Nonetheless, he's healthy and Oregon Live has a profile:
"It's funny," Shanteau said. "I went back and watched some of the interviews from 2008. I was caught on camera several times saying, 'Oh, this is it for me.'"
He pauses for a second, pondering what led him to stick with the sport that has been such a big part of his life, even when cancer threatened to derail it.
"I just felt like I still had something to prove," Shanteau said. "It just kind of snowballed from there. I started swimming well and better and faster than I ever had before. I just took off and kept going, and here I am four years later."
Shanteau still undergoes cancer screenings twice a year, and there's been no sign of a recurrence. But the disease still casts a heavy toll on his family, having claimed his father's life after Beijing.
"Obviously, losing a parent is very difficult," Shanteau said. "I miss my dad every day, but I know he would be proud to see me continuing to swim and going for another shot at the Olympics."
There have been plenty of good times, as well. Just this week, Shanteau celebrated the first anniversary of his marriage to Jeri Moss, an event that brought some much-needed balance to his life.