Diagnosing Cancer

How is cancer diagnosed?

The process of diagnosing cancer usually begins with a visit to a health care provider with a specific complaint or symptom, or because something was detected during a routine check-up or screening. Your doctor may order laboratory tests, scans, or procedures to help determine the diagnosis.

To confirm a cancer diagnosis, a biopsy is usually performed. A biopsy is a procedure to remove a sample of tissue or cells from the body. The sample is sent to a lab for analysis and a pathology report is sent to your doctor or specialist describing what was found.  

The pathology report helps your health care team understand the type of cancer you have and prepare a treatment plan. 

What is cancer?

Cancer is not a single disease: it is a family of more than one hundred different diseases. These different kinds of cancer are usually named according to the part of the body where they first developed.

Cancer develops when certain cells in your body begin to grow out of control. These abnormal cells sometimes form a mass, or lump called a tumour. Tumours can be cancerous (malignant) or non-cancerous (benign).

Benign (be-NINE) tumours do not spread to other parts of the body and are not cancer.

Malignant (ma-LIG-nant) tumours are cancer and can spread to other parts of the body. Cancer spreads when cells break away from the tumour and travel to other parts of your body. In some types of cancer, these cells start to grow in many places at the same time. When cancer cells spread, it is called metastasis.

Metastasis (me-TA-sta-sis) happens through the blood or lymphatic systems. Wherever cancer cells grow and spread, they can prevent healthy cells and organs from doing their job. 

What are the types of cancer?

Types of cancers are named by the place in the body where they started. For example, cancer cells found in the breast are called breast cancer.

However, if a cancer has spread, the cancer cells found in other parts of the body can be from the original cancer. For example, lung cancer that has spread to the brain is called a lung cancer with brain metastases.

Carcinomas (car-sin-NO-ma) are the most common types of cancer. They start in an organ such as a lung, breast, prostate, bowel, or ovary.

Sarcomas (sar-KO-ma) are cancers that start in the muscles, bones and tissues that connect different parts of the body. 

Leukemias (lu-KEY-mee-ya), or blood cancers, are cancers of the white blood cells.

Lymphomas (lim-FO-ma) are cancers of the lymphatic system, a series of vessels that carry lymph to different parts of the body. Lymph is a watery fluid that contains cells that fight infection and disease.

 What does cancer stage mean?

Cancer staging is a way to describe how much cancer is in the body. Doctors may do a physical exam, blood tests, imaging or a biopsy to determine cancer stage. There are different staging systems used for solid tumours, cancers of the blood (leukemias) and cancers of the immune system (lymphomas).

Staging generally describes where a cancer is located and its size, how far it has grown into nearby tissues, and if it has spread to other parts of the body. It is used to plan treatment and predict the course of the disease or the chance of recovery. 

Who do I talk to about a cancer diagnosis?

Your family doctor or nurse practitioner can help explain test results and the next steps in your care at any time during a diagnosis and treatment. If you are seeing a specialist (for example, a surgeon or oncologist), it is helpful to come prepared with a list of questions.

The cancer patient navigator is also available to speak with you and your family. You don’t need to wait until you see a cancer doctor (oncologist) to ask for information or support.