Correlation between gene mutation status and molecular subtypes
Rectum Adenocarcinoma (Primary solid tumor)
23 May 2013  |  analyses__2013_05_23
Maintainer Information
Citation Information
Maintained by TCGA GDAC Team (Broad Institute/MD Anderson Cancer Center/Harvard Medical School)
Cite as Broad Institute TCGA Genome Data Analysis Center (2013): Correlation between gene mutation status and molecular subtypes. Broad Institute of MIT and Harvard. doi:10.7908/C1VH5KWK
Overview
Introduction

This pipeline computes the correlation between significantly recurrent gene mutations and molecular subtypes.

Summary

Testing the association between mutation status of 3 genes and 7 molecular subtypes across 69 patients, 4 significant findings detected with P value < 0.05 and Q value < 0.25.

  • KRAS mutation correlated to 'MRNA_CHIERARCHICAL' and 'CN_CNMF'.

  • TP53 mutation correlated to 'MRNA_CNMF' and 'MRNA_CHIERARCHICAL'.

Results
Overview of the results

Table 1.  Get Full Table Overview of the association between mutation status of 3 genes and 7 molecular subtypes. Shown in the table are P values (Q values). Thresholded by P value < 0.05 and Q value < 0.25, 4 significant findings detected.

Clinical
Features
MRNA
CNMF
MRNA
CHIERARCHICAL
CN
CNMF
RPPA
CNMF
RPPA
CHIERARCHICAL
MIRSEQ
CNMF
MIRSEQ
CHIERARCHICAL
nMutated (%) nWild-Type Fisher's exact test Fisher's exact test Chi-square test Fisher's exact test Chi-square test Fisher's exact test Fisher's exact test
KRAS 38 (55%) 31 0.249
(1.00)
0.00641
(0.115)
0.00233
(0.0467)
0.83
(1.00)
0.817
(1.00)
0.292
(1.00)
0.0465
(0.79)
TP53 45 (65%) 24 0.000428
(0.00899)
0.00307
(0.0584)
0.21
(1.00)
0.16
(1.00)
0.603
(1.00)
0.812
(1.00)
0.288
(1.00)
APC 57 (83%) 12 0.568
(1.00)
0.849
(1.00)
0.0561
(0.897)
0.362
(1.00)
0.598
(1.00)
0.337
(1.00)
1
(1.00)
'KRAS MUTATION STATUS' versus 'MRNA_CHIERARCHICAL'

P value = 0.00641 (Fisher's exact test), Q value = 0.12

Table S1.  Gene #2: 'KRAS MUTATION STATUS' versus Clinical Feature #2: 'MRNA_CHIERARCHICAL'

nPatients CLUS_1 CLUS_2 CLUS_3
ALL 23 26 15
KRAS MUTATED 16 8 11
KRAS WILD-TYPE 7 18 4

Figure S1.  Get High-res Image Gene #2: 'KRAS MUTATION STATUS' versus Clinical Feature #2: 'MRNA_CHIERARCHICAL'

'KRAS MUTATION STATUS' versus 'CN_CNMF'

P value = 0.00233 (Chi-square test), Q value = 0.047

Table S2.  Gene #2: 'KRAS MUTATION STATUS' versus Clinical Feature #3: 'CN_CNMF'

nPatients CLUS_1 CLUS_2 CLUS_3 CLUS_4 CLUS_5
ALL 1 15 17 25 10
KRAS MUTATED 1 3 7 19 8
KRAS WILD-TYPE 0 12 10 6 2

Figure S2.  Get High-res Image Gene #2: 'KRAS MUTATION STATUS' versus Clinical Feature #3: 'CN_CNMF'

'TP53 MUTATION STATUS' versus 'MRNA_CNMF'

P value = 0.000428 (Fisher's exact test), Q value = 0.009

Table S3.  Gene #3: 'TP53 MUTATION STATUS' versus Clinical Feature #1: 'MRNA_CNMF'

nPatients CLUS_1 CLUS_2 CLUS_3
ALL 24 21 19
TP53 MUTATED 8 15 17
TP53 WILD-TYPE 16 6 2

Figure S3.  Get High-res Image Gene #3: 'TP53 MUTATION STATUS' versus Clinical Feature #1: 'MRNA_CNMF'

'TP53 MUTATION STATUS' versus 'MRNA_CHIERARCHICAL'

P value = 0.00307 (Fisher's exact test), Q value = 0.058

Table S4.  Gene #3: 'TP53 MUTATION STATUS' versus Clinical Feature #2: 'MRNA_CHIERARCHICAL'

nPatients CLUS_1 CLUS_2 CLUS_3
ALL 23 26 15
TP53 MUTATED 8 20 12
TP53 WILD-TYPE 15 6 3

Figure S4.  Get High-res Image Gene #3: 'TP53 MUTATION STATUS' versus Clinical Feature #2: 'MRNA_CHIERARCHICAL'

Methods & Data
Input
  • Mutation data file = READ-TP.mutsig.cluster.txt

  • Molecular subtypes file = READ-TP.transferedmergedcluster.txt

  • Number of patients = 69

  • Number of significantly mutated genes = 3

  • Number of Molecular subtypes = 7

  • Exclude genes that fewer than K tumors have mutations, K = 3

Fisher's exact test

For binary or multi-class clinical features (nominal or ordinal), two-tailed Fisher's exact tests (Fisher 1922) were used to estimate the P values using the 'fisher.test' function in R

Chi-square test

For multi-class clinical features (nominal or ordinal), Chi-square tests (Greenwood and Nikulin 1996) were used to estimate the P values using the 'chisq.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

This is an experimental feature. The full results of the analysis summarized in this report can be downloaded from the TCGA Data Coordination Center.

References
[1] Fisher, R.A., On the interpretation of chi-square from contingency tables, and the calculation of P, Journal of the Royal Statistical Society 85(1):87-94 (1922)
[2] Greenwood and Nikulin, A guide to chi-squared testing, Wiley, New York. ISBN 047155779X (1996)
[3] 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)