# Examination of histopathological growth patterns of liver metastases in a retrospective, consecutive, single-center, cohort study

## TL;DR

This study examines how different growth patterns of liver metastases relate to clinical factors in a large patient cohort.

## Contribution

The study provides new insights into the association between histopathological growth patterns and clinicopathological factors in liver metastases.

## Key findings

- Replacement pattern was the most common histopathological growth pattern observed in liver metastases.
- Histopathological growth patterns were significantly associated with tumor subtype, grade, venous spread, and metastasis size.
- Neuroendocrine tumors predominantly showed pushing growth patterns, while non-epithelial tumors often showed replacement patterns.

## Abstract

Histopathological growth patterns (HGPs) were identified as prognostic factors for colorectal adenocarcinomas; however, they have been examined in a consecutive setting with controversial results. Our study aimed to examine HGPs’ association with clinicopathological factors in a retrospective, consecutive, single-center, cohort study.

Our study comprised the data of patients who were treated for liver metastases from 2011 to 2023. In all cases, general clinicopathological data were registered. The histological slides of all metastatic foci were individually evaluated. Statistical analyses were carried out by using the Kruskal-Wallis and Fisher’s exact test. P-values less than 0.05 were considered significant.

Altogether 336 liver metastases from 205 patients have been included in our retrospective, consecutive, single-center, cohort study. The male-to-female ratio was 116:89, and the average age of patients was 68 years (median: 69.5; range: 27-93). Most examined cases were of colorectal origin (n = 164). Replacement pattern was found to be the most common (n = 99). The 163 colorectal adenocarcinoma metastasis cases reflected a similar order of magnitude of replacement type (n = 78) and desmoplastic (n = 68) HGPs. The majority (70%) of neuroendocrine tumours (n = 10) showed pushing HGP, while 3 of 5 non-epithelial tumours were associated with replacement-type HGP. A significant association was found between HGPs and histological subtype (p < 0.001), grade (p = 0.002), the presence of venous spread (p = 0.02), and the largest diameter of liver metastasis (p = 0.023).

Even though our study highlights the HGPs’ association with several clinicopathological parameters that might influence prognosis, their role in the treatment process of colorectal or other carcinomas remains controversial.