Correlations Between the Histologic Growth Patterns of Peritoneal and Liver Metastases From Colorectal Cancer

BACKGROUND: Histologic growth patterns (HGPs) of both peritoneal metastasis (PM) and liver metastasis (LM) have emerged as prognostic factors for patients undergoing curative surgery for metastatic colorectal cancer (CRC). The main objectives of the study were, first, to evaluate the correlation between PMHGP and LMHGP of CRC patients who underwent curative-intent cytoreductive surgery (CRS) and LM resection and, second, to assess the prognostic impact of HGP type. METHODS: This retrospective bicentric study included patients treated with both CRS and LM resection for metastatic CRC. Histologic growth patterns were classified as pushing (P-HGP) and infiltrating (I-HGP) for PM, and as desmoplastic HGP (D-HGP) and non-desmoplastic (ND-HGP) for LM. Correlation between PMHGP and LMHGP was assessed using the chi-square test. Overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan-Meier and Cox regression. RESULTS: The study included 44 patients. Of the 44 patients, 9 (20.5%) had P-HGP + D-HGP, 23 (52.3%) had I-HGP + ND-HGP, 5 (11.4%) had P-HGP + ND-HGP, and 7 (15.9%) had I-HGP + D-HGP. Significant correlation was observed between PMHGP and LMHGP (p = 0.0085; Φ = 0.3965). The patients with I-HGP + ND-HGP had shorter OS and DFS than those with other combinations: 34 versus 64 months (HR, 2.067; p = 0.0672) for OS, and 14 versus 25 months (hazard ratio [HR], 1.775; p = 0.1071) for DFS. CONCLUSIONS: This study highlighted a significant correlation between PMHGP and LMHGP in metastatic CRC. However, survival trends were nonsignificant.