History and Advent of Cancer Treating Chemotherapy – Nitrogen Mustard as Anti-Cancer drug, Invention of Red Clover to treat Respiratory & Malignant Lung Cancers

Chemotherapy is the use of cytotoxic or anti-cancer drugs to destroy malignant or tumor cells that grow in the lungs, lymph nodes, pleura and the peritoneum. Apart from treating malignant cancer, chemotherapy also helps in curing leukaemia and lymphoma. Currently, there are over 100 chemotherapy drugs & treatments out there in the market, with the most popular drugs being Pemetrexed and Cisplatin. With there being so many varieties of drugs, many times multiple chemotherapy drugs are given to 1 patient to help relieve or cure a particular type of cancer. This type of treatment therapy is known as combination chemotherapy with combination referring to the amalgamation of multiple chemo drugs. Pemetrexed is a chemotherapy drug manufactured by the Eli & Lilly Company and its main purpose is the treatment of pleural mesothelioma and non-small cell lung cancer. Pemetrexed is also known as Alimta and came in to use in February 2004 when it was approved by the United States Food and Drug administration.

Invention of Chemotherapy

The term chemotherapy was invented by the ancient Greeks but the first chemo drug was pioneered in the 1940s using chemical called nitrogen mustard. Since then, over 50 different chemotherapy drugs have been invented to find out which one is the most effective in treating & curing lung cancer and other types of cancer. Chemotherapy drugs are not only used to treat cancer but also to relieve pain. More specifically, two US pharmacologists, Louis S. Goodman and Alfred Gilman were hired by the US department of Defence to investigate the discovery of nitrogen mustard as a chemical warfare agent that could be used as an effective source of cancer treatment. It was later discovered that chemotherapy could be used on animals (mice) to treat them from lymphoma which is a type of cancer that originates in lymphocytes of the immune system and forces lymph nodes to enlarge and become cancerous. The growth of nitrogen mustard grew when during World War II; a group of soldiers were accidentally exposed to mustard gas and were later found to have very low white blood cell counts. Doctors thought to themselves, an agent that has such capability to completely destroy white blood cell counts could have the same effect on cancer, and thus it could destroy cancer cells fast. Thus, doctors looked beyond just nitrogen mustard to all sorts of other chemicals, and whether they had the capability to destroy cancer cells. The image on the left is of alkylating agents which are anti-cancer drugs that are used to stop the growth of cancer cells and kill them alongside. They are injected in to the veins through intravenous injections and an example of such a chemical is nitrogen mustard, also known as Mechlorethamine.

The advent of Chemotherapy came even before the 1940s. For instance, as early as 300 BC, a substance known as Galangal which is a root in the ginger family of plants was used to treat skin cancer. Furthermore, a plant called red clover (Trifollium pratense) was discovered in 300 BC and was used in treatment of certain types of Cancer. Red clover (an image of red clover is on the left) is a wild plant used for grazing cattle and other animals and most recently, it has been used in the treatment of skin inflammations, respiratory problems, excessive cough and cancer. Red clover contains substances known as isoflavones that can inhibit or stop the growth of cancerous cells in the body and prevent them from multiplying.

How Anti-Cancer Drugs Work and Kill Cancer Cells

When cells in the body are normal, they stop dividing or growing too fast when they come in to contact with other like cells, this process is known as contact inhibition. However when cells become cancerous or malignant, they lose this ability to stop dividing or growing too fast. Thus, cancer cells at this point no longer have the balance required to maintain a healthy stock of cells in the body and limit cell division. The ability of chemotherapy to kill cancer cells depends on its ability to stop cell growth and cell division. Chemotherapy drugs usually work by instructing the RNA or DNA to stop copying themselves and stop dividing. There is a tendency that the faster the cells are dividing, the faster chemotherapy drugs can kill them causing any malignant tumors to shrink. Chemo drugs also induce cell suicide which is forcing the cells to kill themselves.

Chemo drugs that affect cells only when they are dividing are known as cell-cycle specific drugs while chemo drugs that kill cells when they are at rest are known as cell-cycle non-specific drugs. Medical doctors therefore set the scheduling of chemotherapy drugs based on the type of cells, how fast they are dividing and the time at which the drug given is expected to be the most effective. The image on the left shows the role of cell division in cancer. The top right side shows normal cell division where if one cell out of many gets damaged, it is automatically killed via the process of apoptosis. On the bottom right hand side, we see cells dividing & multiplying beyond control and breaking away from each other and starting new tumors in another part of the cell; this process is known as metastasis. These dividing cells become malignant if they invade nearby tissues and other organs.