What is screening tests?
Screening is the activity of finding very early forms of malignant tumors, or diseases that precede the development of malignant tumors, in people who do not yet have symptoms indicative of cancer (precancerous conditions).
What cancers can be detected by screening?
Due to the large number of people screened and hence the high cost, screening is only warranted for the most common cancers, such as breast cancer, colorectal cancer and cervical cancer. For screening to be rational, it must also be possible to effectively treat the detected non-advanced, asymptomatic malignancies and precancerous conditions. Moreover, such studies must use simple and relatively cheap methods of detecting the mentioned changes.
Who should participate in screening programs?
Population screening is, by definition, intended for people who do not have high-risk factors for developing a particular cancer. This means that if, for example, there is a BRCA mutation in the family (which increases the risk of breast cancer), family members, i.e. potential carriers of such a gene, should be subject to a special surveillance program, not population screening. In addition, screening should involve people who meet certain criteria, such as age, gender, etc.
What screening programs are currently underway?
In Poland, there are current screening programs aimed at early detection of:
- breast cancer
- cervical cancer
- colorectal cancer.
The breast cancer screening program involves mammography every 24 months for women aged 50 and over. Possible additional examinations (e.g. breast ultrasound or breast magnetic resonance imaging) are recommended by the doctors if the mammography results indicate such a need.
In the case of cervical cancer, the tool enabling early diagnosis of the disease is the cytological evaluation of the cervical smear. It is worth pointing out that in Finland, the introduction of this study in the entire population resulted in a significant reduction in the number of deaths due to this cancer.
For colorectal cancer, it is now recommended that both women and men from the age of 50 undergo a colonoscopy (i.e. examination with a bowel endoscope). If the test result is normal, it should be repeated after 10 years.
Currently, no data from research studies justify regular determination of the concentration of prostate-specific antigen – PSA in all men over 50 in order to detect prostate cancer (prostate cancer, commonly known as prostate cancer). There are also no indications for population-based lung cancer screening.