Senator John McCain is recovering at home after having a tumor removed from his brain. The 80-year-old was diagnosed with Glioblastoma.

Glioblastoma is a rare type of brain cancer, seen in with fewer than 200,000 cases a year.

However, Doctor Lodovico Balducci, the Director of the Senior/Adult Oncology Program at Moffitt Cancer Center, said he is seeing an increase of the rare cancer in older patients like McCain.

“It's becoming more and more common in people ages 70 and older; in fact, there has been a sevenfold increase between the 50's and now," Balducci said.

Balducci said there isn’t a reason for the increase in the aggressive cancer, but advancements in treatments have helped patients prolong their lives.

“The new technology in radiation, as well as the new approach with chemotherapy has benefited many patients," said Balducci.

Patients like 57-year-old Mariela Pow-Sang, a neurologist/oncologist diagnosed three years ago. She’s had a tumor removed twice.

“When the tumor gets removed in the place she has it, it's the motor control, and she has the tumor on the left side so it affected her right side of her body, but she's lucky because she's able to walk," said Mariela’s sister, Cindielie Pow-Sang.

After radiation, chemotherapy, and clinical trials, Mariela is currently cancer-free. She was given 11 months to live.

‘Right now she is on temodar, which is chemotherapy medicine, she's done with the radio therapy, and now she's on temodar only," Cindielie said.

However, Balducci said the disease is difficult to cure.

Kristen Magill, 36, was diagnosed when she was 30 years old and pregnant. She had most of her tumor removed and has been in the clear.

“Mine cleared up for the past four years and now that it's coming back I need to start some more chemo," Magill said.

Magill, like many patients, said it will likely be a lifelong battle.

The average survival time for the aggressive cancer is around 14 months, even with treatment.