Doctors expect the Oscar-winning actor to make a full recovery from the illness, but have warned him he may never act again after undergoing radiation and chemotherapy treatment for the tumour.
The 65-year-old star is expected to undergo therapy in New York and early reports suggest treatment is due to start this week with doctors pursuing an aggressive course of treatment to avoid conducting surgery on Michaels` larynx.
Dr. Lawrence Tena, a physician in the department of radiation and oncology at the Beth Israel Comprehensive Cancer Center in New York City, told Fox News: "When a patient is getting radiation and chemotherapy combined, they typically have an advanced stage of cancer.
"Sixty to 70 percent of patients, even with advanced cancers, survive."
Lawrence added the positive news is most throat cancers are localised within the body.
He added: "Localised means the cancer has not spread below the clavicle. The body has the ability to keep cancers above the clavicle; it is just the nature of the immune system and lymphatic system. If it is local, it is curable."
However, if radiation and chemotherapy doesn`t work Michael would have to undergo surgery, and a partial or complete laryngectomy would leave him with a changed voice, or no voice at all.
The `Basic Instinct` star is remaining positive about his cancer fight and released a statement saying: "I am very optimistic."
While he waits for his treatment to start Michael is spending time with his wife Catherine Zeta-Jones and their two children Dylan, 10 and Carys, seven.
He has pulled out of all work commitments for the next two months, including speaking at a forum in Honk Kong and any promotional activities for his latest film `Wall Street: Money Never Sleeps`.