Neil Spector of the Duke University Medical Center said, "This is very rare. I have a lot of people come to me and want to have their disease cured but I rarely see anyone who understands how to get to that point like Josh."
Spector said that he initially reacted with "skepticism" to Sommer's efforts, which "very rapidly thereafter" turned into "optimism."
Dr. Michael Kelly, also at Duke, agreed. He credits Sommer with jump-starting the field of chordoma research.
"I would not have predicted this in my wildest dreams but he's a very talented individual and he has applied himself very rigorously," Kelly said. "Josh did everything he had to do. So there was nothing that needed to be done that he didn't take up for himself; analyze, explore and really plot a pathway to an answer."
And, as all good students do to their mentors, Sommer has been constantly prodding Kelly to speed up.
"[Sommer has] pushed me to go faster and to consider ideas that previously I would have not ordinarily pursued, to think more broadly," he said. "Most importantly, he has brought an urgency to all of us."
For Sommer, it was a practical passion. "It's problem-solving essentially, and it's very personal because I realize that the result could save my life and could save the lives of a lot of other people," he said.
Now, nearly two years into that seven-year average survival, Sommer is feeling the clock ticking. The hardest thing, he says, is the uncertainty.
"Not knowing what's going to happen," he said. "You kind of feel like you're on a ship that is slowly sinking. And I think if everyone was on a ship that was slowly sinking, they would do everything they could to try to get off or prevent the ship from sinking. You don't know when it's going to sink. You know that it's happening and you just have to work as hard as you can to try and get off."
"I look back and I think 'wow,' we've done a lot. But at the same time it sort of feels like we're moving in slow motion because I want to go faster," he said.
Sommer's ambitious goal is to cure chordoma and, in the process, provide insight to other more common cancers.
"I hope as a country, we prioritize cancer because ... it's the No. 2 killer [in the nation] and it just seems amazing to me that it's not more of a political issue, it's not more of a discussion topic," he said. "I think people just say that it happens, that cancer kills people. But I don't think we have to accept that. I don't think we have to accept the status quo."
Jung Hwa Song contributed to this report.