Geisinger: Pittston Man Emerges Healthier After Medication Side Effect

David Centak of Pittston is just your average guy. He enjoys spending time with his wife, Tiffany, and he loves hosting game nights, cooking and grilling, gaming, and spending time outside with his two Australian shepherds, Grace and Hope.

What makes the 35-year-old so much more than an average guy is the incredible health battle he overcame and how he emerged on the other side of that journey healthier than ever before.

Centak always knew that he was at high risk for colon cancer because of a genetic condition called Lynch syndrome. People with the condition have DNA that lacks the ability to repair their own cells. As cells grow and make copies of a person’s DNA, errors may occur. DNA will make corrections to repair these errors, but for a person with Lynch syndrome the errors may duplicate themselves, resulting in an increased risk for cancer.

Because of the condition, Centak had regular screenings. And in the fall of 2024, he was diagnosed with colon cancer.

“My doctors recommended a hemicolectomy, but at my age I did not want to undergo that radical of a surgery,” he said. Not ready to have a surgery to remove a section of his colon, he sought other options and found a clinical trial with immunotherapy at Memorial Sloan Kettering Cancer Center in New York.

“I received the first dose and when I went back for the second dose, they noticed that my blood glucose level was 561,” Centak said. “It was the day after New Year’s, so I was dehydrated and attributed it to eating Wawa that morning and having an energy drink on the way to the appointment.”

The medical team gave him some time and rechecked his levels, and when the number fell to 210, he received his second dose of the medication. On his way home, he received a call from the doctor at Memorial Sloan Kettering telling Centak to go the emergency room immediately. The doctor worried Centak had a very rare side effect from the medication that could affect how his body processed glucose.

Centak immediately went to Geisinger Wyoming Valley Medical Center’s emergency room. Following some tests, they confirmed that the medication had likely caused him to develop Type 1 diabetes.

“The emergency room doctor explained that a reaction like this most likely meant that the immunotherapy had worked to stop the cancer from growing,” Centak said. “That was good news but it had also destroyed the beta cells in my pancreas.”

He needed to stop the clinical trial immediately to avoid risk of further major organ damage. Luckily since the trial had stopped the cancer, he would not need radiation or chemotherapy, but now he had to learn to manage having diabetes at 35 years of age.

After meeting with Mihail Voica, MD, Geisinger endocrinologist, he connected with a certified diabetes care and education specialist to learn how to deal with his new condition.

“I met with Jessica Kozlosky and she had an amazing level of understanding and knowledge,” Centak said. “We talked about my insulin shots, and she offered dietary advice. Early on, I met with her every week and that was critical for me getting everything managed.”

Kozlosky, a registered dietitian nutritionist, explained to Centak that she had diabetes herself and shared some tips on how she managed her condition to put his mind at ease and give him reassurance on managing his blood sugars.

“Diabetes is a personalized disease. Something that works for one person might not work for someone else, but David was open to my experiences and really wanted to learn more about how he could manage the disease through his eating habits,” Kozlosky said. “He comes to appointments with really great questions and is truly invested in managing his disease.”

She explained carbohydrate counting as a tool to help Centak manage his diabetes and talked him into using a pump to make managing insulin and blood sugars easier.

“The Omnipod (insulin pump) was a game changer. Getting that advice from someone who understands was invaluable. She explained that I can still enjoy my life,” Centak said. “She also explained things to my father and my wife at a couple of appointments, explaining the course of action and creating a level of trust with my family so they understood it was under control.”

Follow-up tests revealed a small spot of cancer still remaining in his colon, so he underwent a partial colectomy in August to remove about one-third of his colon. He has recovered fully from the surgery, has been managing his diabetes and feels great.

 “This might sound funny to say, but I feel better than I did before all of this happened,” he says. “I am healthier. I sleep better and I feel better, even with these conditions.”

Kozlosky is not surprised.

“His success is not surprising because he puts the work in. He comes to appointments with questions and is willing to do anything. He is very analytical and looks at trends and the data,” she said. “I have a really positive outlook for him.”