Management Of Stage Iv Rectal Cancers With Oligometastatic Disease At Presentation: A Single Institutional Experience

Colorectal cancer is one of the most common types of cancer and about 20-25% of patients will demonstrate metastatic disease at presentation. The liver is the most common location of metastatic disease followed by the lung. Various management strategies have been devised that combine systemic treatment with radiation and surgery for this group of patients. Due to the natural history of the disease, varying 5-year survival outcomes ranging from 15 to 40% have been reported for patients with oligo-metastatic disease who receive aggressive treatment. At our center, we typically offer patients with oligo-metastatic potentially resectable disease, and good performance status (ECOG 0-2), neo-adjuvant chemo-radiation (NACRT) followed by resection of the primary and metastatic disease and subsequent systemic chemotherapy. The aim of this retrospective study is to identify the benefit of this approach when compared to currently available evidence. 37 consecutive stage IV rectal cancer patients with potentially resectable oligometastatic disease at presentation, treated at our center between 2010 and 2016 were included in this study. All patients received NACRT followed by resection of primary tumor +/- metastectomy and systemic chemotherapy. Follow-up outcomes were analyzed for survival and local recurrence events. 16 patients with hepatic mets, 7 with pulmonary mets, 6 with hepatic and pulmonary mets, 6 with non-regional nodal mets and 3 with bone mets received NACRT followed by surgery and systemic chemotherapy. At a median follow-up of 6 years, 53% (8) of patients with hepatic mets alone were alive, with a mean survival of 62.9 months; median survival not yet reached. 42.9% (3) of patients with pulmonary and 33.3% (2) of patients with both hepatic and pulmonary mets were alive with a median survival of 50 and 36 months respectively. Patients with non-regional nodal mets and bone mets fared the worst with a median survival of 22 and 7 months respectively. There was only 1 (2%) local recurrence in the whole cohort. 5 patients (13.5%) from the cohort were free of any disease at 5 years of follow-up with 4 of them being patients with liver only mets (25%). NACRT followed by staged or concurrent surgery for primary and metastases is a reasonable management option for patients with oligometastatic rectal cancer at presentation and good performance status. Patients with liver only metastases at presentation fares significantly better with this strategy than currently reported management protocols.