Predicting response using blood biomarkers and PET-CT during neoadjuvant chemoradiation Table 6.6
Calculated AUC-values of all parameters: AUC-values of the predicted probability for TRG1-2 as positive predicted outcome combined with the 95%CI and p-values are shown.
ROC TRG 1-2 vs TRG 3-5 (AUC pred. prob.) treatment moment/period
t=0 days
t=0-15 days
t=15-90 days
parameters
AUC
95% CI
p
AUC
95% CI
p
AUC
95% CI
p
serum CEA
0,656
0.542 - 0.769
0,011
0,602
0.471 - 0.733
0,120
0,602
0.452 - 0.751
0,188
serum CRP
0,494
0.373 - 0.614
0,916
0,298
0.179 - 0.417
0,002
0,539
0.384 - 0.694
0,615
serum Leucocytes
0,538
0.417 - 0.659
0,533
0,473
0.343 - 0.604
0,690
0,556
0.404 - 0.708
0,468
Flow %parent Monocytes
0,490
0.368 - 0.613
0,874
0,560
0.430 - 0.690
0,364
0,624
0.473 - 0.774
0,112
Flow %parent act. Mac.
0,442
0.320 - 0.564
0,347
0,518
0.388 - 0.648
0,786
0,512
0.358 - 0.666
0,876
Flow %parent CEA-IM
0,531
0.410 - 0.652
0,613
0,524
0.394 - 0.655
0,716
0,475
0.317 - 0.634
0,755
SUVMax
0,455
0.328 - 0.582
0,478
0,475
0.329 - 0.620
0,731
0,669
0.522 - 0.816
0,035
SUVMean
0,464
0.335 - 0.594
0,573
0,487
0.338 - 0.636
0,863
0,706
0.524 - 0.887
0,059
MTV
0,666
0.549 - 0.783
0,008
0,524
0.377 - 0.670
0,751
0,584
0.381 - 0.788
0,439
ROC TRG 1-2 vs TRG 3-5 (AUC pred. prob.)
subgroup-analysis
treatment moment/period
t=0-7 days
t=7-15 days
parameters
AUC
95% CI
p
AUC
95% CI
p
serum CEA
0,504
0.291 - 0.717
0,970
0,487
0.269 - 0.706
0,906
serum CRP
0,816
0.659 - 0.972
0,002
0,410
0.189 - 0.631
0,395
Table legend
serum Leucocytes
0,605
0.393 - 0.817
0,321
0,550
0.341 - 0.759
0,635
value: AUC>0.6
Flow %parent Monocytes
0,589
0.377 - 0.802
0,406
0,737
0.558 - 0.915
0,028
value: AUC>0.7
Flow %parent act. Mac.
0,607
0.402 - 0.812
0,318
0,464
0.252 - 0.677
0,739
sign. discriminating
Flow %parent CEA-IM
0,540
0.319 - 0.761
0,708
0,518
0.296 - 0.740
0,872
parameter if →
SUVMax
na
na
na
na
na
na
95%CI [≥0.5 – any]
SUVMean
na
na
na
na
na
na
(equals p≤0.05)
MTV
na
na
na
na
na
na
3.3.2
Pathological response (ypTN)
3.3.2.1 ypT0N0 vs. >ypT0N0 MTV is the only significantly discriminative parameter at t=0 when using pCR as an outcome measure. CEA, leucocytes, SUVMax and SUVMean pose no significant discriminative potential although their AUC's range from 0.602-0.625. AUC-values at t=0-15 days and t=15-90 days are 0.623 and 0.631 respectively, showing metabolic tumour volume is continuous in its discriminative potential, although it is not significant during the whole neoadjuvant treatment period. Subgroup-analyses show only the fraction of CEA-IM at t=7-15 days as significantly discriminative (AUC=0.762, p=0.032). In the overall treatment period (t=0-15 days) and later time points this discriminative power is not reproduced. Significance may be erroneous due to n=8 but needs to be evaluated in a larger cohort to confirm. Other parameters in the subgroup-analysis show no significant discriminative power; only serum leucocytes (n=21 vs. n=13) at t=7-15 shows an
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