# Relationship of Desmoplastic Reaction and Tumour Budding in Primary and Lung Metastatic Lesions of Colorectal Cancer and Their Prognostic Significance

## TL;DR

This study shows that certain tissue features in lung metastases of colorectal cancer are linked to worse survival, offering new clues for predicting patient outcomes.

## Contribution

The study is the first to examine desmoplastic reaction and tumour budding in lung metastases of CRC and their prognostic value.

## Key findings

- Immature desmoplastic reaction in lung metastases correlates with poor survival in CRC patients.
- Higher tumour budding in lung metastases is associated with worse overall survival.
- Tumour budding shows moderate correlation between primary CRC and lung metastases.

## Abstract

Colorectal cancer (CRC) is a significant global health burden, with substantial morbidity and mortality rates. Hence, there is a significant need for prognostic measures to enhance the care and management of patients. However, no study has examined the relationship between histological indicators, including desmoplastic reaction (DR) and tumour budding (TB), in metastatic lung lesions of CRC. Findings from this study demonstrated that higher TB and immature-type DR in metastatic lung lesions were significantly poor prognostic indicators. Accordingly, histological indicators of metastatic lung lesions in CRC may provide important prognostic information for oncologists that can help promote patient care, management, and overall survival of patients with CRC. Additional studies are required to elucidate the mechanisms underlying DR in metastatic lung lesions.

Background/Objectives: Histopathological indicators, including desmoplastic reaction (DR) and tumour budding (TB), are significant prognostic indicators for metastatic liver lesions in patients with colorectal cancer (CRC). However, the relationship of DR and TB in primary CRC and metastatic lung lesions and their prognostic significance has not yet been examined. This study aimed to elucidate the association of DR and TB in primary CRC and metastatic lung lesions. Methods: Patients with pT3 or pT4 CRC with lung metastasis who underwent surgical resection of the primary CRC and synchronous or metachronous metastatic lung lesions were enrolled. DR was classified into immature (IM) and non-IM types, and TB was classified into TB1 (<4 buds), TB2 (5–9 buds) and TB3 (≥10 buds) in both the primary CRC and metastatic lung lesions. Results: Overall, 40 patients with CRC (males, 21; females, 19; median age, 70 years; right-side colon, 6; left-side colon, 9; rectum, 25; pT3, 31; pT4, 9) were evaluated. Six and thirty-four patients were classified as having IM and non-IM DR in the metastatic lung lesions, respectively. Thirty-one, seven, and two patients were classified as having TB1, TB2, and TB3, respectively. There was no significant correlation between primary and lung metastatic lesions for DR (κ = 0.08, p = 0.086), whereas TB demonstrated a moderate correlation (κ = 0.47, p = 0.015). The presence of IM DR and TB2/3 in metastatic lung lesions significantly correlated with poor overall survival (p = 0.0020 and 0.044, respectively). Conclusions: histological indicators of metastatic lung lesions in CRC may provide important prognostic information for better patient care.