Correlation between APOBEC groups and selected clinical features
Head and Neck Squamous Cell Carcinoma (Primary solid tumor)
02 April 2015  |  analyses__2015_04_02
Maintainer Information
Citation Information
Maintained by Hailei Zhang (Broad Institute)
Cite as Broad Institute TCGA Genome Data Analysis Center (2015): Correlation between APOBEC groups and selected clinical features. Broad Institute of MIT and Harvard. doi:10.7908/C1RB73M9
Overview
Introduction

This pipeline computes the correlation between APOBRC groups and selected clinical features.

Summary

Testing the association between APOBEC groups identified by 2 different apobec score and 13 clinical features across 506 patients, 6 significant findings detected with Q value < 0.25.

  • 3 subtypes identified in current cancer cohort by 'APOBEC MUTLOAD MINESTIMATE'. These subtypes correlate to 'YEARS_TO_BIRTH',  'PATHOLOGY_T_STAGE',  'GENDER', and 'NUMBER_PACK_YEARS_SMOKED'.

  • 3 subtypes identified in current cancer cohort by 'APOBEC ENRICH'. These subtypes correlate to 'YEARS_TO_BIRTH' and 'GENDER'.

Results
Overview of the results

Table 1.  Get Full Table Overview of the association between APOBEC groups by 2 different APOBEC scores and 13 clinical features. Shown in the table are P values (Q values). Thresholded by Q value < 0.25, 6 significant findings detected.

Clinical
Features
Statistical
Tests
APOBEC
MUTLOAD
MINESTIMATE
APOBEC
ENRICH
Time to Death logrank test 0.297
(0.482)
0.276
(0.481)
YEARS TO BIRTH Kruskal-Wallis (anova) 0.000134
(0.00348)
0.000487
(0.00633)
NEOPLASM DISEASESTAGE Fisher's exact test 0.147
(0.426)
0.214
(0.467)
PATHOLOGY T STAGE Fisher's exact test 0.00937
(0.0487)
0.278
(0.481)
PATHOLOGY N STAGE Fisher's exact test 0.462
(0.614)
0.47
(0.614)
GENDER Fisher's exact test 0.00085
(0.00737)
0.00119
(0.00773)
HISTOLOGICAL TYPE Fisher's exact test 0.844
(0.864)
0.696
(0.787)
RADIATIONS RADIATION REGIMENINDICATION Fisher's exact test 0.416
(0.614)
0.759
(0.822)
NUMBER PACK YEARS SMOKED Kruskal-Wallis (anova) 0.0195
(0.0846)
0.107
(0.369)
YEAR OF TOBACCO SMOKING ONSET Kruskal-Wallis (anova) 0.273
(0.481)
0.216
(0.467)
NUMBER OF LYMPH NODES Kruskal-Wallis (anova) 0.529
(0.625)
0.114
(0.369)
RACE Fisher's exact test 0.207
(0.467)
0.484
(0.614)
ETHNICITY Fisher's exact test 0.864
(0.864)
0.496
(0.614)
APOBEC group #1: 'APOBEC MUTLOAD MINESTIMATE'

Table S1.  Description of APOBEC group #1: 'APOBEC MUTLOAD MINESTIMATE'

Cluster Labels 0 HIGH LOW
Number of samples 252 127 127
'APOBEC MUTLOAD MINESTIMATE' versus 'YEARS_TO_BIRTH'

P value = 0.000134 (Kruskal-Wallis (anova)), Q value = 0.0035

Table S2.  Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #2: 'YEARS_TO_BIRTH'

nPatients Mean (Std.Dev)
ALL 506 61.0 (12.0)
0 252 58.5 (12.3)
HIGH 127 64.6 (11.2)
LOW 127 62.4 (11.2)

Figure S1.  Get High-res Image Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #2: 'YEARS_TO_BIRTH'

'APOBEC MUTLOAD MINESTIMATE' versus 'PATHOLOGY_T_STAGE'

P value = 0.00937 (Fisher's exact test), Q value = 0.049

Table S3.  Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #4: 'PATHOLOGY_T_STAGE'

nPatients T0+T1 T2 T3 T4
ALL 48 131 98 168
0 28 72 46 76
HIGH 7 24 19 57
LOW 13 35 33 35

