Prediction of nodal metastasis and prognosis of breast cancer by ANN-based assessment of tumour size and p53, Ki-67 and steroid receptor expression.

BACKGROUND: Tumour stage and the appropriate course of treatment in patients with breast cancer are primarily characterized by the state of metastasis in the axillary lymph nodes. In recent years, substantial research has focused on the prediction of lymph node status based on various pathological and molecular markers in order to obviate the necessity to carry out axillary dissection. In the present study, artificial neural network (ANN) is employed as the analysis platform to examine the prognostic significance of a group of well-established prognostic markers for breast cancer outcome prediction in terms of nodal status. Furthermore, we investigated existing interactions between these markers. PATIENTS AND METHODS: The data set contained 66 patient records, where 5 pathological and molecular markers including tumour size, oestrogen receptor status (ER), progesterone receptor status (PR), Ki-67 and p53 expression had been assessed for each patient. The spread of metastasis to the axillary lymph nodes was clinically diagnosed and patients were accordingly categorized into node-positive and node-negative groups. The aforementioned markers were analyzed using a probabilistic neural network (PNN) for nodal status prediction which was considered as the network output. Furthermore, the interactions between these markers were evaluated using different marker combinations as the network input for finding the best marker arrangement for nodal predication. RESULTS: The best prediction accuracy was obtained by a 3-marker combination including tumour size, PR and p53 with 71% accuracy for nodal prediction. Leaving out ER and PR from the full marker set showed approximately the same variations in the results, which is an indication of the direct correlation of these two markers. Furthermore, tumour size was proved to be the most significant individual marker for predicting nodal metastasis. However, when used in combination with Ki-67 the prediction results drop significantly. CONCLUSION: The results presented here indicate that molecular and pathological markers can provide useful information for early-stage prognosis. However, the interactions between these markers must be considered in order to achieve accurate and reliable prediction.

Mutation analysis of p53, K-ras, and BRAF genes in colorectal cancer progression.

Gene mutations in APC, K-ras, and p53 are thought to be essential events for colorectal cancer development. Recent data seem to indicate that K-ras and p53 mutations rarely co-exist in the same tumor, indicating that these alterations do not represent a synergistic evolutionary pathway. Moreover, an inverse relation between K-ras gene activation and BRAF mutations has been demonstrated, suggesting alternative pathways for colorectal cancer transformation. To reconstruct the chronological modulation of these gene mutations during cell transformation and colorectal cancer progression, mutations of p53, K-ras, and BRAF genes were analyzed by Single Strand Conformation Polymorphism (SSCP) or sequencing analysis in 100 colorectal cancer samples, evenly distributed among different Dukes' stages. We found mutations in p53, K-ras, and BRAF genes in 35%, 30%, and 4% of tumors, respectively, and observed a minimal or no co-presence of these gene alterations. Moreover, the frequency of molecular p53 mutations increased as tumor stage increased, suggesting an important role for this gene in the progression of colorectal cancer. Conversely, K-ras or BRAF genes were not related to tumor stage or location. These data seem to indicate the absence of a co-presence of the genes, highlighting the possibility of multiple pathways for colorectal tumor progression. Moreover, mutations in p53, K-ras, and BRAF are not present in about one-third of colorectal cancers and therefore other gene mutations need to be investigated to better understand molecular mechanisms at the basis of cell transformation and the progression of colorectal cancer.

Detection of colorectal cancer by a quantitative fluorescence determination of DNA amplification in stool.

DNA amplification of exfoliated cells in stool represents an inexpensive and rapid test, but has only 50% to 60% sensitivity. A new quantitative method, called fluorescence long DNA, was developed and validated in our laboratory on stool obtained from 86 patients with primary colorectal cancer and from 62 healthy individuals. It consists of the amplification of stool DNA with fluorescence primers and the quantification of the amplification using a standard curve. Results are arbitrarily expressed in nanograms. The potential of the new method compared to the conventional approach was analyzed in a subgroup of 94 individuals (56 patients and 38 healthy volunteers). In the present series, DNA amplification analysis showed a specificity of 97% and a sensitivity of only 50%. Conversely, fluorescence DNA evaluation, using the best cutoff of 25 ng, showed a sensitivity of about 76% and a specificity of 93%. Similar sensitivity was observed regardless of Dukes stage, tumor location, and size, thus also permitting the detection of early-stage tumors. The present study seems to indicate that quantitative fluorescence DNA determination in stool successfully identifies colorectal cancer patients with a sensitivity comparable, if not superior, to that of multiple gene analysis but at a lower cost and in a shorter time.

