Prognostic value of p53 for colorectal cancer after surgical resection of pulmonary metastases

Cong Li, Qi Xu, Lei Chen, Cong Luo, Yinbo Chen, Jieer Ying

Pulmonary metastases occur in up to 25% of colorectal cancer (CRC) patients. Many studies have reported that pulmonary metastasectomy might increase 5-year survival of these patients. The aim of this study was to describe our experience with pulmonary metastasectomy for metastatic colorectal cancer and to explore the prognostic value of p53 overexpression and other factors. Between July 2002 and December 2013, the clinicopathological data of 88 patients with colorectal carcinoma who underwent pulmonary metastases resection were retrospectively reviewed and analyzed. Clinical, biochemical and imaging, and operative data, and expression of p53 were retrospectively collected. Immunohistochemical staining for p53 was performed on paraffin-embedded 5-μm sections using mouse anti-human tumor protein p53 monoclonal antibody (DO-7, Dako, Denmark). Overall survival (OS) was calculated from resection of pulmonary metastases to death. The prognostic effect of each variable on survival was evaluated using the Kaplan-Meier method and log-rank test. For the multivariate analysis of prognostic factors, the Cox regression model was used. There were 58 men and 30 women in this study, and their median age was 55 (range 31 to 85). Video-assisted thoracoscopic surgery (VATS) was performed in 59 cases (78%), and 29 patients (19%) underwent thoracotomy. Lung wedge resection and pulmonary lobectomy were performed in 52 (59.1%) and 36 (40.9%) patients, respectively. After a median follow-up duration of 44 months, the cumulative 5-year survival was 45.4%, and the median overall survival was 57.8 months. The expression of p53 significantly influenced survival. In patients with p53 protein overexpression, we observed a median OS of 46.1 months, whereas the median OS of patients with negative protein expression of p53 was 62.6 months (p = 0.047). However, in multivariate analysis, p53 overexpression was failed to be an independently significant prognostic factor for survival. Pulmonary resection of metastatic colorectal cancer might offer a chance to prolong survival including those patients with extrapulmonary metastases. p53 protein expression was identified as a prognosis-related factor for surgery.