RESUMO
In breast cancer, the number of lymph node metastases is the strongest predictor of outcome. However, histopathology may underestimate the frequency of metastasis. Here we compare automated molecular detection of cytokeratin 19 mRNA by one-step nucleic acid amplification (OSNA) with histopathology of single tissue sections for the staging of axillary lymph nodes in patients with breast cancer. Axillary lymph nodes were collected from 55 patients with primary breast cancer and sentinel lymph node (SLN) metastases. The central 1-mm portion of each node was processed for hematoxylin-eosin staining, and the remaining tissue was analyzed by OSNA. According to OSNA, histopathology misclassified 41.8% of patients as negative for axillary node metastasis (P=0.007). Of the individual nodes considered negative by histopathology, 4.5% contained micrometastases and 2.5% contained macrometastases according to OSNA. Furthermore, 80% of micrometastases identified by histopathology were reclassified as macrometastases by OSNA. Histopathology failed to identify 81.1% of nodes shown to contain metastasis by OSNA. However, OSNA yielded no false-negative results. On the basis of OSNA results, 3 patients were reclassified to a higher pathologic stage. The number of SLN and non-SLN metastases was unrelated according to OSNA (P=0.891). These results show that, compared with molecular detection, histopathology of single tissue sections significantly underestimates the frequency of axillary node metastases. We discuss the implications of these findings in light of current recommendations on the staging of breast cancer.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/secundário , Queratina-19/genética , Linfonodos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Carcinoma Ductal de Mama/metabolismo , Feminino , Humanos , Queratina-19/metabolismo , Metástase Linfática , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Estadiamento de Neoplasias , Técnicas de Amplificação de Ácido Nucleico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica , Adulto JovemRESUMO
OBJECTIVES: The endorectal MR spectroscopic imaging (MRS) is a new imaging technique that allows a more accurate and reliable evaluation for the localization and staging of prostate cancer(PCa) than the sole morphological study offered by endorectal MR alone. The combination of endorectal MRI and MRS allows a simultaneous morphologic and metabolic study that improves the detection of PCa. Moreover, the technical improvements recently introduced in the spectroscopic study of the prostate have led to an increase of reliability in the detection of PCa. METHODS AND RESULTS: We present in this article the advantages this technique offers in the detection of PCa in patients at high risk, as well as in patients with progressive PSA rising and previous negative biopsies. It also seems to be useful in the study of biochemical recurrences of PSA in previously treated patients, and for the study of the central gland. We comment, as well, the chance to use this tool in the staging of PCa. Our group is actually working with MRS in the detection of PCa, in collaboration with AATRM (Agency of Evaluation of medical technology for medical research) and we present some recent results in the use of this technique. CONCLUSIONS: MRS is a non-invasive method that allows the detection of PCa in the peripheral gland with a greater reliability than endorectal MRI alone, in selectyed patients. It is also a good technique for the study of the central gland, in which the detection of PCa is difficult by morphological methods. So, RMS allows the evaluation of metabolic disorders in the whole prostatic gland and improves the overall accuracy in the detection of PCa, either in the central or peripheral gland.
