Response of liver metastases to preoperative radiochemotherapy in patients with locally advanced rectal cancer and resectable synchronous liver metastases

No standard treatment for advanced rectal cancer with synchronous resectable liver metastases (LM) has been defined. Radiochemotherapy prior to simultaneous or staged curative resection of both primary tumor and LM is one of the treatment options available. The response of LM to radiochemotherapy has never been evaluated and, in particular, the risk for progression of LM is unknown.Between 2000 and 2011, 20 patients underwent preoperative radiochemotherapy for advanced rectal cancer with synchronous limited but resectable LM. Imaging responses of LM to radiochemotherapy were analyzed on per-patient and per-lesion bases using Response Evaluation Criteria in Solid Tumors (RECIST) criteria.Of the patients, 20 had 41 LM; 15 of the 20 patients (75%) had rectal cancer with expected circumferential margins1 mm on magnetic resonance imaging (MRI), and 50% had a solitary LM before treatment. Of the patients, 13 received oxaliplatin-based chemotherapy, and 7 received fluorouracil (FU)-based chemotherapy in combination with radiation. Of the 41 LM, 7 showed complete response (17%); 7 showed partial response (17%); 20 remained stable (49%); and 7 progressed (17%). Of the 25 LM treated with oxaliplatin-based chemotherapy, only 1 LM (4%) progressed. All 20 patients were suitable for resection of LM with curative intent after the radiochemotherapy.In patients with advanced rectal cancer and synchronous limited, but resectable LM, the risk for progression of LM during radiochemotherapy is low, especially if the chemotherapy regimen contains oxaliplatin. This low risk does not compromise a curative surgical approach to LM.