What is it?
A drug that works through your blood to ‘treat’ cancer. Where surgery and radiation are local treatments targeting only where the tumour is, chemotherapy attacks cells, all cells (cancerous and normal), throughout the body. This helps if it has spread (Metastases).
All cells divide and grow. Normal cells know when to stop dividing and growing when they come into contact with similar cells. Cancer cells do not have this turn off switch thus keep multiplying and building up as a tumour.
Chemo or ‘Chemical Treatment’ or ‘Treatment with Cell Killing’ halts the division process. This causes the tumour to shrink or become tumorcidal (cell suicide). There are cell-cycle specific chemo drugs (for when cells are dividing) and cell-cycle non-specific (for attacking the cells when they rest) But mainly the cell-cycle specific drugs are the chemo drugs we use most often. These affect cells that divide and grow quite often – other cells of this nature include stomach and bowel cells for example, as they regrow in order reline the stomach when digesting. Hair and nail cells are also constantly growing, skin cells too as they replace new skin all the time and bone marrow, which produces your blood cells. So these are also affected by chemo drugs. And, as you can imagine, I may notice changes to these more frequent areas with side effects. So far chemo is unable to decipher between cancer and normal cells. The good thing is that the normal cells grow back only.
History of Chemo drugs
So, Chemotherapy was discovered during the use of chemical warfare in World War 2, in the use of Mustard Gas. One part of the gas, Nitrogen Mustard, in particular. When a group of soldiers were exposed to the mustard gas, upon inspection of doctors, they found that their white blood cell counts were low and that it had affected their bone marrow and lymph nodes. From this discovery doctors explored using this agent and thought it may help fight diseases like lymphoma and cancers. They tested it on animals and found that it worked. It wasn’t until 1946 (after the war and secrecy of these gas programs, that findings were published). Then in 1955, interest was big to discover more chemicals against cancer which then lead to a national screening program.
However, at this time Nitrogen Mustard effects did not last long. They began using various drugs to combat Childhood Leukaemia and Hodgkin’s disease. There was a 50% remission rate, which lasted longer. Around 1970 people began to now believe cancer was curable which was a force to bring to bear, as scientists believed there was a possibility of finding a cure so then were granted time and money and approval to focus their work, and it research progressed.
What Chemo drugs am I receiving?
There are hundreds of different chemo drugs. My standard treatment will use Cisplatin – the most common. The clinical trial, Interlace, will provide me with Carboplatin & Paclitaxel (Carbo/Taxol) or PC. All three of these chemo drugs are listed on the World Health Organisation List of Essential Medicines.
Carbo/Taxol is normally given every three weeks over 5/6 months when sometimes administered for Breast Cancer. In my instance in this trial, I will be having this first, but every week, and for 6 weeks. Thus, the dosage is one third of its normal amount given and this amount is also based on my body mass to see how much my body can handle. They give you the max amount and can be adjusted, incase I can’t cope for example. Little bit of experimentation along the way sure, why not!
Paclitaxel, aka Taxol, is made from pine needles from the Yew Tree. Well, it used to be. The demand for the drug at its discovery was higher than the ability to harvest the trees so Robert A Holton, a professor of Florida University, began synthesising the drug. It was discovered in 1962 during the time when the National Cancer Institute had put on a screening program to collect samples of a 1000 plant species per year.
A man, by the name of Arthur S Barclay, had collected bark during this screening program, from the Pacific Yew Tree and when processed by subcontractors, they found it was cytotoxic (Cancer cell killing). It was developed commercially by Bristol-Myers Squibb (BMS) with some controversies along the way. A lot of controversies actually. Financial ones at that.
In 1978, mice, with leukaemia, were the first to benefit from its effects. In 1979 Susan B. Howitz published that Taxol had the ability to stabilise microtubules (these microtubules undergo continual assembly and disassembly of cells. They determine the shape of cells in a variety of movements, the intracellular transport of organelles, and the separation of chromosomes during mitosis – yes you are thinking, ‘basically’) Paciltaxel works by stopping the doubling of cancer cells. In 1982, trials for humans began.
After Phase 2 of these trials, ecological concerns were voiced, even though they had been having remarkable responses in ovarian cancer patients. About 360,000 trees were needed each year to provide enough bark for the drug to be made. This sparked the need to reach out for help, financial help, in order to further clinical trials and handle the isolation of taxol. This received a lot of fleck as one company bought exclusive marketing rights of the life saving therapy drug. They went on to make over $1billion dollars of profit from Taxol, using Robert A Holton’s synthesising methods. He got rich, Florida State University got rich and so did Bristol-Myers Squibb. The cost of Taxol? – if you had four cycles of treatment with Taxol, it would cost the NHS £4000 ($6000).
Carboplatin & Cisplatin
These are cell-cycle non-specific drugs meaning it attacks during the rest phase of cell division. They are platinum based drugs, discovered in the ’80s. Carboplatin was made after Cisplatin (parent drug) and has fewer side effects.
Cisplatin was discovered by accident. A researcher, named Barnett Rosenberg, wanted to explore the effects of an electric field on the growth of bacteria. When the bacteria stopped dividing once it was placed in an electric field, he found that it was because of the electric field of the platinum electrode rather that the field generated itself. Thus cell division in this way was explored further in rats – alas, successful results gained approval for human use and in 1978 in US, 1979 in UK, Cisplatin was used to treat ovarian and testicular cancer.
When the compound enters a cancer cell it becomes positively charged when water molecules replaces its chloride ions (further research is looking at how to manage the amount of chloride we have in order to boost a maximum effect). This charge attacks the DNA charge, creating cross links in DNA making it hard for the cell to duplicate that DNA section, thus dying.
There is, unfortunately, resistance to Cisplatin that can occur. In situations where this is the case, Paciltaxel (Taxol) is used to boost its effect – reasons are unknown why this works so far but discovering this during my research makes me glad I opted for the Interlace trial! (Cisplatin is administered as the Standard Treatment, Taxol as part of the Trial I was fortunate to take part in). Also various studies and meetings are held across the globe that discuss aspects of the drugs uses; in San Diego they are discussing the possibility of predicting the resistance of cancer cells to Cisplatin by measuring DNA damage. In Scotland and Australia, they are discussing the possibility of using external magnets to draw the platinum-based Cisplatin to the targeted tumour. In MIT, a professor is restructuring the platinum compound and his research indicates a 4-40 times higher potency to cisplatin so far. Isn’t this so interesting! I loved knowing so many really intelligent people were working all round the world, trying to make it all better.
I’m basically throwing three DNA suicide bombs on the tumour, not just one. Sometimes DNA repair pathways become resistant to a particular chemo drug and due to ongoing research, we are still unable to accurately predict how one person will be affected by any particular chemotherapy, if the tumour becomes resistant and if it grows back. There are many unknown elements that may happen and yet there is still an outstanding amount of success to the treatment of cancer.
Now for the ‘fun’ bit of this post…..random side effects.
Along with the predicted side effects (feeling crappy, hair loss, fatigue, etc) I found some side effects that were offered an amusing surprise. I’ve not decided if I am alarmed or just plain old, amused:
Loss of hearing
Loss of taste
Electric shock when bending your neck
Loss of colour vision
Hiccups. Yes, hiccups.
Increased risk of developing cancer. Yes, you can re-read that again. Crazy.
Yellow eyes and skin – what is the solution for this. Must ask Vogue.
Burning hands and feet – So, jandles in winter?
No urine output – if over 12 hours this is a serious emergency I’d suspect!!
The Uninvited Guest - Cervical Cancer 