When Should You Get Screened for Cancer? Here’s the Latest Guidance.

Medical groups have lowered the ages for breast and colorectal cancer screenings in recent years, as more people under 50 are getting diagnosed with these and some other cancers.

But screenings and tests designed to signal cancer risk have their own drawbacks, including false alarms. How often you should get screenings and when you should start can depend on your family history and individual risk, doctors said. Most recommendations apply to people at average risk, and your doctor might recommend screenings sooner if your risk is higher.

Here’s the current guidance on cancer screening and genetic risk tests:

When should I get screened for breast cancer?

Women at average risk should start getting mammograms at age 40, according to the most recent drafted guidance from the U.S. Preventive Services Task Force. The task force is a government-backed panel of volunteer experts, and its recommendations often dictate insurance coverage.

The group says that women should get screened every other year, but there are other doctors who advocate for annual screening. Medical groups also disagree on when women should stop getting mammograms. The task force said they should be discontinued at age 75.

Some groups and medical centers recommend that women with dense breasts get additional screening with an ultrasound or MRI. The task force said that there wasn’t enough evidence for or against the practice, and it isn’t always covered by insurance.

Before screening, all women should talk with their doctors by age 25 to figure out if they are at elevated breast cancer risk, according to the American College of Radiology.

When and how should I get screened for colorectal cancer?

People at average risk should start colorectal cancer screening at age 45, down from a starting age of 50 from a few years ago, according to the task force and other health groups.

How often you get screened depends on the test. For stool tests, including the ones that can be done at home, people should get screened every one to three years. Colonoscopies should be done once every 10 years, and doctors can remove precancerous polyps during that exam.

Screening should continue until age 75, according to the task force, after which it depends on the individual patient and their doctor until age 85, when it is no longer recommended.

What other cancer screening tests are recommended?

Medical groups recommend that some people get annual low-dose CT scans to screen for lung cancer. That applies to adults between the ages 50 and 80 who have a cigarette smoking history equal to a pack a day for 20 years. They also have to either currently smoke or have quit within the past 15 years.

The prostate-specific antigen test, called the PSA test, can help doctors screen for prostate cancer. Right now, the task force says that the decision on whether to get regular PSA testing for men ages 55 to 69 is an individual one, but it is currently reviewing this guidance.

Women should also get screened for cervical cancer with a Pap smear once every three years from ages 21 through 65. Starting at 30, women can also get HPV testing once every five years. This guidance is also under review right now.

Can I get a blood test to screen for cancer?

Yes, there are a few blood tests—sometimes called liquid biopsies—including the Galleri test that can look for signs of cancer, and more are being developed. But doctors are split on whether people should take them now.

The Galleri test looks for signals for more than 50 cancer types and came on the market in June 2021. It hasn’t been cleared by the U.S. Food and Drug Administration and isn’t widely recommended or covered by insurance. Many doctors are excited about the potential promise of these tests but want to see more data before advocating for their use.

How do I test for genetic cancer risk? Should I get tested?

Around 5% to 10% of all cancers are thought to run in families. People with genetic conditions including Lynch Syndrome or BRCA mutations have an increased risk of developing cancers including colorectal, breast, ovarian and pancreatic.

Not everyone needs to get tested for genetic cancer risk. People should consider counseling and genetic testing for several reasons, including if there is a strong family history, a family member with multiple cancers or a relative with a known genetic mutation, according to the American Cancer Society. Some groups including people with Ashkenazi Jewish ancestry should also consider testing.

You can get genetic testing through your doctor’s office, where it will most likely be covered through insurance if your doctor recommends it. Some companies also offer at-home test kits where people can mail-in saliva samples for testing, but they often only look for a limited number of genetic mutations.

Write to Brianna Abbott at brianna.abbott@wsj.com