Detection of microsatellite alterations in the spectrum of melanocytic nevi in patients with or without individual or family history of melanoma.

We studied a group of patients with or without individual or family history of melanoma for the occurrence of genetic alterations at microsatellite DNA sequences, usually referred to as microsatellite instability (MSI), and loss of heterozygosity (LOH). Microsatellite analysis of 3 markers located on chromosome 9p21-22 was performed for 88 melanocytic lesions, including 27 melanomas and 35 dysplastic and 26 common nevi, from 48 patients. Three additional markers, on 11q23, 17q21 and 5q22, were investigated in 16 melanomas. Overall, microsatellite alterations of the type usually considered low-level instability at 9p21-22 were observed in 22% of melanomas and 31% of dysplastic and 23% of common nevi. LOH at the same loci was found in 15% of melanomas and 8% of dysplastic nevi but never in common nevi. Cases with a positive family history of melanoma compared to those with a negative family history showed a higher microsatellite alteration frequency (43% vs. 20%), and the same was observed in melanoma compared to non-melanoma carriers (31% vs. 16%). Our results show that (i) MSI is common in all melanocytic lesions, though with differences in the group of patients which could have clinical relevance if confirmed, whereas LOH is restricted to melanomas and dysplastic nevi; (ii) various melanocytic lesions from the same patient represent clonally distinct tumors; (iii) the phenotype suggestive of DNA repair deficiency is influenced by a family or an individual history of melanoma; (iv) the microsatellite alteration frequency correlates with patient groups ordered according to increasing melanoma risk.

Biochemical uncovering of mdm2/p53 complexes in liposarcomas parallels their immunohistochemical detection.

Recent observations indicate the existence of pathogenetically distinct groups of well-differentiated (WD) dedifferentiated (DD) liposarcomas. In the retroperitoneal WD-DD liposarcomas, the predominant phenotype is represented by the aberrant (overexpressed) mdm2+/p53+ wild-type profile. At the nonretroperitoneal site, the WD liposarcomas present a wider association of MDM2/P53 gene expression; i.e., mdm2+/p53+, mdm2+/p53-, mdm2-/p53+ and mdm2-/p53-, and TP53 mutations seem to correlate with the dedifferentiation process. A biochemical study of mdm2-p53 association in 11 tumor samples characterized by the presence of different mdm2 and p53 immunophenotypes was performed. Immunoprecipitation assays using a p53-specific antibody were performed on tumor tissue and surrounding normal tissue; the immunoprecipitated material was then investigated for the presence of p53 (control) and of coimmunoprecipitated mdm2. This biochemical analysis showed that, in mdm2+/p53+/wild-type retroperitoneal liposarcomas, a band corresponded to mdm2 protein in the cellular lysates immunoprecipitated with a p53-directed antibody. In contrast, the mdm2+/p53- liposarcoma did not evidence the presence of mdm2 protein nor was p53 protein available to direct immunoprecipitation, as in the p53 mutant tumor samples with mdm2-/p53+ and mdm2-/p53- phenotypes. From the normal counterpart of retroperitoneal liposarcoma lysates, no p53 protein was immunoprecipitated. The findings in this study agree with the molecular data and they show the physical association of mdm2 and p53 in fresh liposarcoma surgical specimens.

Pathobiologic identification of two distinct breast carcinoma subsets with diverging clinical behaviors.

Many different pathological and biological variables which characterize breast carcinomas have been found to be associated. The aim of this work was to analyze the complex relationship among these parameters. The pathologic, biologic, and clinical characteristics of a series of primary breast carcinomas from 676 patients were retrospectively investigated. Multiple correspondence analysis of 13 factors revealed clustering of eight pathobiologic variables, that is histologic grade, necrosis, lymphoid infiltration, number of mitoses, c-erbB-2 overexpression, p53, progesterone receptor, and bcl2 expression. An index for each tumor calculated on the basis of these eight factors served to distinguish two different tumor phenotypes, designated A and B. Phenotype A is represented by tumors sharing most of the biologic features of normal breast tissues: indeed, these tumors are characterized by a relatively high degree of differentiation, low proliferation, no necrosis or leukocyte infiltration, and no gene alterations. By contrast, phenotype B is quite divergent from the normal tissue because of its poor differentiation, high proliferation, frequent gene alterations and evidence of a host immune reaction. As regards the disease progression, these two subsets showed marked differences: phenotype A tumors had a low recurrence rate per year that remained constant over time and affected more frequently elderly patients, whereas group B tumors showed high aggressivity in the first years after surgery followed by a low long-term recurrence rate and were more frequently seen in younger patients. These data suggest that breast carcinoma consists of two different subsets that can be identified on the basis of pathobiologic features.

c-erbB2/neu gene and chromosome 17 analysis in breast cancer by FISH on archival cytological fine-needle aspirates.

