One cluster has been found among Auburn University alumni.

Ocular melanoma, also known as uveal melanoma, is a very rare type of cancer. Each year, only 2,500 people — or about 5 in 1 million — receive a diagnosis with this type of eye cancer.

That statistic is exactly why two small towns — Huntersville, North Carolina, and Auburn, Alabama — are such anomalies. Both towns are associated with a high number of ocular melanoma (OM) cases. Researchers want to know why.

“We see patients from all over the country and some patients from outside of the country. Certainly if we have patients who know each other or who lived and grew up in the same town, that has been kind of a red flag for us in trying to figure out if there’s something else going on,” said Dr. Marlana Orloff, an oncologist at Thomas Jefferson University Hospital in Philadelphia who specializes in the treatment and study of OM.

Take Auburn, for example. The town of 63,000 people is in a state of just under 5 million people. It’s home to one of Alabama’s largest universities, Auburn University.

Thirty-three people with connections to the town or university have received diagnoses of OM. The main common thread between them seems to be that they all lived or worked in the town between 1980 and the early 1990s.

Huntersville, a small town north of Charlotte, is slightly smaller, with a population of almost 55,000. But 18 people who lived, worked, or spent substantial amounts of time in the town since 2000 have received diagnoses of OM.

As the number of cases continues to grow in these areas, so does the interest in people who’ve developed the cancer — and, perhaps more importantly, what they all have in common.

According to the American Academy of Ophthalmology, OM is the most common primary cancer of the eye in adults. The cancer develops in the cells that produce the eye’s pigment. It can also develop on the conjunctiva, the mucus membrane that cover the eye and line the eyelid.

Most eye melanomas develop in a part of the eye you can’t see. The early stages of the cancer rarely cause any signs or symptoms. That’s why you might not be able to spot this type of melanoma the way you might a freckle or unusual mole on your skin.

However, people may spot warning signs of the cancer as it grows. Symptoms of OM include blurry or distorted vision, a blind spot in your vision, seeing “flashing” lights, or a dark spot in your field of vision.

As the cancer progresses, you may notice that the shape of your pupil changes. A dark spot or “freckle” may develop on the iris.

“Sometimes it will get picked up on a routine eye exam. Other times, patients will be having symptoms, often symptoms of a retinal detachment,” Orloff said. “They go to an eye doctor, they get referred to a retinal specialist, and then ultimately to an ocular oncologist who makes the diagnosis.”

Ocular Melanoma Foundation statistics identify 55 years of age as the median age for an OM diagnosis.

Those two facts alone make the cases in Huntersville and Auburn even more unique.

In both towns, women have received diagnoses more frequently, Orloff says, and all of the individuals with OM have been younger, well below the median age of a typical diagnosis.

In 2001, Allyson Allred, an Auburn University graduate living in Hoover, Alabama, received an OM diagnosis. A year earlier, she told, Allred was sent a prayer request for an Auburn alum — and a woman who had lived in the same dorm as she during their freshman and sophomore years at the school — who had been diagnosed with this same rare cancer.

When Allred received her diagnosis, she reached out to the woman, and they connected over the shared diagnosis.

Eleven years later, in 2012, another woman with connections to Auburn and the same dorm joined their circle.

While these three women bonded and helped one another through the ups and downs of the disease, across town and unbeknownst to them, another Auburn alum was fighting his own OM battle.

Mark McWilliams, a 1994 and 1995 graduate of Auburn University, received a diagnosis of OM in 2011 at the age of 38. The Birmingham, Alabama, architect started experiencing vision problems in his right eye and went for an exam. That’s when his doctors discovered the cancer.

“He had some sort of wave or distortion in his vision,” said Susan McWilliams, Mark McWilliams’ wife. The couple, who met as part of a supper club, started dating after his initial diagnosis. “He knew there was something weird about the vision in the right eye. We were all just stunned.”

McWilliams was referred to Wills Eye Hospital and Dr. Takami Sato, director of the metastatic uveal melanoma program at Thomas Jefferson University Hospital, both in Philadelphia. Orloff joined Sato after McWilliams was a patient.

Under Sato’s treatment, McWilliams received plaque radiation, the standard treatment for this type of cancer.

