[Relationship between primary tumor lymph node indicators and prognosis and treatment response in colorectal cancer patients with lung metastases].

Objective: To analyze the relationship between primary tumor lymph node indicators and prognosis and clinical efficacy in colorectal cancer patients with lung metastases. Methods: A retrospective analysis was performed on the clinical data of 204 patients diagnosed with colorectal cancer accompanied by solitary pulmonary metastases at the Cancer Hospital, Chinese Academy of Medical Sciences between January 2010 and December 2020. The cohort comprised 121 male and 83 female, with a mean age of (58.6±9.1) years. Patient survival status was documented, and the follow-up continued until the patient's death or December 31, 2024. The influencing factors of overall survival (OS) in colorectal cancer patients with pulmonary metastases were analyzed using a multivariate Cox proportional hazards regression model. Survival curves were plotted using the Kaplan-Meier method, and the log-rank test was employed to evaluate the differences in OS among colorectal cancer patients with lung metastases who had primary colorectal tumors with different lymph node statuses. An efficacy analysis was also conducted for patients with pulmonary metastases who solely received medical treatment. Results: A total of 204 patients were followed up for 48.0(34.1, 80.4) months. One patient was lost to follow-up, and 39.7% (81/204) patients had died. The median OS was 48.0 months (95%CI: 11.5-119.3 months), with a 5-year overall survival rate of 58.5%. Multivariate analysis showed that pathological lymph node stage (pN) (+) (HR=2.14, 95%CI: 1.17-3.92), number of negative lymph node (NLN)<13 (HR=1.97, 95%CI: 1.22-3.18), carcinoembryonic antigen (CEA) during lung metastasis≥10 μg/L (HR=2.25, 95%CI: 1.28-3.98), multiple lung metastases (HR=2.16, 95%CI: 1.08-4.31), and non-surgical resection of lung metastases (HR=2.28, 95%CI: 1.11-4.65) were risk factors affecting OS in patients with colorectal cancer lung metastasis. Kaplan-Meier survival curves showed that patients with colorectal cancer lung metastases had shorter OS when primary tumor pN (+), primary tumor logarithmic odds of positive lymph node (LODDS)≥-1.1, primary tumor lymph node ratio (LNR)≥0.02, primary tumor NLN<13, or primary tumor total number of lymph node (TLN)<16(all P<0.05). Among the 204 patients, 72 with pulmonary metastases did not undergo surgical intervention and solely received medical treatment. Based on their prognosis, they were categorized into the partial response (PR) group (n=32) and the stable disease (SD)+progressive disease (PD) group (n=40). The results indicated that the PR group had significantly lower rates of pN(+), LODDS≥-1.1, LNR≥0.02, NLN<13, and TLN<16 compared to the SD+PD group (all P<0.05). Conclusions: Patients with colorectal cancer lung metastases who have primary tumors with pN(+), LODDS≥-1.1, LNR≥0.02, NLN<13, or TLN<16, tend to have shorter OS and poorer treatment outcomes. It is recommended to adopt an intensified systemic therapy strategy to improve the efficacy of medical treatment and, if possible, create conditions for surgical intervention.