Table 1. Summary of included studies for lung cancer.
| Study | Level of evidence | Quality score | Number | Population | Age (years) | Outcome measure | Time to surgery/delay groups | Follow up | Worse outcome | Summary finding |
|---|---|---|---|---|---|---|---|---|---|---|
| Bott et al., 2015 (7) | 2b | 8 | 55,653 | Stage I NSCLC | 68.1±10.0 | Upstaging | ±8 weeks | NS | Yes | Upstaging: >8 weeks OR 1.10 (1.03–1.16) |
| Coughlin et al., 2015 (8) | 2b | 7 | 222 | Stage I or II NSCLC | Mean 64–69 depending on group | Upstaging, OS | <1, ≥1–2, ≥2–3, ≥3–4 months | Stage I: 30±11 months; Stage II: 26±13 months |
Yes | Upstaging: no difference; OS: Stage I ND, Stage II: ≥2–3 months vs. <1 HR 3.6 (1.09–12.09) |
| Gao et al., 2016 (9) | 2b | 8 | 1,623 | T1–3N2 NSCLC with nCRT | Mean 60.3–61.2 depending on TTS | OS | 0–3, >3 to ≤6, >6 to ≤9, >9 to ≤12 weeks | NS: 5-year survival | Yes | OS: 0–3 weeks ref; >3–6 weeks, HR 1.26 (0.94–1.67); >6–9 weeks, HR 1.33 (1.01–1.76); >9–12 weeks, HR 1.02 (1.01–1.02) |
| Kanarek et al., 2014 (10) | 2b | 8 | 174 | Stage I–II NSCLC | NS: 61%>65 | OS | ±6 weeks | >3 years | Yes | OS: each additional week: HR 1.05 (1.01–1.09) |
| Liberman et al., 2006 (11) | 2b | 5 | 256 | Stage I–IV NSCLC | Mean 65.3 (SD 10.2) | Upstaging | Continuous variable | None | No | Symptoms to surgery: OR 1.00 (0.999–1.001); surgeon to surgery: OR 1.00 (0.997–1.002) |
| Maiga et al., 2017 (11) | 2b | 7 | 265 | Suspected lung cancer with resection | Median 66 (range, 60–72) | Upstaging | ≤60, >60 days | None | No | Upstaging: ≤60 vs. >60 days, 22% vs. 30% (P=0.278) |
| Marulli et al., 2018 (12) | 2b | 8 | 231 | NSCLC cT1–3N0 | Median 68 (IQR 62–74) | Upstaging | PET/CT to surgery <31, 31–60, >60 days | None | No | Nodal upstaging: no association with TTS (P=0.470) |
| Odell et al., 2019 (13) | 2b | 6 | 240,680 | NSCLC pN1-2 with nCRT | NS | OS | ±120 days | NS | Yes | OS: <120 days ref; >120 days HR 1.17 (1.07–1.27) |
| Rice et al., 2020 (14) | 2b | 8 | 5,946 | NSCLC stage IIIa with nCRT | Median 63 (range, 56–69) | OS | <77, 77–114, >114 days | NS: 3-year survival | Yes | OS: <77 days ref; 77–114 days, HR 1.073 (0.964–1.195); >114 days, HR 1.25 (1.103–1.416) |
| Samson et al., 2016 (15) | 2b | 9 | 55,653 | NSCLC stage I | Mean 68.8, SD: 9.8 | Upstaging, OS | ±8 weeks | NS | Yes | Upstaging: <8 vs. ≥8 weeks, 16.6% vs. 18.3% (P<0.001); OS: <8 vs. ≥8 weeks, 69.2 vs. 57.7 months (P<0.001) |
| Shin et al., 2013 (16) | 2b | 6 | 398 | Locoregional NSCLC | Mean 63.5, SD: 8.7 | OS | ≤1, >1 to 4, >4 to 8, >12 weeks | Median 4.7 years | No | OS: >1–4 weeks ref; <1 week, HR 1.13 (0.77–1.66); >4–8 weeks, HR 1.05 (0.67–1.65); >8–12 weeks, HR 0.65 (0.28–1.48); >12 weeks, HR 0.79 (0.42–1.48) |
| Yang et al., 2017 (17) | 2b | 8 | 4,984 | NSCLC stage IA | Median 70 (IQR 64–76) | OS | ±37 days | Median 32 months | Yes | OS: >37 days HR 1.13 (1.02–1.25) |
HR, hazard ratio; IQR, interquartile range; nCRT, neoadjuvant chemoradiotherapy; NSCLC, non-squamous cell lung cancer; NS, not stated; OR, odds ratio; OS, overall survival; ref, reference group; TTS, time to surgery;