Correlation between mRNAseq expression and clinical features
Esophageal Carcinoma (Primary solid tumor)
17 October 2014  |  analyses__2014_10_17
Maintainer Information
Citation Information
Maintained by Juok Cho (Broad Institute)
Cite as Broad Institute TCGA Genome Data Analysis Center (2014): Correlation between mRNAseq expression and clinical features. Broad Institute of MIT and Harvard. doi:10.7908/C12V2F0F
Overview
Introduction

This pipeline uses various statistical tests to identify mRNAs whose log2 expression levels correlated to selected clinical features.

Summary

Testing the association between 23512 genes and 9 clinical features across 108 samples, statistically thresholded by P value < 0.05 and Q value < 0.3, 4 clinical features related to at least one genes.

  • 80 genes correlated to 'AGE'.

    • RIPK3|11035_CALCULATED ,  CBX1|10951_CALCULATED ,  SIX1|6495_CALCULATED ,  MCM2|4171_CALCULATED ,  KIF3C|3797_CALCULATED ,  ...

  • 13 genes correlated to 'PATHOLOGY.T.STAGE'.

    • R3HDML|140902_CALCULATED ,  RAP1GAP2|23108_CALCULATED ,  NHSL1|57224_CALCULATED ,  TNFRSF11A|8792_CALCULATED ,  PLEKHG6|55200_CALCULATED ,  ...

  • 1 gene correlated to 'GENDER'.

    • TXLNG2P|246126_CALCULATED

  • 1109 genes correlated to 'RACE'.

    • RNF217|154214_CALCULATED ,  TMC5|79838_CALCULATED ,  HAP1|9001_CALCULATED ,  TMTC3|160418_CALCULATED ,  ALOX12P2|245_CALCULATED ,  ...

  • No genes correlated to 'Time to Death', 'NEOPLASM.DISEASESTAGE', 'PATHOLOGY.N.STAGE', 'PATHOLOGY.M.STAGE', and 'NUMBERPACKYEARSSMOKED'.

Results
Overview of the results

Complete statistical result table is provided in Supplement Table 1

Table 1.  Get Full Table This table shows the clinical features, statistical methods used, and the number of genes that are significantly associated with each clinical feature at P value < 0.05 and Q value < 0.3.

Clinical feature Statistical test Significant genes Associated with                 Associated with
Time to Death Cox regression test   N=0        
AGE Spearman correlation test N=80 older N=14 younger N=66
NEOPLASM DISEASESTAGE Kruskal-Wallis test   N=0        
PATHOLOGY T STAGE Spearman correlation test N=13 higher stage N=1 lower stage N=12
PATHOLOGY N STAGE Spearman correlation test   N=0        
PATHOLOGY M STAGE Kruskal-Wallis test   N=0        
GENDER Wilcoxon test N=1 male N=1 female N=0
NUMBERPACKYEARSSMOKED Spearman correlation test   N=0        
RACE Wilcoxon test N=1109 white N=1109 asian N=0
Clinical variable #1: 'Time to Death'

No gene related to 'Time to Death'.

Table S1.  Basic characteristics of clinical feature: 'Time to Death'

Time to Death Duration (Months) 0-122.1 (median=4.9)
  censored N = 67
  death N = 34
     
  Significant markers N = 0
Clinical variable #2: 'AGE'

80 genes related to 'AGE'.

Table S2.  Basic characteristics of clinical feature: 'AGE'

AGE Mean (SD) 62.52 (12)
  Significant markers N = 80
  pos. correlated 14
  neg. correlated 66
List of top 10 genes differentially expressed by 'AGE'

Table S3.  Get Full Table List of top 10 genes significantly correlated to 'AGE' by Spearman correlation test

SpearmanCorr corrP Q
RIPK3|11035_CALCULATED 0.4809 1.378e-07 0.00324
CBX1|10951_CALCULATED -0.4763 1.889e-07 0.00444
SIX1|6495_CALCULATED -0.4759 1.934e-07 0.00455
MCM2|4171_CALCULATED -0.4747 2.094e-07 0.00492
KIF3C|3797_CALCULATED -0.4625 4.66e-07 0.011
TMC5|79838_CALCULATED 0.4622 4.776e-07 0.0112
CDC7|8317_CALCULATED -0.4596 5.625e-07 0.0132
HIST1H2BO|8348_CALCULATED -0.4571 7.448e-07 0.0175
WDHD1|11169_CALCULATED -0.4519 9.16e-07 0.0215
MCM5|4174_CALCULATED -0.4517 9.282e-07 0.0218
Clinical variable #3: 'NEOPLASM.DISEASESTAGE'

No gene related to 'NEOPLASM.DISEASESTAGE'.

