Evidence map›Paper›PMID 29415044›Full record

ArticlePLoS computational biology2018

A computational approach to distinguish somatic vs. germline origin of genomic alterations from deep sequencing of cancer specimens without a matched normal.

James X Sun, Yuting He, Eric Sanford, Meagan Montesion, Garrett M Frampton, Stéphane Vignot, Jean-Charles Soria, Jeffrey S Ross, Vincent A Miller, Phil J Stephens and 2 more

Abstract read
In one paragraph

Article in PLoS computational biology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 166 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
166citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

166 citing papers in PubMed, 2 syntheses or guidelines pooled it.

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  15. Tissue-Specific Prevalence and Clonal Architecture ofbioRxiv : the preprint server for biology · 2026
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  18. Cancer genomic profiling predicts pathogenicity ofmedRxiv : the preprint server for health sciences · 2026
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106 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

James X SunFoundation Medicine, Inc., Cambridge, MA, United States of America.ORCID 0000-0003-0475-9391
Yuting HeFoundation Medicine, Inc., Cambridge, MA, United States of America.
Eric SanfordFoundation Medicine, Inc., Cambridge, MA, United States of America.ORCID 0000-0002-9232-9334
Meagan MontesionFoundation Medicine, Inc., Cambridge, MA, United States of America.ORCID 0000-0001-9155-556X
Garrett M FramptonFoundation Medicine, Inc., Cambridge, MA, United States of America.
Stéphane VignotInstitut National de la Santé et de la Recherche Médicale (INSERM) U981, Gustave Roussy, Villejuif Grand, Paris, France.ORCID 0000-0002-1292-6631
Jean-Charles SoriaInstitut National de la Santé et de la Recherche Médicale (INSERM) U981, Gustave Roussy, Villejuif Grand, Paris, France.
Jeffrey S RossFoundation Medicine, Inc., Cambridge, MA, United States of America.
Vincent A MillerFoundation Medicine, Inc., Cambridge, MA, United States of America.
Phil J StephensFoundation Medicine, Inc., Cambridge, MA, United States of America.
Doron LipsonFoundation Medicine, Inc., Cambridge, MA, United States of America.
Roman YelenskyFoundation Medicine, Inc., Cambridge, MA, United States of America.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

A key constraint in genomic testing in oncology is that matched normal specimens are not commonly obtained in clinical practice. Thus, while well-characterized genomic alterations do not require normal tissue for interpretation, a significant number of alterations will be unknown in whether they are germline or somatic, in the absence of a matched normal control. We introduce SGZ (somatic-germline-zygosity), a computational method for predicting somatic vs. germline origin and homozygous vs. heterozygous or sub-clonal state of variants identified from deep massively parallel sequencing (MPS) of cancer specimens. The method does not require a patient matched normal control, enabling broad application in clinical research. SGZ predicts the somatic vs. germline status of each alteration identified by modeling the alteration's allele frequency (AF), taking into account the tumor content, tumor ploidy, and the local copy number. Accuracy of the prediction depends on the depth of sequencing and copy number model fit, which are achieved in our clinical assay by sequencing to high depth (>500x) using MPS, covering 394 cancer-related genes and over 3,500 genome-wide single nucleotide polymorphisms (SNPs). Calls are made using a statistic based on read depth and local variability of SNP AF. To validate the method, we first evaluated performance on samples from 30 lung and colon cancer patients, where we sequenced tumors and matched normal tissue. We examined predictions for 17 somatic hotspot mutations and 20 common germline SNPs in 20,182 clinical cancer specimens. To assess the impact of stromal admixture, we examined three cell lines, which were titrated with their matched normal to six levels (10-75%). Overall, predictions were made in 85% of cases, with 95-99% of variants predicted correctly, a significantly superior performance compared to a basic approach based on AF alone. We then applied the SGZ method to the COSMIC database of known somatic variants in cancer and found >50 that are in fact more likely to be germline.

Indexed as

Computational BiologyGerm-Line MutationHigh-Throughput Nucleotide SequencingAlgorithmsAllelesBreast NeoplasmsCarcinoma, Non-Small-Cell LungColonic NeoplasmsComputer SimulationDatabases, GeneticDNA Copy Number VariationsExomeExonsFemaleGene FrequencyGenome, Human

Identifiers

PMID29415044
PMCPMC5832436

What OpenQuestion holds

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LicenceCC BY
Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.