The detection of specific genetic alterations in breast cancer is useful for diagnosing, predicting prognosis and planning preoperative treatment. c-erbB2/neu overexpression is usually detected by immunocytochemistry (ICC), although this technique is neither completely reproducible nor highly reliable, owing to specimen and methodologic variability and antibody sensitivity. Here, we combine two well-established techniques, fine-needle aspiration (FNA) and fluorescence in situ hybridization (FISH), to detect c-erbB2/neu amplification in patients candidate to primary chemotherapy and, in part, previously analysed for c-erbB2/neu overexpression. Sixty smears from FNA were used to simultaneously detect c-erbB2/neu and chromosome 17 centromere. FISH was successful in 58 cases and detected 24 amplified cases, three of which were negative by immunophenotyping, 28 negative cases, with evidence of two normal c-erbB2/neu/signals, two cases with deletion of c-erbB2/neu, and four cases with polysomy, thus providing more reliable and informative results than ICC. This study underlines the advantages offered by the FNA and FISH combination which are two rapid, reliable, simple and informative techniques, to analyse one of the most important genetic markers for predicting prognosis and chemotherapy planning for breast carcinoma in particular in the light of the recently proposed trials of primary chemotherapy.

Percutaneous intraductal sampling for cyto-histologic diagnosis of biliary duct strictures.

BACKGROUND: Percutaneous transhepatic biliary drainage (PTBD) allows ductal material to be collected for cyto-histologic examination. We evaluated the data from a large series of patients with a PTBD in whom endobiliary cyto-histologic sampling techniques were employed in order to define a strategy for their use in the diagnostic work-up. PATIENTS AND METHODS: Ductal samples for cyto-histologic examination were obtained from 409 consecutive patients with a PTBD for stenosing lesions of the biliary tree. Bile aspirate cytology was performed for all patients and ductal biopsy specimens were obtained, generally after negative cytology, from 49 of them (11.9%), all candidates for a therapeutic procedure. The cyto-histologic results of intraductal sampling were compared with pathologic surgical data in 210 patients and with clinical-radiologic follow-up in 199. RESULTS: Overall, 22 out of the 409 patients had a final diagnosis of benign stenosis and 177 had samples positive for neoplastic disease. The sensitivity of bile cytology was 43.8% while ductal biopsies showed a sensitivity of 60.4%. The combination of the two sampling techniques achieved a sensitivity of 65.1%. For both sampling methods the specificity was 100%. Hilar metastases from neoplastic lesions of the GI tract and primary lesions of the biliary ducts showed the highest sensitivity. CONCLUSION: Cyto-histologic assessment of stenosing lesions of the biliary ducts is mandatory when highly sophisticated interventions (e.g. wide hepatic resection or liver transplantation) or non-surgical treatments are envisaged. The collection of cyto-histologic samples from bile ducts, in patients with a percutaneous bile drainage, is an easy, safe and valuable method to obtain the diagnosis. In view of the absence of false positive results in our series and in others, intraductal biopsy serves no purpose when positive exfoliative cytology is positive for malignancy. In the presence of negative cytology it is felt that an intraductal biopsy should be mandatory when the choice of a therapeutic program depends on the result of the cyto-histologic diagnosis.

Ten year results of a randomised trial comparing two conservative treatment strategies for small size breast cancer.

