Screening for cancer

Screening for cancer refers to the use of simple tests in healthy people to identify individuals who have cancer, but do not yet have symptoms. Screening is usually done in the most commonly occurring cancers and only when the screening tests have shown to be effective in diagnosing cancer. Examples include breast cancer screening using mammography, cervical cancer screening using Pap smears and prostate cancer using PSA.

The goal of cancer screening is to detect cancer at an early stage when it can still potentially be cured. Earlier diagnosis results in better chances of survival and reduced number of deaths.

When you go to your doctor for your screening it is important that you mention any of your family that may have been diagnosed with cancer. The screening intervals may vary depending on the higher risk for developing cancer that is so identified.

Screening guidelines recommend testing in specific age groups. However, cancer can happen at any age, even before the recommended screening begins. So, the awareness of and acting on any warning signs at any age is still important.

Breast cancer screening

 Breast cancer is still the most frequently diagnosed cancer in women. Therefor every woman should know what their breasts look like and feel like so that you can immediately seek advice from your family practitioner if any change is detected.

 Screening recommendations for breast cancer depends on whether you are of average risk of getting breast cancer or of high risk. A person is considered as high risk if she has a family history of breast cancer or is aware that she carries the gene mutation that increases the risk for getting breast cancer (the BRCA gene).

 Regular clinical examination by your doctor or breast self-examination, referring to examining of the breasts by yourself, has not been shown in research to be an effective screening method. However, regular breast self-examination will help with being familiar with the look and feel of your breasts. Doctors will also continue to offer clinical breast examinations during routine health screening examinations.

 The mammogram, which is a low-dose x-ray of the breasts, is used to screen for cancer and has been proven to detect breast cancer early before any symptoms develop.

For women with average risk of developing breast cancer, screening mammography is recommended optionally between the ages of 40 to 45, but recommended yearly from the ages of 45 to 54. After 55 years of age, it could be done every two years.

Your doctor may recommend earlier start of screening mammography if you fall into the high-risk category for developing breast cancer.

 For the best results on how to do a breast self -examination you can visit the CANSA website: https://cansa.org.za/steps-how-to-do-a-breast-self-examination-bse/

 Just a reminder: Do not ever ignore a change that you observe in a breast or when you think you feel a lump in your breast – see your doctor immediately.

Cervical cancer in women

The cervix is the lowest part of the uterus (womb) in women. It can be seen and reached high up in the vagina. Cervical cancer ranks as the second most common cancer among women in South Africa, and the second most common cancer among women between 15 and 44 years of age. The importance is that it is a cancer that is both preventable and can be cured when it is diagnosed early and treated appropriately.

About 24.0 per cent of women in the general population are estimated to harbor strains of Human Papillomavirus (HPV) infection of the cervix which causes cancer of the cervix. Immunisation against HPV is therefore strongly recommended in girls or women who have not been sexually active or with normal pap smears and who is HPV negative.

Cervical cancer screening uses the Pap smear that has been supplemented by human papillomavirus (HPV) testing. No screening is needed before the age of 21 years. Screening usually starts age 21 and continues until the age of 65 years and should be repeated every 3 years. After the age of 65, Pap-smears can be discontinued if three Pap smears in a row were negative for abnormalities of cancer.  Your doctor will advise should the frequency be different.

Prostate cancer in men

The prostate is a small gland only found in men and is part of the male reproductive system. It is found beneath the bladder.

Many prostate cancers grow very slowly. Consequently, many men with prostate cancer may die of something else before their prostate cancer causes any symptoms. The danger of prostate cancer depends on how aggressive the cancer is, how early it is detected, how effectively it is treated, a man’s age, and his other medical problems. Prostate cancers that grow more rapidly can impact on survival and quality of life.

The screening tests for prostate cancer consists of a digital rectal examination (which means the doctor will feel the prostate though inserting a finger through the anus into the rectum) and a blood test called Prostate Specific Antigen (PSA). If the PSA is elevated your doctor will refer you to a urologist for a biopsy of the gland.

Screening should start yearly at the age of 50 years and continue until the age of 75. If there is a risk factor like prostate cancer in the family, screening can be considered from 40 years.

Colon cancer in men and women

The colon is the large intestine in the abdomen. The average risk to develop colon cancer is defined as those individuals who are aged 50 or older with no history of polyps in colon, no family history of colon cancer or inflammatory bowel disease. However, about 12 per cent of colon cancer cases will be diagnosed in people under 50 with a steep increase in younger age groups in recent years. So, any change in bowel habits or bleeding as seen in the stools you should consult your doctor.

Screening for colon cancer is a test of a small sample of your stool done by the laboratory to detect small traces of blood not seen by the naked eye, the Faecal Occult Blood Test or Faecal Immunochemical Test. This test should be done every two years for people 40 years and older. If this test is positive, you will be referred for a colonoscopy to a specialist. A colonoscopy is an examination by which a long, flexible tube (colonoscope) is inserted into the rectum to view the entire colon through a tiny video camera at the tip of the colonoscope. Changes or abnormalities in the colon are detected and biopsies taken during the procedure. In individuals with an average risk of developing colon cancer colonoscopy screening can start at the age of 50 years and repeated every 10 years if normal. Individuals with a higher risk to develop colon cancer will be advised on an earlier screening programme by their doctor.

Lung cancer

Lung cancer is of special importance because it can be prevented by not smoking. It is also one of the cancers which is difficult to cure. Normal chest x-rays are not a good screening method.

Patients at risk for developing lung cancer include:

Tobacco Smokers: The exposure to cigarette smoking, and thus the risk to develop lung cancer from cigarette smoking, is calculated by the so-called pack-years of smoking. One pack-year equals smoking 20 cigarettes a day for one year. So, smoking 30 cigarettes a day for 20 years amounts to 30 pack-years history. There are no specific screening programmes for lung cancer. For smokers over the age of 55 years with more than 30 pack-years’ history of smoking and less than 15 years since quitting, the medical science support that patients at high risk for lung cancer undergo  low dose CT-based screening annually.

Occupational exposure to specifically asbestos, chrome, nickel, and arsenic. A follow-up of all asbestos-exposed workers in the country, even after they have stopped working, is needed to ensure complete reporting of asbestos-related diseases and lung cancer.

Malignant melanoma

A malignant melanoma refers to a very serious kind of skin cancer that develop mainly from moles on your skin. Exposure to the sun is a risk factor and therefore South Africa has the second highest risk for the development of malignant melanoma after Australia. The most common site in males is the torso and in females the lower legs. People with a family history of malignant melanoma, with a very fair complexion which is easily sun-burned and with moles, are considered at risk to develop this kind of skin cancer. Although there is no specific screening programme for malignant melanoma, it is proposed that for early detection of melanoma an annual total body skin examination is done by a health care professional, the recording of which is called mole-mapping. Skin self-examination is important, and it is recommended that you consult your doctor if any changes in colour, shape or size of a mole is detected.

* Compiled by Dr Martin de Villiers, Medical Director at Medwell SA.

For more information visit www.medwell.co.za