Table 2. Kaplan-Meier Estimates and Multivariable Survival Models.
| CTC-RT Group | Kaplan-Meier Estimate, All Patients | AFT Multivariable Analysis | ||||||
|---|---|---|---|---|---|---|---|---|
| All Patients | Matched Cohorts | |||||||
| No. of Patients (No. of Events) | RMS (95% CI), moa | Survival Proportion, % (95% CI)b | Log-Rank P Value | TR (95% CI) | P Valuec | TR (95% CI) | P Valuec | |
| NCDB Cohortd | ||||||||
| CTC-positive, no RT | 172 (18) | 78.6 (74.2-83.0) | 88.0 (82.3-94.2) | .005 | 1 [Reference] | NA | 1 [Reference] | NA |
| CTC-positive, RT | 227 (7) | 85.5 (83.3-87.6) | 94.9 (90.8-99.1) | 2.34 (1.26-4.35) | .006 | 1.65 (1.26-2.17) | <.001 | |
| CTC-negative, no RT | 563 (34) | 82.3 (80.1-84.4) | 93.4 (91.1-95.9) | 1.93 (1.13-3.30) | .02 | 1.90 (1.46-2.48) | <.001 | |
| CTC-negative, RT | 735 (33) | 82.9 (79.5-86.3) | 93.9 (91.7-96.1) | 1.72 (1.07-2.74) | .02 | 1.59 (1.23-2.07) | <.001 | |
| SUCCESS Cohorte | ||||||||
| DFSf | ||||||||
| CTC-positive, no RT | 46 (8) | 73.7 (62.9-84.4) | 75.2 (61.5-91.9) | .002 | 1 [Reference] | NA | 1 [Reference] | NA |
| CTC-positive, RT | 248 (35) | 81.1 (78.0-84.2) | 88.0 (83.9-92.4) | 3.77 (1.77-8.03) | <.001 | 2.83 (2.02-3.98) | <.001 | |
| CTC-negative, no RT | 216 (23) | 82.0 (78.4-85.7) | 88.3 (83.5-93.4) | 3.28 (1.51-7.12) | .002 | 2.16 (1.41-3.33) | <.001 | |
| CTC-negative, RT | 1006 (87) | 84.9 (83.6-86.3) | 92.3 (90.5-94.0) | 5.05 (2.47-10.33) | <.001 | 3.61 (2.58-5.03) | <.001 | |
| LRFSg | ||||||||
| CTC-positive, no RT | 46 (4) | 82.8 (74.1-91.5) | 85.7 (73.6-99.8) | .003 | 1 [Reference] | NA | 1 [Reference] | NA |
| CTC-positive, RT | 248 (7) | 90.3 (88.8-91.8) | 98.2 (96.4-100.0) | 3.59 (1.45-8.94) | .005 | 4.35 (2.60-7.28) | <.001 | |
| CTC-negative, no RT | 216 (7) | 89.8 (88.0-91.6) | 96.2 (93.3-99.2) | 2.65 (1.11-6.36) | .03 | 2.12 (1.21-3.72) | .008 | |
| CTC-negative, RT | 1006 (23) | 90.1 (89.2-91.1) | 98.1 (97.3-99.0) | 4.31 (1.88-9.86) | <.001 | 5.99 (3.36-10.70) | <.001 | |
| OSh | ||||||||
| CTC-positive, no RT | 46 (5) | 81.5 (73.2-89.9) | 84.5 (72.7-98.2) | .008 | 1 [Reference] | NA | 1 [Reference] | NA |
| CTC-positive, RT | 248 (20) | 86.8 (84.8-88.9) | 92.4 (88.9-95.9) | 2.73 (1.16-6.41) | .02 | 2.05 (1.41-2.97) | <.001 | |
| CTC-negative, no RT | 216 (11) | 87.4 (84.9-89.9) | 95.2 (92.0-98.5) | 2.92 (1.22-6.99) | .02 | 1.99 (1.21-3.30) | .007 | |
| CTC-negative, RT | 1006 (41) | 88.9 (88.0-89.8) | 96.7 (95.6-97.9) | 4.04 (1.80-9.08) | <.001 | 2.89 (1.96-4.25) | <.001 | |
| Pooled Cohort | ||||||||
| BCSi | ||||||||
| CTC-positive, no RT | 49 (9) | 73.6 (63.7-83.5) | 73.3 (59.4-90.3) | <.001 | 1 [Reference] | 1 [Reference] | ||
