Table 2.

Associations between clinical characteristics and Prediction Analysis of Microarray class predictions (stage A like or D like) based on 128 metastasis-associated genes for 95 stage B and 93 stage C colorectal cancer patients

Stage B patientsStage C patients
Stage A–like (n = 36)Stage D–like (n = 45)Not classified (n = 13)P*PStage A–like (n = 27)Stage D–like (n = 48)Not classified (n = 16)P*P
Age
    Median, range66 (43-86)71 (30-92)71 (38-92)0.9460.78971 (26-84)63.5 (26-90)69 (30-81)0.1470.719
Gender
    Female172260.8271171890.0990.583
    Male2023712307
T stage
    T20.3230.0514410.5370.137
    T3344410234212
    T4313223
N stage
    N12530120.0371
    N24184
Lymph nodes examined
    Median, range15 (1-33)10 (1-31)14 (5-51)0.0800.33313 (3-37)14.5 (4-73)12 (6-43)0.3910.506
Tumor location
    Colon31381310.2032544140.4660.680
    Rectum670442
Adjuvant therapy
    No2934100.7991101440.6230.769
    Yes8113193412

NOTE: For single-sample Prediction Analysis of Microarray classification, previous (expected) 6-year recurrence probabilities were set as 20% for stage B and 40% for stage C patients based on relapse rates observed in clinical practice (21). Class predictions with a >90% probability were scored. The Welch two-sample t test was used for age and lymph nodes examined, and the Fisher's exact test was used for all other clinical variables. The number of lymph nodes examined was not available for five stage B and two stage C patients.

  • *The P values are for the comparison of stage A–like with stage D–like patients.

  • The P values are for the comparison of classified with not classified patients.