Table 3 Grading of Recommendations, Assessments, Developments, and Evaluation (GRADE) quality assessment of evidence for each comparison
Number of studies | Study design | Certainty assessment | Number of patients | Effect | Certainty | Importance | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | SV-UCB | C-UCB | Relative (95% CI) | Absolute (95% CI) | ||||
Pathologic T stage 2 and lower | ||||||||||||
4 | Observational studies | Not serious | Serious | Not serious | Not serious | Strong association | 156/349 (44.7%) | 34,499/47,936 (72.0%) | OR 0.41 (0.23–0.71) | 207 fewer per 1000 (from 348 to 74 fewer) | ⨁⨁◯◯ LOW | CRITICAL |
Pathologic T stage 3 and higher | ||||||||||||
4 | Observational studies | Not serious | Not serious | Not serious | Not serious | Strong association | 122/349 (35.0%) | 8862/47,936 (18.5%) | OR 2.06 (1.64–2.59) | 134 more per 1000 (from 86 to 185 more) | ⨁⨁⨁◯ MODERATE | CRITICAL |
High grade | ||||||||||||
2 | Observational studies | Not serious | Serious | Not serious | Serious | None | 24/26 (92.3%) | 395/549 (71.9%) | OR 2.61 (0.02–286.71) | 151 more per 1000 (from 671 fewer to 279 more) | ⨁◯◯◯ VERY LOW | CRITICAL |
Concomitant carcinoma in situ | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Not serious | Strong association | 4/33 (12.1%) | 316/959 (33.0%) | OR 0.25 (0.09–0.72) | 220 fewer per 1000 (from 287 to 68 fewer) | ⨁⨁⨁◯ MODERATE | CRITICAL |
Positive lymph node | ||||||||||||
3 | Observational studies | Not serious | Not serious | Not serious | Serious | None | 11/48 (22.9%) | 400/1421 (28.1%) | OR 0.79 (0.40–1.59) | 45 fewer per 1000 (from 146 fewer to 102 more) | ⨁◯◯◯ VERY LOW | CRITICAL |
Positive surgical margin | ||||||||||||
3 | Observational studies | Not serious | Not serious | Not serious | Serious | None | 2/48 (4.2%) | 126/1421 (8.9%) | OR 0.55 (0.15–1.98) | 38 fewer per 1000 (from 74 fewer to 73 more) | ⨁◯◯◯ VERY LOW | CRITICAL |
Overall survival (unadjusted) | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Not serious | None | – | – | HR 1.24 (1.07–1.44) | 1 fewer per 1000 (from 1 to 1 fewer) | ⨁⨁◯◯ LOW | IMPORTANT |
Cancer-specific survival (unadjusted) | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Not serious | Strong association | – | – | HR 2.08 (1.63–2.66) | 2 fewer per 1000 (from 3 to 2 fewer) | ⨁⨁⨁◯ MODERATE | IMPORTANT |
Overall survival (adjusted) | ||||||||||||
3 | Observational studies | Not serious | Serious | Not serious | Serious | None | – | – | HR 1.41 (0.95–2.08) | 1 fewer per 1000 (from 2 to 1 fewer) | ⨁◯◯◯ VERY LOW | CRITICAL |
Cancer–specific survival (adjusted) | ||||||||||||
2 | Observational studies | Not serious | Serious | Not serious | Serious | None | – | – | HR 1.54 (0.95–2.52) | 2 fewer per 1000 (from 3 to 1 fewer) | ⨁◯◯◯ VERY LOW | CRITICAL |
Progression-free survival | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Serious | None | – | – | HR 1.16 (0.57–2.38) | 1 fewer per 1000 (from 2 to 1 fewer) | ⨁◯◯◯ VERY LOW | IMPORTANT |
Neoadjuvant chemotherapy | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Serious | None | 0/36 (0.0%) | 83/1191 (7.0%) | OR 0.34 (0.05–2.45) | 45 fewer per 1000 (from 66 fewer to 85 more) | ⨁◯◯◯ VERY LOW | CRITICAL |
Adjuvant chemotherapy | ||||||||||||
3 | Observational studies | Not serious | Serious | Not serious | Serious | None | 85/424 (20.0%) | 3205/14,401 (22.3%) | OR 1.15 (0.48–2.79) | 25 more per 1000 (from 102 fewer to 221 more) | ⨁◯◯◯ VERY LOW | CRITICAL |
Neoadjuvant chemotherapy on OS | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Serious | None | – | – | HR 0.73 (0.51–1.05) | 1 fewer per 1000 (from 1 to 1 fewer) | ⨁◯◯◯ VERY LOW | CRITICAL |
Adjuvant chemotherapy on OS | ||||||||||||
2 | Observational studies | Not serious | Not serious | Not serious | Serious | None | – | – | HR 0.88 (0.66–1.17) | 1 fewer per 1000 (from 1 to 1 fewer) | ⨁◯◯◯ VERY LOW | CRITICAL |