Cancer screening tests look for signs of cancer before symptoms appear. Finding cancer early often makes treatment more successful and can save lives.

. Two screening recommendations were outdated and have been corrected against current U.S. Preventive Services Task Force guidance: the start age for mammography (now age 40 for all women at average risk, every other year through 74, rather than a decision to be made somewhere between 40 and 50), and the framing of prostate-cancer screening (an individual decision for men aged 55 to 69, with routine PSA screening not recommended at 70 and older).

Cancer screening means testing for cancer when you have no symptoms. The goal is to find cancer early, when it may be easier to treat. Some screening tests can even find changes that might become cancer, allowing your doctor to remove them before cancer develops.

Not all cancers have good screening tests. Medical experts recommend screening only when tests are accurate, safe, and proven to save lives or prevent serious illness. Your age, sex, family history, and personal risk factors determine which screenings you need and when to start them.

This article covers the most common cancer screening tests that medical organizations recommend for adults. Your doctor will help you decide which tests are right for you based on your individual situation.

Breast Cancer Screening

Mammograms use low-dose X-rays to look for breast cancer. The U.S. Preventive Services Task Force recommends that all women at average risk begin screening mammography at age 40 and continue every other year through age 74. This replaced the earlier guidance, which asked women in their forties to make an individual decision about when to start. Women with higher risk due to family history or genetic factors may need to start earlier.

How often you need mammograms depends on your age and risk. Many women get them every one to two years. Clinical breast exams by your doctor and breast self-awareness (knowing how your breasts normally look and feel) are also important parts of breast health.

Some women with dense breast tissue or higher risk may need additional imaging tests like ultrasound or MRI along with mammograms. Your doctor will discuss what combination of tests makes sense for you.

Colorectal Cancer Screening

Colorectal cancer screening looks for cancer or polyps (growths that can become cancer) in the colon and rectum. Most adults should begin screening at age 45. Several different tests can screen for colorectal cancer, and each has advantages and disadvantages.

Colonoscopy examines the entire colon with a flexible tube and camera. It can find and remove polyps during the same procedure. If results are normal, you typically need this test every 10 years. Stool-based tests check samples of your bowel movements for hidden blood or abnormal DNA. These tests are done at home and sent to a lab. They need to be repeated yearly or every few years depending on the type.

People with a family history of colorectal cancer or polyps, inflammatory bowel disease, or certain genetic conditions may need to start screening earlier and get tested more often. Your doctor will recommend the best screening approach for your situation.

Cervical Cancer Screening

Cervical cancer screening includes Pap tests and HPV tests. A Pap test collects cells from the cervix to check for changes that might become cancer. HPV testing looks for the human papillomavirus, which causes most cervical cancers.

Women should begin cervical cancer screening at age 21. Between ages 21 and 29, most women need a Pap test every three years. Women ages 30 to 65 can get a Pap test every three years, an HPV test every five years, or both tests together every five years. Women over 65 who have had regular normal screenings can usually stop testing.

Women who have had a total hysterectomy (removal of the uterus and cervix) for reasons other than cancer usually do not need cervical cancer screening. Women with certain risk factors, such as HIV infection or a weakened immune system, may need more frequent screening.

Lung Cancer Screening

Lung cancer screening uses low-dose CT scans to look for lung cancer in people at high risk. This screening is recommended for adults who have a significant smoking history and currently smoke or have quit within the past 15 years.

Screening is typically recommended for people aged 50 to 80 who have smoked the equivalent of one pack per day for 20 years or more (or two packs per day for 10 years, etc.). The exact age to start and eligibility criteria may vary based on updated guidelines.

If you are eligible for lung cancer screening, you will need a CT scan once a year. Quitting smoking is the most important thing you can do to reduce your lung cancer risk, regardless of whether you get screened.

Other Cancer Screenings and Risk Assessment

Prostate cancer screening involves testing PSA (prostate-specific antigen) levels in the blood and sometimes a digital rectal exam. For prostate cancer, the U.S. Preventive Services Task Force frames screening as an individual decision for men aged 55 to 69, to be made after a conversation about the benefits and harms of the PSA blood test; it recommends against routine PSA screening in men 70 and older. Men at higher risk — including Black men and men with a father or brother who had prostate cancer — may reasonably start that conversation earlier.

Skin cancer screening involves checking your skin for unusual moles or growths. You can perform self-checks at home and have your doctor examine your skin during regular visits. People with many moles, fair skin, or a family history of skin cancer may benefit from regular exams by a dermatologist.

Other screening tests may be recommended based on your personal or family history. For example, people with strong family histories of certain cancers may benefit from genetic counseling and testing. Some people with genetic mutations need specialized screening programs starting at younger ages.

Cancer Screening Checklist by Age and Sex

Age 21+, women: Begin cervical cancer screening (Pap test)
Age 40, women: Begin mammography, repeated every other year through age 74
Age 45+, all adults: Begin colorectal cancer screening
Age 50+, current/former heavy smokers: Discuss lung cancer screening
Age 50+, men: Discuss prostate cancer screening pros and cons
All ages: Know your family cancer history and share it with your doctor
All ages: Perform regular skin self-checks for unusual moles or growths
Any age with strong family history: Ask about genetic counseling

When to Contact a Clinician

Contact your doctor if you notice any new or changing symptoms between screening tests, such as unusual bleeding, persistent pain, unexplained weight loss, a new lump or mass, changes in bowel or bladder habits, persistent cough, or a mole that changes in size, shape, or color. Do not wait for your next scheduled screening if you develop concerning symptoms. Also contact your doctor to schedule overdue cancer screening tests or to discuss which screenings are right for you based on your age and risk factors.

Questions to Ask at a Medical Visit

Which cancer screening tests do I need at my age?
When should I start each screening test?
How often do I need to repeat each screening?
Does my family history change which tests I need or when I should start?
What are the benefits and risks of each screening test?
What happens if a screening test finds something abnormal?
Are there lifestyle changes I can make to lower my cancer risk?

Main Takeaway

Cancer screening saves lives by finding cancer early or preventing it altogether. The screenings you need depend on your age, sex, and personal risk factors. Most adults need regular screening for colorectal cancer starting at age 45. Women need cervical cancer screening starting at age 21 and mammography every other year starting at age 40. People with significant smoking history should discuss lung cancer screening, and men should discuss prostate screening with their doctor. Talk with your physician about creating a personalized screening schedule based on your individual situation and family history.

References and Further Reading

U.S. Preventive Services Task Force — Cancer screening recommendations for breast, cervical, colorectal, lung, and prostate cancer
American Cancer Society — Cancer screening guidelines for average-risk adults
National Cancer Institute — Overview of cancer screening tests and their benefits and harms
American College of Obstetricians and Gynecologists — Cervical cancer screening recommendations
Centers for Disease Control and Prevention — Cancer screening programs and recommendations

Cancer Screening: When and What Tests You Need