Histologic features and genomic alterations of primary colorectal adenocarcinoma predict growth patterns of liver metastasis

BACKGROUND Different histological growth patterns (HGPs) of colorectal carcinoma (CRC) liver metastasis are associated with patient's prognosis and response to antiangiogenic therapy. However, the relationship between HGPs of liver metastasis and clinicopathologic_al and genomic characteristics of primary cancer has not been well established. AIM To assess whether certain clinicopathological and genomic features of primary CRC could predict the HGPs of liver metastasis. METHODS A total of 29 patients with paired resections of both primary CRC and liver metastasis were divided into two groups: A (15 cases with desmoplastic liver metastasis) and B (14 cases with replacement liver metastasis). Clinical information was obtained from patients' charts. Mismatch repair proteins, BRAFV600E, and PD-L1 were evaluated by immunohistochemistry. Five cases were selected randomly from each group for whole exome sequencing (WES) analysis. RESULTS In the primary tumor, expanding growth pattern, low tumor budding score (TBS), and Crohn's disease-like response (CDR) were associated with desmoplastic liver metastasis and better overall survival, whereas infiltrating growth pattern alone of primary carcinoma could predict the replacement liver metastasis and worse overall survival (P < 0.05). On WES analysis, primary carcinoma with desmoplastic liver metastasis showed mutations in APC (4/5); TP53 (3/5); KRAS, PIK3CA, and FAT4 (2/5); BRCA-1, BRCA2, BRAF, and DNAH5 (1/5), whereas primary carcinoma with replacement liver metastasis showed mutations in APC and TP53 (3/5); KRAS, FAT4, DNH5, SMAD, ERBB2, ERBB3, LRP1, and SDK1 (1/5). CONCLUSION The HGPs, TBS, and CDR of primary CRC as well as the presence of specific genetic mutations such as those in PIK3CA could be used to predict the HGPs of liver metastasis, response to therapy, and patients' prognosis.