After 40 years, another United States president has declared war on cancer. President Obama in his latest and last ‘State of the Union’ address to the US Congress said among other things that cancer should be cured or eradicated. The question really is can we ever actually eradicate cancer? The answer is obviously no. Cancer is a by-product of normal activity of the cells in the body. Cells are dividing all the time and producing new cells. Some of these new cells are abnormal and the body itself corrects or else kills these abnormal cells after they are produced.
So in essence our bodies are continuously producing cancer cells. And most of the time, the body is taking care of these ‘bad’ cells. In essence equilibrium exists between the production and the destruction or repair of these cancerous cells. However, certain things can upset this equilibrium and allow cancer to become established. There are three major factors that can influence this balance.
First are genetic or inherited tendencies that increase the production of abnormal cells and can overwhelm the protective mechanisms of the body. Some cancers run in families. The most famous example of such a cancer is the inherited tendency for breast and ovarian cancer in women. A few years ago Angelina Jolie-Pitt, a famous Hollywood actress, underwent removal of both her breasts even though there was no cancer present in either breast. The reason was the presence of a particular gene in her body that increased greatly the possibility of future cancer to a high level of probability.
It is however extremely important to remember that not all people with a family history of cancer will develop cancer themselves. Yes they might have an increased risk but not an absolute chance of being so afflicted. It is for this reason that for most cancers that run in families, close monitoring is advised rather than pre-emptive treatment for possible cancer.
The second group of stimuli that increases the production of abnormal cells includes external factors. Chemicals that enter the human body and increase the production of abnormal cells are referred to as ‘carcinogens’. The most famous among this class of substances is cigarettes and other tobacco products. Another important factor is radiation. Exposure to radiation is a risk factor for developing cancer in almost every organ system in the body. Perhaps the most common form of such radiation is exposure to sunlight leading to an increased incidence of skin cancers. Less common cause is exposure to medical radiation (X-Rays).
Here again it is important to remember that not all smokers or people exposed to sun will develop cancers. As a matter of fact it will be a small percentage of people exposed that will develop cancers though the incidence will still be much higher than in those people that are not exposed to cigarettes or the sun.
Besides increasing the number of abnormal cells being produced in the body beyond the ability of the body to take care of them, the other major reason why people will get cancer is because their bodies are ‘weakened’ due to some reason and therefore they cannot destroy all the abnormal cells that are being produced. Interestingly science has been unable to identify any specific reasons for this except in patients in whom the immune system of the body is not working properly.
During the early years of organ transplantation when major medicines were used to severely suppress the body’s immune system so that it would not ‘reject’ the transplanted organ, these patients over the course of years would often develop unusual forms of cancers. Also in patients with immune deficiency syndrome (AIDS) before it was treated effectively, as consequence of immune suppression patients developed Kaposi’s Sarcoma (an unusual form of cancer) quite often.
However, whichever way we look at it, the development of cancer in a person is often a matter of pure chance. We can talk all we want of the reasons mentioned above but most cancers occur without any known reason. And that is the problem with ‘curing’ cancer. Only if we can figure out who is going to get cancer we can prevent the cancer from occurring and if it does occur, treat it when it is still in its very early stages.
Coming to the treatment of cancer, the first step is obviously prevention. Avoiding known risk factors like cigarettes or the sun are obvious starters. Then patients with known family history or genetic factors predisposing to certain cancers should be checked and in certain cases like the one mentioned above of the actress Jolie-Pitts, removal of the ‘target’ organ will definitely prevent the occurrence of cancer. The problem is that most cancers occur at random.
In general, cancer is best treated when it is at an ‘early’ stage. Early usually means that the cancer is still small in size and is more or less confined to one place. The cancers that are difficult to diagnose early or those that are ignored until they spread out of the place where they started are much more difficult to treat and usually have poor results in terms of survival.
Over the last few decades medical initiatives have been developed that help to identify cancer early. In women regular breast exams and ‘mammography’ or breast X-Rays can detect early cancer. Also the PAP smear can identify early cancer in the mouth of the uterus (cervix) and make treatment more effective. In males PSA a blood test can identify early cancer in the prostate gland and provide better treatment. Similarly a ‘colonoscopy’ or visual examination of the lower part of the intestine can identify colon cancer early on. More sensitive tests are in the pipeline that might identify early cancer from just examining a drop of blood.
Treatment of cancer has evolved considerably. More than 40 years ago, primary treatment for cancer, if possible, was surgical removal. Extensive, disfiguring and severely debilitating surgery was the norm. Breast cancer is an example of this evolution. In the early seventies, ‘radical mastectomy’ or extensive disfiguring removal of the breast was the accepted form of treatment. Today, attempt is made to remove just the tumour (lumpectomy) rather than an entire breast and spread of cancer is determined by looking at local lymph nodes. Then based on the type of cancer, different types of medicines (chemotherapy) that can kill cancer cells are used. Hormones and radiation (X-Ray treatment) are also added options.
Eventually it will be genetic manipulation, immune system modification, early detection using different ‘scanning’ technologies and ‘targeted’ chemotherapy that will eradicate most cancers. The important point I want to make is that cancer is not one disease that will require one treatment to cure it. There are literally hundreds of different types of cancers. One of the lectures I remember vividly from my days in medical college was about female cancers involving the pregnant uterus. Our professor declared that a particular cancer called choriocarcinoma was now curable with the use of a medicine called Methotrexate. This is circa 1970. Since then we have come a long way but we still have a long way to go.