Urine telomerase: an important marker in the diagnosis of bladder cancer.

Telomerase activity is present in most human malignant tumors, whereas it is generally not detectable, with some exceptions, in normal cells. Therefore, it represents a potential tool for tumor detection. In the present study, telomerase activity was determined in urine from 79 healthy individuals and 121 previously untreated bladder cancer patients using a highly sensitive telomeric repeat amplification protocol (TRAP) assay and the results were expressed as arbitrary enzymatic units (AEU). This approach enabled us to identify cutoff values characterized by high sensitivity (from 75% to 93%) and specificity (from 72% to 92%). Moreover, analysis as a function of gender showed a higher accuracy of TRAP assay in males (93% sensitivity and 90% specificity at the cutoff of 50 AEU) than in females. This sensitivity was confirmed in patients with nonassessable or negative cytology. In women, morphological and immunocytochemical determinations using a monoclonal antibody (anti-hTERT) recently developed in our laboratory showed a large fraction of immunoreactive inflammatory or nonbladder cells, which may justify the false-positive TRAP results. In conclusion, this assay represents an important noninvasive diagnostic tool to detect bladder cancer also in patients with negative or nonassessable urine cytology and with low-grade and early-stage lesions.

Pathology of ovarian cancers in BRCA1 and BRCA2 carriers.

PURPOSE: Germline mutations in the BRCA1 and BRCA2 genes confer increased susceptibility to ovarian cancer. There is evidence that tumors in carriers may exhibit a distinct distribution of pathological features, but previous studies on the pathology of such tumors have been small. Our aim was to evaluate the morphologies and immunophenotypes in a large cohort of patients with familial ovarian cancer. EXPERIMENTAL DESIGN: We performed a systematic review of ovarian tumors from 178 BRCA1 mutation carriers, 29 BRCA2 mutation carriers, and 235 controls with a similar age distribution. Tumors were evaluated by four pathologists blinded to mutation status. Both morphological features and immunochemical staining for p53 and HER2 were evaluated. RESULTS: Tumors in BRCA1 mutation carriers were more likely than tumors in age-matched controls to be invasive serous adenocarcinomas (odds ratio, 1.84; 95% confidence interval, 1.21-2.79) and unlikely to be borderline or mucinous tumors. Tumors in BRCA1 carriers were of higher grade (P < 0.0001), had a higher percentage solid component (P = 0.001), and were more likely to stain strongly for p53 (P = 0.018). The distribution of pathological features in BRCA2 carriers was similar to that in BRCA1 carriers. CONCLUSIONS: Use of pathological features can substantially improve the targeting of predictive genetic testing. Results also suggest that BRCA1 and BRCA2 tumors are relatively aggressive and may be expected to have poor prognosis, although this may be treatment dependent.

HER-2 expression and cell proliferation: prognostic markers in patients with node-negative breast cancer.

PURPOSE: We analyzed the clinical relevance of HER-2 expression, widely investigated in breast cancer but with contradictory results, in the largest case series of node-negative breast cancer patients investigated to date. PATIENTS AND METHODS: The pure prognostic value of HER-2 expression was investigated in 529 patients treated with locoregional therapy alone until early relapse. Proliferative activity was evaluated as [3H]thymidine labeling index and HER-2 expression by immunohistochemistry. All biologic determinations were conducted within the context of an intra- and interlaboratory National Quality Control Program. RESULTS: HER-2 expression was not related to relapse-free survival in the overall series but was a significant discriminant of prognosis in the subgroup of patients with rapidly proliferating tumors. Six-year rate of relapse was 40% for patients with highly (> or =30%) positive tumors and 26% for those with weakly HER-2-expressing tumors (P =.039). CONCLUSION: HER-2 expression in association with proliferative activity identifies a subgroup of node-negative breast cancer patients with the worst prognosis, who are candidates for specific intensive adjuvant therapy.

