Surgical treatment of malignant colon polyps / Tratamento cirúrgico do pólipo maligno do cólon

ABSTRACT Background: In the therapeutic decision about the malignant colon polyp, several factors predicting residual disease after the endoscopic resection guide the decision of surveillance or surgical intervention. This is a challenging decision, because even in the presence of high-risk predictors currently used, only 15-30% of the patients will have residual disease in the surgical specimen. Objective: To evaluate patients with a diagnosis of malignant colon polyp at the Hospital Center of São João, who were indicated for surgical treatment, studying the predictors of residual disease in the surgical specimen. Methods: A retrospective study was carried out, based on the patients with malignant colon polyp diagnosed and treated at the Hospital Center of São João in the city of Porto, Portugal, between 2009 and 2016. The endoscopic, anatomopathological, surgical and follow-up data were reviewed. Results: Of the total number of patients in the study (n = 96), 59 (61.5%) were indicated for surgery after a multidisciplinary discussion. Of this group, 21 patients (35.6%) had residual disease in the surgical specimen, with presence of lymph node invasion in 8 patients (13.6%). The presence of malignancy in the surgical resection specimen was statistically significantly associated with: size of the resected polyp (p = 0.023); sessile polyp (p = 0.007); piecemeal resection (p = 0.002). Conclusions: The persistence of malignancy in the surgical specimen was associated with larger sessile polyps and piecemeal removal. A significant number of patients did not show malignancy in the surgical resection specimen, with more markers being required to better stratify patients.

RESUMO Contexto: Na decisão terapêutica do pólipo maligno do cólon diversos fatores preditores de doença residual após a recessão endoscópica norteiam a decisão de vigilância ou intervenção cirúrgica. Esta é uma decisão desafiadora, uma vez que mesmo na presença dos preditores de alto risco usados atualmente, apenas 15% a 30% dos doentes terão doença residual na peça cirúrgica. Objetivo: Avaliar os doentes com diagnóstico de pólipo maligno do cólon no Centro Hospitalar de São João que foram orientados para tratamento cirúrgico, estudando os preditores de doença residual na peça cirúrgica. Métodos: Foi realizado um estudo retrospetivo, tendo por base os doentes com pólipo maligno do cólon diagnosticado e tratado no Centro Hospitalar de São João no Porto, Portugal, entre 2009 e 2016. Os dados endoscópicos, anatomopatológicos, cirúrgicos e o seguimento foram revistos. Resultados: Do total de doentes em estudo (n = 96); 59 (61,5%) tiveram indicação para cirurgia após discussão multidisciplinar. Deste grupo, 21 doentes (35,6%) apresentavam doença residual na peça cirúrgica, com presença de invasão ganglionar em 8 doentes (13,6%). A presença de malignidade na peça de ressecção cirúrgica associava-se de forma estatisticamente significativa a: tamanho do pólipo ressecado (p = 0,023); pólipo séssil (p = 0,007); ressecção em piecemeal (p = 0,002). Conclusões: A persistência de malignidade na peça cirúrgica associou-se a pólipos sésseis, de maiores dimensões e à remoção em piecemeal. Um número importante de doentes não apresentava malignidade na peça de ressecção cirúrgica, sendo necessários mais marcadores para melhor estratificar os doentes.

Pólipos colorrectales no hereditarios / Non hereditary colorectal polyps

Antecedentes: La mayoría de los pólipos colorrectales son pequeños, no neoplásicos, asintomáticos y hallados durante la pesquisa o en forma incidental. Algunos de mayor tamaño pueden causar sangrado u obstrucción, aunque su verdadera importancia radica en que los adenomatosos preceden en más del 90 por ciento, al cáncer colorrectal (CCR), siguiendo en la mayoría de los casos una secuencia adenoma-carcinoma de lenta progresión que involucra múltiples alteraciones en genes supresores y oncogenes. En los últimos años una creciente evidencia demuestra otra vía de carcinogénesis a partir de los pólipos aserrados. Estos son precursores de cánceres colorrectales con inestabilidad microsatélite alta y extensa metilación del ADN, alteraciones genéticas diferentes a las de la vía tradicional que presenta inestabilidad cromosómica. El prolongado lapso de la clásica secuencia adenoma-carcinoma permite la realización de pruebas para la pesquisa de los pólipos adenomatosos y, ante su hallazgo el tratamiento endoscópico, como una forma efectiva de prevenir el CCR. Alrededor del 5 por ciento de los pólipos extirpados endoscópicamente presentan un adenocarcinoma invasor de la submucosa. La pesquisa ha llevado a encontrar más frecuentemente estos pólipos malignos que son por definición carcinomas tempranos T1. La polipectomía endoscópica se considera segura si es completa y el pólipo no tiene factores histológicos de riesgo para presentar metástasis linfáticas y recurrencia local. Sin embargo, hay cierta controversia en la literatura sobre cuáles son estos factores que permiten definir a los pólipos de alto riesgo para un resultado desfavorable con la polipectomía sola y que requieren una resección quirúrgica oncológica. Varios adelantos tecnológicos, algunos surgidos muy recientemente, pueden ayudar en la decisión terapéutica diferenciando las lesiones benignas de las malignas...

Background: Most colorectal polyps are small, non neoplastic, asymptomatic, and are found during screening or incidentally. Some larger polyps may cause bleeding or obstruction, however, their real importance is based on the fact that colorectal cancer (CRC) is preceded in more than 90 per cent by adenomatous polyps, in most cases through a slow progression of the adenoma-carcinoma sequence, involving multiple alterations in suppressor genes and oncogenes. In latest years, accumulative evidence shows that there is another pathway to carcinogenesis, arising in serrated polyps. These polyps are the precursors of CRCs with high microsatellite instability, and extensive DNA metylation, genetic alterations different from those seen in the traditional pathway, which presents chromosomal instability. The long period of time of the classical adenoma-carcinoma sequence allows performance of screcning tests for adenomatous polyps, and their endoscopic treatment when found, as an elective way to CRC prevention. Nearly 5 per cent of polyps removed endoscopically have an adenocarcinoma invading into the submucosa. The screening has lead to find these malignant polyps, early carcinomas T1 by definition, more frequently. Endoscopic polypectomy is considered safe if complete, and the polyp lack histological risk factors for lymphatic metastases and local recurrence. However, there is some controversy in the literature regarding which are these factors that define the high risk polyps for an unfavorable outcome with polypectomy only, and require an oncologic resection. Several technological advances, some very recently aroused, can assist in the therapeutic decision, by differentiating benign from malignant lesions. Others, like transanal endoscopic microsurgery, or laparoscopic technique, have contributed with the advantages of minimally invasive surgery...