Fig 1.
Flowchart of eligible studies identification.
11 studies (4 RCTs and 7 non-RCTs) with a total of 1984 patients were included in this meta-analysis.
Table 1.
Characteristics and Jadad scores of included studies.
Fig 2.
Meta-analysis of cumulative overall survival.
There was no significant difference in OS between SCRT and LCRT groups (HR = 0.92, 95% CI: 0.75–1.13, p = 0.44). The subgroup analysis of RCTs or non-RCTs found similar results.
Fig 3.
Meta-analysis of cumulative disease free survival.
No significant difference was found (HR = 0.94, 95% CI: 0.79–1.12, p = 0.50) in disease free survival. Subgroup analysis showed that the difference remained insignificant when RCTs and non-RCTs were analyzed separately.
Fig 4.
Meta-analysis of 3-year local recurrence.
There was no difference between CRT and LCRT (OR = 0.73, 95% CI: 0.49–1.08, p = 0.11) in 3-year local recurrence. Subgroup analysis found no significant difference in either RCTs or non-RCTs as well.
Fig 5.
Trial sequential analysis of 4-year overall survival.
5a, Trial sequential analysis of 4-year overall survival. The required heterogeneity-adjusted information size using 5% risk of type I error and 20% risk of type II error. The cumulative z curve crossed the futility boundary, suggesting firm evidence for lack of on average a -10% relative risk reduction in 4-year OS. 5b, Trial sequential analysis of 4-year disease free survival. When compared with LCRT treatment in 4-year DFS, neither the traditional boundary nor the trial sequential monitoring boundary was crossed for a -10% relative risk reduction with SCRT. In addition, the futility boundary was not crossed.
Table 2.
Quality of evidence for each outcome using GRADE system.