Secondary prevention of cancer refers to the strategies and interventions aimed at early detection and diagnosis of cancer in individuals who do not yet show symptoms but may be at risk. This includes screening programs and diagnostic tests to identify cancer at an early stage when it is more likely to be treatable and potentially curable. The goal is to reduce morbidity and mortality by detecting cancer before it becomes symptomatic and progresses.
There is a difference between early cancer and late cancer. The former is similar to ordinary diseases and can obtain a high cure rate; The latter develops rapidly, metastasizes, and has been difficult to cure.Here are some examples of early detection, early treatment and prevention of cancer.
Secondary prevention of cancer:Case of the United States
According to the report of American scholar shiparo in 1980, the health insurance plan of New York City has conducted a long-term study on 60000 women, which shows that the death rate of breast cancer has been reduced by 30% in 10 years for women older than 50 who accept physical examination and mammography. Stenkvist reported in 1984 that the late mortality of cervical cancer could be reduced by 75% through cervical smear examination. At present, 80% of women aged 20-39 in the United States have accepted the census, and 57% of women aged 40-70 have accepted the cervical cancer census.
Secondary prevention of cancer: cases of the China
Jing’an County, Jiangxi Province, China carried out a general survey of cervical cancer from 1974 to 1985, achieving early detection, early diagnosis and early treatment. In the past 10 years, the incidence of cervical cancer has decreased by 56.03%, and the mortality has decreased by 84.56%. In Daixi Township, Tonggu County, adjacent to Jing’an County, as a control without continuous census, there was no significant difference in cervical cancer incidence between 1978 and 1988 census.
The experience of local researchers is as follows:
- cervical cancer screening alone can only reduce the mortality of cervical cancer.
- treatment (prevention and treatment measures) for cervical atypical hyperplasia and cervical erosion found in the census can significantly reduce the mortality and incidence of cervical cancer.
- it is better to carry out regular continuous census than only one-time census; The effect of census combined with prevention and treatment measures is better than that of cervical cancer census only.
China has carried out a preliminary screening survey of lung cancer, breast cancer, cervical cancer, gastric cancer, esophageal cancer, liver cancer, colorectal cancer, nasopharyngeal carcinoma and other cancers in high-risk areas and high-risk groups of various cancers, as well as in some cities, industrial and mining areas, rural areas and troops. Many early-stage patients have been found and saved their lives. Therefore, the “secondary prevention” of cancer is to strive for early detection, early treatment, and race against time to prevent cancer from developing to an advanced stage.
Screening programs for secondary prevention of cancer
Screening programs for secondary prevention of cancer typically involve the systematic application of tests or examinations to identify individuals with unrecognized disease among those who appear healthy. These programs are designed to detect cancer at an early stage, often before any symptoms are present. The specific methods used can vary depending on the type of cancer being screened for, but common approaches include:
- Mammography: Used for breast cancer screening, particularly in women over a certain age.
- Pap Smear: Employed for cervical cancer screening to detect abnormal cells that could lead to cancer.
- Colonoscopy: Utilized for colorectal cancer screening to identify and remove polyps before they become cancerous.
- PSA Testing: Prostate-specific antigen tests are used for prostate cancer screening in men.
- Low-Dose CT Scans: Recommended for lung cancer screening in high-risk individuals, such as long-term smokers.
These screening methods are often combined with lifestyle interventions and education to encourage behaviors that can reduce cancer risk. The effectiveness of screening programs is continually evaluated to ensure they provide benefits that outweigh any potential harms, such as overdiagnosis or unnecessary treatment.
Diagnostic tests for secondary prevention of cancer
Diagnostic tests for cancer are used to confirm the presence of cancer after an individual has been identified as having an abnormal screening result or is showing symptoms suggestive of the disease. These tests are more invasive and specific than screening tests and are designed to provide detailed information about the type, location, and stage of the cancer. Common diagnostic tests include:
- Biopsy: A sample of tissue is removed from the suspected area and examined under a microscope to look for cancer cells. This can be done through various methods, such as needle biopsy, surgical biopsy, or endoscopic biopsy, depending on the location of the suspected cancer.
- Imaging Tests: These include X-rays, CT scans, MRI scans, and ultrasound. They provide detailed pictures of the inside of the body to help locate tumors and assess their size, shape, and position.
- Laboratory Tests: Blood and urine tests can provide information about how the body is functioning and may indicate the presence of cancer. For example, elevated levels of certain substances can suggest the presence of cancer.
- Endoscopic Examination: An endoscope, a flexible tube with a light and camera, is used to visually inspect the inside of the body, such as the gastrointestinal tract or respiratory system. Tissue samples can also be taken during this procedure.
- Molecular and Genetic Tests: These tests analyze the DNA, RNA, or proteins in a sample of tissue to identify specific genetic mutations or other molecular changes that are characteristic of certain types of cancer.
The results of these diagnostic tests help physicians determine the best treatment options and provide a prognosis. They are crucial in the management of cancer and ensuring that patients receive the most appropriate care.
