In the United States, 98,620 women and 114,760 men had lung cancer in 2007, according to John Minna, M.D., in “Harrison’s Principles of Internal Medicine.” Lung cancer is the number one cause of cancer deaths for women and men. More people die from this cancer every year than the total number of people who die from prostate, colon and breast cancers. There are chemotherapy treatments available depending upon the type of lung cancer and the stage.
Cisplatin
Cisplatin is a chemotherapeutic treatment that works by interfering with the formation of DNA. It interferes with the structure of DNA by making it fold on itself and break. And it does it in such a way, that the tumor cells cannot repair it. Dr. Minna writes in “Harrison’s Principles of Internal Medicine” that cisplatin is a chemotherapy treatment for some of the non-small cell lung cancers and for the Pancoast tumor of the lung. There are three different types of non-small cell lung cancers.
Etoposide
This medication makes the cells take a longer time to duplicate. It interferes with an enzyme called topoisomerase II. Enzymes are proteins the cells use to speed up the time a reaction will take. The cells use the topoisomerase II enzyme when they duplicate their DNA before they divide. In “Harrison’s Principles of Internal Medicine,” Dr. Minna writes that etoposide is an alternative treatment for some of the non-small cell lung cancers and the Pancoast tumor.
Cyclophosphamide
Cyclophosphamide interferes with the DNA of a cell. It makes links, or folds, in the DNA. This leads to less DNA in the cell, which prevents the cells from being able to divide. It is one of the treatments for small cell lung cancer, according to Waun Ki Hong, M.D., Professor of Medicine at the University of Texas M.D. Anderson Cancer Center in “The Merck Manual for Healthcare Professionals.”
Gemcitabine
This is another chemotherapy treatment for small cell lung cancer, per Dr. Hong in “The Merck Manual for Healthcare Professionals.” It also interferes with the DNA of a cell. Gemcitabine is changed to two substances when it is inside of a cell. These two substances then prevent the formation of DNA by interfering with two enzymes called DNA polymerase and ribonucleotide reductase. Cells use both of these enzymes to make DNA.
Doxorubicin
Also known as adriamycin, this medication is a treatment for small cell lung cancer. It interferes with the formation of DNA and RNA. It inhibits the enzyme called topoisomerase II and adheres to the DNA of the cell. In addition, doxorubicin can adhere to the cell membrane and make substances called free radicals. These substances can destroy both DNA and cells.
Vincristine and Vinblastine
Dr. Hong writes in “The Merck Manual for Healthcare Professionals” that both of these medications are chemotherapy treatments for small cell lung cancer. To be able to divide, cells have to form structures called microtubules. Cells use these microtubules during cell division to line up and divide the chromosomes. Both vincristine and vinblastine interfere with the formation of these microtubules. This stops cell division.
Paclitaxel
A medication for small cell lung cancer, paclitaxel prevents the microtubules from breaking down. Normally, they will break down after the chromosomes have divided. Paclitaxel interferes with this, and this interferes with cell division.
References
- “Harrison’s Principles of Internal Medicine”; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D. et al.; 2008
- The Merck Manual for Healthcare Professionals: Lung Carcinoma
