Histopathological growth patterns of liver metastases - a retrospective, consecutive, single- center, pilot study and literature review of non-colorectal carcinoma metastasis studies

Objective Histopathological growth patterns (HGPs) in liver metastases have been identified to have prognostic value; however, they currently do not influence therapeutic decisions, and the literature mainly focuses on colorectal adenocarcinoma metastases. Hitherto, they have only been examined in a consecutive setting in 5 studies. Methods Patients between 2011 and 2016 were included with the ICD code C7870. General clinicopathological data were obtained from medical charts. Histological slides of the metastases were evaluated by two pathologists with consensus. Statistical analyses were carried out by using the Kruskal-Wallis (continuous variables) and Fisher’s exact test (categorical variables). The Kaplan-Meier method was used to estimate progression-free (PFS) and overall survival (OS), and time-to-progression (TTP) curves, and the logrank test was applied to compare survival curves. All statistical tests were two-sided and p -values less than 0.05 were considered statistically significant. Results Altogether 41 patients were included in our study. The majority were diagnosed with secondary colorectal adenocarcinoma (n = 32). Replacement pattern proved to be the most common (n = 22), followed by desmoplastic (n = 15), and pushing (n = 4). There was no significant association found between HGPs and stage (p = 0.105), secondary tumour focality (p = 0.898), largest diameter primary (p = 0.316) and secondary carcinoma (p = 0.441), completeness of resection (p = 0.492), and the presence of venous spread (p = 1). There were no significant results found between HGPs and PFS (p = 0.417), OS (p = 0.297), and TTP (p = 0.267). Conclusions Further studies regarding the prognostic utility of HGPs have to be carried out in the future. Our results reflect that HGPs may not be valuable in a consecutive setting.