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

BackgroundThe lungs are the second most common organ site for metastases in patients with colorectal cancer (CRC). Lymph node metastasis of CRC represents aprognostic factor for survival.ObjectiveThe present study investigated the influence of CRC lymph node metastasis on lung metastasis, in particular thoracic lymph node metastasis.Material and methodsA retrospective analysis of 88patients (n=56male) 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.ResultsIn 48patients apositive lymph node status of CRC and in 9patients 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).ConclusionScreening for pulmonary metastases should be included in the staging and follow-up of all patients with CRC, especially in patients with apositive lymph node status of the CRC.