SECONDARY CANCER PREVENTION
25 April 2023
OVERVIEW
Secondary preventative approaches against cancer involve screening and early detection interventions. Cancer screening constitute various tests that detect early signs of cancer in people without symptoms. It should be noted that cancer treatment is most effective when the malignancy is detected early, especially before the onset of symptoms.
Various screening options are available; these include physical examinations, imaging tests, laboratory and genetic tests. It is important to follow recommendations for cancer screening tests, as these may differ according to risk group, particularly the recommended age to start.
Health experts recommend that certain screening tests should only be used for people who have known risk factors for certain types of cancer, such as:
- A personal history of cancer;
- A strong family history of cancer;
- Certain gene mutations that have been associated with cancer; for instance, mutations of tumour suppressor genes BRCA1 and BRCA2 increase the risk of developing breast, ovarian, pancreatic and prostate cancer;
- Exposure to environmental or occupational cancer-causing agents such as asbestos, silica or underground mining exposure to radon or uranium;
- Lifestyle-related cancer risk factors, such as excessive alcohol consumption or tobacco use;
- Age – the incidence of cancer tends to increase with age.
People that have a high risk of developing cancer may start cancer screening approaches earlier. Currently, there is not enough evidence on sensitivity and specificity to support screening programs for other types of cancer besides breast, bowel, and cervical cancer. Regular screening checks could thus detect these cancers early.
Nonetheless, it is very important that you consult with your doctor or other qualified health provider before having any screening test – to understand the risks and benefits associated with the relevant screening test, and to determine whether the screening test is right for you.
COMMON CANCER SCREENING TESTS
1. Breast cancer
Globally, breast cancer is the leading cause of cancer incidence amongst women, with an estimated 2.3 million new cases (11.7%) diagnosed in 2020. Common screening tests for breast cancer include clinical breast examination and mammography.
Currently, a mammogram is considered the universal standard to detect breast cancer in most women of screening age. A mammogram is an X-ray image of the breast that can identify signs of cancer before the patient displays symptoms or feels a lump in the breast.
Women ages 40 to 44 should have the choice to start annual mammogram screening if they wish to do so; however, starting at age 45, women should get mammograms every year.
Breast cancer symptoms may differ, and some people may not even experience any symptoms. For this reason, it is very important to know how your breasts normally look and feel and to report any changes to a health care provider immediately.
2. Colorectal cancer
Colorectal cancer (CRC), also known as bowel cancer, is the third most diagnosed cancer and is one of the leading causes of cancer-related deaths worldwide; accounting for 10 % of the global cancer incidence in 2020.
Current detection methods for CRC include stool-based tests, or structural/visual examinations (colonoscopy). It is recommended that people at average risk should start testing at age 45.
Colorectal cancer is generally asymptomatic, and when symptoms (such as rectal bleeding, anemia, unexplained weight loss or abdominal pain) appear, most patients are already in the advanced stage where cancers are aggressive, malignant, and metastatic.
Regular check-ups or screening interventions for CRC are thus highly important factors in improving therapeutic outcomes for this disease.
3. Cervical cancer
Worldwide, cervical cancer is the fourth most diagnosed cancer in women. In 2020, an estimated 604000 cases were diagnosed, and 341843 women died from the disease.
Notably, the majority of cervical cancer-related deaths were in less-developed regions of the world; where access to prevention, screening, and treatment services are severely limited. Although decreasing trends in incidence and mortality rates have been observed in some developed regions of the world, cervical cancer remains a major public health problem for women globally.
Certain types of human papilloma virus (HPV) infection have been identified as causative agents of at least 90% of cancers of the cervix. Screening tests for cervical cancer include the HPV and Pap smear test. The HPV test looks for signs of infection by the human papillomavirus, while the Pap smear test detects cell changes on the cervix. Both tests involve collection of a sample of cells from the cervix and can be performed in a doctor’s office or clinic.
According to the American Cancer Society, it is recommended that cervical cancer screening should start at the age of 25, with HPV testing every five years through age 65, the Pap smear test every three years, or having a combination of both tests every five years.
Cervical cancer screening aims to detect pre-cancerous changes, which, if not treated, may lead to cancer. It is very important to get screened regularly.
REFERENCES
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The content provided is for educational purposes and is not intended to offer personal medical advice. You should seek the advice of your physician or other qualified health providers with any questions you may have relating to a medical condition.
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