Table 2.
Summary of Subgroup Analysis, Incorporating Individual Patient Data From 24 Available Studies, Evaluating Key Variables and Their Association With OS and EFS Based on the Presence or Absence of pCR, Represented by Estimated HRs With Corresponding 95% CIs
| Subgroup Analyses | OS |
EFS |
||||||
|---|---|---|---|---|---|---|---|---|
| N Studies | Sample size | HR | 95% CI | n Studies | Sample size | HR | 95% CI | |
| Overall | 23 | 6292 | 0.49 | (0.43–0.55) | 7 | 1530 | 0.46 | (0.36–0.58) |
| Treatment type | ||||||||
| CT | 4 | 779 | 0.39 | (0.23–0.64) | 4 | 779 | 0.31 | (0.19–0.53) |
| CT/CRT | 6 | 2328 | 0.44 | (0.35–0.54) | 1 | 145 | 0.36 | (0.21–0.60) |
| CRT | 13 | 3185 | 0.52 | (0.45–0.60) | 2 | 606 | 0.58 | (0.42–0.80) |
| Geographic region | ||||||||
| Asia-Pacific | 9 | 1067 | 0.45 | (0.34–0.60) | 4 | 774 | 0.51 | (0.38–0.67) |
| Europe | 5 | 949 | 0.41 | (0.30–0.57) | 2 | 614 | 0.31 | (0.18–0.53) |
| Middle East | 1 | 124 | 0.46 | (0.29–0.71) | 0 | 0 | N/A | N/A |
| North America | 8 | 4152 | 0.51 | (0.44–0.60) | 1 | 142 | 0.34 | (0.05–2.42) |
| Study type | ||||||||
| Retro cohort | 16 | 5513 | 0.51 | (0.45–0.58) | 4 | 983 | 0.51 | (0.39–0.67) |
| Prospective trial | 5 | 260 | 0.29 | (0.16–0.52) | 2 | 55 | 0.49 | (0.17–1.43) |
| Prospective cohort | 1 | 27 | 0.07 | (0.00–1.32) | 0 | 0 | N/A | N/A |
| RCTs | 1 | 492 | 0.35 | (0.19–0.66) | 1 | 492 | 0.28 | (0.15–0.53) |
| pCR definition | ||||||||
| T0N0 | 12 | 4141 | 0.51 | (0.44–0.58) | 2 | 154 | 0.50 | (0.21–1.15) |
| T0 | 5 | 1185 | 0.52 | (0.38–0.71) | 3 | 1089 | 0.48 | (0.36–0.64) |
| Not defined | 6 | 966 | 0.40 | (0.29–0.54) | 2 | 287 | 0.37 | (0.23–0.62) |
| Adjuvant therapy | ||||||||
| Yes | 5 | 2045 | 0.42 | (0.32–0.56) | 3 | 547 | 0.31 | (0.18–0.54) |
| No | 18 | 4247 | 0.50 | (0.44–0.57) | 4 | 983 | 0.51 | (0.39–0.67) |
| % of stage III patients | ||||||||
| 100% | 15 | 4657 | 0.51 | (0.45–0.59) | 4 | 751 | 0.56 | (0.41–0.76) |
| 50%–100% | 4 | 909 | 0.46 | (0.34–0.60) | 1 | 145 | 0.36 | (0.21–0.60) |
| <50% | 4 | 726 | 0.28 | (0.16–0.50) | 2 | 634 | 0.29 | (0.16–0.52) |
| Number of preoperative chemotherapy cycles | ||||||||
| ≥3 | 6 | 1194 | 0.45 | (0.35–0.60) | 2 | 634 | 0.29 | (0.16–0.52) |
| ≤2 | 10 | 1172 | 0.43 | (0.33–0.57) | 5 | 896 | 0.50 | (0.38–0.66) |
| Not reported | 7 | 3926 | 0.52 | (0.45–0.60) | 0 | 0 | N/A | N/A |
| Radiation dose | ||||||||
| ≥50 Gy | 7 | 2590 | 0.52 | (0.44–0.61) | 1 | 32 | 0.71 | (0.19–2.63) |
| <50 Gy | 11 | 1559 | 0.47 | (0.38–0.58) | 2 | 719 | 0.51 | (0.38–0.67) |
| Not reported | 5 | 2143 | 0.43 | (0.32–0.58) | 4 | 779 | 0.31 | (0.19–0.53) |
CI, confidence interval; CRT, chemoradiotherapy; CT, chemotherapy; EFS, event-free survival; HR, hazard ratio; N/A, not applicable; OS, overall survival; pCR, pathologic complete response; RCT, randomized controlled trial; Retro, retrospective.