October 2017 is Breast Cancer Awareness Month – an annual international campaign to highlight how important breast awareness, education and research are, as well as to support those who have the disease. Breast cancer is the most common cancer in the UK with around 62, 000 people diagnosed each year. We often think only women get breast cancer, but men do too, although it’s rare. Less than 1% of cases of breast cancer are in men.
About 1 in 8 women will get breast cancer in their lifetime. Apart from female gender, the other risk factors for getting breast cancer are being older and having a family history of breast cancer. Over 80% of breast cancers are in women who are over 50 and when men are diagnosed, they are usually over 60. Only about 5% of people with breast cancers get it because they have inherited a faulty gene called BRCA – that means that breast cancer that runs in families is not common. For most people, the risks for getting cancer are multiple and many beyond our control. However, research suggests that being overweight with an inactive lifestyle are two of several risk factors for breast cancer. These are things that most of us can control to reduce our risk.
Although we are now more aware of cancer, there are still a lot of misconceptions about what it is…and isn’t. These misconceptions can feed into a fear that contributes to unnecessary suffering for those with cancer and their loved ones. This article will explain some good-to-know facts about what cancer is.
What is cancer?
All of our organs like the heart, lungs, liver and skin are made up of building blocks called cells. These cells look and work differently depending on their job, but they all grow in the same controlled and orderly way. When they are damaged or become old, they automatically die. This is called programmed cell death or apoptosis (a-po-to-sis).
When cells are damaged, the genetic material in them called DNA – that’s the stuff that codes for all of our features – also becomes damaged. This can cause ‘mutations’ – abnormal changes in the DNA – many of which instruct cells to grow out of control. If this damage is not repaired, the mutated cell can continue to grow and divide and never die. As these now mutated cells grow without dying, a lump called a tumour forms.
Tumours can be benign or malignant:
A benign tumour does not grow into or spread to other parts of the body. Once it is removed, it usually doesn’t grow back.
A malignant tumour, which is what a cancer is, can grow and spread to other parts of the body and can sometimes grow back even after it has been removed.
So a cancer is a malignant tumour made up of cells that are growing in an uncontrolled and disorderly manner and that can spread to different parts of the body.
What types of cancer are there?
There are over 200 types of cancers. Cancers are usually named according to the organ or type of cell they come from. So, breast cancer starts in the breast, colon (bowel) cancer starts in the colon, lung cancer starts in the lung, and so on. You might also hear of cancer being described as carcinoma or sarcoma or lymphoma or leukaemia; this is another way of grouping cancers according to the cells that they start from. So:
Carcinomas are cancers that start from the skin or the linings of our organs. They are then given names such as adenocarcinoma or squamous cell carcinoma depending on what type of cells they started from – an adenocarcinoma starts from glandular type cells (the Latin prefix adeno- means gland) and squamous cell carcinoma starts from squamous type cells. Squamous cells are flat, scale–like cells that are found on the surface of the skin and linings of some of our organs. Carcinomas are the most common type of cancer and make up about 80-90% of all cancer types.
Sarcomas are cancers that start from the bones or soft tissue (like muscle, cartilage and blood vessels). They are rare and make up 1% of all cancers.
Leukaemias are cancers that start from blood cells; these cancers don’t usually form a lump. Together with lymphomas, these make up about 7% of cancers.
Lymphomas and myelomas are cancers that start from the cells or organs of the immune system like the lymph glands.
Central nervous system cancers start from the brain (brain tumour) and the spinal cord. They are also rare and make up about 3% of all cancers.
What is the difference between a primary and a secondary cancer?
The primary site of a cancer is where it first started to grow, so a primary cancer is the original or first cancer. For example if a cancer first started in the breast, the original lump in the breast is the primary. At the primary stage, many cancers can be completely removed with an operation (surgery).
Now if the cells from that primary breast cancer were to spread to another part of the body, like the lungs and form new malignant tumours, the new tumours are called secondaries or metastases. These secondary’s are still a breast cancer and would be treated like a breast cancer – not as a lung cancer. They are now called breast cancer secondary’s or breast cancer metastases.
How does cancer spread?
Malignant cells that make up cancers are different from those cells in benign tumours because they can break free and spread to other parts of the body.
First of all, the malignant cells can grow into surrounding normal tissue. Using the example of a lung cancer, the malignant cells can grow into the normal lung tissue around it. They then come up to blood and lymphatic vessels and grow into these channels. Blood vessels carry blood cells and lymphatic vessels belong to the immune system and carry lymph fluid and special types of white cells that fight all diseases including cancer.
The blood and lymph fluid can transport the malignant lung cells around the body. They lodge or become blocked in small blood vessels called capillaries, and eventually squeeze their way out into surrounding tissues. If the conditions are right for them in this new location, they then start to grow into new lumps. Breast cancer cells for example seem to be able to grow in liver and bone tissue. In their new location, the breast cancer cells are able to stimulate the growth of their own blood supply that can provide the nutrition they need to grow.
The process of metastasis (cancer spread) is complicated for many reasons. For example:
The malignant cells can instruct normal cells to help them spread
The malignant cells can hide from the immune system which is constantly working to rid the body of abnormal cells
Not all cells that get into the blood or lymph system will grow into secondaries
In some cases, it may be years before secondaries appear, in other cases, just weeks or months
One of the main aims of cancer treatments, old and new, is to stop the growth of secondaries. It is much easier to cure or control a cancer at the primary stage, when it’s in one location. This is the main reason why health education drives to increase public knowledge of the signs and symptoms are so important. It is also why campaigns such as Breast Cancer Awareness Month are important and worthy of our support.
For more information on Breast Cancer Awareness Month and what you can do, go to: https://www.breastcancercare.org.uk/