Sept. 30, 2011 -- The Portland, Ore., family of missing bicyclist Mark Bosworth is desperate for leads now that his doctor says a recurrence of lymphoma may have spread to his brain, causing disorientation and, eventually, immobility.
The missing map expert and two-time cancer survivor had been touring the countryside as a volunteer with Cycle Oregon, a weeklong bike event that raises money for each of the small communities where the 2,300 riders travel.
On the night of the 16th, one day before the bike ride would end, the group pitched tents in Riddle, Ore. Around 11:15 p.m. his wife, Julie Bosworth, said her 54-year-old husband told friends he didn't remember where his tent was. A friend offered to show him, and handed Bosworth a bike headlamp.
"He took the light, he said 'No, I'll be fine,' and that was the last time he was seen," said Julie Bosworth.
Now, two weeks later, the search for her husband has become even more urgent because Mark Bosworth's non-Hodgkin's lymphoma (NHL) may have returned.
Bosworth was first diagnosed with the most common form of NHL, diffuse large B cell lymphoma, in the summer of 2007. The cancer went into remission after he underwent chemotherapy, but in the summer of 2009, the same cancer returned, this time spreading to his eyes and crossing the blood-brain barrier, which works to prevent foreign substances from entering the brain. After eight months of treatment he had a bone marrow transplant in April 2010 and appeared to be in remission.
Mark Bosworth's lymphoma has a three to five percent chance of spreading to the brain, said Dr. Paul Barr, who treats lymphoma patients at the Wilmot Cancer Center in Rochester, N.Y. But the risk increases when patients relapse.
"When lymphoma is in the brain or nervous system, we consider that situation to be an emergency requiring immediate therapy," Barr said. "Once you have a headache, it suggests there's enough cancer to increase pressure inside the brain -- that's where you get headaches, nausea … if it increases it doesn't take that much extra pressure to make someone unconscious."
About three weeks before the bike event, Bosworth complained to his wife about severe headaches, but he told her they were probably due to a pulled muscle in his neck.
"He wasn't his usual enthusiastic self. He was repeating himself, forgetting he told me things," she said.
He made appointments with his doctors but scheduled them for the days following Cycle Oregon, insisting he was well enough to volunteer.
During the ride participants said Mark Bosworth seemed confused. As a volunteer, he was supposed to drive a van every day but he stopped when it became clear he had trouble following the traffic signs. Sometimes he would just stand alone and stare. During a phone conversation with his wife around 8 a.m. on Sept. 14, he told her he was on the East Coast and was excited to be there, and then, during the same conversation, he told her he was in Canada.
"I said, What are you talking about? He said, 'Oh, they flew us here.' He said it was a surprise. I said, 'Mark, you're crazy -- what are you talking about?'" Julie Bosworth, 57, recalled. "When we connected later in the day, he said he must have been waking up from a very vivid dream and wasn't that funny. Again, he was covering up that he was experiencing confusion."
His family now worries he could be anywhere -- especially because three credible eyewitnesses saw a person who looked like Mark Bosworth hitchhiking and shining an LED light erratically near the I-5.
"I have repeatedly gone to the last place he was seen and thought 'Honey, where did you go?' We just are in a rabbit hole of puzzlement," Julie Bosworth said.
The family fears it's possible he had even tried to hitchhike to New York City, where he and his wife lived for 10 years during the 1980s.
"Other than Portland it's the place we're most connected to," his wife said.
This week Julie Bosworth met with the doctor who has been treating her husband for four years and learned "the only scenario that matches Mark's symptoms is that the lymphoma has spread to his brain."
"We were sitting there holding hands and crying when [the oncologist] looked into my eyes and told me what he thought," she said.
Her husband's doctor believes the cancer may be exerting pressure on his frontal lobe, she said, which can cause headaches and confusion. It's a gradual process that will only get worse.
"The urgency is that the cancer will spread to the brain stem and we just have to find him and get him to immediate medical care before that happens. He's confused, he probably has amnesia," she said. "This sense of urgency was shocking and terrifying to me, which is why I'm doing everything I can today to ask people to look for Mark."
The Search for Mark Bosworth
For now, the family holds out hope that Mark Bosworth is still able to walk and talk. Cycle Oregon organized a Saturday bike ride in his honor, and his family started a blog, Twitter account and Facebook page to raise awareness.
On Wednesday, the $10,000 reward offered by Julie Bosworth's employer, Deckers Outdoor Corporation, was featured on a digital billboard in Times Square.
Lance Armstrong spread the word Tuesday on Twitter, and on Sunday three-time Tour de France winner Greg LeMond did the same.
But the Douglas County Sheriff's department isn't any closer to finding him.
Spokesman Chris Merrifield told ABCNews.com, "We've had lots of people call in that have said they thought they saw him" but "nothing to give us any lead as to where he moved."
Deer hunting season starts Saturday, so Merrifield is cautioning hunters to remain vigilant.
Bosworth Family Stays Focused
On the Facebook page dedicated to finding Mark Bosworth, he's described as an inspiration to others battling cancer. Despite his health problems, when he wasn't working at Metro the father of two taught mapping courses at Portland State University, sang in a church choir and played guitar in his classic rock band, Rock-It Science.
"We tease him a lot about that name -- we think it's pretty nerdy," Julie Bosworth said.
Music is a big part of Mark Bosworth's life, she said, telling ABCNews.com he has "a beautiful tenor voice." He would cook dinner every night, and the family often sang music afterward.
"[Wednesday] night my girls were singing Carole King, and Simon and Garfunkel," she said. "We've been keeping that tradition."
The Bosworths were planning to celebrate their 25th wedding anniversary this week by renting a flat in London. On Wednesday, Julie Bosworth canceled their Saturday plane tickets.
Now, instead of packing for London, she thinks about the ring her husband gave her on the day of their anniversary, June 28. It was engraved with a special message: "You are my compass, my direction, my description of the world."
"And that's just what I want to be for him because that's what he is for me too," she said.
Mark Bosworth is 6 feet tall, and approximately 180 lbs with grey hair and blue eyes. He was last seen wearing a grey hoodie sweatshirt, black bicycle pants, shoes and a hat. Anyone who sees Mark Bosworth is asked to call 911.