Mattia Barbareschi

Tumor microvessel density, p53 expression, tumor size, and peritumoral lymphatic vessel invasion are relevant prognostic markers in node-negative breast carcinoma.

PURPOSE To determine the absolute and relative value of microvessel density (MVD), p53 and c-erbB-2 protein expression, peritumoral lymphatic vessel invasion (PLVI), and conventional prognosticators in predicting relapse-free (RFS) and overall survival (OS) rates in patients with node-negative breast carcinoma (NNBC). PATIENTS AND METHODS We monitored 254 consecutive patients with NNBC for a median of 62 months. Intratumoral MVD was measured after microvessels were immunostained using anti-CD31 antibody. p53 and c-erbB-2 protein and hormone receptors were also determined immunocytochemically. Results were analyzed by both univariate and multivariate statistical analysis. RESULTS Univariate analysis showed that MVD was significantly predictive of both RFS (odds ratio [OR], 8.30; P = .0001) and OS (OR, 4.50; P = .012) when tested as a continuous or dichotomous variable. Likewise, tumor size (OR, 3.16; P = .0012), PLVI (OR, 4.36; P = .0009), estrogen receptor (ER) status (OR, 2.35; P = .016), progesterone receptor (PR) status (OR, 2.00; P = .017), and expression of p53 protein (OR, 2.82; P = .004) were significantly associated with RFS. Tumor size (OR, 3.80; P = .0038) and expression of p53 protein (OR, 2.58; P = .024) were significantly associated with OS by univariate analysis. Multivariate analysis showed that MVD (P = .0004), p53 protein expression (P = .0063), tumor size (P = .0144), and PLVI (P = .0033) were all significant and independent prognostic factors for RFS. However, only tumor size (P = .004) and MVD (P = .047) were independent predictors for OS. c-erbB2 expression was not associated with outcome by either univariate or multivariate analysis. CONCLUSION MVD, p53 expression, PLVI, and tumor size are independent prognostic indicators of recurrence, which are useful in selection of high-risk NNBC patients who may be eligible to receive adjuvant therapies.

p63, a p53 homologue, is a selective nuclear marker of myoepithelial cells of the human breast.

Myoepithelial cells (MCs) constitute the basal cell layer of normal mammary epithelia, and their identification is of particular diagnostic value because they are retained in most benign lesions while being lost in malignancy. Several MC immunocytochemical markers are currently available for diagnostic purposes, with special reference to smooth muscle-related antigens. p63 is a member of the p53 gene family, and its germline mutations are associated with severe mammary developmental defects in both rodents and humans. Different p63 isoforms have been identified, some of which (&Dgr;Np63) are preferentially expressed in the epithelial basal cells of different organs and have been considered as possible markers of stem cells/reserve cells. We investigated immunohistochemically 384 samples of normal and diseased human breast, including 300 invasive carcinomas, using four antibodies recognizing all p63 isoforms, or the &Dgr;Np63 isoforms. Twenty cytologic specimens were also investigated. Furthermore, snap-frozen tissue samples from three fibroadenomas and 10 invasive ductal carcinomas with their paired non-neoplastic tissues and three corresponding lymph node metastases were evaluated for the expression of p63 mRNA by RT-PCR. In normal breast tissue p63 immunoreactivity was confined to the nuclei of MCs. In all benign lesions p63-immunoreactive cells formed a continuous basal rim along the epithelial structures. Stromal cells, and in particular myofibroblasts, were consistently unreactive. Adenomyoepitheliomas showed nuclear staining in most neoplastic cells. A peripheral rim of p63-immunoreactive cells was retained surrounding lobular and ductal carcinoma in situ, although it was discontinuous as opposed to the normal structures. Invasive breast carcinomas were consistently devoid of nuclear p63 staining, with the exception of the two adenoid–cystic carcinomas, of the two ductal carcinomas with squamous metaplasia, and of 11 (4.6%) ductal carcinomas not otherwise specified, showing p63 immunoreactivity in a minor fraction (5–15%) of the neoplastic cells. In comparison with other MC markers, p63 was the most specific, being restricted exclusively to MCs, whereas antibodies to smooth muscle actin and, to a lesser extent, calponin also decorated stromal myofibroblasts. In the cytologic preparations p63 immunoreactivity was a consistent feature of “naked nuclei” and of a subset of cells surrounding benign epithelial clusters. RT-PCR experiments with primers specific for different p63 isoforms documented that normal tissues and fibroadenomas preferentially expressed the &Dgr;Np63 isoforms. Our study demonstrates that in normal and pathologic breast tissues MCs consistently express the &Dgr;Np63 isoforms. We suggest p63 as a reliable, highly specific, and sensitive MC marker in both histologic and cytologic preparations. Furthermore, because p63 immunoreactivity in adult epithelia is normally restricted to progenitor cells, it can be speculated that it might be a clue for the identification of the still elusive breast progenitor cells.

PCNA and Ki67 expression in breast carcinoma: correlations with clinical and biological variables.

