For the millions of people with a family history of cancer, living in fear of a diagnosis may be the norm.

While cancer is genetic – the root cause stems from a person’s genetic code – it is not always hereditary (passed down from parents to children). 

But what could be inherited are genetic code mutations that increase someone’s likelihood of being diagnosed. 

Take the BRCA1 and BRCA2 genes as an example; they are known to elevate the likelihood of developing breast and ovarian cancer and are passed down through families. However, not every cancer type is linked to specific genes, nor is every family history equally significant in terms of risk.

The National Cancer Institute estimates up to 10 percent of cancers may be caused by inherited genetic changes.

Dr. Helen Messier, a physician-scientist with expertise in genomics, cancer prevention, and precision medicine, informed the Daily Mail that any family history of cancer is something to be cautious about.

But, she adds, close relatives (like a sister or mother) indicate a higher risk.

She mentioned that having just one cousin diagnosed with cancer has ‘minimal genetic impact on your own risk,’ whereas ‘multiple aunts or uncles with the same cancer could point to a familial syndrome.’

Family cancer syndrome

Hereditary cancer syndrome is a rare condition where family members face a heightened risk of certain cancers, caused by inherited genetic mutations in cancer-associated genes.

One sign a family may be affected is if multiple members get diagnosed with the same kind of cancer.

Dr. Messier mentioned that, typically, during standard checkups, doctors will assess a family history of cancer covering a span of at least three generations. If there are any cases of early-onset cancers, genetic counseling and testing will often be recommended.

While there is no outrunning genetics, experts say there are ways to lead a healthier life and reduce your risk of developing cancer yourself. 

Prevention lies in maintaining a healthy lifestyle and being proactive about routine screenings, according to Dr. Cedrek McFadden, a surgeon and associate professor at the University of South Carolina School of Medicine Greenville.

Experts reveal six ways you can reduce your risk of developing genetic cancers that run in your family.

Exercise

No matter the type of cancer in your family, Dr McFadden and Dr Messier both suggest regular exercise to reduce your own risk.

They said people should aim to get 150 minutes of exercise a week – or about 20 to 30 minutes per day, five days a week.

‘But don’t let perfect be the enemy of good,’ Dr McFadden said. ‘Even a brisk 20-minute walk most days adds up. Just move; your body will thank you for it.’

He also said if lung cancer, specifically, runs in your family, exercise is key as ‘healthy lungs love movement.’

Dr Messier added: ‘Exercise controls insulin, soothes inflammation, helps balance hormones and maintains weight – all fundamental cancer-prevention mechanisms.’

A multitude of research has linked physical activity to lower cancer risk.  

One 2022 study in Cancer Cell International found physical activity may reduce the risk of colon cancer, which impacts about 107,000 people per year, by 23 percent when comparing people who exercise the most to those who exercise the least.

A 2019 study published in the World Journal of Gastrointestinal Oncology suggested physical activity could prevent nearly 15 percent of colon cancers.

For breast cancer, which will see about 320,000 new cases this year, a 2016 analysis published in the European Journal of Cancer found the most physically active women had a 12 to 21 percent lower risk than those who were least physically active.

And a 2020 study in the British Journal of Cancer found women who reported the most exercise per week had a 23 percent decreased risk of breast cancer compared to those who exercised the least.

Diet 

Dr Messier said a clean and healthy diet can be crucial for reducing all types of cancer risk.

She said if colon cancer runs in your family, avoiding processed meats like bacon, sausage and deli products can help. 

A diet high in fiber, fruits, vegetables and whole grains has also been found to lower colon cancer risk.

Dr McFadden echoed those sentiments. 

He told the Daily Mail: ‘If [a parent] had colon cancer, it’s worth cutting back on processed meats… and even limiting red meat in general.

‘I tell my patients to lean into a fiber-rich diet… Your gut bacteria thrive on that, and over time, that supports a healthier colon.’ 

Overall, both experts said no food is a magic bullet, but the Mediterranean diet ‘gets a lot of praise for a reason’.

It includes ‘lots of plant-based foods, healthy fats like olive oil, lean proteins and fewer processed snacks or sugary drinks.’

The doctors agree that, ‘Basically, if it grew from the ground, it’s probably good for you.’

