McCain’s rare type of can­cer in­cur­able

Glioblas­toma digs into brain

The Washington Times Weekly - - National - BY LAURA KELLY

The an­nounce­ment of Sen. John McCain’s brain tu­mor di­ag­no­sis was met with an out­pour­ing of sup­port by well-wish­ers high­light­ing the Ari­zona Repub­li­can’s fight­ing spirit and for­ti­tude.

Yet his type of tu­mor — a pri­mary glioblas­toma — is an en­tirely dif­fer­ent ad­ver­sary than any he has faced be­fore.

“I greatly ap­pre­ci­ate the out­pour­ing of sup­port — un­for­tu­nately for my spar­ring part­ners in Congress, I’ll be back soon, so stand-by!” Mr. McCain said Thurs­day in a tweet.

Of the 80,000 cases of brain tu­mors typ­i­cally di­ag­nosed each year, about 15 per­cent are glioblas­tomas, ac­cord­ing to the Amer­i­can Brain Tu­mor As­so­ci­a­tion.

The ag­gres­sive na­ture of the tu­mor and its amor­phous shape — ex­pand­ing and bury­ing it­self in the soft tis­sue of the brain — makes it dif­fi­cult to re­move with surgery.

The Amer­i­can Can­cer So­ci­ety es­ti­mates that more than 23,000 cases of ma­lig­nant brain tu­mor will be di­ag­nosed this year and that more men than women will be af­fected. The prog­no­sis is dire: Pa­tients with glioblas­toma typ­i­cally are given less than a year to live. With treat­ment, life ex­pectancy grows to about 14 months to three years.

“Ten per­cent of peo­ple may sur­vive five years or longer, but it’s not clear what in­di­vid­ual char­ac­ter­is­tics may con­trib­ute to them sur­viv­ing longer,” said Ni­cole Will­marth, chief sci­ence of­fi­cer for the Amer­i­can Brain Tu­mor As­so­ci­a­tion. “When treat­ing pa­tients, doc­tors will look at a num­ber of fac­tors — over­all health, co-mor­bidi­ties — one al­ways has to weigh the risks and ben­e­fits of treat­ments.”

Mr. McCain’s tu­mor was dis­cov­ered af­ter he un­der­went surgery to re­move a blood clot in his brain. In a state­ment re­leased Wed­nes­day, the Mayo Clinic in Ari­zona con­firmed that the clot was as­so­ci­ated with a glioblas­toma and that the sen­a­tor un­der­went fur­ther surgery to re­move can­cer­ous tis­sue. Mr. McCain, his fam­ily and his doc­tors are con­sid­er­ing fur­ther treat­ment, in­clud­ing chemo­ther­apy and ra­di­a­tion.

Glioblas­tomas usu­ally are dis­cov­ered when the brain tu­mor gets to a size that it im­pairs a per­son’s func­tion­ing. A pa­tient will re­port symp­toms in­clud­ing headache, nau­sea, vom­it­ing and drowsi­ness. It also can cre­ate changes in per­son­al­ity, mem­ory loss, dif­fi­culty with speech, changes in vi­sion, seizures and weak­ness on one side of the body — de­pend­ing on where the tu­mor takes hold.

The sen­a­tor’s can­cer an­nounce­ment shed new light on his per­for­mance last month dur­ing a Se­nate hear­ing with for­mer FBI Di­rec­tor James B. Comey. Mr. McCain was un­char­ac­ter­is­ti­cally in­co­her­ent and ram­bling dur­ing his ques­tion­ing of Mr. Comey. He later blamed his fa­tigue on stay­ing up late watch­ing a base­ball game the night be­fore.

Mr. McCain’s for­mer Demo­cratic col­league, Sen. Ed­ward M. Kennedy, suc­cumbed to glioblas­toma in 2009, as did Beau Bi­den, a son of for­mer Vice Pres­i­dent Joseph R. Bi­den, in 2105.

There is no known cause for glioblas­toma, and re­searchers have not linked its oc­cur­rence to a fam­ily his­tory of can­cer or tu­mors. Cer­tain ge­netic syn­dromes are linked to glioblas­tomas, al­though th­ese cases are rare.

The tu­mor is known to de­velop from rogue as­tro­cytes, star-shaped cells es­sen­tial to the func­tion­ing of the brain and cen­tral ner­vous sys­tem. There are five grades of as­tro­cy­tomas — tu­mors from as­tro­cytes — and about 60 per­cent are glioblas­tomas, which are clas­si­fied as ei­ther pri­mary or sec­ondary.

Mr. McCain’s di­ag­no­sis is pri­mary glioblas­toma, the most com­mon type in older peo­ple. Mr. McCain is 80. Sec­ondary glioblas­toma tu­mors most fre­quently ap­pear in peo­ple younger than 45 and de­velop at a slower pace than pri­mary glioblas­toma tu­mors. Sec­ondary tu­mors rep­re­sent about 10 per­cent of glioblas­tomas, ac­cord­ing to the Amer­i­can Brain Tu­mor As­so­ci­a­tion.

Surgery is the first course of ac­tion, but the tu­mor’s ten­ta­cle­like reach into the crevices of the brain make it dif­fi­cult for sur­geons to ex­cise all parts of the tu­mor.

Af­ter surgery, pa­tients typ­i­cally are pre­scribed oral chemo­ther­apy in con­junc­tion with ra­di­a­tion. This is the stan­dard of care, but clin­i­cal tri­als and re­search con­tinue to push the bound­aries of treat­ing this dis­ease.

Be­cause glioblas­toma is such a rare form of brain can­cer, the Food and Drug Ad­min­is­tra­tion con­sid­ers re­search and de­vel­op­ment for treat­ments to be “or­phan drugs.” Congress has en­acted leg­is­la­tion to give phar­ma­ceu­ti­cal com­pa­nies in­cen­tives to de­velop treat­ments for such rare dis­eases and con­di­tions.

Sci­en­tists have been re­search­ing iden­ti­fi­ca­tion of cer­tain biomark­ers — the oc­cur­rence of spe­cific mol­e­cules in the body — that could in­di­cate how a per­son is ex­pected to re­spond to chemo­ther­apy.

“There are pa­tients with a cer­tain marker that tend to ben­e­fit more from chemo — that would be a fac­tor to con­sider when de­ter­min­ing what treat­ments to give in­di­vid­ual pa­tients,” Ms. Will­marth said.

In 2015, the FDA ap­proved a treat­ment us­ing a head cap called Op­tune that sends elec­tric cur­rents into the brain to dis­rupt can­cer cells from di­vid­ing, halt­ing the growth of the tu­mor.

In clin­i­cal stud­ies, the tu­mor stopped grow­ing for at least seven months for pa­tients wear­ing the Op­tune cap while on oral chemo­ther­apy treat­ment. For those only on oral chemo­ther­apy drugs, tu­mors were held at bay for at least four months.

This ar­ti­cle is based in part on wire ser­vice re­ports.

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