A few short months later, doctors told him the cancer was gone. However, they also warned him — and genetic tests confirmed — the likelihood of recurrence was high.

“Most of the treatments are very effective at preventing the tumor from coming back in the eye,” Orloff said. “But what we see is there’s a good portion for patients who may recur with disease notably in their liver at some point down the line.”

According to research from the Memorial Sloan Kettering Cancer Center, half of all people with OM ultimately develop metastatic cancer and find new lesions in their body outside of the eye.

Indeed, McWilliams found new cancerous spots on his liver, a year and a half after his first diagnosis.

“We were going along, fighting it, and the whole family was doing research on it,” Susan said. “If we hadn’t had the doctors in Philadelphia, he might not have lived six months. We fought very hard for a few more years of life.”

McWilliams died due to OM in 2014. Since his death, Mark’s parents, as well as Susan, have been involved with OM awareness groups. They hope to help patients and families learn about the cancer, including meeting with people from Auburn who may be impacted by the same disease that took Mark.

“It seems like this is the thing they have in common,” Susan said. “It seems like that very much, but of course, they all came from different places, have now gone to different places. The higher the numbers get, really, it seems uncanny.”

Orloff understands that concern. “If you have a bunch of people who went to the same university over a relatively short period of time, it would be abnormal for a lot of leukemia cases,” she said. “When you’re talking about more common cancers like breast cancer or lung cancer, they’re certainly more common, but when you’re talking about a rare cancer, it certainly raises a red flag.”

Orloff says Auburn and Huntersville are the only two towns or locations where researchers have found an increased incidence, but that doesn’t mean there aren’t more.

“Just because of the rare nature of the disease, you wouldn’t expect people to know five or six people within their small group of friends who have this disease,” she said.

That’s in part why she and other OM organizations are working to raise awareness — and funds — for research.

Last April, Huntersville received a $100,000 grant from the North Carolina state legislature to begin studying possible causes of OM. Dr. Michael Brennan, a retired ophthalmologist in nearby Burlington, is helping spearhead the group. He works closely with the University of North Carolina, Duke University, and both Orloff and Sato at Jefferson in Philadelphia, according to The Charlotte Observer.

The group’s first target for research was environmental exposures and genetic traits. Findings from these studies are set to be released this summer.

As word about the Auburn University-related group spread north, some of these researchers also ventured down to meet with concerned former alumni, parents, and others.

At their first meeting in February of this year, the researchers recorded information for people they met. They cast a wide net to hopefully discover more people who may have been impacted by this cancer but left the city or school years ago.

“These cases aren’t always picked up accurately [by a cancer registry], especially because people are often diagnosed outside of the state,” Orloff said. “In Auburn and in North Carolina, it was a lot of younger women. They went to high school or college there. They could now be living somewhere else. For the sake of the cancer registry, although these people lived in the state for that narrow window of time, they weren’t diagnosed there, so they’d fall out of the calculation.”

That, Orloff says, is a big target they’re aiming to correct. It begins with getting the word out about the rare cancer and the possible connections to these two small towns.

Last month, an Alabama state senator requested $100,000 so research could begin for the Auburn-related cases, but the funding was denied.

However, that’s not stopping Dr. Fred Kam, the executive medical director of Auburn University Medical Clinic. Kam was instrumental in bringing researchers from North Carolina and Philadelphia to the town. He’s also helping establish a committee to investigate and lobby for funding.

“The committee’s initial goal will be to lobby for and apply to reputable national entities, such as the CDC [Centers for Disease Control and Prevention], NIH [National Institutes of Health], or National Cancer Institute, to fund and be involved in a study looking for a cause if we have an increased incidence,” Kam said.

“We also hope to bring knowledge and expertise in scientifically approaching and helping obtain answers to questions this cohort of people may have, from genetics to environment, causation, treatment, and prevention,” he said.

Both groups have a presence on social media, which has helped several new cases come to their attention. In fact, the Auburn Ocular Melanoma Page on Facebook helped the group connect to more than a dozen individuals with the rare cancer just after going live in early 2018.

The Huntersville Ocular Melanoma Cancer Cluster page on Facebook also shares updates and relevant information for people with OM and those interested in learning more.

For now, Kam says, people with a connection to the university or anyone worried about their potential risk for OM should continue to have routine eye exams.