[HER2 epidermal growth factor receptor, tests used to look for its amplification in breast cancer: Principles and limitations]

HER2-positive breast cancer accounts for 20 % of all invasive breast cancers. It is associated with increased recurrence, a higher risk of brain metastases and a shorter overall survival than luminal A and B cancers. The presence of ERBB2 gene amplification is predictive of a good response to anti-HER2 therapies. Determining HER2 status is a hot topic, given recent studies on HER2-low subtypes. Although several techniques are available, the latest 2018 update from the American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) recommends a first immunohistochemical study followed by a fluorescence in situ hybridisation study indicated only for equivocal cases. This article summarises the different techniques used to determine HER2 status and provides a detailed review of the literature on pre-analytical factors and intrinsic tumour-specific factors that can distort or complicate the interpretation of results.

[2021 update of the GEFPICS' recommendations for HER2 status assessment in invasive breast cancer in France]

The last international guidelines on HER2 determination in breast cancer have been updated in 2018 by the American Society of Clinical Oncology and College of American Pathologists, on the basis of a twenty-year practice and results of numerous clinical trials. Moreover, the emerging HER2-low concept for 1+ and 2+ non amplified breast cancers lead to refine French practices for HER2 status assessment. The GEFPICS group, composed of expert pathologists, herein presents the latest French recommendations for HER2 status evaluation in breast cancer, taking into account the ASCO/CAP guidelines and introducing the HER2-low concept. In the era of personalized medicine, HER2 status assessment remains one of the most important biomarkers in breast cancer and its quality guaranties the optimal patients' care. French pathologists' commitment in theranostic biomarker quality is more than ever required to provide the most efficient cares in oncology.

Human papillomavirus detection using in situ hybridization and correlations with histological and cytological findings

BACKGROUND AND OBJECTIVE

The human papillomavirus (HPV) is the main causative agent of cancerous and precancerous lesions in cervical cancers. The infection detection is performed by cytological and histological examination. However, molecular testing for HPV infection remains necessary to distinguish nonspecific inflammatory lesions from HPV-related lesions. We aimed to compare cytological and histological diagnosis of HPV lesions and to confront histological findings with molecular detection of HPV by in situ hybridization (ISH).

MATERIAL AND METHODS

A total of 2399 pap smears were collected between 1997 and 2002. Twenty-nine of them presented with lesions indicative of HPV infection. Colposcopy and biopsy were performed on 23 of these 29 pap smears, with a comparison of the cytological and histological findings. Molecular testing for HPV by ISH was performed on 11 pap smears.

RESULTS

A 79% cytological and histological agreement was observed. ISH revealed the presence of the virus in seven case patients, amounting to a 63% histological and molecular agreement. Seven HPV genotypes were categorized (6-11-16-18-31-33-51).

CONCLUSION

HPV detection by ISH adds little to the diagnosis of HPV-associated lesions based on cytological and histological features. It, however, helps improve the specificity of the diagnosis and determine the viral genotype which, in turn, helps better define the lesion prognosis.