RESUMEN
AIM: The main cause of local recurrence (LR) in rectal cancer is involvement of the circumferential resection margin (CRM). However, patients with a negative CRM can also develop LR, suggesting that additional factors are important for LR. The aim of this study was to identify histopathological factors predictive for the development of LR after primary rectal cancer treatment. METHODS: T x N x M0 patients treated for locally recurrent rectal cancer at the Catharina hospital from 1994 to 2006 (n=92) were matched with a control group of patients who did not develop LR after primary rectal cancer treatment for at least 2 years (n=185) based on the type of neoadjuvant treatment in a 1:2 ratio. The pathology of all primary rectal cancers was reviewed. Patient, treatment and histopathological characteristics were studied in relation to the development of LR with logistic regression. RESULTS: Logistic regression indicated the presence of lymphovascular invasion (LVI, OR 4.66, P<0.001), extramural venous invasion (EMVI, OR 4.54, P<0.001), positive CRM (OR 2.56, P=0.032), serosal involvement (OR 6.74, P=0.035) and poor differentiation (OR 2.59, P=0.012) as factors with an increased risk to develop LR. Older age was a protective factor (OR 0.95, CI 0.93-0.98, P=0.001). CONCLUSION: Apart from a positive CRM and serosal involvement, LVI, EMVI and poor differentiation are important independent predictive factors for the development of LR. Adjuvant therapy may be considered in the presence of these features in order to decrease the risk of a local recurrence.