Data Collection

TCGA

TCGA somatic mutations (mc3.v0.2.8 version) were downloaded from (https://gdc.cancer.gov/about-data/publications/pancanatlas). We then grouped mutations according to their patient’s cancer type into 32 different cohorts. Additionally, we kept somatic mutations passing the somatic filtering from TCGA (i.e., column FILTER == “PASS”).

PCAWG

PCAWG somatic mutations were downloaded from the International Cancer Genome Consortium (ICGC) data portal (https://dcc.icgc.org/releases/PCAWG/consensus_snv_indel/). Note that only ICGC samples can be freely downloaded from this site, the TCGA portion of the callsets is controlled data. Instructions on how to obtain them can be found in the same webpage.

cBioPortal

Somatic mutations from Whole Exome Sequencing (WXS) and Whole Genome Sequencing (WGS) cohorts uploaded in cBioPortal that were not part of any other projects included in the analysis (i.e., TCGA, PCAWG, St. Jude or HARTWIG) were downloaded on 2018/09/01 (http://www.cbioportal.org/datasets). We then created cohorts following the next criteria:

  1. Cohorts with a limited number of samples (i.e., lower than 30 samples) associated to cancer types with extensive representation (such as Breast cancer, Prostate cancer or Colorectal adenocarcinoma) across the compendium of cohorts were removed.

  2. Samples were uniquely mapped into one single cohort. If the same sample was originally included in two cohorts, we removed the sample from one of them.

  3. Samples not sequenced from human cancer biopsies were discarded (cell lines, xenografts, normal tissue, etc.).

  4. When patient information was available, only one sample from the same patient was selected. The criteria to prioritize samples from the same patient was: WXS over WGS; untreated over treated, primary over metastasis or relapse and, finally, by alphabetical order. When there is no patient information we assume that all patients have only one sample in the cohort.

  5. When sequencing platform information was available, samples from the same study but with different sequencing platforms were further subclassified into WXS and WGS datasets (only if the resulting cohorts fulfilled the requirements herein described; otherwise, the samples were discarded).

  6. When variant calling information was available, samples from the same cohort and sequencing type were further classified according to their calling algorithm (VarScan, MuTect, etc.). If the resulting cohorts for each subclass fulfilled the requirements herein described, the samples were included;otherwise, the samples were discarded. When variant calling information was not available we assumed that all the samples went through the same pipeline.

  7. When treatment information was available, samples from the same cohort, sequencing type, calling algorithm were further classified according to their treatment status (i.e, treated versus untreated). If the resulting cohorts from the subclassification fulfilled the requirements herein described, the samples were included;otherwise, the samples were discarded. When information was not available we assumed that samples had not been treated.

  8. When biopsy information was available, samples from the same cohort, sequencing type, calling algorithm, treatment status were further classified according to their biopsy type (i.e, primary, relapse or metastasis). If the resulting datasets from the subclassification fulfilled the requirements herein described, the samples were included; otherwise, the samples were discarded. When information was not available we assumed that the biopsy type of the sample was primary.

Hartwig Medical Foundation

Somatic mutations of metastatic WGS from Hartwig Medical Foundation https://www.hartwigmedicalfoundation.nl/en/database/ were downloaded on 2021/10/21 through their platform. Datasets were split according to their primary site. Samples from unknown primary sites (i.e., None, Nan, Unknown, Cup, Na), double primary or aggregating into cohorts of fewer than 5 samples (i.e., Adrenal, Myeloid, Thymus and Eye) were not considered. A total of 25 different cohorts were created.

ICGC

Somatic mutations from Whole Exome Sequencing (WXS) and Whole Genome Sequencing (WGS) studies uploaded in ICGC Data Portal (https://dcc.icgc.org/repositories) not overlapping with other projects included in the analysis (i.e., TCGA, PCAWG, CBIOP or St. Jude) were downloaded from release 2019 on on 2021/10/21. We then created cohorts following the criteria used for the cBioPortal datasets (cBioPortal).

St. Jude

Somatic mutations from Whole Exome Sequencing (WXS) and Whole Genome Sequencing (WGS) of Pediatric Cancer Genome Project uploaded in the St. Jude Cloud (https://www.stjude.cloud/data.html) were downloaded on 2018/07/16. Cohorts were created according to their primary site and their biopsy type (i.e., primary, metastasis and relapse). Resulting datasets with fewer than 5 samples were discarded.

PedcBioPortal

Somatic mutations from Whole Exome Sequencing (WXS) and Whole Genome Sequencing (WGS) studies uploaded in PedcBioPortal that were not part of any other projects included in the analysis (i.e., St. Jude or CBIOP) were downloaded on 2018/10/01 (http://www.pedcbioportal.org/datasets). We then created cohorts following the criteria described in the cBioPortal dataset (cBioPortal).

TARGET

Somatic SNVs from WXS and WGS of four TARGET studies, Neuroblastoma (NB) and Wilms Tumor (WT), from the TARGET consortium were downloaded on 2019/03/07, Osteosarcoma (OS) and Acute Myeloid Leukemia (AML) we downloaded in 2020/09/17 from the Genomic Data Commons Portal.

Beat AML

We downloaded unfiltered somatic mutations from samples included in the Beat AML study from the Genomic Data Commons Portal. We next applied the following criteria to create our Beat AML cohort:

  1. We focused on somatic single nucleotide variants from VarScan2 using skin as normal control. All samples that did not belong to this class were not further analyzed.

  2. Samples from relapses were filtered out.

  3. Samples from bone-marrow transplants were discarded.

  4. If there were several samples per patient fulfilling the points 1-3, we selected the first in chronological order.

257 independent samples of Beat AML tumors composed our Beat AML cohort.

CGCI

Somatic mutations from Whole Genome Sequencing (WGS) of the The Cancer Genome Characterization Initiative (CGCI) were downloaded from the Genomic Data Commons (GDC portal) on 2021/05/06.

CPTAC

Somatic mutations from Whole Exome Sequencing (WXS) of the Clinical Proteomic Tumor Analysis Consortium (CPTAC) were downloaded from the GDC portal on 2021/05/06.

Literature

We also manually collected publicly available cohorts from the literature. Each cohort was filtered following the same steps than mentioned above for the cBioPortal dataset (see above).

Note

For further information of all datasets used in the latest release of intOGen, please visit https://www.intogen.org/beta/download.