Table S4.  Basic characteristics of clinical feature: 'NEOPLASM.DISEASESTAGE'

NEOPLASM.DISEASESTAGE Labels N
  STAGE I 7
  STAGE IA 4
  STAGE IB 4
  STAGE II 1
  STAGE IIA 30
  STAGE IIB 17
  STAGE III 11
  STAGE IIIA 8
  STAGE IIIB 7
  STAGE IIIC 3
  STAGE IV 2
     
  Significant markers N = 0
Clinical variable #4: 'PATHOLOGY.T.STAGE'

13 genes related to 'PATHOLOGY.T.STAGE'.

Table S5.  Basic characteristics of clinical feature: 'PATHOLOGY.T.STAGE'

PATHOLOGY.T.STAGE Mean (SD) 2.35 (0.86)
  N
  0 1
  1 19
  2 26
  3 49
  4 3
     
  Significant markers N = 13
  pos. correlated 1
  neg. correlated 12
List of top 10 genes differentially expressed by 'PATHOLOGY.T.STAGE'

Table S6.  Get Full Table List of top 10 genes significantly correlated to 'PATHOLOGY.T.STAGE' by Spearman correlation test

SpearmanCorr corrP Q
R3HDML|140902_CALCULATED -0.6038 1.342e-06 0.0315
RAP1GAP2|23108_CALCULATED -0.4539 2.676e-06 0.0629
NHSL1|57224_CALCULATED -0.4508 3.19e-06 0.075
TNFRSF11A|8792_CALCULATED -0.443 4.934e-06 0.116
PLEKHG6|55200_CALCULATED -0.4417 5.293e-06 0.124
DDIT4L|115265_CALCULATED 0.4435 5.369e-06 0.126
SEC16B|89866_CALCULATED -0.4387 6.236e-06 0.147
CPT1A|1374_CALCULATED -0.4358 7.271e-06 0.171
ACOT11|26027_CALCULATED -0.4341 7.998e-06 0.188
PLCB3|5331_CALCULATED -0.4313 9.256e-06 0.218
Clinical variable #5: 'PATHOLOGY.N.STAGE'

No gene related to 'PATHOLOGY.N.STAGE'.

Table S7.  Basic characteristics of clinical feature: 'PATHOLOGY.N.STAGE'

PATHOLOGY.N.STAGE Mean (SD) 0.63 (0.78)
  N
  0 51
  1 34
  2 9
  3 3
     
  Significant markers N = 0
Clinical variable #6: 'PATHOLOGY.M.STAGE'

No gene related to 'PATHOLOGY.M.STAGE'.

Table S8.  Basic characteristics of clinical feature: 'PATHOLOGY.M.STAGE'

PATHOLOGY.M.STAGE Labels N
  M0 77
  M1 1
  M1A 1
  MX 15
     
  Significant markers N = 0
Clinical variable #7: 'GENDER'

One gene related to 'GENDER'.

Table S9.  Basic characteristics of clinical feature: 'GENDER'

GENDER Labels N
  FEMALE 16
  MALE 92
     
  Significant markers N = 1
  Higher in MALE 1
  Higher in FEMALE 0
List of one gene differentially expressed by 'GENDER'

Table S10.  Get Full Table List of one gene differentially expressed by 'GENDER'. 9 significant gene(s) located in sex chromosomes is(are) filtered out.

W(pos if higher in 'MALE') wilcoxontestP Q AUC
TXLNG2P|246126_CALCULATED 644 1.14e-05 0.268 1
Clinical variable #8: 'NUMBERPACKYEARSSMOKED'

No gene related to 'NUMBERPACKYEARSSMOKED'.

