Understanding Cancer

At the end of last year, an estimated 225,000 Canadians were diagnosed with cancer, while there were an estimated 19 million new cases diagnosed worldwide – with an estimated 10 million people dying from cancer each year, making it the second-leading cause of death. Cancer occurs when the normal cells in our bodies change and lead to uncontrolled and abnormal growth of tumours, which can also potentially spread to other areas of the body if not caught early enough or if left untreated.

Divided into three groups, tumours can be:

• Benign
• Malignant
• Precancerous/Premalignant

When a tumour is benign, it is not considered to be cancerous and usually is not considered life-threatening but should be watched carefully. When you have a tumour that is malignant, these grow faster than tumours that are benign and can destroy tissue as well as metastasize (spread to other areas of the body.) When a tumour is considered precancerous/premalignant, this involves cells that appear abnormal and are likely to develop into cancer.

There are also five main types of cancer:

• Carcinoma
• Sarcoma
• Lymphoma/Myeloma
• Leukemia
• Brain/Spinal Cord

Carcinoma is a type of cancer that arises in the lining of the cells that help protect our organs known as the epithelial cells. Carcinomas can invade organs and tissues, as well as affect the lymph nodes and other areas of the body. Common types of cancer in this category include lung cancer, breast cancer, prostate cancer and colon cancer. Sarcoma is a type of malignant tumour that can affect the soft tissues (such as the muscle, blood vessels, nerves, and fat), or bone. With lymphoma/myeloma, these are types of cancers that affect the immune system’s cells. Lymphoma impacts the lymphatic system (which is responsible for balancing body fluid levels as well as defending the body from infections), while myeloma starts in a type of white blood cell known as plasma, which produces antibodies to help the body fights infection. When one is diagnosed with myeloma, the ability to produce these antibodies decreases. Leukemia is another type of cancer that also affects both the white blood cells and the tissue that is responsible for forming blood cells (known as bone barrow.) There are also cancers of the brain and spinal cord which affect the central nervous system (CNS). The central nervous system is responsible for a wide range of bodily functions – including awareness, memory, sensations, and movement.

As many as one-third of cancers can be prevented by making lifestyle changes, such as improving your diet, getting regular physical activity, maintaining a healthy weight, avoiding alcohol and tobacco, and avoiding workplace hazards (such as asbestos.) These are known as modifiable risk-factors. However, things like age, genetics, the immune system, and carcinogens (substances that affect how cells behave) also play a role in the diagnosis of cancer. These are known as non-modifiable risk-factors.

Depending on the type of cancer and its stage, symptoms can include things like unusual swelling or lumps (which are often painless), extreme fatigue, unexpected bleeding, coughing, difficult swallowing, unexplained weight loss, changes in bowel habits, problems with urination, loss of appetite, sores that won’t heal, persistent heartburn or indigestion, and night sweats.

Early detection of cancer is important, as this allows for not only earlier treatment, but better treatment options and an improved quality of life. Depending on age and risk-factors, your physician will recommend various types of screening – including screening for breast cancer, prostate cancer, colon cancer, and lung cancer.