Open AccessImpact of Primary Tumor Location on Survival After Curative Resection in Patients with Colon Cancer: A Meta‐Analysis of Propensity Score‐Matching Studies
Author(s) -
Ishizuka Mitsuru,
Shimizu Takayuki,
Shibuya Norisuke,
Takagi Kazutoshi,
Hachiya Hiroyuki,
Nishi Yusuke,
Suda Kotaro,
Aoki Taku,
Kubota Keiichi
Publication year - 2021
Publication title -
the oncologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.176
H-Index - 164
eISSN - 1549-490X
pISSN - 1083-7159
DOI - 10.1002/onco.13555
Subject(s) - propensity score matching , medicine , meta analysis , confidence interval , subgroup analysis , colorectal cancer , overall survival , surgery , oncology , retrospective cohort study , cancer
Background Recent retrospective subgroup analyses of patients with unresectable colon cancer (CC) receiving systemic chemotherapy have demonstrated that there is a significant difference in treatment outcome between patients with right‐sided CC (RSCC) and those with left‐sided CC (LSCC). However, it is impossible to divide patients with CC randomly into RSCC and LSCC groups before surgery. Therefore, the aim of this study is to explore the impact of primary tumor location (PTL) on survival after curative surgery for patients with CC using propensity score‐matching (PSM) studies instead of randomization. Materials and Methods We performed a comprehensive electronic search of the literature up to January 2019 to identify studies that had used databases allowing comparison of postoperative survival between patients with RSCC and those with LSCC. To integrate the impact of PTL on 5‐year overall survival (OS) after curative surgery, a meta‐analysis was performed using random‐effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected PSM studies. Results Five studies involving a total of 398,687 patients with CC were included in this meta‐analysis. Among 205,641 patients with RSCC, 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with LSCC, 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5‐year OS (RR, 0.98; 95% CI, 0.89–1.07; p = .64; I 2 = 97%). Conclusion This meta‐analysis has demonstrated that there was no significant difference in 5‐year OS between patients with RSCC and those with LSCC after curative resection. Implications for Practice To integrate the impact of primary tumor location (PTL) on 5‐year overall survival (OS) after curative surgery, five propensity score‐matching (PSM) studies involving a total of 398,687 patients with colon cancer (CC) were included in this meta‐analysis. Among 205,641 patients with right‐sided CC (RSCC), 69,091 (33.6%) died during the observation period, whereas among 193,046 patients with left‐sided CC (LSCC), 63,380 (32.8%) died during the same period. These results revealed that patients with RSCC and those with LSCC had almost the same 5‐year OS (risk ratio, 0.98; 95% confidence interval, 0.89–1.07; p = .64; I 2 = 97%).