Dr Messier also said a ‘Mediterranean-type diet abundant in the plants is the gold standard – packed with vegetables, legumes, whole grains, healthy fats such as olive oil and lean proteins like fish. 

‘Minimize ultra-processed foods, sugars and alcohol. Foods high in phytonutrients, such as berries, cruciferous vegetables, turmeric and green tea also may be protective.’

Avoiding alcohol and maintaining a healthy weight are also two factors to consider when trying to cut your familial cancer risk, Dr Messier said. 

Avoid toxins

Dr Messier told the Mail that even if you have never smoked, a close family member who was a smoker and was eventually diagnosed with lung cancer could still put you at risk. 

Lung cancer is estimated to affect about 227,000 people in 2025, with 124,000 deaths. People exposed to secondhand smoke have a 20 to 30 percent increased risk of lung cancer.

Both doctors advise quitting smoking, avoiding secondhand smoke and steering clear of all tobacco products.

They also urge people to avoid other toxins – particularly radon. 

Dr Messier and Dr McFadden recommend testing your home for radon, a radioactive gas that has no color, smell or taste. 

The gas – which comes from the natural decay of uranium, a radioactive element found in nearly all soils – is present in both indoor and outdoor air and there is no known safe level of exposure to the substance.

Studies show radon exposure is the second most common cause of lung cancer in the US after smoking, leading to about 21,000 deaths each year, according to the EPA.

Genetic testing 

Dr Charles Oyesile, a medical research physician, told the Daily Mail people with a family history of cancer should consult with an oncologist and genetics counselor to assess their individualized risk given their family history.

Testing can help determine the best course of action – whether that is undergoing genetic testing to see if you are a carrier of any cancer-related genes, or starting cancer screenings at an earlier age.

While genetic tests won’t prevent cancer, they can tell you if you are at a heightened risk, which could help you make certain life choices – such as exercising more, quitting smoking, following a cleaner diet or undergoing certain preventative procedures.

In addition to the BRCA genes, a blood test can identify genetic variants in the APC gene.

This tumor suppressor gene is crucial for preventing the development of colon cancer. Mutations in the APC gene can lead to familial adenomatous polyposis, an inheritable condition that causes polyps in the colon.

This, in turn, raises the risk of colon cancer.

Dr McFadden said, ‘In some cases, a genetic test can tell us which screenings you actually need and when. Don’t guess – ask your doctor. We’d much rather have that conversation now than after something shows up later.’

Prophylactic surgery 

Having prophylactic surgery to remove organs that increase your risk of cancer is one way to fend off a familial pattern of disease. 

For example, if genetic testing shows you carry the BRCA1 or BRCA2 gene, you may opt for a prophylactic double mastectomy (removal of the breasts) or oophorectomy (removal of the ovaries) – procedures Angelina Jolie had when she found out she was a carrier.

Jolie underwent genetic testing because her mother battled cancer for nearly a decade and died at 56. 

When she tested positive for the BRCA1 gene, doctors estimated Jolie had an 87 percent risk of breast cancer and a 50 percent risk of ovarian cancer.

She chose to have both breasts removed and get implants in 2013. Her chances of developing breast cancer dropped to 5 percent, she wrote in a piece for The New York Times.

Two years later, she had her ovaries and fallopian tubes removed to prevent ovarian cancer. 

Other types of preventive surgeries include a colectomy – where part or all of the colon is removed to prevent colorectal cancer.  

Preventative screenings 

Screenings also won’t prevent cancer, but they can help detect the disease in earlier stages – and an early-stage diagnosis means the cancer may be easier to treat and could have a higher survival rate. 

If your grandmother, mother or sister was diagnosed with breast cancer, Dr Messier suggests talking to your doctor about beginning screenings like mammograms earlier than the generally recommended starting age of 40 years old.

Dr McFadden said a colonoscopy to screen for colon cancer may be warranted earlier than recommended – typically 45 years old – if a sibling was diagnosed with the cancer before the age of 50.

‘That’s where personalized screening plans come in,’ he said, ‘and they can make a big difference.

‘[Screenings are] not one-size-fits-all. If it’s colon cancer, you might start colonoscopy earlier. If it’s breast or prostate cancer, we might begin mammograms or PSA testing sooner.’