What Screening Does
Screening looks for cancer before symptoms appear, when treatment is more likely to succeed. Some tests (colonoscopy, Pap/HPV) even prevent cancer by finding and removing precancerous changes.
U.S. Screening Recommendations (Average Risk)
Based on U.S. Preventive Services Task Force recommendations. People at higher risk may need earlier or more frequent screening.
| Cancer | Who | Test & frequency |
|---|---|---|
| Breast | Women 40–74 | Mammogram every 2 years |
| Cervical | Ages 21–65 | Pap every 3 years (21–29); HPV test every 5 years or Pap every 3 years (30–65) |
| Colorectal | Adults 45–75 | Colonoscopy every 10 years, or stool tests (FIT yearly, stool DNA every 1–3 years), or CT colonography |
| Lung | Adults 50–80 with a 20 pack-year history who smoke or quit within 15 years | Low-dose CT every year |
| Prostate | Men 55–69 | PSA test — an individual decision after discussing benefits and harms |
Talk to Your Doctor If
- You have a strong family history or a known inherited mutation (BRCA, Lynch syndrome)
- You had radiation to the chest at a young age
- You have inflammatory bowel disease or prior polyps
- You are unsure which tests you are due for
Frequently Asked Questions
Is screening the same as diagnostic testing?
No. Screening is for people without symptoms. If you have symptoms, you need diagnostic testing, which is more detailed.
Can screening cause harm?
Possible harms include false positives, overdiagnosis and procedure complications, which is why guidelines balance benefits and risks by age.
Medically reviewed content for education only — not a substitute for advice from your oncology team.