations and DNA aneuploidy were both detected in 29 of 116 (25%) cases. DNA aneuploid index was in the near-diploid region in the majority of cases. DNA aneuploidy was strongly associated with G-->C/T transversions. An association was also found between low S-phase values and G-->A transitions. These findings were confirmed using multivariate logistic regression analysis to account for the effects of size, dysplasia, site, type, age, and sex. These data suggest that specific K-ras2 mutations in a subgroup of human sporadic colorectal adenomas play a role in chromosome instability and, contrary to expectations, are associated with inhibition of proliferation.