The benefits are certain in some cases: life years gained for those with curable disease, avoidance of morbidity, reassurance that cancer genetic lesions disease is at a very early stage, avoiding expenses of treatment for advanced cancers and extra years of productivity. But screening tests also have disadvantages, so a balanced decision must be made, with the help of clinical randomized trials.
In this article I will present the current methods for screening accepted for general population and particular screening reserved for persons at high risk. Although in the first case the benefit is proven, the use of these methods in practice varies largely due to lack of resources and well designed health programs. Beneficiile sunt evidente în anumite cazuri: prelungirea supravieţuieii la cei cu boală curabilă, scăderea morbidităţii, asigurarea pacientului că boala se află în stadiu incipient, evitarea costurilor crescute asociate cu tratamentul formelor cancer genetic lesions de boală şi creşterea numărului de ani de productivitate.
Dar testele de screening au şi dezavantaje, aşa cancer genetic lesions un echilibru trebuie găsit, cea mai importantă contribuţie în acest sens fiind dată de testele clinice randomizate. În acest articol voi prezenta metodele curente acceptate pentru populaţia generală şi cele rezervate pentru persoanele cu risc înalt. Deşi în primul caz beneficiile sunt dovedite, utilizarea lor în practică variază larg din cauza lipsei de resurse şi a lipsei implementării programelor de sănătate publică.
Checking for cancer or for conditions that may become cancer cancer genetic lesions people who cancer genetic lesions no symptoms is called screening. cancer genetic lesions
Cancer prevention through screening programs
It is usually assimilated with secondary prevention and involves the use of diagnostic tests in cancer genetic lesions apparently healthy population. Many people wrongly mistake screening for prevention 2. There are several forms of prevention: Primary prevention - aims to prevent disease before it ever occurs.
This is done by preventing exposures to hazards that cause the disease, altering unhealthy or unsafe behaviors that can lead cancer genetic lesions disease, and increasing resistance to disease if exposure occurs.
One example is vaccination 3.
Secondary level of prevention - treatment of precancerous or cancerous lesions in early stages, when cancer genetic lesions clinical expression is present, which leads to avoidance of developing invasive or metastatic disease. It includes screening asymptomatic patient and early detection diagnose in phase of minimal symptoms of disease.
It also applies to advanced disease which is asymptomatic or without complications at time being.
The fourth level of prevention - according to some authors, could be considered prevention of suffering from side effects of treatment and complications, pain and maintaining the quality of life cancer genetic lesions the patients 4. Screening can be proposed for a certain cancer in the following situations: if it is frequent, has a long preclinical evolution, is associated with increased mortality and morbidity, long preclinical non-metastasis faze and if early detection offers access to treatment that improves outcomes.
It is important to remind that screening tests can have potential harms as well as benefits. Some cancer genetic lesions tests may have side effects, cause discomfort or severe complications.
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Screening tests can have false-positive results. Screening tests can have false-negative results.
Overdiagnosis is possible. This happens when a screening test correctly shows that a person has cancer, but the cancer is slow growing and gastric cancer pubmed not have harmed that person in his or her lifetime.
This can lead to overtreatment 5.
Screening tests that have been shown to reduce cancer deaths Colonoscopy, sigmoidoscopy, and fecal occult blood tests FOBTs Colon cancer is the third most frequent cancer in both men and women.
Although usually met in persons after 50 years, there is a trend o increase incidence among young adults. The major risk factors are family history and old age, other conditions being associated with greater probability of cancer alcohol, smoking, lack of physical exercise, poor fiber diet and rich in red processed meat.
Another risk is found in people with ulcerative colitis and Crohn disease 6. Genetic consult, thorough history till second degree relatives and IHC imunohistochemical and genetic testing should be considered in those with HNPCC hereditary nonpolyposis colorectal cancer - like in Lynch syndrome with its variant - Turcot patients with MMR - mismatch repair gene mutations and brain tumoursand Muir-Torre syndrome MTS - cutaneous gland tumours like keratoacanthomas and sebaceous tumors associated with colon, breast, and genitourinary tract neoplasia.
Guaiac FOBT: is used to detect a part of the blood protein hemoglobin. It requires avoidance of certain food before testing red meat. FIT: implies use of antibodies to detect human hemoglobin specifically. No dietary restrictions cancer genetic lesions needed. Cancer genetic lesions suggest testing every year beginning with the age of 50 until 80 cancer genetic lesions it helps reduce death from CCR by up to 33 percent 8,9.
Prevenirea cancerului prin intermediul unor programe de screening
Sigmoidoscopy has the advantage of visualizing the rectum and sigmoid colon and being able to biopsy suspect lesions.
Preparation for the test is less demanding than that needed for colonoscopy.
Trials have shown an up to 70 percent lowered risk of death from cancer of sigmoid and rectum using this method. A randomized study showed that just one sigmoidoscopy done between 55 and 64 years old can offer an important reduction in CCR incidence and mortality.
The usual recommendation is for the test to be done every 5 years in conjunction with FOBT every 3 years Colonoscopy examines the whole colon and rectum. A form of sedation is recommended for patient comfort. A more complex cleaning of the colon is needed before the investigation.
It has the advantage of biopsy, too. Death from CCR is reduced by about 70 percent. The usual recommendation of cancer genetic lesions is at 10 years, cancer genetic lesions long as other tests are negative Double-contrast barium enema : less sensitive than colonoscopy for detecting small polyps and cancers; has an utility for those who cannot undergo colonoscopy. New screening tests are under investigation: stool DNA cancer de osos trials showed a high rate of false positivesvirtual colonoscopy and capsule endoscopy; they should not yet be used for screening.
It had two arms: one used low dose helical CT and the other, standard chest X ray. On average over the three rounds of screening exams, The results showed that using the CT screening there is a 15 to 20 percent lower risk of dying from lung cancer when compared with chest X ray.
The adenocarcinomas and squamous types were the most frequently detected, while small cell lung cancer, known for its agresivity, was infrequently found on either CT or chest X ray Mammography This screening test for breast cancer has been shown to reduce mortality from the disease in women aged 40 to 74, especially in those aged 50 or older.
To date, no differences are between classic film mammography and the digital one. Women with breast implants should continue to have mammograms. A special technique called implant displacement views may be used. Modern mammograms cancer genetic lesions a very small amount of radiation. Usually, the risk of exposing to radiation is surpassed by the benefits of the test, but total dose of radiation after several tests must be kept in notice.
This test has the advantage of the possibility of being installed in mobile cancer genetic lesions. A new technique - 3D mammography tomosynthesis - has not been compared with 2D mammography in randomized studies, and cannot yet be recommended for screening purpose. Pap test and Human Papilloma Virus HPV testing These tests reduce the incidence of cervical cancer because they allow abnormal cells to be identified and treated before they transform into cancer.
They also help reduce death from the disease. It is generally recommended to begin at the age of 21 or 3 years after becoming sexually active and to end at the age of 65, as long as recent results have been normal.