Oncogenic role of the ubiquitin ligase subunit Skp2 in human breast cancer.

Estrogen receptor (ER) expression and Her-2 amplification define specific subsets of breast tumors for which specific therapies exist. The S-phase kinase-associated protein Skp2 is required for the ubiquitin-mediated degradation of the cdk-inhibitor p27 and is a bona fide proto-oncoprotein. Using microarray analysis and immunohistochemistry, we determined that higher levels of Skp2 are present more frequently in ER-negative tumors than in ER-positive cases. Interestingly, the subset of ER-negative breast carcinomas overexpressing Skp2 are also characterized by high tumor grade, negativity for Her-2, basal-like phenotype, high expression of certain cell cycle regulatory genes, and low levels of p27 protein. We also found that Skp2 expression is cell adhesion-dependent in normal human mammary epithelial cells but not in breast cancer cells and that an inhibition of Skp2 induces a decrease of adhesion-independent growth in both ER-positive and ER-negative cancer cells. Finally, forced expression of Skp2 abolished effects of antiestrogens, suggesting that deregulated Skp2 expression might play a role in the development of resistance to antiestrogens. We conclude that Skp2 has oncogenic potential in breast epithelial cells and is overexpressed in a subset of breast carcinomas (ER- and Her-2 negative) for which Skp2 inhibitors may represent a valid therapeutic option.

Vascular endothelial growth factor and prognosis in patients with node-negative breast cancer.

Vascular endothelial growth factor (VEGF) has emerged as one of the most important angiogenic growth factors from experimental in vitro and in vivo studies. In the present study, we investigated the relationship between VEGF expression and microvessel density (MVD) and defined their prognostic relevance on a series of 242 patients with node-negative breast cancer, using immunohistochemical methods. In parallel, estrogen and progesterone receptors were quantitatively assessed using the dextran-charcoal technique and cell proliferation was evaluated as S-phase cell fraction according to (3)H-thymidine-labeling index (TLI). The percentage of VEGF-expressing cells varied from 0-95% in the different tumors and was unrelated to menopausal status, tumor size or steroid receptor status. Conversely, a significant inverse relation was observed with patient age or tumor cell proliferation, albeit with very poor correlation coefficients. A significant relation was observed between VEGF expression and MVD (r(s) = 0.55, p < 0.001). Clinical outcome analyzed as a function of high and low VEGF expression showed slight differences in terms of both disease-free survival (DFS) and overall survival (OS) that never reached statistical significance. Moreover, the trend was paradoxically in favor of patients with highly VEGF-expressing tumors. Finally, DFS and OS curves, when analyzed as a function of VEGF expression or MVD, were superimposable. In conclusion, our study did not highlight a prognostic relevance of VEGF expression in patients with node-negative breast cancer, as already observed for MVD.

p27/kip1 expression in normal epithelium, benign and neoplastic breast lesions.

The development of cancer in the breast and in other sites is a complex process requiring a number of different genetic and epigenetic alterations. The accumulation of the genetic changes is thought to underlie the progression from precancerous lesions to carcinomas. The expression of p27/kip1 protein, a cyclin-dependent kinase inhibitor, was investigated by immunohistochemistry in normal epithelial specimens, benign alterations, and malignant lesions of the breast. The number of p27/kip1-positive cells ranged from none to more than 98% in the overall series. Wide ranges of p27/kip1-positive cells were consistently observed within each histological category, but the median value progressively decreased in typical hyperplasia and fibroadenoma, with an even more marked reduction in malignant lesions, compared with normal epithelium. Moreover, the percentage of cells expressing p27/kip1 in tumours was about three times lower in invasive than in in situ lesions and was inversely related to tumour size, but not to lymph node involvement. In conclusion, the degree to which p27 expression is altered in typical hyperplastic lesions and fibroadenomas indicates that the deregulation of p27 may occur very early on during breast cell transformation, but the usefulness of its determination to categorize subgroups of lesions at different risk of evolution remains somewhat doubtful.