Detection of occult lymph node tumor cells in node-negative gastric cancer patients / Identificação de células tumorais ocultas em linfonodos de pacientes com câncer gástrico classificados como pn0

ABSTRACT Background: The presence of lymph nodes metastasis is one of the most important prognostic indicators in gastric cancer. The micrometastases have been studied as prognostic factor in gastric cancer, which are related to decrease overall survival and increased risk of recurrence. However, their identification is limited by conventional methodology, since they can be overlooked after routine staining. Aim: To investigate the presence of occult tumor cells using cytokeratin (CK) AE1/AE3 immunostaining in gastric cancer patients histologically lymph node negative (pN0) by H&E. Methods: Forty patients (T1-T4N0) submitted to a potentially curative gastrectomy with D2 lymphadenectomy were evaluated. The results for metastases, micrometastases and isolated tumor cells were also associated to clinicopathological characteristics and their impact on stage grouping. Tumor deposits within lymph nodes were defined according to the tumor-node-metastases guidelines (7th TNM). Results: A total of 1439 lymph nodes were obtained (~36 per patient). Tumor cells were detected by immunohistochemistry in 24 lymph nodes from 12 patients (30%). Neoplasic cells were detected as a single or cluster tumor cells. Tumor (p=0.002), venous (p=0.016), lymphatic (p=0.006) and perineural invasions (p=0.04), as well as peritumoral lymphocytic response (p=0.012) were correlated to CK-positive immunostaining tumor cells in originally negative lymph nodes by H&E. The histologic stage of two patients was upstaged from stage IB to stage IIA. Four of the 28 CK-negative patients (14.3%) and three among 12 CK-positive patients (25%) had disease recurrence (p=0.65). Conclusion: The CK-immunostaining is an effective method for detecting occult tumor cells in lymph nodes and may be recommended to precisely determine tumor stage. It may be useful as supplement to H&E routine to provide better pathological staging.

RESUMO Racional: A presença de metástase em linfonodos é um dos indicadores prognósticos mais importantes no câncer gástrico. As micrometástases têm sido estudadas como fator prognóstico no câncer gástrico, sendo relacionadas à diminuição da sobrevida global e aumento do risco de recidiva da doença. Entretanto, sua identificação é limitada pela metodologia convencional, uma vez que podem não ser identificadas pela rotina histopatológica por meio da coloração de H&E. Objetivo: Investigar a presença de células tumorais ocultas através de imunoistoquimica utilizando as citoqueratinas (CK) AE1/AE3 em pacientes com câncer gástrico com linfonodos histologicamente classificados como negativos por H&E. Métodos: Quarenta pacientes (T1-T4N0) submetidos à gastrectomia potencialmente curativa com linfadenectomia D2 foram avaliados. A presença de metástases, micrometástases e células tumorais isoladas foram correlacionadas com características clínicopatológicas e impacto no estadiamento. Os depósitos tumorais nos linfonodos foram classificados de acordo com o sistema TNM (7º TNM). Resultados: Um total de 1439 linfonodos foi obtido (~36 por paciente). Células tumorais foram detectadas por imunoistoquimica em 24 linfonodos de 12 pacientes (30%). As células neoplásicas estavam presentes na forma isolada ou em cluster. Invasão tumoral (p=0,002), venosa (p=0,016), linfática (p=0,006) e perineural (p=0,04), assim como resposta linfocítica peritumoral (p=0,012) foram correlacionadas com linfonodos CK-positivos que originalmente eram negativos à H&E. Dois pacientes tiveram o estadiamento alterado, migrando do estádio IB para IIA. Quatro dos 28 CK-negativos (14,3%) e três dos 12 CK-positivos (25%) tiveram recorrência da doença (p=0,65). Conclusão: A imunoistoquimica é meio eficaz para a detecção de células tumorais ocultas em linfonodos, podendo ser recomendada para melhor determinar o estágio do tumor. Ela pode ser útil como técnica complementar à rotina de H&E, de modo a fornecer melhor estadiamento patológico.

Isolated tumor cells and micrometastases in regional lymph nodes in stage I to II endometrial cancer / 부인종양

OBJECTIVE: The aim of this study was to clarify the clinical significance of isolated tumor cells (ITCs) or micrometastasis (MM) in regional lymph nodes in patients with International Federation of Gynecology and Obstetrics (FIGO) stage I to II endometrial cancer. METHODS: In this study, a series of 63 patients with FIGO stage I to II were included, who had at least one of the following risk factors for recurrence: G3 endometrioid/serous/clear cell adenocarcinomas, deep myometrial invasion, cervical involvement, lympho-vascular space invasion, and positive peritoneal cytology. These cases were classified as intermediate-risk endometrial cancer. Ultrastaging by multiple slicing, staining with hematoxylin and eosin and cytokeratin, and microscopic examination was performed on regional lymph nodes that had been diagnosed as negative for metastases. RESULTS: Among 61 patients in whom paraffin-embedded block was available, ITC/MM was identified in nine patients (14.8%). Deep myometrial invasion was significantly associated with ITC/MM (p=0.028). ITC/MM was an independent risk factor for extrapelvic recurrence (hazard ratio, 17.9; 95% confidence interval [CI], 1.4 to 232.2). The 8-year overall survival (OS) and recurrence-free survival (RFS) rates were more than 20% lower in the ITC/MM group than in the node-negative group (OS, 71.4% vs. 91.9%; RFS, 55.6% vs. 84.0%), which were statistically not significant (OS, p=0.074; RFS, p=0.066). Time to recurrence tended to be longer in the ITC/MM group than in the node-negative group (median, 49 months vs. 16.5 months; p=0.080). CONCLUSIONS: It remains unclear whether ITC/MM have an adverse influence on prognosis of intermediate-risk endometrial cancer. A multicenter cooperative study is needed to clarify the clinical significance of ITC/MM.

Micrometástasis: estrategias para su detección / Micrometastases: strategies for detection

La micrometástasis o enfermedad mínima residual ha adquirido una importancia trascendental en oncología al representar un verdadero problema clínico que debe ser solucionado, ya que aún se desconoce la respuesta de estos focos tumorales a los diferentes tratamientos que se usan para el control del cáncer. Aun cuando este es un problema específico fundamental a ser solucionado, ya existen métodos de ensayo inmunohistoquímicos y de biología molecular, que han permitido la ubicación de microfocos de células tumorales en diferentes órganos y tejidos, existiendo diferentes técnicas para determinar y cuantificar estas lesiones. Dentro de estas técnicas destacan la citometría de flujo y diferentes técnicas moleculares que van desde las ya tradicionales hasta las más nuevas y sofisticadas. El objetivo de la presente revisión está dirigido evaluar los nuevos métodos de diagnóstico que permitan la identificación de esta enfermedad residual, lo cual serviría para establecer tratamientos individualizados que pudieran prevenir la recurrencia de la enfermedad en los pacientes de cáncer bajo tratamiento.

Micrometastasis or minimal residual disease has become critically important in oncology since it represents a true clinical problem that must be solved, as the response of these tumor foci to the different treatments that are used for the control of cancer, is still unknown. Even though this is a fundamental specific problem to be solved, there are already immunohistochemical and molecular biology diagnostic methods that have allowed microfoci location of tumor cells in various organs and tissues, and different techniques are available to determine and quantify these lesions. Within these techniques, flow cytometry and different molecular methods are included, and they range from the traditional to the newest and most sophisticated. The goal of this review was aimed to evaluate new diagnostic methods that permit the identification of this residual disease, which would serve to establish individualized treatments and prevent the recurrence of the disease in cancer patients under treatment.