Ever since Beastie Boys member Adam "MCA" Yauch was [article id="1616542"]diagnosed with cancer[/article]
 of the parotid gland, a salivary gland in the throat in 2009, the rapper kept an upbeat attitude in public about his chances of beating the disease.

Unfortunately, Yauch, 47, wasn't able to win his three-year battle and [article id="1684488"]died on Friday[/article]
 after several years spent out of the spotlight as he struggled to regain his health. Spokespeople for Yauch have not revealed what the cause of death was, but according to Dr. Spiro Manolidis, a head and neck cancer specialist in the Department of Otolaryngology at Beth Israel Medical Center in Manhattan, it is not unusual for this type of cancer to turn deadly.

"This is a very tricky cancer," said Manolidis, who did not treat Yauch, but whose sub-specialty is skull-based surgeries dealing with recurrences of this type of cancer. "It strikes at random and there are no known risk factors. Unlike other cancers, if you look at the statistical curve, these type tend to occur very far out, the patients do well for [several] years and then there is a recurrence. It has a tendency to come back."

At the time of his diagnosis, Yauch said the cancer was localized and hadn't affected his voice. According to the American Cancer Society, the type of salivary cancer Yauch suffered from was very rare, with just two adults in 100,000 diagnosed with it every year. Most are 55 or older and doctors aren't sure what causes it, though traditional factors such as smoking and alcohol consumption are not thought to raise the risk.

The parotid gland is just in front of the ears and surgery to remove the cancerous cells is tricky because the facial nerve goes through the parotid, according to the Cancer Society. While surgery and radiation treatments are most often used, targeted drugs have not yet been developed for this rare disease.

Manolidis said tumors in the parotid tend to crawl long on nerves and travel within the body, which makes them hard to treat surgically or with radiation. "As a general rule, no chemotherapy has proven to work effectively on these tumors," he said. "The other tendency is for them to lie quiet and you assume the patient is cured and many years later they reappear as distant metastasis, with the lungs and bones being the favored locations."

It's unknown if Yauch had a recurrence of the same cancer and if he continued to pursue surgery as a treatment. Manolidis said that this type of cancer can be treated with aggressive surgery if it comes back in a localized fashion. "Once you have a situation like that and you [don't use traditional methods to treat it], something potentially curable becomes rapidly incurable," he said.

In July 2009, Yauch [article id="1616542"]announced in a video[/article]
 posted to BeastieBoys.com that he'd been diagnosed with cancer. "The reason we're here talking is because I have some pretty heavy news to say," Yauch said in the video. "About two months ago, I started feeling this little lump in my throat, like what you would feel if you have swollen glands or something like that, and so I didn't really think it was anything. ... They did tests, and I actually have a form of cancer in the gland that's over here, in the parotid gland, and it's also in the lymph node right in that area."

He said then that the cancer had not spread to other areas, which was good news since the survival rate depends on whether the disease has migrated elsewhere. The cancer can spread to the lungs and other organs if surgeons are not able to completely remove it from the gland. According to the American Cancer Society, if it does not spread, the five-year estimated rate of survival is 91 percent, though if it has spread far from the glands and is a "Stage 4" case, the survival rate drops to 39 percent.

Yauch had surgery to remove the tumor and began radiation treatments, which forced the Beastie Boys to cancel their summer touring plans, including headlining gigs at the All Points West Festival and Lollapalooza, in addition to delaying the release of their album Hot Sauce Committee: Part One. The album was finally released in May 2011 under the title Hot Sauce Committee Part Two with a slightly altered track list.

He followed with another note to fans in August of that year, telling fans that he was "rapidly recovering" from the surgery and that while his nick and jaw were still stiff, "things are moving along." By October, he told fans he'd traveled to Dharmsala, India, where he [article id="1623332"]consulted with some Tibetan doctors[/article]
 and attended a seminar by Tibetan spiritual leader the Dalai Lama. "I'm feeling healthy, strong and hopeful that I've beaten this thing," he wrote. "But of course time will tell."

He made a rare public appearance at the Independent Spirit Awards in March 2010 and said that things were "touch-and-go" for a period, but that he was getting his energy back and eager to get back to work. Though he directed the [article id="1662406"]short film for "Fight For Your Right Revisited"[/article]
 and made a brief appearance in it, it marked one of the last times he would be seen in public. He was not present last month when the B-Boys were inducted into the Rock and Roll Hall of Fame, though Ad-Rock read a heartfelt note from MCA giving thanks for the honor.

Share your memories of Adam on Twitter using the hashtag #RIPMCA.