The Kind Of Cancer John McCain Has Been Diagnosed With

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On Wednesday, Arizona Sen. John McCain's office announced that McCain has a glioblastoma brain tumor. According to The New York Times, glioblastoma is based in the brain and is the most aggressive type of brain tumor; it does not spread to other organs. Doctors at the Mayo Clinic Hospital in Phoenix conducted a minimally invasive procedure on Friday to remove McCain's tumor, which was associated with a small blood clot above his left eye.

The American Brain Tumor Association indicates on its website that glioblastoma is the cause of approximately 15.4 percent of all primary brain tumors. It occurs more commonly in men than in women, and is more likely to affect older people. The exact cause of glioblastoma is still unknown, and it is difficult to treat because it contains multiple types of cells.

The American Cancer Society, meanwhile, estimates that roughly 24,000 malignant tumors are diagnosed each year, of which approximately 30 percent are glioblastomas. The ABTA, however, reported that an estimated 12,390 new cases of glioblastoma were expected in 2017; this figure would seem to constitute a higher percentage of malignant tumors.

CNN reported that all of the affected tissue in McCain's brain has successfully been removed, according to post-surgical brain scans completed since Friday's surgery. McCain's glioblastoma reportedly is not related to melanoma, the skin cancer for which he has been treated in the past, though a 2014 study from the Annals of Epidemiology found a slightly higher correlation between melanoma patients and subsequent glioblastomas.

As McCain recovers, many of his fellow lawmakers have issued statements of support for McCain and his family.

The 80-year-old senator also sent out a tweet signifying his recovery, stating that he would be back in Congress soon.

Although scans indicate that McCain has had all of the affected tissue removed, NBC News medical correspondent Dr. John Torres reported that there's always a possibility of microscopic pieces remaining in the brain and spreading. So while the senator's office released a statement saying that McCain is recovering "amazingly well" at his Arizona home, he and his family are discussing treatment options such as radiation and chemotherapy to eliminate any cancer cells that may remain.

According to The New York Times, the prognosis for glioblastoma is poor; Beau Biden, for example, died nearly two years after his diagnosis. The malignant tumor is almost always likely to grow back within a year, and surgeons must operate on it again. Even with this treatment, the median survival rate for glioblastomas is 12 to 18 months, though it's possible that McCain could enter a clinical trial for new treatments.

It should be noted, however, that McCain is known among his constituents as well as his colleagues in Washington as a fighter, and he has thus far received support and well wishes from across the political spectrum.