Man's DNA Sample Saves His Life 9 Years Later

Dennis Massimo hung up on the Penn Medicine BioBank three times before finally answering their calls in April 2025. That decision to pick up the phone saved his life.

Nine years earlier, Dennis had donated a blood sample during a routine tonsil surgery, encouraged by his sister Lauren, a Penn nursing professor. He forgot all about it until researchers found something alarming in his DNA.

The BioBank team discovered Dennis carried a mutation in his MSH2 gene, meaning he had Lynch syndrome. This hereditary condition affects 1.2 million Americans and dramatically increases cancer risk, pushing lifetime colorectal cancer odds from under 5 percent to as high as 50 percent.

Dennis was only 42 and felt perfectly healthy. He had no symptoms and was still three years away from his first recommended colonoscopy screening.

But genetic counselor Jessica Long urged him to get screened immediately. When Dennis woke up from that first colonoscopy in a private recovery room with tissues by his bedside, he knew something was wrong.

Doctors had found a tumor. Dennis had stage III colorectal cancer growing silently in his colon.

"I found out when the cancer was stage III and not stage IV," Dennis said. "It really could have saved my life."

Three weeks later, surgeon Najjia Mahmoud removed the tumor in a partial colectomy. Dennis felt confident from his first appointment with her.

Then came remarkable timing. Dennis' oncologist, Ursina Teitelbaum, had just returned from a major cancer conference where researchers presented breakthrough results for his exact diagnosis.

A new clinical trial showed that adding immunotherapy to standard chemotherapy for patients with Dennis' specific cancer type cut recurrence risk in half. He received this cutting edge treatment plan within weeks of the study's announcement.

The Ripple Effect

The discovery didn't just save Dennis. Because Lynch syndrome is hereditary, genetic counselor Long helped coordinate testing for his entire family.

His sister Lauren, his kids, and extended family members all learned their genetic status. Those who tested positive now know to get early screenings that could catch cancer before symptoms appear.

Dennis and his wife Carla live next door to Lauren and her husband Kevin in West Chester, Pennsylvania. Their children play together in the yard every day, a reminder of how one forgotten blood donation created a ripple of protection across two generations.

Today, Dennis is cancer free and grateful he finally answered that persistent phone call.