Abstract: |
Background: Pathologic response to preoperative chemotherapy for colorectal liver metastases (CLM) is associated with survival after hepatectomy. Histologically, dominant response patterns include fibrosis, necrosis and/ or acellular mucin, but some of these changes can appear without previous chemotherapy and their individual correlation with outcome is unknown. Methods: Pathology slides from patients who underwent CLM resection (irrespective of preoperative chemotherapy status) were rereviewed by a blinded pathologist. Pathologic response was recorded as the summation of percentage necrosis, fibrosis and acellular mucin. Associations between pathologic response, its components, preoperative chemotherapy, and survival were analyzed. Results: Pathology slides were rereviewed in 366 patients undergoing CLM resection from 2003 to 2007. Preoperative chemotherapy was administered in 249 (68 %) patients, who, when compared to no preoperative chemotherapy patients, had higher rates of overall pathologic response (57 vs. 46 %, P <.01), fibrosis (21 vs. 12 %, P <.01) and acellular mucin (6 vs. 3 %, P =.05) but similar rates of necrosis (30 vs. 31 %, P =.30). In patients receiving preoperative chemotherapy, overall pathologic response ≥75 % (5 year, 83 vs. 47 %, P<.01) and fibrosis ≥40 % (5 year, 87 vs. 51 %, P<.01) independently correlated with disease-specific survival after hepatectomy. Preoperative hepatic artery infusion chemotherapy (P =.04) and bevacizumab (P =.05) were marginally associated with overall pathologic response and fibrosis, respectively. Conclusions: Fibrosis is the predominant chemotherapyrelated pathologic alteration driving the association of treatment response with survival after CLM resection. Necrosis in CLM is not related to chemotherapy or outcome. © Society of Surgical Oncology 2012. |