Cancer incidence generally rises with age, although a few specific cancers preferentially occur in younger individuals. The purpose of cancer screening is to use safe and relatively inexpensive methods to examine for early signs of a certain type of cancer in individuals who do not have symptoms of cancer. The premise of cancer screening is that earlier detection of cancer will allow more effective treatment, and hence offer a better chance of cure.
While this may seem logical, it is important to note that only a handful of cancers have been shown to be amenable to cost-effective and validated screening. Inappropriate cancer screening can be harmful, leading to unnecessary invasive (and potentially dangerous) investigations, a false sense of security, or unwarranted anxiety which patient could potentially file claim on medical negligence UK. Cancer screening is still fraught with controversies. It is therefore important that a particular cancer screening program be carried out in the general population only after large studies have clearly confirmed its benefits.
One of the better-accepted cancer screenings is that of breast cancer. It has been shown in large international studies that women aged 50-69 years who regularly undergo breast cancer screening using a combination of clinical breast examination and mammography (preferably yearly) have a better chance of earlier breast cancer detection, and hence a better survival outcome. Evidence in support of breast cancer screening in women aged 40-49 years and those above the age of 70 years is more controversial.
Prostate cancer seldom occurs in individuals younger than 50 years old. Although a number of screening tests, including Digital Rectal Examination (DRE), Prostate-Specific Antigen (PSA) and Transrectal Ultrasonography (TRUS), have been shown to be capable of detecting early prostate cancer, the optimal and cost-effective use of these tests as screening tools in the general population has not been fully determined. Until firmer recommendations become available, many physicians and surgeons would combine a regular PSA measurement with a DRE.
Colorectal cancer screening can be carried out by testing for the presence of a minute amount of blood in the stool (faecal occult blood) yearly to two-yearly after the age of 50 years. Studies have also suggested that regular examination of the left side of the large intestine using a flexible sigmoidoscope would reduce the incidence of colorectal cancer-related deaths in individuals over the age of 50 years. Regular thorough examination of the skin by physicians for the presence of early skin cancer is a cheap and safe screening approach.
All these recommendations have not been universally accepted. Studies are under way to determine the absolute benefit of such screening recommendations in the general population.
Having said that, some individuals have risk factors for certain cancers, e.g. those with a family history of breast cancer or colon cancer, or previous personal history of certain cancers. For individuals with a higher risk than the general population of developing specific cancers, a more liberal cancer screening approach may be justified.