Table S11.  Basic characteristics of clinical feature: 'NUMBERPACKYEARSSMOKED'

NUMBERPACKYEARSSMOKED Mean (SD) 35.68 (20)
  Significant markers N = 0
Clinical variable #9: 'RACE'

1109 genes related to 'RACE'.

Table S12.  Basic characteristics of clinical feature: 'RACE'

RACE Labels N
  ASIAN 36
  WHITE 68
     
  Significant markers N = 1109
  Higher in WHITE 1109
  Higher in ASIAN 0
List of top 10 genes differentially expressed by 'RACE'

Table S13.  Get Full Table List of top 10 genes differentially expressed by 'RACE'

W(pos if higher in 'WHITE') wilcoxontestP Q AUC
RNF217|154214_CALCULATED 259 4.394e-11 1.03e-06 0.8942
TMC5|79838_CALCULATED 2185 5.28e-11 1.24e-06 0.8926
HAP1|9001_CALCULATED 270 9.771e-11 2.3e-06 0.8881
TMTC3|160418_CALCULATED 283 1.309e-10 3.08e-06 0.8844
ALOX12P2|245_CALCULATED 284.5 1.399e-10 3.29e-06 0.8838
TSPAN8|7103_CALCULATED 2081.5 1.513e-10 3.56e-06 0.8876
STL|7955_CALCULATED 288 1.635e-10 3.84e-06 0.8824
KLRG2|346689_CALCULATED 247 2.135e-10 5.02e-06 0.8875
LRP12|29967_CALCULATED 300 2.791e-10 6.56e-06 0.8775
CAGE1|285782_CALCULATED 295 2.992e-10 7.03e-06 0.8777
Methods & Data
Input
  • Expresson data file = ESCA-TP.mRNAseq_RPKM_log2.txt

  • Clinical data file = ESCA-TP.merged_data.txt

  • Number of patients = 108

  • Number of genes = 23512

  • Number of clinical features = 9

Survival analysis

For survival clinical features, Wald's test in univariate Cox regression analysis with proportional hazards model (Andersen and Gill 1982) was used to estimate the P values using the 'coxph' function in R. Kaplan-Meier survival curves were plot using the four quartile subgroups of patients based on expression levels

Correlation analysis

For continuous numerical clinical features, Spearman's rank correlation coefficients (Spearman 1904) and two-tailed P values were estimated using 'cor.test' function in R

ANOVA analysis

For multi-class clinical features (ordinal or nominal), one-way analysis of variance (Howell 2002) was applied to compare the log2-expression levels between different clinical classes using 'anova' function in R

Student's t-test analysis

For two-class clinical features, two-tailed Student's t test with unequal variance (Lehmann and Romano 2005) was applied to compare the log2-expression levels between the two clinical classes using 't.test' function in R

Q value calculation

For multiple hypothesis correction, Q value is the False Discovery Rate (FDR) analogue of the P value (Benjamini and Hochberg 1995), defined as the minimum FDR at which the test may be called significant. We used the 'Benjamini and Hochberg' method of 'p.adjust' function in R to convert P values into Q values.

Download Results

In addition to the links below, the full results of the analysis summarized in this report can also be downloaded programmatically using firehose_get, or interactively from either the Broad GDAC website or TCGA Data Coordination Center Portal.

References
[1] Andersen and Gill, Cox's regression model for counting processes, a large sample study, Annals of Statistics 10(4):1100-1120 (1982)
[2] Spearman, C, The proof and measurement of association between two things, Amer. J. Psychol 15:72-101 (1904)
[3] Howell, D, Statistical Methods for Psychology. (5th ed.), Duxbury Press:324-5 (2002)
[4] Lehmann and Romano, Testing Statistical Hypotheses (3E ed.), New York: Springer. ISBN 0387988645 (2005)
[5] Benjamini and Hochberg, Controlling the false discovery rate: a practical and powerful approach to multiple testing, Journal of the Royal Statistical Society Series B 59:289-300 (1995)