Colorectal cancer pulmonary oligometastases: pooled analysis and construction of a clinical lung metastasectomy prognostic model

Background: Although resecting colorectal cancer (CRC) pulmonary metastasis is associated with long-term survival, identification of prognostic groups is needed for future randomized trials, and construction of a lung metastasectomy prognostic model (LMPM) is warranted. Patients and methods: We searched the PubMed database for retrospective studies evaluating prognostic factors following resecting CRC lung metastasis. Individual patient data were analyzed. Independent prognostic factors were used to construct an LMPM. Results: Between 1983 and 2008, 1112 metastasectomies were carried out on 927 patients included in eight studies. Five-year survival rate was 54.3% following the first lung resection. Multivariate analysis identified three independently poor prognostic factors: pre-thoracotomy carcinoembryonic antigen ≥5 ng/ml, disease-free interval <36 months, and more than one metastatic lesion. Patients with good-, intermediate-, and high-risk groups according to the LMPM had a 5-year survival of 68.2%, 46.4%, and 26.1%, respectively (P < 0.001). Perioperative chemotherapy and previously resected liver metastasis had no influence on survival. Conclusions: The low- and intermediate-risk groups have a good chance of long-term survival following metastasectomy. However, more studies are needed to investigate whether surgery offers any advantage over systemic therapy for the poor-risk group.