A molecular reappraisal of matrix-producing breast metaplastic carcinoma highlighted by PLAG1 and MYC rearrangements.

BACKGROUND: Very little is currently known about molecular alteration of matrix-producing carcinoma of the breast. However, the morphological similarity with other neoplasm with a myxo-chondroid component is remarkable. In this pilot study we evaluated the molecular alterations involving PLAG1 and MYC genes in 12 cases of matrix producing carcinoma. METHODS: We evaluated PLAG1 rearrangements as Break-Apart and Gene Copy Gain, and MYC as amplification and polysomy in 12 cases of matrix producing carcinoma using a FISH method. RESULTS: Among the 12 cases of matrix producing carcinomas we found that the three cases harboring MYC amplification were all negative for PLAG1 break-apart; four cases with MYC polysomy were associated to PLAG1 break-apart and high Gene Copy Number; among four cases wild type for MYC, three showed a PLAG1- break-apart signal and of them two died with disease. One of the deceased patients showed an amplification of MYC with PLAG1- wild-type and the other showed a PLAG1 break-apart (6%) and a MYC wild-type. CONCLUSION: This is the first report to the best of our knowledge that shows a possible correlation between a matrix producing carcinoma with PLAG1 and MYC involvement in the development and progression of this kind of tumor. We can suppose that MYC amplification behaves in an aggressive way together with PLAG1- break-apart in the cases of matrix producing carcinoma presented here. The gene copy gain is a useful diagnostic tool in the case of difficult diagnosis because an increase was observed in more than 50% of cases.

Erlotinib efficacy in NSCLC patients with high polysomy of chromosome 7 and EGFR/KRas wild-type tumors.

BACKGROUND: More than even before, the efficacy of epidermal growth factors (EGFRs) tyrosine kinase inhibitors in non-small-cell lung cancer patients carrying EGFR wild-type tumors has been under investigation. EGFR wild-type patients represent a large and heterogeneous group of patients. In this setting, the role played by high polysomy of chromosome 7 still remains controversial. Indeed, previous reports did not discriminate between chromosome 7 high polysomy and EGFR amplification and/or did not investigate the concurrent presence of EGFR and KRas mutations. METHODS: We retrospectively collected data from 163 patients analyzed for EGFR status (mutation, amplification, chromosome 7 trysomy, and polysomy), in addition to KRas mutation, between 2000 and 2010 in our institute. Erlotinib was administered to 73 of them. Objective responses and progression-free survivals to erlotinib were evaluated. RESULTS: High polysomy of chromosome 7 characterized 17% (28 of 163) of EGFR/KRas wild-type tumors, independently of smoking status. In this group, 13 patients received erlotinib at progression. The treatment led one complete and four partial responses, and five stable diseases. Two patients progressed. One patient was lost to follow-up. The mean time to progression was 9 months. CONCLUSION: Among the EGFR wild-type population, when analyzed separately, high polysomy of chromosome 7 was the only molecular feature conferring clear signs of sensitivity to erlotinib. Therefore, the evaluation of high polysomy of chromosome 7 could become a helpful tool to predict for the benefit from epidermal growth factors tyrosine kinase inhibitors in selected cases.

A case of NUT midline carcinoma with no HPV infection, slight EWSR1 rearrangement and strong expression of EGFR.

NUT midline carcinoma (NMC) is a rare neoplasm with a poor prognosis and involving mostly young patients. Here we describe a classic NMC with a BRD4-NUT fusion gene in a middle-aged woman. We also analyzed some biological features that could potentially influence its clinical behavior such as HPV infection, EWSR1 rearrangement, and the status of the EGFR gene.

Comparative evaluation of an extensive histopathologic examination and a real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 on axillary sentinel lymph nodes of breast carcinoma patients.

OBJECTIVE: To assess the accuracy of a commercially available real-time reverse-transcription-polymerase chain reaction assay for mammaglobin and cytokeratin 19 mRNAs [GeneSearch Breast Lymph Node (BLN) Assay, Veridex LLC, Warren, NJ] in the detection of axillary sentinel lymph nodes (SLNs) metastases in patients with breast carcinoma. SUMMARY BACKGROUND DATA: Because of the lack of standardized and widely accepted protocols for a truly accurate histopathologic examination of SLN, the relative merits of alternative assays based on the identification of tumor specific mRNA markers deserve further assessment. METHODS: : A prospective series of 293 consecutive SLNs from 293 patients was evaluated. The BLN assay results were compared with those of an extensive histopathologic examination of the entire SLNs performed on serial frozen sections cut at 40 to 50 microm intervals. RESULTS: The BLN assay correctly identified 51 of 52 macrometastatic and 5 of 20 micrometastatic SLNs, with a sensitivity of 98.1% to detect metastases larger than 2 mm, 94.7% for metastases larger than 1 mm, and 77.8% for metastases larger than 0.2 mm. The overall concordance with histopathology was 90.8%, with specificity of 95.0%, positive predictive value of 83.6%, and negative predictive value of 92.9%. When the results were evaluated according to the occurrence of additional metastases to non-SLN in patients with histologically positive SLNs, the assay was positive in 33 (91.7%) of the 36 patients with additional metastases and in 22 (66.6%) of the 33 patients without further echelon involvement. CONCLUSIONS: The sensitivity of the reverse-transcription -polymerase chain reaction assay is comparable to that of the histopathologic examination of the entire SLN by serial sectioning at 1.5 to 2 mm.