The Relationship Between Primary Colorectal Cancer Tumour Characteristics and Patient Outcomes Following Surgery for Oligometastatic Pulmonary Metastases: A Single-Centre Retrospective Study

Abstract

Background: Colorectal cancer (CRC) is the third most common cancer globally. Approximately 20% present with metastatic disease, most commonly to the liver and lung. Pulmonary metastasectomy (PM) is the most considered therapeutic option for oligometastatic colorectal lung metastases, though evidence is predominantly retrospective. This study aims to understand the relationship between primary colorectal cancer tumour characteristics and survival in patients undergoing PM. Methods: This single-centre retrospective study included 372 consecutive patients undergoing PM at Manchester University Foundation Trust (2011–2021). Data was extracted from prospectively maintained clinical databases. Overall survival was calculated from the date of PM. Kaplan–Meier log-rank and Cox proportional hazards regression analyses identified prognostic factors. Results: Two-thirds of the patients included were over the age of 65 (65%), and 63% were male. The median follow-up was 48 months, with a median survival of 69 months. On univariate analysis, age ≥ 65, advanced TNM, T stage, right-sided primary tumour location, lymphovascular invasion, and KRAS mutation were associated with reduced overall survival. Upon multivariate analysis, age ≥ 65 (HR 2.60, 95% CI 1.14–5.91, p = 0.023) and lymph node yield ≥ 12 (HR 0.38, 95% CI 0.17–0.83, p = 0.016) were independently associated with survival. Conclusions: Primary tumour characteristics are important determinants of outcomes after PM. Older age, right-sided primary tumour location, inadequate lymph node yield and KRAS mutation are associated with survival, highlighting the need for refined patient selection. These findings support integrating clinical, pathological, and molecular factors to aid decision-making in patients with colorectal pulmonary metastases.