Well-designed retrospective study versus small-sample prospective study in research based on laparoscopic and open radical distal gastrectomy for advanced gastric cancer



Well-designed retrospective studies (RSs) and small-sample prospective studies (PSs) evaluating the efficacy of interventions have received much attention. This study was designed to evaluate the differences between well-designed RSs and small-sample randomized controlled trials based on the efficacy of laparoscopic distal gastrectomy (LDG) and open distal gastrectomy (ODG) for advanced gastric cancer (GC).


The clinicopathological data of 1360 patients with GC who underwent DG were analysed. After propensity score matching (1:1), 380 cases (ODG = 190, LDG = 190) were finally selected in a RS. Meanwhile, data from 120 patients (ODG = 60, LDG = 60) who enrolled in a PS were analysed.


In the PS, the LDG group had less intraoperative blood loss, shorter time to first flatus, and shorter time to fluid diet than the ODG group. In the RS, the LDG group had less intraoperative blood loss, and a shorter postoperative hospital stay than the ODG group. In the PS, the 3-year overall survival (OS) rate was 83.3% in the LDG group and 83.2% in the ODG group (p = 0.877). In the RS, the 3-year OS rate was 68.7% in the LDG group and 66.6% in the ODG group (p = 0.752). No significant interactions were observed between the two groups and any of the variables examined, either in the PS or RS. The recurrence patterns were similar in the two groups. Furthermore, Cox regression analysis showed that surgical method (LDG/ODG) was not a prognostic factor affecting OS or DFS, either prospectively or retrospectively.


The oncologic efficacy of laparoscopic and open distal gastrectomy for advanced GC is comparable. Well-designed RSs can be similar to small sample of PSs in assessing long-term oncologic outcomes of surgical interventions, but the short-term outcomes obtained should be treated with caution.

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We are grateful to the Chinese Gastric Cancer Association, the Chinese Society of Laparo-Endoscopic Surgery, and the Chinese Society of Gastrointestinal Surgery for their scientific support. This study was supported by Scientific and technological innovation joint capital projects of Fujian Province (Grant No. 2016Y9031), Construction Project of Fujian Province Minimally Invasive Medical Center (Grant No. [2017]171), the second batch of special support funds for Fujian Province innovation and entrepreneurship talents (Grant No. 2016B013), general project of Miaopu scientific research fund of Fujian Medical University (Grant No. 2015MP021), Youth Project of Fujian Provincial Health and Family Planning Commission (Grant No. 2016-1-41), and Fujian science and technology innovation joint fund project (Grant No. 2017Y9004).

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Correspondence to Chao-Hui Zheng or Chang-Ming Huang or Ping Li.

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Jia-Bin Wang, Qing Zhong, Qi-Yue Chen, Guang-Tan Lin, Zhi-Yu Liu, Xiao-Bo Huang, Jian-Wei Xie, Jian-Xian Lin, Jun Lu, Long-Long Cao, Mi Lin, Ru-Hong Tu, Ze-Ning Huang, Ju-Li Lin, Hua-Long Zheng, Chao-Hui Zheng, Chang-Ming Huang, and Ping Li have no conflict of interest or financial ties to disclose.

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Wang, JB., Zhong, Q., Chen, QY. et al. Well-designed retrospective study versus small-sample prospective study in research based on laparoscopic and open radical distal gastrectomy for advanced gastric cancer. Surg Endosc 34, 4504–4515 (2020). https://doi.org/10.1007/s00464-019-07237-4

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  • Retrospective study
  • Prospective study
  • Open surgery
  • Laparoscopic surgery
  • Gastric cancer
  • Oncologic efficacy