Cancer: Not smoking or any other bad habits, these genomic pattern decides your cancer risk

Rewriting the textbook explanation of why some people are at a higher risk of developing cancer, researchers from the University of Calgary have for the first time discovered seven DNA fingerprints or

By: Satata Karmakar | | Published: December 24, 2020 12:55 pm

Cancer: These DNA fingerprints can define cancer risk in people

Rewriting the textbook explanation of why some people are at a higher risk of developing cancer, researchers from the University of Calgary have for the first time discovered seven DNA fingerprints or patterns that define cancer risk in people, offering new insight into the multi-generational disease risk. Also Read - Thyroid cancer: In-utero exposures can increase your risk of this disease

Lifestyle, or put another way ‘bad habits’, is one of the textbook explanations for why some people are at higher risk for cancer. Also Read - Make these diet and lifestyle changes to reduce the risk of cancer

NOT ALL SMOKERS GET LUNG CANCER

But not all smokers get lung cancer and not all people who eat cheeseburgers get bowel cancer, and ‘other factors’ must be at play. Also Read - Pancreatic cancer can creep up silently: Be aware of the symptoms for early diagnosis and treatment

“This discovery rewrites the textbook explanation that cancer occurs because of human behavior combined with some bad luck to include one’s genetic make-up,” said University of Calgary scientist Dr. Edwin Wang.

“We believe that a baby is born with a germline genomic pattern and it will not change, and that pattern is associated with a lower or higher cancer risk,” he said in a paper published in the journal Science Advances.

Germline represents the cells that determine our children and the DNA that is passed from parent to child.

HIGHLY-SPECIALISED BIOLOGICAL PATTERNS APPLICABLE TO CANCER RISK

It is the first time scientists have described these highly-specialized biological patterns applicable to cancer risk.

Wang found that the DNA fingerprints could be classified into subgroups with distinct survival rates.

One of the seven germlines offers protection from developing cancer, and the other six germlines present a greater risk for cancer.

“It is interesting that one of these germlines is protective against developing cancer and it appeared frequently in our analysis of genomes,” noted Wang, a professor in the CSM’s Department of Biochemistry and Molecular Biology.

“We know there are individuals who can smoke and have an unhealthy lifestyle but never get cancer, and this discovery may explain that phenomena.”

10% OF CANCERS ARE CAUSED BY SPECIFIC GENE MUTATIONS

For this research, Wang conducted a massive systematic analysis of more than 26,000 germline genomes of individuals, about 10,000 people who had cancer, and the rest without.

The samples include 22 distinct cancers, including lung, pancreatic, bladder, breast, brain, stomach, thyroid, and bone, and a dozen more.

The control group of people without cancer included genomic-sequenced groups from Sweden, England, and Canada.

The massive quantities of data were crunched using machine learning.

Wang said that between five to 10 per cent of cancers are caused by specific gene mutations.

Think of breast cancer and the inherited gene BRCA1 and BRCA2, a gene mutation made widely known by actor Angelina Jolie.

“We found that one DNA-fingerprint was enriched tens to hundreds of times in germline genomes of cancer patients, suggesting that it is a universal inheritable trait encoding cancer risk,” the scientist noted.

BEWARE! SMOKERS BEARING SUCH DNA PATTERNS ARE AT HIGHER RISK

The research also uncovered that another DNA-fingerprint was highly enriched in cancer patients who were also tobacco smokers, indicating that smokers bearing such a DNA-fingerprint have a higher risk of cancer.

“I hope that further studies are carried out to expand upon this work, so that it may eventually be put into practice allowing clinicians to inform patients of their cancer risk and how to take precautions to ensure a healthy life,” Wang said.

OTHER RISK FACTORS FOR CANCER

The list below includes the most-studied known or suspected risk factors for cancer. Although some of these risk factors can be avoided, others — such as growing older — cannot. Limiting your exposure to avoidable risk factors may lower your risk of developing certain cancers.

#Age: Advancing age is the most important risk factor for cancer overall, and many individual cancer types.

#Alcohol: Drinking alcohol can increase your risk of cancer of the mouth, throat, esophagus, larynx (voice box), liver, and breast. The more you drink, the higher your risk. The risk of cancer is much higher for those who drink alcohol and also use tobacco.

#Cancer-Causing Substances: Cancer is caused by changes to certain genes that alter the way our cells function. Some of these genetic changes occur naturally when DNA is replicated during the process of cell division. But others are the result of environmental exposures that damage DNA. These exposures may include substances, such as the chemicals in tobacco smoke, or radiation, such as ultraviolet rays from the sun.

#Hormones: Estrogens, a group of female sex hormones, are known human carcinogens. Although these hormones have essential physiological roles in both females and males, they have also been associated with an increased risk of certain cancers.

#Obesity: People who are obese may have an increased risk of several types of cancer, including cancers of the breast (in women who have been through menopause), colon, rectum, endometrium (lining of the uterus), esophagus, kidney, pancreas, and gallbladder.

Conversely, eating a healthy diet, being physically active, and keeping a healthy weight may help reduce the risk of some cancers. These healthy behaviors are also important to lessen the risk of other illnesses, such as heart disease, type II diabetes, and high blood pressure.

(With inputs from IANS)

Published : December 24, 2020 12:55 pm

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