AIMS: To investigate the expression of two cell cycle related antigens (proliferating cell nuclear antigen (PCNA) and Ki67 related antigen) in a series of breast cancers; and the possible correlations between the PCNA and Ki67 labelling indexes (PCNA-LI and Ki67-LI) and their associations with other biological and clinicopathological variables. METHODS: Ninety six ductal and 10 lobular carcinoma specimens were investigated. Samples were fixed in formalin and in Methacarnoy for localisation of PCNA. Ki67 was immunostained on frozen sections. The PCNA-LI and Ki67-LI were evaluated in relation to tumour size, mitotic count, histological grade, nodal state as well as receptor content and altered expression of the p53 gene. RESULTS: PCNA-LI did not correlate with Ki67-LI, nor was it associated with any other variable examined. A high KI67-LI (above the median value of 13.5) was associated with high grade and mitotic count, negative receptor content, and altered expression of the p53 gene, but not with other variables. CONCLUSIONS: The PCNA-LI does not seem to be a substitute for the Ki67-LI in evaluating the growth fraction in breast cancer.

High syndecan-1 expression in breast carcinoma is related to an aggressive phenotype and to poorer prognosis

Syndecan‐1 is a transmembrane heparan sulphate proteoglycan that is involved in cell–cell adhesion, organization of cell–matrix adhesion, and regulation of growth factor signaling.

CDX-2 homeobox gene expression is a reliable marker of colorectal adenocarcinoma metastases to the lungs

Lung metastases from colorectal carcinomas (CRC) can be resected with improved survival. The distinction between primary lung adenocarcinomas and metastases from CRC may sometimes be difficult, especially on cytologic specimens or small bronchoscopic biopsies. Immunohistochemistry may be of help in this setting: available markers include TTF-1 and SP-A, which are markers of lung origin, whereas there are no good markers of intestinal origin, besides cytokeratin 7 and 20 coexpression pattern, which is not very specific. The nuclear CDX-2 transcription factor, which is the product of a homeobox gene necessary for intestinal organogenesis, is expressed in normal colonic epithelia and most colorectal adenocarcinomas, and could potentially be of diagnostic usefulness. Our aim was to investigate CDX-2 immunohistochemical expression using a new monoclonal antibody and to verify if CDX-2 can be a reliable marker to identify the colorectal origin of lung metastases. CDX-2 expression was evaluated in formalin-fixed, paraffin-embedded samples of normal adult human tissues (50 samples) and in 299 surgically resected carcinomas of different origins, including 125 non-lung adenocarcinomas, 117 primary lung tumors, 5 mesotheliomas, and 52 adenocarcinomas metastatic to the lung. CDX-2 was also evaluated on a series of 20 bioptic and 10 cytologic specimens (5 cases of colorectal metastases to the lung, 5 cases of metastases from other organs, and 10 primary lung adenocarcinomas). In normal tissues CDX-2 immunoreactivity was observed only in ileal and colorectal epithelia. CDX-2 was expressed in almost all primary and metastatic CRC (88 of 90) and was never observed in primary lung tumors. CDX-2 was also expressed in a limited group of adenocarcinomas of other sites (gastric, biliopancreatic, and mucinous ovarian adenocarcinomas). CDX-2 could be easily detected in all bioptic and cytologic samples of CRC metastases. CDX-2 is a reliable, specific, and sensitive immunohistochemical marker of normal and neoplastic intestinal epithelium. CDX-2 can be easily applied to routine histologic and cytologic material and is therefore a useful marker in the differential diagnosis of primary versus metastatic adenocarcinomas in the lung, and among metastases from an unknown primary, supports intestinal origin.

AKT1 E17K in human solid tumours

The serine-threonine kinase AKT1 is a central player in the oncogenic pathway controlled by PI3K. Recently, a somatic mutation in AKT1 (E17K) has been detected in breast, colorectal, lung and ovarian cancers. The E17K change results in constitutive AKT1 activation and induces leukaemia in mice. We determined the occurrence of the E17K variant in a panel of 764 tumour samples. These included breast, lung, ovarian, colorectal and pancreatic carcinomas as well as melanomas and glioblastomas. Despite the fact that these tumours are known to bear alterations in genes involved in the PI3K signalling pathway, AKT1E17K was detected only in breast (16/273), colorectal (1/88) and lung (1/155) cancers. Within the neoplasms of breast origin, the AKT1E17K variant was mutually exclusive with respect to the PIK3CAE454KorH1047R alleles and was present only in ductal and lobular histotypes. Our results, showing that AKT1 mutations seem to occur in a tissue-specific fashion have basic and clinical implications. First, the activity of mutated AKT1 in oncogenic PI3K signalling could be strictly dependent on the cell and tissue milieu. Second, therapeutic efforts aimed at selective targeting the AKT1E17K variant could be effective mainly in specific cancer types.