| CTC-positive, RT | 411 (20) | 87.2 (85.6-88.8) | 93.6 (90.8-96.6) | 3.42 (1.47-8.00) | .004 | 3.42 (2.17-5.40) | <.001 | |
| CTC-negative, no RT | 163 (8) | 86.0 (82.7-89.3) | 92.7 (87.3-98.3) | 3.10 (1.33-7.24) | .009 | 2.82 (1.65-4.81) | <.001 | |
| CTC-negative, RT | 1554 (64) | 87.8 (87.0-88.6) | 95.5 (94.3-96.6) | 3.70 (1.69-8.09) | <.001 | 3.41 (2.21-5.28) | <.001 | |
| Mastectomyj | ||||||||
| CTC-positive, no RT | 169 (14) | 82.6 (78.7-86.5) | 84.3 (76.0-93.6) | .30 | 1 [Reference] | NA | 1 [Reference] | NA |
| CTC-positive, RT | 64 (7) | 82.0 (76.1-87.9) | 88.3 (79.9-97.6) | 0.90 (0.51-1.58) | .64 | 0.96 (0.70-1.31) | .78 | |
| CTC-negative, no RT | 616 (37) | 84.0 (81.8-86.2) | 91.0 (87.8-94.2) | 1.34 (0.94-1.92) | .17 | 1.38 (1.14-1.68) | .001 | |
| CTC-negative, RT | 187 (10) | 85.1 (82.1-88.1) | 95.8 (92.6-99.2) | 1.30 (0.80-2.11) | .29 | 1.66 (1.16-2.37) | .006 | |
Abbreviations: AFT, accelerated time failure; BCS, breast-conserving surgery; CTC, circulating tumor cell; DFS, disease-free survival; LRFS, local recurrence-free survival; NCDB, National Cancer Database; NA, not applicable; OS, overall survival; RMS, restricted mean survival; RT, radiotherapy; SUCCESS, Simultaneous Study of Gemcitabine-Docetaxel Combination Adjuvant Treatment as well as Extended Bisphosphonate and Surveillance; TR, time ratio.
Measured as overall survival in the NCDB and pooled cohorts.
Measured as 4-year survival in the NCDB cohort and 5-year survival in the SUCCESS and pooled cohorts.
Determined by Wald test.
For pairwise interaction terms of CTC status and RT in the AFT multivariable analyses, P = .01 for all patients (n = 1697) and P < .001 for matched cohorts (n = 1197).
For AFT multivariable analysis, includes 1516 for all patients and 1176 for matched cohorts.
For pairwise interaction terms of CTC status and RT in the AFT multivariable analysis, P = .04 for all patients and P = .04 for matched cohorts.
For pairwise interaction terms of CTC status and RT in the AFT multivariable analysis, P = .13 for all patients and P = .20 for matched cohorts.
For pairwise interaction terms of CTC status and RT in the AFT multivariable analysis, P = .16 for all patients and P = .23 for matched cohorts.
For pairwise interaction terms of CTC status and RT in the AFT multivariable analysis, P = .04 for all patients (n = 2177) and P < .001 for matched cohorts (n = 1840).
For pairwise interaction terms of CTC status and RT in the AFT multivariable analysis, P = .82 for all patients (n = 1036) and P = .83 for matched cohorts (n = 932).