Matthew Zachary has always been something of an angry rebel, naturally predisposed “to hate authority,” he says. In nursery school, he was expelled for biting the teacher and the principal because he didn’t like the sleeping mats.

So when he got brain cancer as a college senior in 1995, he found plenty of things to get mad about. Here were some of the things on his list:

* the student health service at Binghamton University, which diagnosed him with meningitis, the flu, a mini-stroke, even carpal tunnel syndrome;

* his shot-to-smithereens plans to go to graduate school to become the next John Williams, the legendary composer of the music for “Star Wars,” “Jaws” and other movies;

* oncologists at Memorial Sloan Kettering Cancer Center who talked about him to his parents as if he weren’t in the room.

But what really infuriated him, and ultimately sent him in a new direction, was the federal report on adolescents and young adults with cancer that he read several years after doctors excised a golf-ball-size tumor from inside his head. The report’s key finding: Compared with other age groups, the 15-to-39 set was neglected and had gone decades with little to no improvement in survival rates.

“No one gave a s---t about us because we were not bald kids or grandparents,” Zachary said.

With memories of his own trauma — punishing radiation, temporary deafness, mood swings and soul-crushing isolation — he left an advertising agency to create a nonprofit for young people with cancer. It eventually got renamed Stupid Cancer.

“I figured that’s what Homer Simpson would call it,” he says.

The rest is history, his and the group’s.

Stupid Cancer now bills itself as the largest nonprofit for young-adult cancer issues, of which there are plenty given the 72,000 adolescents and young adults diagnosed annually in the United States. With a glowering Flip the Bird mascot and a slick, info-packed website, the group is active in advocacy, research, mobile health and social media. Its weekly podcast claims to be “changing the world one chemo infusion at a time.” Its mobile app, called Instapeer, allows cancer patients to find each other anonymously.

As for the frequently profane Zachary, he’s now 41, married, living in Brooklyn and the father of 6-year-old twins. He has released two solo piano albums. In his speeches, he waves Hollywood off the tear-jerking depiction of young cancer tragedy in “Terms of Endearment” and praises “50-50” as pitch perfect.

We caught up with him in advance of CancerCon, his organization’s yearly gabfest and party, which begins Thursday in Denver. Our conversations have been edited for space, clarity and because we just can’t print some of his rantings.

What was it like being 21 years old and diagnosed with brain cancer?

I was told I had a 25 percent chance of surviving the surgery. Afterward, I was subjected to excessively high radiation, ended up getting more than Fukushima and Chernobyl, and lost 110 pounds in three months.

But you turned down chemo because of worries that it would cause nerve damage in your hands and end your days at the piano.

The doctors wanted to do chemotherapy, but I declined. The doctors said, “Holy s---t! What's wrong with you? We are trying to save your life.” I said, “I’d rather die earlier than not play again.”

I had a bucket list, well, more like a f---it list. I decided to hike the Grand Canyon. The doctors said, “You can't possibly do this.” But I did. And I learned the power of self-advocacy.

You’ve said you wanted to create something you wished you’d had back then — a community. First you founded a group called Steps for Living, then you switched that to I’m Too Young For This! until you finally settled on Stupid Cancer in 2012. Why all the name changes?

Its about the brand. Im Too Young for This! is esoteric and takes thought. Stupid Cancer is this guttural thing. Two words capture it. Only when you find your community do you realize how isolated you were. This is not a new concept.

I have no doubt that we would not exist in any way, shape or form without social media. We needed the voice. Its amazing that ACT UP [the AIDS activist group formed in the 1980s] could do what it did without the Internet.

These days, what are some of the issues you’re most concerned about? 

Fertility is a big issue. You have the right to be made aware of fertility risks posed by your treatment, and you should not have to pay to preserve your fertility. It should be that blindingly simple. In other countries, fertility preservation is free, but here insurers dont pay for it.

There is much anecdotal data that if you are among the 20 percent getting care at a comprehensive cancer center, you will probably be made aware of the risk posed to your fertility. But 80 percent of patients are being treated in Bumblef--k, Iowa, and they are not being told. I have nothing against Iowa, by the way.

What else concerns you?

Mental health. For military vets, [post-traumatic stress disorder] and the need for therapy are culturally accepted these days. What about the trauma of cancer, death, possibly not being able to have children?

My oncologist told me when my treatment was ended, “Go live your life,” but its not that easy. You live in fear of recurrence every day.

In a recent post, you complained that pharmaceutical companies frequently want patient groups to help test and promote products but often don’t want to pay them a fair price for that. Your message to the industry was “You need something, you pay for it.” What was that all about?

Pharma thinks it can do anything it wants, that we are just here for the plucking because its in our interest. And if some genomics company with a great screening product comes to us and says, “We would love you to tell your community about this,” then I say, “How much money do you have to advertise with us?”

The companies say, “Come sit on an advisory panel or do a webinar with us.” But no, Im not your monkey.

You’ve expressed skepticism that we will find a cure for cancer. At best, you’ve said, people with a diagnosis might eventually be able to manage the disease, just like HIV or asthma. Which raises the question: What do you think of the “cancer moonshot” effort launched recently by the Obama administration?

The moonshot is too new for me to have an opinion. I want to be optimistic — but I am not genetically an optimist.

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