Doctor Yasmin Rashid has taken over as minister of health in Punjab. As far as I can remember, she is the first doctor in that position that has actually practiced medicine in the Punjab. For most of her professional life, Dr Rashid has served in the public sector and has been attached to different medical colleges including King Edward Medical University (KEMU).

She worked in government hospitals, ran medical departments, and has also taught medical students as well as post graduate trainees. Her medical experience makes her an excellent choice for this position.

Even though I have not known Dr Rashid personally, I have sat across the table from her in the Academic Council meetings of KEMU when I was on the faculty in that institution. I wish her the best of luck and hope that she is able to translate her medical experience into effective policies.

That said, now on to the subject that I wish to address today. And no, it is not advice about ‘how to fix healthcare’. For that I will wait to see what the new government has to offer. What I do want to talk about is cancer in general terms. And I do apologise to Dr Rashid for combining her name and new position with a disease like cancer.

Cancer the disease is named after cancer the crab since most cancerous growths that can be seen in living patients or in post mortem specimens spreads out like the claws of a crab. Today cancer is a term that is used for all disorganised and dangerous (malignant) growths in the human body including diseases of the blood that do not present any resemblance to a crab.

Most cancers that involve body organs present as a mass or ‘knot’ of tissue. These masses are referred to as ‘tumours’. Most cancers present as tumours but all tumours are not cancers. Cancerous tumours are referred to as malignant tumours. Cancers can also be referred to as malignant neoplasms (new growths).

What exactly does cancer represent in the body? The best example I can give to illustrate that point is a well-planned city where suddenly a disorganised and totally unplanned katchi abadi (shanty town) starts to emerge and eventually replaces the entire city.

The healthy human body is very much like a well-planned and well run city. The different organs are like different localities that perform specific functions and these are connected, supplied and cleaned out by a network of blood vessels and ‘lymph’ vessels. There is an ‘immune system’ that is more or less like a security network. And no I do not wish to push this analogy too far.

In most of the human body, cells are continuously dying and being replaced by new ones. Sometimes the new cells are abnormal and if left alone can start producing many more abnormal cells eventually disrupting the entire organ. The immune system steps in and gets rid of the ‘miscreant’ cells before they can become a problem.

In short, the body is continuously producing abnormal cells and the immune system keeps these cells from multiplying. And there is a balance between these two aspects that keeps the body healthy by eliminating these abnormal cells. Sounds harsh but that is how we stay healthy.

So, why then does cancer arise? One of two things has to happen. Either the number of abnormal cells being produced is too much for the immune system to take care of or else the immune system is not strong enough to control the abnormal cells.

The more common cause for cancer is probably an increase in the number of abnormal or cancerous cells being produced. Just as in mental issues there is a role both for ‘nature and nurture’, similarly in the body both inherited as well as environmental factors are in play.

As medical science progressed, the importance of genetics (inheritance) has become more important and it seems that eventually almost all non-infectious diseases that humans suffer from might have an inherited component. That said, except a few types of cancers an inherited tendency is often difficult to establish at this time.

The environmental factors are most notably substances (carcinogens) that are present around us or we consume them that increase the production of abnormal cells and increase the chance of developing certain cancers. Of these the two most well-known are smoking cigarettes for lung cancer and ‘radiation’ for many different cancers especially blood cancers.

As far as radiation is concerned, experience from excessive medical use of X-Rays and radiation to treat patients demonstrated an increased incidence of different cancers. In modern day practice great care is taken to limit radiation exposure for both patients and treating medical personnel. The commonest radiation induced cancer today is probably sun exposure in light skinned people leading to skin cancers.

Some viral infections like the ‘Human Papillomavirus (HPV)’ are also known to predispose to genital cancers especially cervical cancer. In Pakistan the most important cancer caused by a virus is liver cancer that is associated with Hepatitis B and C virus infections.

The other reason that can lead to cancer as I mentioned above is a failure of the immune system. Except in persons suffering from AIDS, a weakness of the immune system as a predisposing reason for cancer is hard to prove.

Here it is important to point out that not all cigarette smokers will get lung cancer, not all Hep B and C infections will lead to liver cancer, not all HPV infections will lead to cervical cancer and that even some Hiroshima survivors lived on without blood cancers.

An important question is why cancer is dangerous. There are a few reasons for that. First of course that if a cancer keeps growing it will destroy the organ it involves. The second reason is that the cancer can produce serious problems by pushing on adjacent organs. And some cancers will spread to other organs in the body through the blood or lymph vessels and eventually destroying those organs also. When a cancer spreads beyond the place where it started, that is referred to as ‘metastases’.

Not all cancers are equal. Some grow slowly while others grow rapidly. In some slow growing cancers in older people treatment is sometimes not needed since a person with such a cancer is more likely to die from something else. Classical example is a slow growing cancer of the prostate gland in an older male patient. However, the definition of ‘older’ from a medical point of view keeps advancing.

Most cancers are ‘graded’ or ‘staged’ based upon size of the tumour, spread to adjacent organs, presence of metastases and biological aggressiveness. Early cancers that are limited in location may be referred to as cancer in situ (cancer in place). Successful treatment often depends on the stage and aggressiveness of the cancer.

One of the major advances in medicine during my life as a physician has been the treatment of cancers. Today the diagnosis of cancer is no longer the ‘death sentence’ it was often felt to be even a few decades ago. And many cancers are ‘curable’. More about treatment another time.