Cancer is caused by changes (mutations) to the DNA within cells. The DNA inside a cell is packaged into a large number of individual genes, each of which contains a set of instructions telling the cell what functions to perform, as well as how to grow and divide. Errors in the instructions can cause the cell to stop its normal function and may allow a cell to become cancerous. These errors are called mutations and are the most common ones found in cancer. But many other gene mutations can contribute to causing cancer.
Gene mutations can occur for several reasons,
Gene mutations you’re born with.
You may be born with a genetic mutation that you inherited from your parents. This type of mutation accounts for a small percentage of cancers.
Gene mutations that occur after birth.
Most gene mutations occur after you’re born and are not inherited. A number of forces can cause gene mutations, such as smoking, radiation, viruses, cancer-causing chemicals (carcinogens), obesity, hormones, chronic inflammation and a lack of exercise.
Gene mutations occur frequently during
normal cell growth.
However, cells contain a mechanism that recognizes when a mistake occurs and repairs the mistake. Occasionally, a mistake is missed. This could cause a cell to become cancerous.
The gene mutations you’re born with and those that you acquire throughout your life work together to cause cancer. For instance, if you have inherited a genetic mutation that predisposes you to cancer, that does not mean you are certain to get cancer. Instead, you may need one or more other gene mutations to cause cancer. Your inherited gene mutation could make you more likely than other people to develop cancer when exposed to a certain cancer-causing substance. It is not clear just how many mutations must accumulate for cancer to form. It’s likely that this varies among cancer types.
Symptoms, Signs and Diagnosis
Often, a diagnosis begins when a person visits a doctor about an unusual symptom. The doctor will talk with the person about his or her medical history and symptoms. Then the doctor will do various tests to find out the cause of these symptoms. Signs and symptoms caused by cancer will vary depending on what part of the body is affected. Some general signs and symptoms associated with, but not specific to, cancer, include:
Fatigue, lump or area of thickening that can be felt under the skin, weight changes (including unintended loss or gain), skin changes (such as yellowing, darkening or redness of the skin, sores that would heal, or changes to existing moles), changes in bowel or bladder habits, persistent cough or trouble breathing, difficulty swallowing, hoarseness, persistent, indigestion or discomfort after eating, persistent, unexplained muscle or joint pain, persistent, unexplained fevers or night sweats, unexplained bleeding or bruising. Please see your doctor if you are experiencing these symptoms or any persistent signs or symptoms that concern you.
If you don’t have any signs or symptoms, but are worried about your risk of cancer, discuss your concerns with your doctor. Ask about which cancer screening tests and procedures are appropriate for you.
Many people with cancer however, have no symptoms. For these people, cancer is diagnosed during a medical test for another issue or condition. Sometimes a doctor finds cancer after a screening test in an otherwise healthy person. Examples of screening tests include colonoscopy, mammography, Pap Smear test. These are routine screening tests done on the population because of the high incidence and prevalence of colon cancer, breast cancer and cervical cancer respectively. All citizens are advised to visit their doctors to get their cancer risk profile and get the relevant screening test if they are at risk for any type of cancer. A person may need more tests to confirm or disprove the result of the screening test. For most cancers, a biopsy is the only way to make a definite diagnosis. A biopsy is the removal of a small amount of tissue for further study.
Dr. Visham Bhimull
Diploma in Family Medicine (UWI)