According to the American Cancer Society, screening can identify persons who may have cancer or pre-cancerous tissue changes that warrant further evaluation. It can also detect cancers earlier in their development, which often can improve the effectiveness of treatment and prevent death.
 
Screening has been shown to reduce mortality from cancers of the breast, cervix, and colon and rectum. There are also other cancers for which screening may be associated with lower mortality, but the evidence is uncertain. The following are recommended guidelines for cancer screening for the early detection of cancer in asymptomatic people:

Breast
The National Cancer Institute and American Cancer Society recommend yearly mammograms are recommended starting at age 40. The age at which screening should be stopped should be individualized by considering the potential risks and benefits of screening in the context of overall health status and longevity.
Clinical breast exam should be part of a periodic health exam, about every three years for women in the 20s and 30s, and every year for women 40 and older.
Women should know how their breasts normally feel and report any breast change promptly to the healthcare providers. Breast self-exam is an option for women starting in their 20s. Women at increased risk (e.g. family history, genetic tendency, past breast cancer) should talk with their doctors about the benefits and limitations of starting mammography screening earlier, having additional tests (i.e. breast ultrasound and MRI) or having more frequent exams.

Colon & Rectum 
Beginning at age 50, men and women should begin screening with one of the examination scheduled below:

• A fecal occult blood test (FOBT) or fecal immunochemical test (FIT) every year
• A flexible sigmoidoscopy (FSIG) every five years
• Annual FOBT or FIT and flexible sigmoidoscopy every five years*
• A double-contrast barium enema every five years
• A colonoscopy every ten years

*Combined testing is preferred over wither annual FOBT or FIT, or FSIG every five years alone. People who are at moderate or high risk for colorectal cancer (e.g. family history, genetic tendency) should talk with their doctor about a different testing schedule.
 
Prostate 
The PSA test and the digital rectal examination should be offered annually, beginning at age 50, to men who have a life expectancy of at least 10 years. Men at high risk (African American men and men with family history of one or more first-degree relatives diagnosed with prostate cancer at an early age) should begin testing at age 45.  For men at average risk and high risk, information should be provided about what is known and what is uncertain about the benefits and limitation of early detection and treatment of prostate cancer so that they can make an informed decision about testing and treatment.

Uterus 
Cervix: Screening should begin approximately three years after a woman begins having vaginal intercourse, but no later than 21 years of age.  Screening should be done every year with regular Pap tests or every two years using liquid-based tests. At or after age 30, women who have had three normal test results in a row may get screened every two to three years. Alternatively, cervical cancer screening with HPV DNA testing and conventional or liquid-based cytology could be performed every three years.  However, doctors may suggest a woman get screened more often if she has certain risk factors, such as HIV infection or weak immune system.  Women 70 years and older who have had three or more consecutive normal Pap tests in the last 10 years may choose to stop cervical cancer screening.  Screening after total hysterectomy (with removal of the cervix) is not necessary unless the surgery was done as a treatment for cervical cancer.

Endometrium: The American Cancer Society recommends that at the time of menopause all women should be informed about the risk and symptoms of endometrial cancer, and strongly encouraged to report any unexpected bleeding or spotting to their physicians.  Annual screening for endometrial cancer with endometrial biopsy beginning at age 35 should be offered to women with or at risk for hereditary nonpolyposis colon cancer (HNPCC). HNPCC is also known as Lynch Syndrome.

Cancer-related checkup
For individuals undergoing periodic health examinations, a cancer-related checkup should include health counseling, and, depending on a person’s age and gender, might include examinations for cancer of the thyroid, oral cavity, skin, lymph nodes, testes, and ovaries as well as for some nonmalignant diseases.