Circumferential Margin Involvement Is the Crucial Prognostic Factor after Multimodality Treatment in Patients with Locally Advanced Rectal Carcinoma

Abstract

Purpose: After preoperative (radio)chemotherapy, histologic determinants for prognostification have changed. It is unclear which variables, including assessment of tumor regression, are the best indicators for local recurrence and survival. Experimental Design: A series of 201 patients with locally advanced rectal cancer (cT3/T4, M0) presenting with an involved or at least threatened circumferential margin (CRM) on preoperative imaging (<2 mm) were evaluated using standard histopathologic variables and four different histologic regression systems. All patients received neoadjuvant radiochemotherapy or radiotherapy. The prognostic value of all factors was tested with univariate survival analysis of time to local recurrence and overall survival. Results: Local recurrence occurred in only 8% of the patients with a free CRM compared with 43% in case of CRM involvement (P < 0.0001). None of the four regression systems were associated with prognosis, not even when corrected for CRM status. However, we did observe a higher degree of tumor regression after radiochemotherapy compared with radiotherapy (P < 0.001). Absence of tumor regression was associated with increasing invasion depth and a positive CRM (P = 0.02 and 0.03, respectively). Conclusions: Assessment of CRM involvement is the most important pathologic variable after radiochemotherapy. Although tumor regression increases the chance on a free CRM, in cases with positive resection margins prognosis is poor irrespective of the degree of therapyinduced regression.

Local recurrence in rectal cancer can be predicted by histopathological factors

“…16 Those who received 50.4 Gy as neoadjuvant treatment were used from a population of patients with locally advanced rectal cancer (LARC) referred to and treated at the Catharina hospital since 1994. 17 From both populations, consecutive patients were included M A N U S C R I P T…”

¿se Justifica El Tratamiento De La Recidiva Local Del Cáncer De Recto?

“…Los más significativos son el compromiso del margen radial o circunferencial (CRM) descrito por Quirke 15 , la invasión linfovascular, el factor T, la invasión venosa extramural y un pobre grado de diferenciación tumoral 16 . Un CRM positivo se define como la extensión tumoral y linfonodos positivos dentro de 1 mm del CRM, que muestra una RL de 37% vs 8% con un CRM negativo 17 . La QRT preoperatoria podría reducir el riesgo de CRM positivo y la RQT adyuvante potencialmente reduce la RL luego de una CRM positivo.…”

“…Lograr una resección R0 es el factor pronóstico más importante, independiente incluso del tipo de RL y se logra en alrededor del 50% de los pacientes intervenidos, es decir, alrededor del 20% del global de pacientes con diagnóstico de una RL 4,5,12,17,[20][21][22][23][24][25][26] . Se considera una contraindicación formal de cirugía de salvataje los pacientes con pelvis congelada con compromiso de la pared lateral, de la escotadura ciática, de los vasos ilíacos con edema de la extremidad, la invasión de S1-S2 y la presencia de enfermedad diseminada 27 .…”

Can Induction Chemotherapy before Concurrent Chemoradiation Impact Circumferential Resection Margin Positivity and Survival in Low Rectal Cancers?

“…It remains unclear if preoperative chemoradiation alters CRM status (Gosens et al, 2007;Smith et al, 2010;Rullier et al, 2013). Preoperative chemoradiation reduces locoregional recurrence but does not alter systemic relapse which is the most common mode of failure in these patients (Gao et al, 2014).…”