We report the 10-year results of a randomised clinical trial in which two different breast conservation treatment strategies were compared in women with small, non-metastatic primary breast cancer: quadrantectomy, axillary dissection and radiotherapy (QUART) versus tumorectomy and axillary dissection followed by external radiotherapy and a boost with 192Ir implantation (TART). No second surgery was given to women with affected surgical margins. Axillary node positive women received adjuvant medical therapy. From 1985-1987, this trial accrued 705 patients, 360 in the QUART and 345 in the TART arm. Crude cumulative incidence curves for intrabreast tumour recurrence (IBTR) and metastases as first events and mortality curves in each of the two treatment arms were computed. A crude cumulative incidence curve of IBTR as a second event (in women who had already had a local recurrence) was also computed. The two groups were compared in terms of hazard for IBTR, metastases or death occurrence by using Cox regression models, both with and without adjustment for patient age, tumour size, number of metastatic axillary nodes and histology. Possible interactions between the aforementioned prognostic factors and the type of surgery were also investigated. The two groups were well matched for baseline patient and tumour characteristics, the only exception being resection margins, which were more often positive in the TART group. At the Cox model, a significant difference between groups was detected for IBTR (P < 0.0001), but not for distant metastases and overall survival. In particular, 5- and 10-year estimates of crude cumulative incidence of IBTR were 4.7 and 7.4% in the QUART group and 11.6 and 18.6% in the TART group. The difference was not substantially affected by patient or disease characteristics. Likewise, the status of resection margins in women who underwent TART treatment did not significantly influence the risk of occurrence of IBTRs. Finally, the rate of second IBTR occurrence was relatively high, when compared with the rate of IBTR occurrence as first event. In summary, the results of this trial show that a better local control of the disease can be obtained with the more extensive surgical resection, i.e. QUART.

Limited role of TP53 and TP53-related genes in myxoid liposarcoma.

AIMS: Circumstantial evidence suggests that genetic changes may lead to tumor progression within the myxoid liposarcoma tumors (MLTs) carrying non-random chromosomal translocation t(12;16). METHODS: To address this subject an immunophenotypic analysis, applying antibodies against proteins encoded by TP53, MDM2 and CDK4 genes, complemented by molecular analysis of eight suitable cases, was performed on 104 consecutive cases. Chromosomal translocations were assessed either by cytogenetic analysis or by RT-PCR in 9 suitable cases and chimeric transcripts were found in all cases but two pleomorphic liposarcomas. RESULTS: Based on immunophenotyping and tumor site, the case material consisted of three groups. The first one was made up of 92 non-retroperitoneal cases carrying a null p53, mdm2, cdk4 immunophenotype, which remained unchanged over the time of recurrences and along the gamut of histologic subtypes. The second group was represented by five p53+, mdm2-, cdk4- non-retroperitoneal cases, 4 of which were further analysed by PCR-SSCP for p53 mutation. The immunophenotypic profile of these cases, complemented by the molecular findings, supported a role of TP53 in tumor progression in three high-grade MLTs. The third group, consisting of 7 retroperitoneal cases, showed a heterogeneous immunophenotype, sharing immunophenotypic and molecular features with the well-differentiated/evoluted (dedifferentiated) liposarcoma group. CONCLUSIONS: TP53 mutations seem to play a role in tumor progression in a few cases of MLTs (2.8%) showing more aggressive histologic characteristics. The unexpected finding that a number of retroperitoneal LMTs display the immunophenotypic profile of the well differentiated/evoluted (dedifferentiated) liposarcomas, deserves further investigation.

Molecular abnormalities in liposarcoma: role of MDM2 and CDK4-containing amplicons at 12q13-22.

It has recently been shown that mdm2 overexpression with stabilization of p53 represents a characteristic of retroperitoneal well-differentiated-dedifferentiated, here renamed evolved (WD-E), liposarcomas at the immunocytochemical, molecular, and cytogenetic level. This make-up appears to be confined to half the cases in non-retroperitoneal well-differentiated liposarcomas. Since in different tumours MDM2 amplification involves amplicons encompassing flanking genes, such as CDK4, the possibility was investigated that in these tumours, CDK4 could act as an alternative or additional gene involved in the transformation mechanism. Forty-one retroperitoneal (R)/non-retroperitoneal (NR) well-differentiated-dedifferentiated (WD-DD) and 33 myxoid/round cell liposarcomas were reanalysed by immunocytochemical, molecular (nine cases) and fluorescence in situ hybridization (FISH) (one case) techniques. The results showed that all but one R WD-E cases carried the mdm2+, p53+, cdk4+ immunophenotype. In NR-WD liposarcomas, this immunophenotype was shared in five cases and the remainder showed mdm2+, p53-, cdk4+ in four and mdm2-, p53-, cdk4+ in one case, showing ring chromosomes by FISH analysis. TP53 mutations are confirmed to be closely correlated with NR-DD liposarcomas and no CDK4 involvement was found in the myxoid/round cell liposarcoma group. As well as confirming the synergistic effect of MDM2 and CDK4, these results are consistent with the concept that amplicon(s) excluding MDM2 may contribute to transformation and support a role of CDK4 in opposing p53 function, particularly in NR WD liposarcoma.

Evaluation of residual cellularity and proliferation on preoperatively treated breast cancer: a comparison between image analysis and light microscopy analysis.

