Pascal Genin

Histological Detection of Minimal Metastatic Involvement in Axillary Sentinel Nodes: A Rational Basis for a Sensitive Methodology Usable in Daily Practice

There is no consensus method for the histological analysis of axillary sentinel nodes (SN). This study aimed to (1) assess the rate of occult metastases in SN using large serial sectioning and immunohistochemistry (IHC), (2) evaluate whether occult metastases were predictive of metastases in the downstream axillary nodes, and (3) specify a methodology of analysis of SN that could be both sensitive and applicable in daily practice. One hundred three patients with breast carcinoma underwent SN biopsy and then axillary dissection. SN free of tumor at standard examination of one section were sectioned at six levels (150-μm intervals) and immunostained for cytokeratin. The number and localization of labeled metastatic cells (occult metastases) were recorded. In 29 of the 103 patients (28%), SN were found to be metastatic after standard examination. The SN of the remaining 74 patients were further analyzed using IHC. Occult metastases were detected in 35 of these patients (47.3%), leading to an overall SN involvement rate of 62% (29+35/103). In 33 of these 35 cases, the plurality and the dispersion of the immunostained cells implied that the screening of only 3 of the 6 levels would have led to the detection of diagnostic positive events. Only one of the 35 patients (2.8%) with occult metastases showed metastatic lymph node in the downstream axilla. In our series of axillary SN, the analysis of one standard histologic section and, when negative, of only three additional sections after IHC revealed >60% of metastasis or occult metastasis. Metastasis detected by standard analysis had a high predictive value of downstream node metastasis, whereas the predictive value of occult metastasis revealed by IHC was poor. The clinical significance of occult metastases in SN needs to be specified by long-term follow-up analysis.

Sentinel lymph node biopsy in patients with conjunctival and eyelid cancers: experience in 17 patients.

Purpose: To assess lymph node invasion through the use of sentinel lymph node biopsy (SLNB) in conjunctival and eyelid tumor patients and ascertain the impact of this technique in therapeutic management recommended by the multidisciplinary consensus committee. Methods: A single center prospective nonrandomized clinical study was conducted between January 2008 and January 2010. Seventeen patients were included: 4 (2 conjunctiva and 2 eyelid) melanomas, 4 eyelid Merkel cell tumors, 8 (2 conjunctiva, 2 eyelid, 2 eyelid and conjunctiva, 2 cornea and conjunctiva) squamous cell tumors, and 1 eyelid meibomian carcinoma. Preoperative lymphoscintigraphy was done the day before surgery to label lymph node(s). The surgical biopsy was then performed along with an extemporaneous pathological examination followed by secondary complete lymph node dissection only in instances of positive histology. Results: In all cases, one or more sentinel lymph nodes were identified (3–13). Two biopsies (1 Merkel cell carcinoma and 1 squamous cell carcinoma) revealed neoplastic invasion and led to complete cervical node dissection. Adjunct regional treatment was indicated for 1 melanoma, for 4 Merkel cell tumors, and for 2 squamous cell carcinomas. One false negative result was noted in the group of squamous cell carcinomas after 6 months, and it was treated. No relapse or death was observed for the other 16 patients. The mean overall follow-up was 18.2 months. Conclusion: As in previous studies, we found that SLNB for eyelid and conjunctival tumors is safe and effective in identifying microscopically positive SLNs. This procedure may also revive interest in the study of cervicofacial lymphatic drainage. Our current investigation is to be expanded and extended to other medical teams.

Overexpression/Amplification of HER-2/neu is uncommon in invasive carcinoma of the uterine cervix

The aim of this study was to investigate HER-2/neu (c-erbB2) overexpression/amplification in carcinoma of the uterine cervix using immunohistochemistry and fluorescent in situ hybridization (FISH) to assess whether anti-p185c-erbB2 therapy might have potential benefits in patients with advanced invasive cervical carcinoma. The authors used a protocol for p185c-erbB2 immunohistochemistry (clone CB11) that has been previously calibrated using FISH as the gold standard, showing a 98% accuracy rate in a large series of breast carcinomas. Immunolabeling for p185c-erbB2 was present in 24 of 82 (29%) of the tumors, but only 2 tumors (2%) with a labeling of more than 60% of the cells were considered positive for overexpression. FISH analysis did not find HER-2/neu gene amplification in these cases, although five other tumors showed weak and/or focal immunolabeling. There was no correlation between the presence of immunolabeling and age, histologic type, or clinical stage. Overexpression/amplification of HER-2/neu is uncommon in invasive cervical carcinoma, suggesting that there is little indication for using anti-p185c-erbB2 therapy in the treatment of these patients.

Increased cell size and Akt activation in HER-2/neu-overexpressing invasive ductal carcinoma of the breast

Aims:  To determine whether cell size is related to HER‐2/neu status and/or to Akt activation in breast carcinomas. HER‐2/neu overexpression is observed in 20–30% of invasive breast carcinomas with poor pronostic features, but little is known about the cell phenotype associated with HER‐2/neu activation. Akt has been found to be involved in the HER‐2/neu signal transduction pathway and Akt activation has been associated with increased cell size in various models.

Optimization of routine KRAS mutation PCR-based testing procedure for rational individualized first-line-targeted therapy selection in metastatic colorectal cancer

KRAS mutation detection represents a crucial issue in metastatic colorectal cancer (mCRC). The optimization of KRAS mutation detection delay enabling rational prescription of first‐line treatment in mCRC including anti‐EGFR‐targeted therapy requires robust and rapid molecular biology techniques. Routine analysis of mutations in codons 12 and 13 on 674 paraffin‐embedded tissue specimens of mCRC has been performed for KRAS mutations detection using three molecular biology techniques, that is, high‐resolution melting (HRM), polymerase chain reaction restriction fragment length polymorphism (PCR‐RFLP), and allelic discrimination PCR (TaqMan PCR). Discordant cases were assessed with COBAS 4800 KRAS CE‐IVD assay. Among the 674 tumor specimens, 1.5% (10/674) had excessive DNA degradation and could not be analyzed. KRAS mutations were detected in 38.0% (256/674) of the analysable specimens (82.4% in codon 12 and 17.6% in codon 13). Among 613 specimens in whom all three techniques were used, 12 (2.0%) cases of discordance between the three techniques were observed. 83.3% (10/12) of the discordances were due to PCR‐RFLP as confirmed by COBAS 4800 retrospective analysis. The three techniques were statistically comparable (κ > 0.9; P < 0.001). From these results, optimization of the routine procedure consisted of proceeding to systematic KRAS detection using HRM and TaqMan and PCR‐RFLP in case of discordance and allowed significant decrease in delays. The results showed an excellent correlation between the three techniques. Using HRM and TaqMan warrants high‐quality and rapid‐routine KRAS mutation detection in paraffin‐embedded tumor specimens. The new procedure allowed a significant decrease in delays for reporting results, enabling rational prescription of first‐line‐targeted therapy in mCRC.