Adenoid cystic carcinoma and basaloid carcinoma of the breast: A clinicopathological study.

Adenoid cystic carcinoma of the breast (ACCB) is a rare triple negative tumor (TNT) with an excellent prognosis in most cases. Three different histologic types are recognized: classic ACCB, solid basaloid ACCB (SB-ACCB), and ACCB with high-grade transformation. A majority of these tumors show characteristic molecular and immunohistochemical (IHC) features, with fusion of MYB and NFIB genes and overexpression of MYB, respectively. Basaloid carcinomas of the breast (BCB) are infrequently described. They resemble SB-ACCB and TNT of no special type (TNT-NST). We have studied the clinicopathological features of 17 ACCB and 9 BCB, investigating the expression of MYB by IHC and the rearrangements of MYB by fluorescence in situ hybridization (FISH). MYB was expressed by IHC in 15 ACCB and in 3 BCB. MYB FISH detected rearrangements in 11 ACCB and in 2 BCB. After a mean follow-up of 90 months, with a range of 12-204 months, 2 patients with ACCB with high-grade transformation and 1 patient with BCB developed metastases and died of disease. In summary, most ACCB have a good prognosis, but tumors with adverse histopathological features may metastasize. BCB may overlap with ACCB and TNT-NST, and their prognosis should be further studied.

Estudio comparativo entre el método One step nucleic acid amplification y el método convencional en la estadificación en cáncer de mama: un aumento en la detección de micrometástasis / Comparative study of the One step nucleic acid amplification method and the conventional method in axillary staging in breast cancer: an increase in the detection of micrometastases

Objetivos. El método One step nucleic acid amplification (OSNA) se ha incorporado para el estudio del ganglio centinela (GC) en cáncer de mama como alternativa al estudio convencional histológico (MC). El propósito de nuestro estudio fue comparar la estadificación por ganglio centinela (EGC) obtenida por el método OSNA con la obtenida mediante MC. Material y métodos. Se seleccionaron pacientes con cáncer de mama y EGC recogidas durante los años 2009-2010 y 2012-2013, estudiadas con MC y método OSNA. Se analizaron diferentes parámetros clínico-patológicos. Resultados. Se incluyó a 1.124 pacientes, 590 estudiadas por MC y 534 por método OSNA. La EGC inicial fue: pN0: MC 349 (59,2%) y OSNA 335 (62,7%); pN0(i+): MC 74 (12,5%) y OSNA 14 (2,6%); pN1mi: MC 59 (10%) y OSNA 77 (14,4%); pN1: MC 108 (18,3%) y OSNA 108 (20,3%). Se encontraron diferencias estadísticamente significativas entre la EGC por método OSNA y MC (p<0,001), a expensas de las tasas de pN1mi y pN0(i+). Se seleccionó a 224 pacientes con EGC pN1mi y pN0(i+) para determinar si las diferencias encontradas podrían atribuirse a distintas características clínico-patológicas. El método OSNA detecta el doble de micrometástasis (84,6%). Conclusiones. En nuestra casuística, por el método OSNA se observa un incremento significativo de pN1mi (84,6% vs. 44,4%) y una disminución de pN0(i+) respecto al estudio convencional, diferencias que no están condicionadas por los parámetros clínico-patológicos. El 75% de casos con pN1mi por OSNA muestra un número de copias inferior a 1.000 (AU)

Objetives. The One Step Nucleic Acid Amplification (OSNA) method has been incorporated in the study of the sentinel lymph node (SLN) in breast cancer as an alternative to conventional histological study. The aim of our study was to compare sentinel lymph node staging (SLNS) obtained by the OSNA method with that obtained by the conventional method (CM). Material and methods. We identified patients with breast cancer and SLN study during the periods 2009-2010 and 2012-2013, who underwent the CM and by OSNA. We analysed different clinicopathological parameters. Results. A total of 1124 patients were studied, 590 by CM and 534 by OSNA. SLNS was: pN0: CM 349 (59.2%) and OSNA 335 (62.7%); pN0(i+): CM 74 (12.5%) and OSNA 14 (2.6%); pN1mi: CM 59 (10%) and OSNA 77 (14.4%); pN1: CM 108 (18.3%) and OSNA 108 (20.3%). Statistically significant differences were found between the SLNS by OSNA and CM (p <0.001), due to the rates of pN1mi and pN0(i+). To determine whether this statistical significance could be attributed to different clinicopathological features, 224 patients were selected from the initial series with SLN pN1mi and pN0(i+). In this subgroup, the OSNA method detected twice as many micrometastases (pN1mi) (84.6%). Conclusions. In our series, the OSNA method resulted in a significant increase in pN1mi (84.6% vs 44.4%) and a decrease in pN0(i+) compared with the conventional method. Those differences were not affected by clinicopathological parameters. Most cases (75%) with pN1mi by OSNA showed less than 1000 copies (AU)