Table 1.
Characteristics of all included studies in the meta‐analysis
| First author | Year | Study design | Country | E | N | Smokers (%) | LD‐SCLC (%) | Male (%) | Age (mean, range) | Treatment | Outcome | Analysis type | NOS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Zhou et al. 6 | 2020 | R | China | A | 219 | 81.74% | 0% | 87.90% | 60.5 | C, R | O | U | 7 |
| Yilmaz et al. 7 | 2020 | R | Japan | A | 216 | 56.94% | 27.30% | 85.20% | NA | C, R | O | U | 7 |
| Xu et al. 8 | 2020 | R | China | A | 136 | 61.03% | 47.80% | 76.50% | 61.6 | C, R | O | U | 6 |
| Wu et al. 9 | 2020 | R | China | A | 146 | 73.97% | 40.40% | 78.10% | 57 (19–74) | C, R | O | U | 7 |
| Wang et al. 10 | 2020 | R | China | A | 653 | 62.48% | 58.50% | 64.60% | NA | C, R | O | M | 8 |
| Wang et al. 11 | 2019 | R | China | A | 228 | 79.39% | 50% | 69.70% | 58 (39–71) | C, R | O | U | 7 |
| Li et al. 12 | 2019 | R | China | A | 122 | 54.92% | 100% | 68.90% | 58 | C, R | O, P | U | 7 |
| Liu et al..13 | 2018 | R | China | A | 303 | 77.23% | 37.30% | 90.10% | 63 | C, R | O, P | M | 9 |
| Jin et al. 14 | 2018 | R | China | A | 1156 | 57.96% | 61.90% | 64.40% | 57 (23–85) | C, R | O | M | 8 |
| Guo et al. 15 | 2018 | R | China | A | 128 | 61.72% | 52% | 55.50% | 62 (30–83 | C, R | O | U | 7 |
| Fan et al. 16 | 2018 | R | China | A | 120 | 72.50% | 39.20% | 71.70% | 63.2 | C, R | O | U | 7 |
| Hong et al. 17 | 2018 | R | China | A | 936 | 66.03% | 59.10% | 69.30% | NA | C, R | O, P | M | 8 |
| Pan et al. 18 | 2017 | R | China | A | 275 | 70.18% | 54% | 87% | 62 (33–86) | C, R | O | M | 8 |
| Jiang et al. 19 | 2017 | R | China | A | 107 | 87.85% | 39.30% | 78.50% | 63 | C, R | O | U | 7 |
| Deng et al. 20 | 2017 | R | China | A | 320 | 67.19% | 38.10% | 74.70% | 58 (24–81) | C, R | O, P | U | 7 |
| Chen et al. 21 | 2016 | R | China | A | 393 | 71.76% | 39.90% | 81.90% | 57 | C, R | O, P | U | 7 |
| Cai et al. 22 | 2016 | R | China | A | 144 | 68.06% | 40.50% | 88.50% | 60 (25–80) | C, R | O | M | 8 |
| Xie et al. 23 | 2015 | R | China | A | 383 | 73.11% | 100% | 47.50% | 66.7 | C, R | O | M | 7 |
| Sun et al. 24 | 2015 | R | China | A | 391 | 87.21% | 46.30% | 85.40% | 65 | C, R | O | M | 8 |
| Liu et al. 25 | 2015 | R | China | A | 247 | 67.21% | 52.20% | 81.40% | 70.7 (65–83) | C, R | O | U | 7 |
| Hong et al. 26 | 2015 | R | China | A | 919 | 61.70% | 60.10% | 69.10% | NA | C, R | O | M | 7 |
| Hong et al. 27 | 2015 | R | China | A | 724 | 82.87% | 55.40% | 86.60% | 59 (19–86) | C, R | O | M | 7 |
| Liu et al. 28 | 2013 | R | China | A | 485 | 67.84% | 44.50% | 74.00% | NA | C, R | O | U | 7 |
| Wu et al..29 | 2012 | R | China | A | 200 | 77.50% | 0% | 62.40% | NA | C, R | O | U | 6 |
| Chen et al. 30 | 2010 | R | China | A | 264 | 97.35% | 100% | N | 65 | C, R | O | M | 8 |
| Arinc et al. 31 | 2010 | R | Turkey | A | 200 | 92.00% | 55.80% | 91.40% | 57 (35–78) | C, R | O | U | 7 |
| Ou et al. 5 | 2009 | R | multiple countries | C, A | 2632 | 96.47% | 0% | 53.40% | 68 | C, R, S | O | M | 8 |
A, Asian; C, Caucasian; E, ethnicity; M, multivariate analysis; NA, not available; NOS, Newcastle‐Ottawa Scale; O, overall survival; P, progression‐free survival.; R, retrospective study; U, univariate analysis.[Correction added on 13 October 2020, after first online publication: in Arinc et al. 2010, Ethnicity has been updated from ‘C’ to ‘A’. In Ou et al. 2009, Country and Ethnicity have been updated from ‘China’ to ‘multiple countries’ and ‘C’ to ‘C, A’.]