Chemotherapy is often cited as an example of the cure being worse than the disease – the side effects can be unpleasant to say the least. For many cancer patients, however, chemotherapy remains among their best options. This month, Dr. Prasad Abeysinghe, a Consultant Oncologist at the Maharagama Cancer Hospital explains how chemotherapy works, when it is most effective and why it’s important that you understand exactly what you are getting into.
How Chemotherapy works
“Chemotherapy is a chemical agent used to treat a malignancy,” says Dr. Abeysinghe, explaining that it works by targeting rapidly dividing cells in the body. While such cells occur in healthy bodies, a cancer appears when abnormal cells start to multiply indiscriminately. Normal cells will die when the body no longer needs them, but cancerous or malignant cells divide quickly and spread, invading the surrounding tissue. They might even make the leap to other organs in the body, a process known as metastasis. Cancers cover the full spectrum and can affect almost any tissue or organ - from breast to bone to brain - and are thought to be caused by a combination of your genetic inheritance and the effect of environmental toxins.
But cancer cells aren’t the only quickly dividing cells in the body – your hair cells divide quickly, as do your blood cells. The mucous membrane that coats your digestive track from mouth to anus, and the membrane that protects your respiratory tract are also made of up of rapidly dividing cells. “So how does a chemotherapy drug differentiate between a good cell and a bad cell? In reality it can’t,” reveals Dr. Abeysinghe. The fact that chemotherapy attacks your healthy cells as well as your sick ones gives rise to the treatment’s dreaded side effects.
Playing match maker: Chemotherapy and different cancers
“Different cells react differently to chemotherapy. Each cancer has its own sensitivity towards chemotherapy,” says Dr. Abeysinghe, explaining that they “take that therapeutic advantage” to optimise the effectiveness of the treatment. For starters, chemotherapy isn’t recommended for all cancers - melanomas or liver cancers for instance respond poorly to chemotherapy, while leukaemia and lymphomas typically respond well to treatment.
There is also the matter of timing. For those who have taken chemotherapy, it must seem particularly taxing that a doctor will first administer a treatment that devastates your body’s defences, will wait for you to recover, and only then repeat step one all over again. The fact is that the cyclical administration of chemotherapy is required – this way the cancer cells are attacked again and again until they slowly decline and then hopefully disappear. “If you delay chemotherapy too much even cancer cells can sometime regroup,” he adds.
The course can be so demanding that not everyone can survive it. “Not all patients that you see should receive chemotherapy,” says Dr. Abeysinghe, explaining that patients are rated on the basis of their ‘performance status’ on a scale from 0 – 4, with 0 being the healthiest and 4 the weakest. Many cancer patients present with co-existing problems, and serious heart related illnesses or conditions like severe diabetes and even malnutrition can disqualify a patient from being suitable for chemotherapy. Explaining that these decisions are made on a case by case basis, Dr. Abeysinghe says patients should also be consulted and that extra testing to ascertain health before administering chemotherapy is always a good idea.
Toxic therapy
Chemotherapy works because unlike the other normal cells in your body, cancer cells don’t bounce back as fast, says Dr. Abeysinghe. “They just don’t have the same capacity to regenerate,” he says, explaining that doctors will often use a combination of the chemotherapy drugs that attack the abnormal cells in different points of their cycle. This comprehensive strategy is meant to increase the ‘kill rate,’ he explains, even as it reduces the possibility that the cancer will develop resistance to one particular agent.
Unfortunately, chemotherapy is hard on patients in more ways than one. While your hair falling out might damage your vanity, the real threat is how chemotherapy can undermine your immune system. The rapidly dividing cells in your bone marrow are among the hardest hit. “Your bone marrow produces white cells, red cells and platelets and each of these have their own specific functions,” explains Dr. Abeysinghe. The first defend the body, the second transport oxygen in the blood and the third are essential to proper blood coagulation. While chemotherapy will leave you weak and fatigued, as your white cell count drops you also become increasingly vulnerable to infections of every description. It’s the reason why patients must maintain high standards of personal hygiene, avoid other sick people and eat only nutritious, properly cooked food.
Some dangers are hard to avoid though, as they come from inside. As the lining of the gut is damaged, patients are adversely exposed to naturally occurring micro-organisms in their own systems, which can now cause severe infections. Symptoms like fever, painful urination, cramping, severe diarrhoea, and rectal bleeding are signs that could indicate the presence of an infection. “It’s very important to monitor these side effects when you administer chemotherapy,” cautions Dr. Abeysinghe.
Asking the tough questions
Your doctor might recommend you undergo a course of chemotherapy for three different reasons. In essence these are:
- Cure cancer: Chemotherapy is sometimes the single most effective treatment, and can be used on its own as a treatment for cancer, without there being any need for surgery. In such cases, surgery may restricted to something small like collecting a biopsy to aid in diagnosis. It can also be used prior to surgery, where a doctor will first administer a dose of chemotherapy to either shrink the cancer or make it more manageable. This also reduces the chance of recurrence.
- Control cancer and prolong life: In instances where cure is no longer possible, chemotherapy can be used as an agent to control the spread of cancer, to slow its growth or to destroy parts of the cancer that have metastasised to other parts of the body.
- Ease cancer symptoms (also called palliative care): In cases where chemotherapy cannot cure cancer, it can still offer temporary relief from symptoms. For instance, it could be used to shrink a painful malignancy.
Knowing why your doctor has made a certain recommendation is important, as is understanding exactly what this regimen of chemotherapy is intended for. Make sure you know what side effects to expect and how many times you will be hospitalised over the course of the treatment. Medicine has taken leaps and bounds forward in managing the side effects such as nausea, and these should be taken full advantage of.
There is also the question of the new generation of molecular targeted therapies. Though they are supposed to have fewer generalised side effects, they’re also a great deal more expensive, and some have been associated with serious allergic reactions and cardiac myopathies. “Overwhelmingly, the majority of the successes we have are from the conventional chemotherapy,” says Dr. Abeysinghe.
It’s also crucial to look past the numbers. Especially in cases where the cancer is expected to be fatal, one treatment may be touted as giving you more time than the other.
However, Dr. Abeysinghe cautions that quality of life should be a determining factor. These are difficult decisions – but some therapies might give you an additional month but involve multiple stays in the hospital, while another therapy might offer a shorter period but a great deal more freedom and better general health. In the end, it pays to make an informed choice. |
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