Correlation between APOBEC groups and selected clinical features
Skin Cutaneous Melanoma (Metastatic)
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/C19P30RR
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 14 clinical features across 288 patients, no significant finding detected with Q value < 0.25.

  • 3 subtypes identified in current cancer cohort by 'APOBEC MUTLOAD MINESTIMATE'. These subtypes do not correlate to any clinical features.

  • 3 subtypes identified in current cancer cohort by 'APOBEC ENRICH'. These subtypes do not correlate to any clinical features.

Results
Overview of the results

Table 1.  Get Full Table Overview of the association between APOBEC groups by 2 different APOBEC scores and 14 clinical features. Shown in the table are P values (Q values). Thresholded by Q value < 0.25, no significant finding detected.

Clinical
Features
Statistical
Tests
APOBEC
MUTLOAD
MINESTIMATE
APOBEC
ENRICH
Time from Specimen Diagnosis to Death logrank test 0.12
(0.419)
0.486
(0.833)
Time to Death logrank test 0.353
(0.779)
0.579
(0.833)
YEARS TO BIRTH Kruskal-Wallis (anova) 0.0657
(0.263)
0.734
(0.833)
PRIMARY SITE OF DISEASE Fisher's exact test 0.444
(0.833)
0.735
(0.833)
NEOPLASM DISEASESTAGE Fisher's exact test 0.617
(0.833)
0.336
(0.779)
PATHOLOGY T STAGE Fisher's exact test 0.626
(0.833)
0.243
(0.757)
PATHOLOGY N STAGE Fisher's exact test 0.35
(0.779)
0.752
(0.833)
PATHOLOGY M STAGE Fisher's exact test 0.725
(0.833)
0.654
(0.833)
MELANOMA ULCERATION Fisher's exact test 0.0548
(0.256)
0.0278
(0.256)
MELANOMA PRIMARY KNOWN Fisher's exact test 0.362
(0.779)
0.669
(0.833)
BRESLOW THICKNESS Kruskal-Wallis (anova) 0.868
(0.9)
0.773
(0.833)
GENDER Fisher's exact test 0.0213
(0.256)
0.458
(0.833)
RACE Fisher's exact test 0.048
(0.256)
0.0377
(0.256)
ETHNICITY Fisher's exact test 1
(1.00)
0.0164
(0.256)
APOBEC group #1: 'APOBEC MUTLOAD MINESTIMATE'

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

Cluster Labels 0 HIGH LOW
Number of samples 85 70 133
APOBEC group #2: 'APOBEC ENRICH'

Table S2.  Description of APOBEC group #2: 'APOBEC ENRICH'

Cluster Labels FC.HIGH.SIG FC.LOW.NONSIG FC.NEUTRAL
Number of samples 4 83 201
Methods & Data
Input
  • APOBEC groups file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/APOBEC_Pipelines/SKCM-TM/15234021/APOBEC_clinical_corr_input_15234069/APOBEC_for_clinical.correlaion.input.categorical.txt

  • Clinical data file = /xchip/cga/gdac-prod/tcga-gdac/jobResults/Append_Data/SKCM-TM/15087681/SKCM-TM.merged_data.txt

  • Number of patients = 288

  • Number of selected clinical features = 14

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)