Evaluation of histopathological heterogeneity of colorectal cancer liver metastasis sites after preoperative chemotherapy

Patients with liver metastases from colorectal cancer (CRLMs) frequently receive chemotherapy prior to liver resection. Histopathological assessment of the resected specimen can evaluate the response to chemotherapy. The present study analyzed the association between histopathological changes in the primary site and liver metastases. The present study comprised 45 patients with resectable CRLMs at the Surgical Oncology Department of Gifu University School of Medicine (Gifu, Japan) between January 2006 and August 2015. The study included 24 men and 21 women. The primary colonic tumor was located in the right side in 13 (28.9%) patients and the left side in 32 (71.9%) patients. The present study evaluated patients with metastatic colorectal cancer (31/45) after excluding those in whom histopathological heterogeneity between the primary and liver metastasis changed to grade 3 after chemotherapy. The group that underwent hepatectomy after chemotherapy (n=25) was compared with the group that underwent hepatectomy alone (n=6). In 16 (53.3%) out of 25 patients, histopathological heterogeneity of the liver metastasis was lost (P=0.04). In conclusion, chemotherapy appeared to change histopathological heterogeneity. The present study suggested that the histopathological change of intratumoral heterogeneity is reflected by the response to chemotherapy.