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Table 2 Performance of predictive models for classification of clinico-pathological characteristics in tumour tissue

From: Mass spectrometry protein expression profiles in colorectal cancer tissue associated with clinico-pathological features of disease

CHARACTERISTICS 1Advanced Dukes'
stage
Poorly differentiated Lymph node
involvement
Invasiveness 2Disease recurrence
Number of features 5 2 4 9 10
Positive prediction rate 6/12 10/13 5/13 3/7 5/6
Sensitivity 0.500 0.769 0.385 0.429 0.833
3CI 0.223-0.777 0.460-0.938 0.151-0.677 0.118-0.798 0.364-0.991
Positive predictive value 0.750 0.833 0.625 0.750 0.833
CI 0.356-0.955 0.509-0.971 0.259-0.898 0.219-0.986 0.364-0.991
Negative prediction rate 17/19 16/18 15/18 23/24 22/23
Specificity 0.894 0.889 0.833 0.958 0.957
CI 0.654-0.981 0.639-0.981 0.577-0.956 0.768-0.998 0.760-0.998
Negative predictive value 0.739 0.842 0.652 0.852 0.957
CI 0.513-0.889 0.585-0.958 0.428-0.828 0.654-0.951 0.760-0.998
Absolute error 0.258 0.161 0.355 0.161 0.069
4ROC error 0.302 0.171 0.391 0.307 0.105
Fisher's exact test P = 0.020 P = < 0.001 P = 0.133 P = 0.027 P = < 0.001
  1. 1Includes Dukes' C1 and C2; 2 Median follow-up time for recurrent disease patients: 33 months; median follow-up time for disease-free patient: 27 months (analysis excludes patients who died through surgical complications - see Table 1); 3CI = 95% confidence interval; 4ROC = receiver-operator characteristics
  2. The KNN algorithm [29] was used in 'leave-one-out' cross-validation prediction with the number of features (marker peaks) specified. Marker peaks were selected using a t-test statistic except for lymph node involvement and invasiveness characteristics of tumour tissue where the SNR test statistic was used.