Histopathology has been suggested as a reliable method for tumour reduction evaluation of preoperatively treated breast cancer. Immunocytochemistry can be used to enhance the visibility of residual tumour cellularity and in the evaluation of its proliferative activity. We compared Image Analysis (IA) with Light Microscopy Analysis (LMA) on sections of breast carcinomas treated with preoperative chemo- or chemo/radiotherapy in the evaluation of the Neoplastic Cell Density (NCD) (69 cases) and the Proliferation Index (PI) (35 cases). NCD was expressed as the immunoreactive area to cytokeratin over the total original neoplastic area and PI was expressed as the number of immunostained tumoural nuclei with MIB 1 MoAb over the total of tumoural nuclei. The intraobserver agreement and that between IA and LMA for both indices were estimated by the common (kappa(w)) and the jackknife weighted kappa statistic (kappa(w)). The extent of agreement of each considered category was also assessed by means of the category-specific kappa statistics (kappa(cs)). The intraobserver agreement within LMA for NCD and PI and that between IA and LMA for PI were both satisfactory. Upon evaluation of the NCD, the agreement between IA and LMA showed unsatisfactory results, especially when the ratio between the residual tumour cells and the background was critical.

Early breast cancer: evaluation of the prognostic role of the site of the primary tumor.

PURPOSE: The prognostic role of the site of the primary breast cancer has not been clarified. This study aimed to gather more information about this issue from a large series of patients with long-term follow-up data. PATIENTS AND METHODS: Data from 2,396 patients treated for early breast cancer with a conservative approach were reviewed (1973 to 1989). In 1,619 patients, the tumor had a lateral site, while in 777 cases, it was situated in the internal/central quadrants. The characteristics of the two groups were well balanced, apart from axillary nodal metastases, which were more frequent for lateral tumors (38.1% v 26.3%). RESULTS: Analysis of distant metastases indicated that the regression coefficient associated with tumor site was significant and the hazards ratio estimate was 1.291, which indicates the risk of distant metastases was increased by approximately 30% for internal/central tumors. The analysis of overall survival yielded a significant coefficient and a hazards ratio of 1.192, which indicates an approximately 20% increase of mortality for internal/central tumors. CONCLUSION: Early breast cancers situated in central/ internal quadrants have a worse prognosis compared with those in lateral quadrants, in terms of distant metastases and survival. Irradiation of the internal mammary chain for internal/medial tumors could be suggested, but, to date, the therapeutic strategy is still controversial.

Detection of TP53 mutation, loss of heterozygosity and DNA content in fine-needle aspirates of breast carcinoma.

Recent preclinical and clinical data suggest that TP53 status and TP53 mutations may be important in determining tumour aggressiveness and therapy response. In this study we investigate the feasibility of a structural and quantitative analysis of TP53 on fine-needle aspiration (FNA) material obtained from 31 consecutive female patients with breast carcinoma, enrolled in a primary chemotherapy protocol. Tumours were screened for p53 protein overexpression and TP53 mutations (exons 5-8) using immunocytochemistry, polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing analyses, and finally using fluorescence in situ hybridization (FISH) analysis. Positive nuclear staining was identified in six cases whereas mutations were detected in nine. Although the immunoreactive pattern fitted fully with the characterized TP53 mutation type, the considerable number of null p53 mutations (i.e. four) coupled with the lack of information regarding the localization of TP53 mutations make immunocytochemistry an inadequate indicator of TP53 function deregulation. Combining molecular and FISH analyses, we detected three cases with TP53 deletion and one case with deletion and mutation. Finally, DNA static-image analysis performed on 29 cases showed aneuploidy in 26 cases, which included all TP53-mutated cases. The present results show that FNA may assist clinical decisions by allowing the evaluation of a variety of biological parameters relevant for prognosis and treatment planning.

Characterization of ten novel and 13 recurring BRCA1 and BRCA2 germline mutations in Italian breast and/or ovarian carcinoma patients. Mutations in brief no. 178. Online.

