CANCER - Part II

Let me share an example from Siddhartha Mukherjee's book with few modifications. Two guys, Mr. X and Mr. Y, develop a cancer at the same in 1991. Both don't have any symptoms as the disease slowly progresses. Always cautious about health, Mr. X goes for a regular cancer screening in 1995 and diagnosed with cancer. Surgery-radiation-chemotherapy combo is performed on Mr. X. Life of Mr. X is saved for another five years due to early diagnosis and treatment. In 2000, the cancer relapses with vengeance and he dies. On the other hand, Mr. Y never cares about health and did not go for any screening. In 1999, the cancer spreads all over his body and lethal symptoms force him to be hospitalised. Surgery-radiation-chemo cycle is performed on Mr. Y in 1999. However, due to late diagnosis his life could be saved only for an year. He dies after one year of therapy, in 2000. Well. Mr. X and Mr. Y die almost on same time. However, the early diagnosis gave Mr. X five years of life and late diagnosis gave Mr. Y only an year. 

Despite the crude reality, the above example does not demean the importance of early diagnosis. Cancers like breast cancer, uterine cancer or cervical cancer can be 'completely' cured by early diagnosis. We have successfully developed methods to diagnose these cancers at very early stage. The early diagnosis in case of breast cancer has gone to the extent that the women who are genetically prone to breast cancer remove their breasts proactively, even before any possible development of cancer! Vaccination helps to prevent some cancers of viral origin.

As far as preventive life style is concerned, we know that tobacco causes cancer. Apart from tobacco, we have a laundry list of carcinogenic chemicals, but the chances of encountering them in normal life is rare. Robin Cook's 'Fever' is based on cancer due to benzene. It was a common solvent used in chemistry labs until two decades ago. It is completely out of laboratory use nowadays. Radiation and asbestos may be encountered sometimes, but highly avoidable. Alcohol is not carcinogenic, but it can be a secondary agent to lead a damaged liver to cancerous. Other than these, we are in the primitive stage to define an ideal life which may be cancer free. We could not even definitely say whether the use of cell phones causes brain cancer or not. All studies conducted in this regard have holes at the bottom. 

The first reported case of cancer was as early as 2500 BC. The Egyptian hieroglyphs mention about it. However, if we look at the history of our battle against this disease, it is not certainly a battle that we have won; neither have we lost. I haved my beloved family members succumbed to this disease. I have also seen my family members who have survived this disease. My grandmother lived for many years without any relapse. She underwent radiation therapy for uterine cancer in late 1970s at Adyar Cancer Research Institute (Chennai) and she was not under any anti-cancer medication as far as I know. She would not have taken, even if prescribed - I guess. After reading the literature on cancer, I think any oncologist would conclude that her case was a miracle. Cancer is known for its violent return after the treatment. Once relapsed, it is mostly the end. The relapse can happen after days, months or years. 

When Siddhartha Mukherjee started writing his Pulitzer winning book on cancer in mid-2004, he had also started treating an young lady, Carla, diagnosed with acute lymphoblastic leukaemia. Ninety five percent of her white blood cells were malignant, cancerous. The book naturally starts with the chapter about her arrival to hospital and the events followed by. Siddhartha had thought that the final chapter of the book would perhaps about the death of Carla. The book describes the merciless chemotherapy cycles performed on her. Siddhartha finished his book in June 2010. On the last days of completing the book, he carried out routine blood test on Carla. There was no trace of cancer, no relapse. The distinguished oncologist, Siddhartha, calls it a miracle at the last chapter of his book. However, we must not forget that there are many such miracles. 

My first - may be the last - practical acquaintance with cancer was during my post graduation when we tried to test a newly synthesised drug coupled with photo energy on cancer cell lines. The method is called photodynamic therapy whose origin may be traced back to Dracula! We all know that we need oxygen for life. How does oxygen get absorbed into our blood? You will wonder if I say it is through the rusting of our blood. The iron forms rust when it comes into contact with oxygen and water. Rust is nothing but the oxides of iron. In our blood, we have haemoglobin. At its centre, haemoglobin has a plate like molecule called porphyrin. At the centre of porphyrin, there sits an iron atom. When the blood is exposed to oxygen in our lungs, the iron atom 'rusts'. It forms an oxide like complex with oxygen. This oxygen is carried to our cells through blood. Due to some metabolic malfunction, the formation of porphyrin does not happen properly in some people. They will have defective porphyrins in their haemoglobin that cannot fit iron atom. These defective porphyrins, literally useless, are deposited by the body in the fast multiplying cells especially their skin cells. This disease is called 'porphyria'. 

Well. What is the link to Dracula and cancer?! When the skin of the porphyria affected people is exposed to sun light, the defected porphyrins deposited in the skin excite, corrode and kill the skin cells. Therefore, they cannot come our during day. They also get some tendency to drink blood which moderates the severity of the disease. Garlic increases the severity of the disease. You would have guessed it now. The scientists believe that the people with porphyria might have been called as vampires! However, this strange disease gave a clue for cancer therapy. The defective porphyrins are naturally deposited in fast multiplying cells. When exposed to light, the cells are corroded and destroyed. Since cancer has fast multiplying cells, the porphyrins can be used to kill the cancer cells. This paved way for photodynamic therapy. Porphyrin type compounds are injected to a cancer patients who have cancer in the visible areas such as skin or eye. Once the porphyrin compound is naturally deposited in the cancer cells, the cancer area is exposed to light rays. The cells get killed. This is what we tried with some porphyrin compounds synthesised at our lab. Since we cannot try on patients, we bought cancer cells and tried on them. The results were instantly perfect. However, there are several practical difficulties with this therapy which have made its application limited. A drug based on this therapy, verteporfin, is under trials for cancer treatment.

Cancer is a lucrative area for any pharmaceutical company. We have basketful of cancer drugs, but the treatment and cure are still elusive. Why? For this we need to understand the emperor of all maladies, cancer. I will write about it later.