Figure S2.  Get High-res Image Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #4: 'PATHOLOGY_T_STAGE'

'APOBEC MUTLOAD MINESTIMATE' versus 'GENDER'

P value = 0.00085 (Fisher's exact test), Q value = 0.0074

Table S4.  Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #6: 'GENDER'

nPatients FEMALE MALE
ALL 139 367
0 52 200
HIGH 49 78
LOW 38 89

Figure S3.  Get High-res Image Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #6: 'GENDER'

'APOBEC MUTLOAD MINESTIMATE' versus 'NUMBER_PACK_YEARS_SMOKED'

P value = 0.0195 (Kruskal-Wallis (anova)), Q value = 0.085

Table S5.  Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #9: 'NUMBER_PACK_YEARS_SMOKED'

nPatients Mean (Std.Dev)
ALL 282 45.5 (35.6)
0 153 44.7 (35.1)
HIGH 58 39.7 (31.7)
LOW 71 52.2 (39.0)

Figure S4.  Get High-res Image Clustering Approach #1: 'APOBEC MUTLOAD MINESTIMATE' versus Clinical Feature #9: 'NUMBER_PACK_YEARS_SMOKED'

APOBEC group #2: 'APOBEC ENRICH'

Table S6.  Description of APOBEC group #2: 'APOBEC ENRICH'

Cluster Labels FC.HIGH.SIG FC.LOW.NONSIG FC.NEUTRAL
Number of samples 220 251 35
'APOBEC ENRICH' versus 'YEARS_TO_BIRTH'

P value = 0.000487 (Kruskal-Wallis (anova)), Q value = 0.0063

Table S7.  Clustering Approach #2: 'APOBEC ENRICH' versus Clinical Feature #2: 'YEARS_TO_BIRTH'

nPatients Mean (Std.Dev)
ALL 506 61.0 (12.0)
FC.HIGH.SIG 220 63.6 (11.2)
FC.LOW.NONSIG 251 58.6 (12.3)
FC.NEUTRAL 35 61.9 (12.0)

Figure S5.  Get High-res Image Clustering Approach #2: 'APOBEC ENRICH' versus Clinical Feature #2: 'YEARS_TO_BIRTH'

'APOBEC ENRICH' versus 'GENDER'

P value = 0.00119 (Fisher's exact test), Q value = 0.0077

Table S8.  Clustering Approach #2: 'APOBEC ENRICH' versus Clinical Feature #6: 'GENDER'

nPatients FEMALE MALE
ALL 139 367
FC.HIGH.SIG 74 146
FC.LOW.NONSIG 51 200
FC.NEUTRAL 14 21

Figure S6.  Get High-res Image Clustering Approach #2: 'APOBEC ENRICH' versus Clinical Feature #6: 'GENDER'

Methods & Data
Input
  • APOBEC groups file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/APOBEC_Pipelines/HNSC-TP/15648694/APOBEC_clinical_corr_input_15648744/APOBEC_for_clinical.correlaion.input.categorical.txt

  • Clinical data file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/Append_Data/HNSC-TP/15078978/HNSC-TP.merged_data.txt

  • Number of patients = 506

  • Number of selected clinical features = 13

APOBEC classification

APOBEC classification based on APOBEC_MutLoad_MinEstimate : a. APOBEC non group -- samples with zero value, b. APOBEC hig group -- samples above median value in non zero samples, c. APOBEC hig group -- samples below median value in non zero samples.

APOBEC classification based on APOBEC_enrich : a. No Enrichmment group -- all samples with BH_Fisher_p-value_tCw >=0.05, b. Small enrichment group -- samples with BH_Fisher_p-value_tCw = < 0.05 and APOBEC_enrich=<2, c. High enrichment gruop -- samples with BH_Fisher_p-value_tCw =< 0.05 and APOBEC_enrich>2.

Survival analysis

For survival clinical features, the Kaplan-Meier survival curves of tumors with and without gene mutations were plotted and the statistical significance P values were estimated by logrank test (Bland and Altman 2004) using the 'survdiff' function in R

Fisher's exact test

For binary clinical features, two-tailed Fisher's exact tests (Fisher 1922) were used to estimate the P values using the 'fisher.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] Bland and Altman, Statistics notes: The logrank test, BMJ 328(7447):1073 (2004)
[2] 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)
[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)