Objective: We aimed to identify prognostic factors after pulmonary metastasectomy for colorectal cancer and propose the clinical application of them. Furthermore, we endeavored to provide a rationale for pulmonary metastasesectomy.
Background: Several prognostic factors have been proposed, but clinical application of them remains unclear. Moreover, there is no theoretical evidence that pulmonary metastasectomy is indicated for colorectal cancer.
Methods: We retrospectively analyzed 1030 patients who underwent pulmonary metastasectomy for colorectal cancer from 1990 to 2008. Prognostic factors were identified and the relationship of recurrent sites after pulmonary resection to pulmonary tumor size was assessed.
Results: Overall 5-year survival was 53.5%. Median survival time was 69.5 months. Univariate analysis showed tumor number (P < 0.0001), tumor size (P < 0.0001), prethoracotomy serum carcinoembryonic antigen (CEA) level (P < 0.0001), lymph node involvement (P < 0.0001), and completeness of resection (P < 0.0001) to significantly influence survival. In multivariate analysis, all remained independent predictors of outcome. In patients whose recurrent sites extended downstream from the lung via hematogenous colorectal cancer spread, pulmonary tumor size was significantly larger than in those with recurrent sites confined to the lung and regions upstream from the lung.
Conclusions: We should utilize these prognostic factors to detect patients who might benefit from surgery. Therefore, we should periodically follow up advanced colorectal cancer patients by chest computed tomography to detect small pulmonary metastases before serum CEA elevation. Metastases to the lung or organs upstream from the lung are regarded as semi-local for colorectal cancer. This concept provides a rationale for validating surgical indications for pulmonary metastases from colorectal cancer.
We retrospectively analyzed 1030 patients who underwent pulmonary metastasectomy for colorectal cancer. Tumor number, tumor size, prethoracotomy serum carcinoembryonic antigen level, lymph node involvement, and completeness of pulmonary resection significantly influenced survival. We also found a statistically significant correlation between recurrent sites after pulmonary resection and maximum pulmonary tumor size.
*Department of Thoracic Surgery, Kimitsu Central Hospital, Chiba, Japan
†Division of General Thoracic Surgery, Department of Surgery, School of Medicine, Keio University, Tokyo, Japan
‡Department of Thoracic Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
§Department of Thoracic Surgical Oncology, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
‖Department of Thoracic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
¶Division of Thoracic Surgery, Tochigi Cancer Center, Tochigi, Japan
**Department of Thoracic Surgery, Tokyo Medical University, Tokyo, Japan
††Department of General Thoracic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan
‡‡Department of Thoracic Surgery, National Defense Medical College, Saitama, Japan
§§Department of Chest Surgery, Toho University Medical Center Omori Hospital, Tokyo, Japan
‖‖Department of Surgery II, Kyorin University School of Medicine, Tokyo, Japan
¶¶Division of General Thoracic Surgery, Teikyo University School of Medicine, Tokyo, Japan
***Faculty of Engineering, Tokyo University of Science, Tokyo, Japan.
Reprints: Tomohiko Iida, MD, Department of Thoracic Surgery, Kimitsu Central Hospital, 1010 Sakurai, Kisarazu, Chiba 292–8535, Japan. E-mail: email@example.com.
Disclosure: The authors declare no conflicts of interest.