A double round of chemotherapy didn't work, but Britton was one of the lucky ones. He got a bone-marrow match in just two months.
Caucasians like the Douglas twins are more likely to find matches because their genetic make-up is less diverse. African-Americans and Hispanics have a much harder time finding matches since their DNA is more heterogeneous.
And due to what some attribute to socio-economic reasons, they are less apt to become donors, according to DKMS.
But transplant experts say many people have misconceptions about bone marrow donation, which is safe and relatively non-invasive. The risk to the donor is minimal and the body regenerates bone marrow.
Alina Supranova, vice president of partner relations for DKMS, said the kits have "huge potential."
"We want to get people talking and understanding this is a big disease and many out there need our help," she said. "We are not asking for money, but a part of themselves. You can donate yourself to save another person's life."
Who Can Donate; How it Works
Generally, anyone from age 18 to 55 and in good health can donate. "It's less restrictive than being a blood donor," said Supranova.
DKMS receives the swab by mail and asks the potential donor for more information, then schedules a lab test to determine tissue and human leukocyte antibody (HLA) type.
"If the hospital requests you as a donor, they let us know," said Supranova. "There are tens of thousands of combinations of HLA, which is why it's difficult to find a match."
There are two ways to donate: having blood collected from the arm during an outpatient setting or directly extracted from the hip in a surgical procedure that requires anesthesia. The first takes about five hours and the second requires an overnight stay in the hospital.
Once collected, doctors separate out the stem cells needed for transplant. Patients recover quickly and regenerate their bone marrow.
Supranova's dream is that every donor might one day meet the person whose life they saved.
Britton eventually met his donor -- a firefighter in his 40s from Fort Hood in Texas, a father with two children.
"He's a really down-to-earth nice guy," he said. "He does realize that he has affected my life and I have his life a lot, too."
Graham still remembers the pain his brother endured. Britton's recovery was a "game of inches," he said. "It was a big deal when he was allowed out to go to the mailbox."
Were it not for his twin, Britton would never have been able to register for online classes that spring semester when he was recovering. He was too weak to leave the house so Graham memorized his brother's Social Security number and posed as him in order to attend the required orientation.
"I know my experience really hit him hard," said Britton. "I cannot imagine what it must have been like to go through that second hand -- to watch someone extremely close to you who is near death."
Today, the brothers' love runs deep, even though they live 2,500 miles apart.
"Everyone says twins can feel each other's pain, and I think it's true," said Britton. "Even though we spent our childhood beating the crap out of each other."
To sign up for a bone marrow registration kit go to Get Swabbed.