Yun Jung-A, Huh Jung Wook, Park Yoon Ah, Cho Yong Beom, Yun Seong Hyeon, Kim Hee Cheol, Lee Woo Yong, Chun Ho-Kyung
1Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea 2Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
Dis Colon Rectum. 2014 Sep;57(9):1049-58. doi: 10.1097/DCR.0000000000000193.
The prognostic role of surgical resection of primary tumors is not well established in patients with asymptomatic unresectable stage IV colorectal cancer.
The aims of this study were to reveal the prognostic role of surgical resection of primary tumors and to define prognostic factors affecting long-term oncological outcomes in patients with asymptomatic unresectable synchronous metastases.
This study was a retrospective analysis of prospectively collected data.
Between 2000 and 2008, a total of 416 patients with asymptomatic unresectable stage IV colorectal cancer were analyzed with propensity score matching.
Prematching baseline characteristics were compared by bivariate analysis, and 113 pairs were selected after 1:1 matching with propensity scores estimated from logistic regression. The primary end point was overall survival.
Among 416 patients, 218 (52.4%) underwent palliative resection of the primary tumor. Before propensity score matching, palliative resection resulted in a better survival rate than nonresection in univariate analysis (p < 0.001), but not in multivariate analysis (p = 0.08). After matching, the 5-year overall survival rate was significantly lower for patients with peritoneal metastasis and clinical M1b stage tumors in univariate analysis (p = 0.004 and p = 0.02). However, neither peritoneal metastasis nor clinical M1b stage showed any prognostic significance in multivariate analysis. The overall 5-year survival rate of the postmatching group was 4.9% and 3.5% in the palliative resection and nonresection groups. Consequently, palliative resection was not associated with a significant increase in survival compared with nonresection (p = 0.27). A subgroup analysis performed according to the site of metastasis also did not show any significant survival benefit of palliative resection after matching.
Selection bias and potential confounders were limitations of this study.
Resection of the primary tumor in patients with asymptomatic unresectable stage IV colorectal cancer was not associated with an improvement in overall survival after propensity score matching.
对于无症状的不可切除IV期结直肠癌患者，原发性肿瘤手术切除的预后作用尚未明确。
本研究旨在揭示原发性肿瘤手术切除的预后作用，并确定影响无症状不可切除同步转移患者长期肿瘤学结局的预后因素。
本研究是对前瞻性收集的数据进行回顾性分析。
在2000年至2008年期间，共对416例无症状不可切除IV期结直肠癌患者进行倾向评分匹配分析。
通过双变量分析比较匹配前的基线特征，根据逻辑回归估计的倾向评分进行1:1匹配后选择113对。主要终点是总生存期。
在416例患者中，218例（52.4%）接受了原发性肿瘤的姑息性切除。在倾向评分匹配前，单变量分析中姑息性切除的生存率优于未切除（p<0.001），但多变量分析中并非如此（p = 0.08）。匹配后，单变量分析中腹膜转移和临床M1b期肿瘤患者的5年总生存率显著较低（p = 0.004和p = 0.02）。然而，在多变量分析中，腹膜转移和临床M1b期均未显示出任何预后意义。匹配后组的姑息性切除组和未切除组的5年总生存率分别为4.9%和3.5%。因此，与未切除相比，姑息性切除并未使生存率显著提高（p = 0.27）。根据转移部位进行的亚组分析在匹配后也未显示姑息性切除有任何显著的生存获益。
选择偏倚和潜在混杂因素是本研究的局限性。
在倾向评分匹配后，无症状不可切除IV期结直肠癌患者的原发性肿瘤切除与总生存期改善无关。
