A DNA swab solves the mystery of the origin of cancer

Is knowing where your ancestors came from the key to better cancer treatment? Maybe, but where to put the keys? How do we find modern solutions from the root causes of cancer? For Alexander Krasnitz, a research professor at the Cold Spring Harbor Laboratory (CSHL), the answer may lie deep in
vast databases and hospital archives containing hundreds of thousands of tumor samples.

Krasnitz and CSHL postdoc Pascal Belleau are working to uncover a lineage link
between cancer and race or ethnicity.
They developed a new software that accurately infers continental ancestry
from tumor DNA and RNA.
Their work could also help clinicians develop new strategies
for early cancer detection and personalized treatment.

"Why do people of different races and ethnicities have different rates of developing different types of cancer?" Krasnitz said
.
"They have different habits, living conditions, exposure to various social and environmental factors
.
But there may also be genetic factors
.
”

Krasnitz's team used hybrid DNA profiles to train their software tools
.
They created these profiles
from cancers of known background and unrelated cancer-free genomes.
They then tested the software's performance
on specimens from patients with pancreatic, ovarian, breast, and blood cancers of known ancestry.
The team found that the software matched their mixed features with continental populations with more than 95 percent
accuracy.

Krasnitz said: "We have a good development model
.
But very few come from a single ancestor
.
In a way
, we are all mixed together.
So now we're digging deeper, testing tumor samples of unknown ancestors, revealing ancestral mixtures, and achieving more regional specificity
.
"How? Now, compare West Africa with East Africa
.

Krasnitz and Belleau recently joined a colorectal cancer study
in collaboration with Northwell Health and SUNY Lower State Medical Center.
This study allowed them to explore how colorectal cancer mutates genes
in different ways depending on specific races or ethnicities.
They hope to further refine their software to infer the ancestry of not only the entire genome, but also each individual sequence within it
.

"If we can identify more local ancestors that are susceptible to different cancers or other aggressive diseases, we can help us identify the specific parts of the genome that are responsible and treat
them," Belleau said.

Now, a simple DNA swab can tell you where you're from and what diseases
you might inherit.
In the future, it may also give you the means to
beat them.

Pascal Belleau, Astrid Deschê nes, Nyasha Chambwe, David A.
Tuveson, Alexander Krasnitz.
Genetic Ancestry Inference from Cancer-Derived Molecular Data across Genomic and Transcriptomic Platforms.
Cancer Research