Different Prognostic Roles of Mutations in the Helical and Kinase Domains of the PIK3CA Gene in Breast Carcinomas

Purpose: In breast cancer, the PIK3CA gene is frequently mutated at “hotspots” in exons 9 and 20, corresponding to the helical and kinase domains, respectively. We decided to investigate the association of PIK3CA mutations with pathologic features and clinical outcome in a large series of patients with breast cancer. Experimental Design: Frozen samples from 163 consecutive patients were analyzed for PIK3CA mutations using PCR single-strand conformation polymorphism and sequence analyses. Results: We identified 46 missense mutations, 24 (53%) in exon 9, and 21 (47%) in exon 20. Twelve (50%) of the 24 mutations in exon 9 were of the E542K type and 11 (46%) were of the E545K type. Twenty (95%) of the 21 mutations in exon 20 were H1047R substitutions. Mutations in exon 9 were more frequent in lobular carcinomas (42% of cases) than in ductal carcinoma (11% of cases; P = 0.002). At univariate survival analysis, PIK3CA exon 20 mutations were associated with prolonged overall and disease-free survival, whereas mutations in exon 9 were associated with significantly worse prognosis. At multivariate analysis, exon 9 PIK3CA mutations were the strongest independent factor to predict poor prognosis for disease-free survival (P = 0.0003) and overall survival (P = 0.001). Conclusion: Our data show that exon 9 PIK3CA mutations are typical of infiltrating lobular carcinomas. In addition, they indicate that PIK3CA mutations in different exons are of different prognostic value: exon 9 mutations are independently associated with early recurrence and death, whereas exon 20 PIK3CA mutations are associated with optimal prognosis.

p21WAF1 immunohistochemical expression in breast carcinoma: correlations with clinicopathological data, oestrogen receptor status, MIB1 expression, p53 gene and protein alterations and relapse-free survival.

p21 protein (p21) inhibitor of cyclin-dependent kinases is a critical downstream effector in the p53-specific pathway of growth control. p21 can also be induced by p53-independent pathways in relation to terminal differentiation. We investigated p21 immunoreactivity in normal breast and in 91 breast carcinomas [three in situ ductal carcinomas (DCIS) with microinfiltration and 88 infiltrating carcinomas, 17 of which with an associated DCIS; 57 node negative and 34 node positive] with long-term follow-up (median = 58 months). Seven additional breast carcinomas with known p53 gene mutations were investigated. In normal breast p21 expression was seen in the nuclei of rare luminal cells of acinar structures, and in occasional myoepithelial cells. Poorly differentiated DCIS showed high p21 expression, whereas well-differentiated DCIS tumours showed few p21-reactive cells. p21 was seen in 82 (90%) infiltrating tumours; staining was heterogeneous; the percentage of reactive nuclei ranged from 1% to 35%. High p21 expression (more than 10% of reactive cells) was seen in 24 (26%) cases, and was associated with high tumour grade (P = 0.032); no associations were seen with tumour size, metastases, oestrogen receptor status, MIB1 expression and p53 expression. p21 expression in cases with p53 gene mutations was low in six cases and high in one. High p21 expression was associated with short relapse-free survival (P = 0.003).

The prevalence of BCL-2 immunoreactivity in breast carcinomas and its clinicopathological correlates, with particular reference to oestrogen receptor status.

BCL-2 protein plays a pivotal role in overriding programmed cell death (apoptosis), thus favouring a prolonged survival of normal and neoplastic cells. Expression of the bcl-2 gene has been documented in some human tumours (non-Hodgkins lymphomas and prostatic adenocarcinomas), but findings in breast carcinomas have not been reported. We have used the monoclonal antibody 124 to investigate BCL-2 expression in 212 breast carcinomas, and to correlate it with the oestrogen (ER), progesterone (PR) and epidermal growth factor receptor (EGFR) status, and with other clinicopathological variables including tumour type, grade, stage, growth fraction (as evaluated by Ki-67 immunostaining), and p53 accumulation. Of the 212 carcinomas, 173 (81.6%) exhibited BCL-2 immunoreactivity in more than 25% of the neoplastic cells. BCL-2 immunoreactivity was strongly correlated with ER and PR expression (P<0.00001), with the lobular type (P=0.012) and with better differentiated neoplasms (P=0.00003), whereas it was inversely correlated with EGFR (P<0.00001), p53 (P=0.0004) and Ki-67 (P=0.0002) immunoreactivities. No association was found with tumour stage (T and N categories). We conclude that bcl-2 expression in breast cancers is related to the oestrogen-dependent transcription pathway.

Immunohistochemical subtyping of nonsmall cell lung cancer not otherwise specified in fine-needle aspiration cytology: a retrospective study of 103 cases with surgical correlation.

Histopathological subtyping of nonsmall cell lung cancer (NSCLC) is currently relevant in treatment decision because of a differential activity of specific therapeutic agents. Immunohistochemistry highlights cell differentiation lineages and, in this study, it was applied to maximize the proportion of accurately subtyped NSCLC not otherwise specified (NOS) on fine‐needle aspiration cytology (FNAC) samples.