Germline mutations in the BRCA1 and BRCA2 genes are associated with approximately 80% of families with a high incidence of breast and/or ovarian cancers (OMIM database reference numbers: 113705, 600185). Furthermore, constitutional mutations in the these genes have been reported in women with early-onset breast carcinoma and without family history of cancer. We analyzed by protein truncation test (PTT) and single strand conformation polymorphism (SSCP) followed by sequence analysis, BRCA1 exons 11 and 20 and BRCA2 exons 10 and 11 in 142 Italian cancer patients. These included six male breast cancer cases, 61 women with breast carcinoma diagnosed before 36 years old and selected independently of family history of breast cancer and 75 familial breast and/or ovarian cancer patients. In a previous report, we described 11 different BRCA1 mutations in a subset of 70 cases. Here, we report the characterization of 23 additional mutations, 14 in BRCA1 and 9 in BRCA2, subsequently identified. Ten mutations were not previously described, while the other 13 were recurrent. Of the 61 women with early-onset breast cancer, 11 carried a germline mutation in BRCA1 (18.0%) and four in BRCA2 (6.6%). These frequencies indicate that BRCA1/BRCA2 genetic tests should be advised to women with breast cancer diagnosed at early age, independently of family history of cancer.

Insular carcinoma: a distinct de novo entity among follicular carcinomas of the thyroid gland.

We reclassified 720 nonmedullary invasive thyroid carcinomas diagnosed and treated between 1975 and 1993. Twenty-seven cases met the criteria of insular carcinoma and 29 cases those of widely invasive follicular carcinoma. Comparison of these histotypes with respect to pathologic stage and overall, relative, and visceral metastasis-free survival showed a significant association between histotype and pT and pN categories. In particular, pT4 (p < 0.001) and pN1 (p < 0.001) categories were more frequent in the insular carcinoma histotype. By contrast, no significant differences in overall, relative, or visceral metastasis-free survival were observed between insular carcinoma and widely invasive follicular carcinoma. Molecular analysis by polymerase chain reaction-single-strand conformation polymorphism demonstrated RAS gene family point mutations in five of eight cases analyzed in each of the two histotypes, with a high proportion of CAA-->AAA transversion at codon 61 of the N-RAS gene in insular carcinoma. These findings suggest that insular carcinoma represents a de novo entity distinct from widely invasive follicular carcinoma, that widely invasive follicular carcinoma has biologic characteristics more consistent with poorly differentiated than well-differentiated carcinomas, and that both insular carcinoma and widely invasive follicular carcinoma share similar molecular alterations.

Non-small-cell lung carcinoma tumor growth without morphological evidence of neo-angiogenesis.

Neoplastic growth is usually dependent on blood supply, and it is commonly accepted that this is provided by the formation of new vessels. However, tumors may be able to grow without neovascularization if they find a suitable vascular bed available. We have investigated the pattern of vascularization in a series of 500 primary stage I non-small-cell lung carcinomas. Immunostaining of endothelial cells has highlighted four distinct patterns of vascularization. Three patterns (which we called basal, papillary, and diffuse) have in common the destruction of normal lung and the production of newly formed vessels and stroma. The fourth pattern, which we called alveolar or putative nonangiogenic, was observed in 16% (80/500) of the cases and is characterized by lack of parenchymal destruction and absence of both tumor associated stroma and new vessels. The only vessels present were the ones in the alveolar septa, and their presence highlighted, through the whole tumor, the lung alveoli filled up by the neoplastic cells. This observation suggests that, if an appropriate vascular bed is available, a tumor can exploit it and grows without inducing neo-angiogenesis. This could have implications for strategies aimed at inhibiting tumor growth by vascular targeting or inhibition of angiogenesis.

Immunocytochemical markers in stage I lung cancer: relevance to prognosis.

PURPOSE: This study investigated the frequency of the expression and prognostic significance of a panel of immunocytochemical markers in resected non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: A total of 515 cases of pathologic stage I NSCLC were analyzed. The median follow-up time of surviving patients was 102 months. The following immunocytochemical markers were tested: blood group A and precursors of blood antigens; laminin receptor; c-erbB1/epidermal growth factor receptor (EGFR) and c-erbB2/Neu; BCl2; p53; and angiogenesis. Kaplan-Meier estimates of survival and time to recurrence were calculated for clinical variables and biologic markers using the Cox model for multivariate analysis. RESULTS: The pathologic tumor extension (pT) represented the most powerful prognostic factor for survival (P = .0008) and time to recurrence (P = .0007). None of the immunocytochemical markers emerged as an independent predictive factor for survival. Bcl2-positive tumors showed a better time to recurrence (P = .03), but the difference lost statistical significance in the multivariate analysis. Of interest, in the group of 137 patients classified as pT1N0, both EGFR expression and nonangiogenic type of vascular pattern were associated with a poorer survival (P = .02). However, data derived from subset analysis must be interpreted cautiously. CONCLUSION: Our findings do not support a relevant prognostic role of immunocytochemical markers in NSCLC. The evidence is not sufficient to alter clinical practice or even to restrict clinical trials of adjuvant treatments to predefined biologic subsets of patients.

