Cancer is when abnormal cells divide in an uncontrolled way, some eventually spreading into other tissues writes Fergus Bescoby.
Every year, over 250,000 people in England are diagnosed with cancer, and around 130,000 die as a result of the disease.
Annual NHS costs for cancer services are £5 billion, but the cost to society - including loss of productivity - is £18.3 billion.
There are over 200 different types of cancer and statistics show that one in two people in the UK will be diagnosed in their lifetime.
Of these, approximately 50% will survive for ten years or more. About a third of cancers are caused by smoking, diet, alcohol and obesity.
The good news is that survival is improving and has doubled in the last 40 years in the UK.
Cell changes and cancer
Cancer starts with changes in one cell or a small group of cells. The cells may grow and multiply too much and form a lump (tumour). Where the cancer starts is called the primary tumour.
Some types of cancer, called leukaemia, start from blood cells and don't form solid tumours.
Instead, the cancer cells build up in the blood and sometimes the bone marrow. For a cancer to start, certain changes take place within the genes of a cell or a group of cells.
Gene changes within cells (mutations)
Genes control the way that cells grow and reproduce. Sometimes a change happens in the genes when a cell divides.
The change is called a mutation and means that a gene has been damaged, lost or copied twice. Some mutations cause the cell to grow out of control. There have to be about half a dozen mutations before a normal cell turns into a cancer cell.
It can take many years for a damaged cell to divide and grow and form a tumour big enough to cause symptoms or show up on a scan.
How mutations happen
Mutations can happen by chance when a cell is dividing. They can also be caused by the processes within the cell or by external elements, such as the chemicals in tobacco smoke.
Some people inherit faults in particular genes that make them more likely to develop a cancer. Once cells start growing too fast, they are more likely to pick up further mutations and less likely to be able to repair the damaged genes.
The main categories of cancer
Cancers can be grouped according to the type of cell they start in. There are five main categories
• Carcinoma - begins in the skin or tissues of internal organs. There are a number of subtypes, including adenocarcinoma, basal cell carcinoma, squamous cell carcinoma, and transitional cell carcinoma
• Sarcoma - begins in the connective or supportive tissues such as bone, cartilage, fat, muscle, or blood vessels
• Leukaemia - starts in blood forming tissue such as bone marrow and causes large numbers of abnormal blood cells to be present in the blood
• Lymphoma and myeloma - begin in the cells of the immune system
• Brain and spinal cord cancers - known as central nervous system cancers
Cancers can also be classified according to where they start in the body, such as breast cancer or lung cancer.
Benign and cancerous (malignant) tumours
Tumours can be benign (non-cancerous) or cancerous (malignant).
Benign tumours
Usually grow quite slowly
Don't spread to other parts of the body
Benign tumours are made up of cells that are quite similar to normal cells. They will only cause a problem as a result of the following:
Grow very large
Press on other body organs
Take up space inside the skull (a brain tumour)
Release hormones that affect how the body works
Malignant tumours are made up of cancer cells. They-
Usually grow faster than benign tumours
Spread into and damage surrounding tissues
May spread (metastasise) to other parts of the body in the bloodstream or though the lymph system to form secondary tumours.
Cancer staging and grading
Staging and grading give an idea of how quickly a cancer may grow and which treatments may work best. The stage of a cancer means how big it is and whether it has spread. Cancer staging systems sometimes include grading of the cancer, which describes how similar a cancer cell is to a normal cell.
There are two main types of cancer staging systems: the TNM system and the number system. Some blood cancers or lymph system cancers have their own staging systems.
The TNM staging system
TNM stands for Tumour, Node, Metastasis. This system describes the size of the initial cancer (primary tumour), whether the cancer has spread to the lymph nodes, and whether it has spread to a different part of the body (metastasised).
The system uses numbers to describe the cancer. The letter c is sometimes used before the letters TNM - for example, cT2. This stands for clinical stage. It means the stage is based on what the doctor knows about the cancer before surgery. The stage is based on clinical information from examining the patient and looking at the test results.
Number staging systems
Number staging systems use the TNM system to divide cancers into stages. Most types of cancer have stages numbered from one to four. Often doctors write the stage down in Roman numerals. So you may see stage four written down as stage IV.
Here is a brief summary of what the stages mean for most types of cancer:
Stage one usually means that a cancer is relatively small and contained within the organ it started in.
Stage two usually means the cancer has not started to spread into surrounding tissue but the tumour is larger than in stage one. Sometimes stage two means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer.
Stage three usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes in the area.
Stage four means the cancer has spread from where it started to another body organ. This is also called secondary or metastatic cancer.
Sometimes doctors use the letters A, B or C to further divide the number categories, for example, stage 3B cervical cancer.
Carcinoma in situ
Carcinoma in situ is sometimes called stage 0 cancer or 'in situ neoplasm'. It means that there is a group of abnormal cells (too few to form a tumour) in an area of the body which may develop into cancer at some time in the future. Doctors and researchers usually call these cell changes 'precancerous changes' or 'non invasive cancer'. Many areas of carcinoma in situ will never develop into cancer because these areas of abnormal cells are so small that they are usually not found unless they are somewhere easy to spot, for example in the skin. A carcinoma in situ in an internal organ is usually too small to show up on a scan. But tests used in cancer screening programmes can pick up carcinomas in situ in the breast or the neck of the womb (cervix).
Treatment
If a cancer is present in just one place, then a local treatment such as surgery or radiotherapy could be enough to get rid of it completely. A local treatment treats only one area of the body.
If a cancer has spread, then local treatment alone will not be enough. In this instance, a treatment that circulates throughout the whole body will be required.
These are called systemic treatments. Chemotherapy, hormone therapy and biological therapies are systemic treatments because they circulate in the bloodstream.
Sometimes doctors aren't sure if a cancer has spread to another part of the body or not. They look at the lymph nodes near to the cancer. If there are cancer cells in these nodes, it is a sign that the cancer has begun to spread. This is called having positive lymph nodes.
The cells have broken away from the original cancer and got trapped in the lymph nodes. But it is not always possible to tell if they have spread to other parts of the body. If cancer cells are found in the lymph nodes, doctors usually suggest adjuvant treatment.
This means treatment alongside the treatment for the main primary tumour (chemotherapy after surgery, for example). The aim is to kill any cancer cells that have broken away from the primary tumour.
Underwriting considerations
The underwriter will always require full details of the tumour type and staging in order to assess the risk properly.
In addition to this, full details of treatment, follow ups, and of any recurrences will need to be provided. A GPR will generally be requested in order to obtain this information.
References
Hannover Life Re
Cancer research UK
Gov.UK
Fergus Bescoby is underwriting development manager at VitalityLife