Sen. John McCain, one of the toughest men in Washington, is now heading into the most difficult fight of his life.
The 80-year-old Republican from Arizona, who often jokes he is, "older than dirt," is admired for surviving five years of torture at the infamous "Hanoi Hilton" while he was a prisoner during the Vietnam War.
Now, his survival is again in jeopardy, in the wake of the grim diagnosis of glioblastoma, a highly aggressive form of brain cancer.
About 12,000 people are diagnosed with glioblastomas every year and most survive only about 14 months after being diagnosed. Seven percent live up to five years, and there are very rare cases of ten-year survival. Glioblastomas killed Senator Ted Kennedy and Beau Biden, son of former Vice-President Joe Biden.
The reason glioblastomas are so deadly is because individual, microscopic cancer cells manage to break away from the main tumor, undetected, and plant themselves into critical brain tissue where they multiply and become difficult to target.
Even when the main glioblastoma tumor has been removed, as was the case with Senator McCain's last week, the cancer usually comes back in a form that is more difficult to treat than the initial removal of the tumor. The cancer cells can also spread throughout the body through the blood stream or the lymph system to grow in places other than the brain.
Right now it appears McCain will embark on the standard treatment of chemotherapy and radiation, which usually takes weeks to months. It is unclear at this point whether he will undergo one or more experimental treatments that are showing some promise.
One of those is immunotherapy, whereby the body's own immune system fights and kills the cancer cells. There are a number of experimental types of immunotherapy, such as engineering viruses in a laboratory to attack the cancer cells while leaving the healthy ones alone.
McCain's glioblastoma was discovered after he complained of double vision during a routine physical exam. An MRI indicated a mass of cells above his left eye, which was surgically removed and determined to be cancerous. It is unknown whether McCain's condition contributed to his somewhat confused line of questioning during fired FBI Director James Comey's appearance on Capitol Hill in June.
McCain, who was elected to a six-year term just last year, has not publicly announced how long he will remain on leave or whether he will return at all.
Well wishes are pouring in from both sides of the aisle, including tweets from presidents Trump, Obama, Clinton and George H.W. Bush.
While McCain is certainly facing an uphill battle, scientists say faith and fortitude play a role in recovery.
Patients who face cancer with courage, a will to survive and a fighting attitude tend to fare better.
As it turns out, science proves that prayer helps people heal better. Dr. Harold Koenig, Director of Duke University's Center for Spirituality, Theology and Health told CBN News that over one-thousand medical studies indicate people who are more religious and who pray have better mental and physical health than those without faith.
Koenig, author of The Healing Power of Faith, says overwhelming scientific evidence shows people with strong religious beliefs get sick less and heal faster than people with no religious convictions. Among other things, people of faith have lower blood pressure and stronger immune systems that people with no faith.
"The benefits of devout religious practice, particularly involvement in a faith community and religious commitment, are that people cope better," he said. "In general, they cope with stress better, they experience greater well-being because they have more hope, they're more optimistic, they experience less depression, less anxiety, and they commit suicide less often."
Likewise, an Indiana University study looked at the effects of prayer by faith healing groups. They conducted their research in Mozambique and Brazil. After being prayed for, 11 subjects with vision problems said they were able to see better, and 14 people who were almost deaf had their hearing improved.