Cancer can be defined as uncontrolled cell growth occurring in body tissues that results in the formation of a malignant tumour, by which is metastasises and forms secondary tumours in the same, or a different part of the body. But how does it even start?
There are two regulatory genes in our body cells, the tumour suppressor genes and oncogenes. These both work to control cell growth by either promoting it, or halting it, however, when a mutation occurs in the tumour suppressor genes (the ones that stop cell growth), our oncogenes (promoting cell growth) are constantly activated and cell growth becomes uncontrolled.
There are supposedly six hallmarks to cancer that allow scientists to know whether cancerous cells are present or not as they appear to occur across all cancers, they are in the figure below.
These mutations can be caused by many factors, such as cell stress from addiction, or it can just happen randomly. For example, smoking is thought to increase the risk of lung cancer, but it does not cause lung cancer, as the mutation in the genes may have randomly occurred, or it might have been induced via the components in a cigarette…
But how are we to know what the cause actually was? All we can speculate is what will give greater risk to a mutation, and how we can reduce the likelihood of it occurring.
In the UK, a person diagnosed with cancer would undergo many tests to identify the specifics of their individual cancer (as it is different in everyone on a molecular scale), and a range of treatments are available.
For example, lets take breast cancer. For a person with breast cancer, they might undergo surgery to physically remove the tumour, followed by chemotherapy to effectively “kill off” any cancer cells lurking round the blood stream that are left after the tumour has been removed, and then finally localised radiotherapy on the site of where the cancer was.
Interestingly, despite radiotherapy damaging cancer cells and healthy cells, healthy cells can recover whereas cancer cells cannot.
Following this, there may be a course of hormone therapy, immunotherapy, stem cell transplants, all depending on the specifics of the patient’s cancer, more detail on the treatments can be found on the Macmillan website.
So why haven’t we cured cancer?
This is because every cancer grows differently, and it can originate from any tissue in the body and develops differently from patient to patient. It becomes even more mind boggling when two people with the same cancer receiving the same drugs have opposite reactions! One gets better… one gets worse. But why?! This is still the main problem posed in the fight against cancer.
Could we not create a vaccine for cancer?
No, we cannot. Due to the variety of cancers that can occur, it is very unlikely to create a vaccine for them all. However, it has been suggested vaccines could be created to target a patient’s individual cancer… but how costly/tricky would this be seeing as 1 in 2 people develop cancer?
However, we can give vaccines to prevent people from contracting viruses, such as HPV, which promote cancer, such as cervical cancer.
On another note, we can start to turn to approaches such as drug repurposing, immunotherapy and microbial therapy which have promising outlooks, I will discuss these in my next blogs… stay tuned.