Nethero’s book is available online at Amazon and Barnes & Noble for $12.95. Information: www.yourmentalmastery.com.

David Nethero remembers precisely when his health battle began. It started on Halloween 2012 with a bout of indigestion that never went away. By mid-December, doctors had diagnosed an intestinal blockage and scheduled surgery. But the results were not good: The operation had uncovered a cancerous tumor.

“I was shocked,” recalls the 60-year-old Brookhaven resident. “There was nothing in my lifestyle leading up to that. The good news was it hadn’t spread to other organs, but I did have to go through chemotherapy. Within eight hours it dawned on me: A diagnosis didn’t necessarily mean death, but it really did change things.”

The semi-retired Nethero began by writing a journal just about his health.

“It seemed like a reasonable time to reflect on my thoughts,” he says. “As time went on, I found it was also a practical recording of how I felt - what symptoms bothered me, how I selected a doctor. There was a lot of substance there, and my wife suggested I put it together so other people can benefit from it.”

The result is “Mental Mastery of Chemotherapy,” a book published in May that shares about 50 of Nethero’s personal experiences. Another 50 pages form a workbook readers can fill with their own stories. It also offers insight on how the author benefited from meditation and positive mental imagery - tools he’d put to good use before to quit smoking.

“I used meditation to ground those positive images in my subconscious, so I my mind was always filled with the imagery I wanted to counteract the concern and anxiety anyone facing chemo has,” he says. “It helped me live in the moment and to be engaged throughout the whole process.”

The journal also offered Nethero a way to be pro-active about his cancer, especially while enduring chemo treatments every other week for half a year that left him fatigued and nauseous. “It gave me a sense of control; I had a rhythm and pattern of experiences,” he says.

Nethero is now in a 5-year surveillance program, but he’s passed his first anniversary of the diagnosis cancer-free. He’s spent the summer sharing his journey with others in talks sponsored by the American Cancer Society and on his website, yourmentalmastery.com.

As for being an author, he’s not tracking how many copies he sells. “For me, if this book helps one person on a journey with cancer, then in my mind, it will be a bestseller.”