[Influence of primary lymph node status of colorectal cancer on the development of pulmonary metastases and thoracic lymph node metastases].

Background: The lungs are the second most common organ site for metastases in patients with colorectal cancer (CRC). Lymph node metastasis of CRC represents a prognostic factor for survival.
Objective: The present study investigated the influence of CRC lymph node metastasis on lung metastasis, in particular thoracic lymph node metastasis.
Material and Methods: A retrospective analysis of 88 patients (n = 56 male) with curative resection of lung metastases of CRC was performed. Primary endpoint: influence of lymph node status of CRC on lung metastases. Secondary endpoints: disease-free survival and overall survival. Statistical evaluation was carried out with SPSS.
Results: In 48 patients a positive lymph node status of CRC and in 9 patients an N+ status of lung metastases were determined. The lymph node status of the CRC significantly affected the incidence of synchronous metastases (p = 0.03), disease-free interval until formation of metachronous lung metastases (p = 0.012) and the overall survival of patients with CRC (p = 0.048). The 5‑year survival rate for CRC patients with lung metastases was 48.7% after pulmonary metastasectomy. Thoracic lymph node involvement also significantly affected survival (p = 0.001).
Conclusion: Screening for pulmonary metastases should be included in the staging and follow-up of all patients with CRC, especially in patients with a positive lymph node status of the CRC.