Understanding Cancer Therapy vs. Chemotherapy

Chemotherapy drugs are a mainstay of mesothelioma treatment. More than 100 chemotherapy drugs are used to treat cancer today and they may be used alone or in combination with other treatments such as radiation and surgery. Chemotherapy drugs “work by interfering with the sequence of activities that a cell must go through to divide into two identical daughter cells,” explains RN and oncology certified nurse (OCN) Judith McKay in her book The Chemotherapy Survival Guide. “If the cell can’t divide,” she says “then it will live out its life span and die. Drugs that act this way are called cell-cycle specific or antimetabolites. They prevent cancer cells from reproducing at a particular phase in the cell’s life span.”

Some of the most common types of cell-cycle specific chemotherapy drugs are:

• 5-fluorouracil (5-FU)
• 6-mercaptopurine (6-MP)
• Capecitabine (Xeloda)
• Cytarabine (Ara-C)
• Floxuridine
• Fludarabine
• Gemcitabine (Gemzar)
• Hydroxyurea
• Methotrexate
• Pemetrexed (Alimta)

Other types of chemotherapy drugs, called cell-cycle nonspecific, affect cancer cells in all phases of life. Says McKay, “these drugs kill cancer cells at any time during the cells life span without waiting for them to divide.” These types of drugs, also called alkylating agents, affect cancer cells far more than healthy cells because cancer cells are often more fragile or immature than normal cells. Some of the most common types of cell-cycle nonspecific chemotherapy drugs are:

• Altretamine
• Busulfan
• Carboplatin
• Carmustine
• Chlorambucil
• Cisplatin
• Cyclophosphamide
• Dacarbazine
• Lomustine
• Melphalan
• Oxalaplatin
• Temozolomide
• Thiotepa

Cell-cycle specific or non, all chemotherapy drugs have certain risks and side effects. Because chemotherapy is a “systemic” treatment, meaning it works throughout the body to destroy rapidly growing cancer cells, it may also effect healthy cells that divide quickly. This can cause side effects such as hair loss, nausea, vomiting, fatigue, pain, mouth sores, and decreased blood cell counts. Bear in mind that chemotherapy is very effective against rapidly growing cancer cells, so the benefits often outweigh the risks.

So, we’ve determined that chemotherapy drugs work by damaging cells that divide frequently, but it may also affect other cells in the body that divide frequently. Researchers have yet to figure out how to stop chemotherapy drugs from damaging healthy cells, but they’re working on it. One way that researchers think they can fix this problem is by developing drugs that target cancer cells specifically, while leaving healthy cells alone. In fact, a number of targeted therapies have already been approved by the U.S. Food and Drug Administration (FDA). A few noteworthy therapies include:

• Afatinib dimaleate (Gilotrif)
• Alectinib (Alecensa)
• Atezolizumab (Tecentriq)
• Bevacizumab (Avastin)
• Ceritinib (LDK378/Zykadia)
• Cetuximab (Erbitux),
• Crizotinib (Xalkori)
• Gefitinib (Iressa)
• Imatinib mesylate (Gleevec)
• Necitumumab (Portrazza)
• Nivolumab (Opdivo)
• Osimertinib (Tagrisso)
• Pembrolizumab (Keytruda)
• Ramucirumab (Cyramza)
• Regorafenib (Stivarga)
• Sunitinib Malate (Sutent)
• Trastuzumab (Herceptin)
• Wrlotinib (Tarceva)

Drugs such as Nivolumab (Opdivo) and Pembrolizumab (Keytruda) have been approved for the treatment of non-small cell lung cancer, which gives hope to patients with malignant pleural mesothelioma. Sutent is currently approved for the treatment of gastrointestinal stromal tumor, kidney cancer, and pancreatic cancer. Researchers are now studying the drug for many other types of difficult to treat cancers, including malignant pleural mesothelioma.

Per the American Cancer Society, targeted therapies such as these can work to:

• Block or turn off chemical signals that tell the cancer cell to grow and divide
• Carry toxins to the cancer cells to kill them, but not normal cells
• Change proteins within the cancer cells so the cells die
• Stop making new blood vessels to feed the cancer cells
• Trigger your immune system to kill the cancer cells

“Some targeted drugs are more “targeted” than others,” says the Society, and “some might target only a single change in cancer cells, while others can affect several different changes. Others boost the way your body fights the cancer cells. This can affect where these drugs work and what side effects they cause.” Not every person will experience side effects, but the most common effects are rashes or other skin changes such as photosensitivity, dry skin, and itching. Targeted therapies can cause changes in hair growth, skin and hair color, and around the eyes.

Other serious side effects may include:

• Autoimmune reactions
• Bleeding or clotting problems
• Heart Damage
• High blood pressure
• Slow wound healing
• Swelling

Though side effects reported have been less severe than those seen with standard chemotherapy drugs, patients undergoing targeted therapy may experience some of the same side effects as those undergoing chemotherapy. Nausea, vomiting, and fatigue are just a few.

The decision about whether targeted cancer therapy, chemotherapy, or a combination of the two is the best treatment path will depend on dozens of factors that can only be assessed by a doctor who specializes in mesothelioma. Your specialist will work with you to determine the course that will be the most effective in treating your specific type mesothelioma. 

 

Sources

Fitzakerley, Janet. "Antineoplastics." University of Minnesota Medical School Duluth. University of Minnesota Medical School, 2015. Web. 07 Mar. 2017.

Ganti, Apar Kishor, and David E. Gerber. OAOL (Oxford American Oncology Library) Lung Cancer. New York: Oxford UP, 2013. Print.

"How Chemotherapy Drugs Work." American Cancer Society. American Cancer Society, Inc., 2017. Web. 07 Mar. 2017.

Lyss, Alan P., Humberto M. Fagundes, and Patricia Corrigan. Chemotherapy & Radiation for Dummies. Hoboken, NJ: Wiley Publishing, Inc., 2005. Print.

McKay, Judith, and Tamera Schacher. The Chemotherapy Survival Guide: Everything You Need to Know to Get through Treatment. Bridgewater, NJ: New Harbinger Publications, Inc., 2010. Print.

Papadakis, Maxine A., Stephen J. McPhee, and Michael W. Rabow. Current Medical Diagnosis & Treatment 2015. New York: McGraw-Hill Education, 2015. Print.

Pallarito, Karen. "Understanding the Benefits and Risks of Chemotherapy." ABC News. ABC News Network, n.d. Web. 07 Mar. 2017.

"Side Effects of Targeted Cancer Therapy Drugs." American Cancer Society. American Cancer Society, Inc., 2017. Web. 07 Mar. 2017.

"Targeted Cancer Therapies." National Cancer Institute. National Institutes of Health (NIH), U.S. Department of Health and Human Services, n.d. Web. 07 Mar. 2017.

"Types of Chemotherapy Drugs." Chemotherapy.com. Amgen, Inc., 2016. Web. 07 Mar. 2017.

"What Is Targeted Cancer Therapy?" American Cancer Society. American Cancer Society, Inc., 2017. Web. 07 Mar. 2017.

"What's New in Malignant Mesothelioma Research and Treatment?" American Cancer Society. American Cancer Society, Inc., 2017. Web. 28 Feb. 2017.