FrançaisWhat is cancer?
The human body is made up of billions of cells which together form organs, tissues and bones. Each cell has a nucleus that contains the genes (DNA) that allow it to carry out its role, to multiply and eventually, to die. Each cell has its own safety system to prevent errors from occurring at the gene level. Unfortunately, mutations can arise and successfully evade control mechanisms. These mutations can appear spontaneously (without any cause), be caused by hereditary genetic abnormalities (at birth) or caused by toxic exposures (smoking, alcohol, solvents, etc). When mutations escape the cell’s safety checks, the cell can multiply exponentially, over a period of time that can take days or years, depending on the severity of the disease. This is called cancer. At first, cancer is just a small collection of cells. The more the cells multiply, the bigger the cancer becomes and is likely to spread elsewhere in the body, that is, to become generalized.
According to the Canadian Cancer Society, it is estimated that 2 in 5 Canadians will develop cancer during their lifetime and that approximately 1 in 4 Canadians will die from it.
What are the different types of cancer?
Cancer can affect people of all ages, but remains more common in people older than 50 years old.
There are hundreds of cancers; any organ/tissue can be the primary site of cancer. Cancers are classified into two categories: blood cancers (hematological) and solid cancers (lung, breast, colon …). Each cancer is unique and can evolve in totally different ways from one person to another. Some cancers can be indolent (little aggressive) or very aggressive. Some can be observed (if very slow in evolution), others can be operated while others will require systemic treatments (see Treatments section).
For hematological cancers, see Hematology section.
For so-called solid cancers, there are rare ones and others more frequent. In Quebec, the 4 most common cancers are breast cancer, lung cancer, prostate cancer and colorectal cancer. Breast cancer is the most common form of cancer in women and the second leading cause of cancer death. In men, the most common cancer is prostate cancer. In both women and men, lung cancer is the leading cause of cancer death. Colorectal cancer is the third most common.
For more statistics, see the Canadian Cancer Society, Statistics Section at cancer.ca
What is oncology?
Oncology, also called cancerology, is the study of cancers and their treatments. This is a medical specialization. A doctor who specializes in cancer is an oncologist. As cancer is a complex disease, this specialty requires teamwork with other specialists, such as surgeons and radiation oncologists. Oncology requires multidisciplinary at all levels, from diagnosis to treatment and even after, during the period known as “surveillance”.
What is the role of an oncologist?
The role of an oncologist is multiple: investigate suspicious masses (for example: nodule in the lung, presence of numerous large lymph nodes, etc.), review the investigations already started and confirm the diagnosis of cancer (with the biopsy results). Once the diagnosis is proven and the type of cancer has been identified, the oncologist determines the appropriate treatment plan. Sometimes a surgical referral will be the first step, sometimes systemic treatments will have to be initiated (see Treatments section). Other times, his role is to make a palliative care orientation, that is, the oncologist does not recommend aggressive treatments and favors a comfort care approach (relieving pain, anxiety).
When systemic treatments are administered, the oncologist does a regular follow-up before each treatment to ensure good tolerance and control of possible side effects. When there is partial or complete remission (disappearance of the cancer), the oncologist continues to ensure close monitoring and intervenes as soon as a recurrence is suspected. From beginning to the end of the process, the oncologist pays particular attention to the physical and psychological health of the people under his care. Continually, the oncologist works in collaboration with other health professionals to preserve the quality of life as much as possible. Relatives are always invited to participate in visits, with the patient’s prior consent, of course.