Valor prognóstico da deteção de macrometástases, micrometástases e células neoplásicas isoladas (itcs) em linfonodos regionais de cadelas com neoplasia mamária maligna
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2019-01-22
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Nas neoplasias mamárias malignas da cadela, a avaliação do envolvimento dos linfonodos regionais fornece informação prognóstica relevante. Contudo, o significado clínico da presença de células tumorais isoladas (ITCs) e de micrometástases não está completamente esclarecido, constituindo objetivo deste trabalho avaliar o seu valor prognóstico. Foram selecionadas 75 neoplasias mamárias malignas, acompanhadas de um ou vários linfonodos regionais. Estes foram avaliados a nível histológico com coloração HE e imuno-histoquímica (panqueratina), categorizando-se as metástases em: macrometástases (> 2 mm), micrometástases (0,2-2 mm) e ITCs (< 0,2 mm). Neste estudo, 49 (65,3%) cadelas apresentaram metastização dos linfonodos regionais: 49% (n = 24) evidenciaram macrometástases, 28,6% (n = 14) apresentaram micrometástases e 22,4% (n = 11) apresentaram ITCs. A dimensão dos focos metastásicos dos linfonodos regionais esteve significativamente associada ao tipo histológico (P = 0,030), grau histológico (P = 0,001) e invasão linfovascular (P < 0,0001). A análise da sobrevivência total (ST) revelou que a presença de metástases ganglionares esteve significativamente associada a um pior prognóstico (média 18,7 vs. 11,6 meses, P = 0,013), não se tendo verificado diferenças significativas no estudo da sobrevivência livre de doença (SLD). Após categorização das metástases ganglionares verificaram-se diferenças estatisticamente significativas entre os diferentes grupos tanto na ST como na SLD (P < 0,0001), apresentando as cadelas com macrometástases taxas de sobrevivência inferiores; as cadelas sem metástases ou com micrometástases/ITCs apresentaram taxas de sobrevivência semelhantes, não havendo diferenças estatisticamente significativas entre os dois grupos. Neste estudo, a presença de metástases de diâmetro inferior a 2 mm nos linfonodos regionais de cadelas com neoplasias mamárias malignas não demonstrou estar associada a pior prognóstico; no entanto, consideramos fundamentais estudos adicionais, com um maior número de animais, que comprovem estes resultados.
In canine malignant mammary tumours, the evaluation of regional lymph node involvement provides relevant prognostic information. However, the clinical significance of isolated tumour cells (ITCs) and micrometastases is not completely clarified. In the present study, 75 canine malignant mammary tumours with regional lymph nodes were selected. Lymph nodes were histologically evaluated by routine histopathology and immunohistochemistry (pankeratin). Metastases were categorized in: macrometastases (> 2 mm), micrometastases (0.2-2 mm) and ITCs (< 0.2 mm). In this study, 49 (65.3%) female dogs exhibited lymph node metastasis: 49% (n = 24) showed macrometastases, 28.6% (n = 14) presented micrometastases and 22.4% (n = 11) presented ITCs. The size of lymph node metastasis was significant associated with histological tumor type (P = 0.030), histological grade (P = 0.001) and lymphovascular invasion (< 0.0001). Overall survival (OS) analysis revealed that the presence of lymph node metastases was significantly associated with poor prognosis (mean 18.7 vs. 11.6 months, P = 0.013); no significant differences were observed for disease free survival (DFS). With lymph node metastasis categorization, statistical significant differences were observed between different groups both in OS and DFS (P < 0,0001), with female dogs with macrometastases showing lower survival rates; female dogs with no metastases or with micrometastases/ITCs presented similar mean survival rates, with no statistical differences between both groups. In this study, the presence of lymph node metastases smaller than 2 mm in female dogs with malignant mammary tumours was not associated with a worse prognosis; additional studies, with a larger case series, are necessary to confirm these findings.
In canine malignant mammary tumours, the evaluation of regional lymph node involvement provides relevant prognostic information. However, the clinical significance of isolated tumour cells (ITCs) and micrometastases is not completely clarified. In the present study, 75 canine malignant mammary tumours with regional lymph nodes were selected. Lymph nodes were histologically evaluated by routine histopathology and immunohistochemistry (pankeratin). Metastases were categorized in: macrometastases (> 2 mm), micrometastases (0.2-2 mm) and ITCs (< 0.2 mm). In this study, 49 (65.3%) female dogs exhibited lymph node metastasis: 49% (n = 24) showed macrometastases, 28.6% (n = 14) presented micrometastases and 22.4% (n = 11) presented ITCs. The size of lymph node metastasis was significant associated with histological tumor type (P = 0.030), histological grade (P = 0.001) and lymphovascular invasion (< 0.0001). Overall survival (OS) analysis revealed that the presence of lymph node metastases was significantly associated with poor prognosis (mean 18.7 vs. 11.6 months, P = 0.013); no significant differences were observed for disease free survival (DFS). With lymph node metastasis categorization, statistical significant differences were observed between different groups both in OS and DFS (P < 0,0001), with female dogs with macrometastases showing lower survival rates; female dogs with no metastases or with micrometastases/ITCs presented similar mean survival rates, with no statistical differences between both groups. In this study, the presence of lymph node metastases smaller than 2 mm in female dogs with malignant mammary tumours was not associated with a worse prognosis; additional studies, with a larger case series, are necessary to confirm these findings.
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Dissertação de Mestrado em Medicina Veterinária apresentada à Universidade de Trás-os-Montes e Alto Douro
Palavras-chave
cadela , neoplasia mamária , linfonodo , metástase , prognóstico