Efficacy, toxicity, and applicability of high-dose sequential chemotherapy as adjuvant treatment in operable breast cancer with 10 or more involved axillary nodes: five-year results.

PURPOSE: To assess the efficacy, toxicity, and applicability of high-dose therapy administered as adjuvant initial treatment to women with breast cancer with extensive nodal involvement. PATIENTS AND METHODS: Sixty-seven patients with stage II to III breast cancer involving > or = 10 axillary nodes received a novel high-dose sequential (HDS) regimen, including the high-dose administration of three non-cross-resistant drugs (cyclophosphamide, methotrexate, and melphalan) given within the shortest interval of time as possible with hematologic and nonhematologic toxicity. RESULTS: Sixty-three patients completed the program as planned, one patient died of acute toxicity, and three patients were switched to standard-dose adjuvant therapy. After a median follow-up duration of 48.5 months and a lead follow-up of 78 months, actuarial relapse-free survival for all 67 registered patients is 57% and overall survival is 70%, respectively. Comparison with a historical control group of 58 consecutive patients showed a significantly superior rate of freedom from relapse for the HDS-treated group (57% v 41%, respectively), in particular when two subgroups of patients, more homogeneous for their number of involved nodes, were compared (65% v 42%). Overall, treatment was of short duration (median, 70 days), required a median of 32 days of hospital stay, and was associated with only a few severe side effects (the most distressing being oral mucositis after melphalan therapy). CONCLUSION: HDS therapy emerges as an effective and applicable regimen, whose major toxicity was occasional. Final assessment of its value in a randomized, multicenter trial is presently underway.

Prognostic factors for metachronous contralateral breast cancer: a comparison of the linear Cox regression model and its artificial neural network extension.

The purpose of the present study was to assess prognostic factor for metachronous contralateral recurrence of breast cancer (CBC). Two factors were of particular interest, namely estrogen (ER) and progesterone (PgR) receptors assayed with the biochemical method in primary tumor tissue. Information was obtained from a prospective clinical database for 1763 axillary node-negative women who had received curative surgery, mostly of the conservative type, and followed-up for a median of 82 months. The analysis was performed based on both a standard (linear) Cox model and an artificial neural network (ANN) extension of this model proposed by Faraggi and Simon. Furthermore, to assess the prognostic importance of the factors considered, model predictive ability was computed. In agreement with already published studies, the results of our analysis confirmed the prognostic role of age at surgery, histology, and primary tumor site, in that young patients (< or = 45 years) with tumors of lobular histology or located at inner/central mammary quadrants were at greater risk of developing CBC. ER and PgR were also shown to have a prognostic role. Their effect, however, was not simple in relation to the presence of interactions between ER and age, and between PgR and histology. In fact, ER appeared to play a protective role in young patients, whereas the opposite was true in older women. Higher levels of PgR implied a greater hazard of CBC occurrence in infiltrating duct carcinoma or tumors with an associated extensive intraductal component, and a lower hazard in infiltrating lobular carcinoma or other histotypes. In spite of the above findings, the predictive value of both the standard and ANN Cox models was relatively low, thus suggesting an intrinsic limitation of the prognostic variables considered, rather than their suboptimal modeling. Research for better prognostic variables should therefore continue.

Lymphoid infiltration as a prognostic variable for early-onset breast carcinomas.

Infiltration by lymphoid cells is a common feature of many human tumors, including breast carcinomas, and the degree of infiltration has been suggested to be a measure of the host immune response. Our analyses in a series of 1919 cases of primary ductal and lobular infiltrating breast carcinomas from women with a long-term follow-up revealed: (a) a 16-17% frequency of infiltrated tumors independent of the patient's age at diagnosis; and (b) a strong positive correlation between survival rates and the presence of lymphocytes at the tumor site in patients less than 40 years of age (P = 0.0002) but no association with prognosis in patients 40 years of age or older. Multivariate analysis indicated that lymphoid infiltration is independent of other conventional prognostic factors such as nodal status and tumor size in predicting survival. Thus, a possible immune response against the tumor seems to be relevant only in women with early-onset tumors. Because the immune system is functionally maximum in younger years, declining with age, this finding might reflect a difference in the efficiency of the immune system. Alternatively, the biology of these tumors might differ, leading to a difference in immuno-genicity.