There may be as many as 50 cases of ocular melanoma that have occurred in two relatively small towns — Huntersville, North Carolina, and Auburn, Alabama.
The cases seem to be more common in women than men, and are being diagnosed at younger-than-expected ages — including in people under 30.
Ocular melanoma is typically more common in men than women and is usually diagnosed in people ages 55 to 60, Dr. Miguel Materin, an American Academy of Ophthalmology spokesperson, told BuzzFeed News.
In Huntersville there have been 15 confirmed cases of ocular melanoma, including 11 in women. Four of the cases were in young women who went to or lived near Hopewell High School in Huntersville. They were diagnosed between 2009 and 2014 when they were in their twenties.
Materin, an ocular oncologist at the Duke Eye Center in Durham, North Carolina, treated three new patients with it in 2017, although some of the patients were older.
"I will call this a huge red flag," said Materin. "Why is this happening, why this town, why young females, and why ocular melanoma?" Researchers don't know the answer to these questions, although Materin said that they did test the patients to see if they carried a susceptibility gene called BAP1, and they did not.
The population of Huntersville is about 55,000 people, and the population of Auburn is about 63,000.
In Alabama, many of the cases are in people who attended Auburn University, including three women who were friends in college.
In Auburn, Alabama, there may be as many as 36 cases of ocular melanoma in people who attended Auburn University, worked there, or lived nearby. However, those cases, which have been collected via word of mouth or by Facebook by other patients, have not all been medically validated, Dr. Marlana Orloff told BuzzFeed News. (In all, 23 patients were examined in Huntersville, but only 15 were medically confirmed as possibly related due to the timing and type of diagnosis, she said.)
Orloff is a medical oncologist at the Sidney Kimmel Cancer Center at Thomas Jefferson University in Philadelphia. Because the hospital is one of the few that treat such a rare disease, Orloff has seen patients from both Huntersville and Auburn.
Like in Huntersville, the first cases in Auburn were in young women. In those cases, the women were diagnosed their twenties, thirties, or early forties, and had attended college around the same time — three had been friends in college. Juleigh Green, Allyson Allred, Ashley McCrary, and Lori Lee, who attended the university and were all diagnosed with the disease, spoke to CBS News about their diagnoses.
McCrary told BuzzFeed News that when she was diagnosed with ocular melanoma in 2012 at age 42, she thought immediately of her two friends, Juleigh Green and Allyson Allred, who also had the condition.
"I went home that day and called both Juleigh and Allyson," said McCrary. "Juleigh and I were sorority sisters, and she is a year younger than I am, and Allyson and I had the same circle of friends." The women all lived in similar dorms when at Auburn, but had not been roommates. McCrary attended Auburn from 1988 to 1992.
McCrary noted that all three women have children who are now attending or will soon be attending the university. "We are not implying that there is anything on campus — we don’t know," she said.
After spreading the word and coverage by the local media, the women have heard about 36 potential ocular melanoma cases in people who went to or worked at Auburn University, although those cases still need to be confirmed, McCrary said. Of the 36 potential cases at Auburn, 19 are in women and 17 are in men, and only six of the women lived on campus.
"Look, at the end of the day, could it all be coincidence? Of course," Orloff said, "But just knowing this disease, and knowing that most people don’t know someone with this disease, let alone a number of your college roommates or a number of girls you went to high school with, just seems very odd."
The cases do not meet the criteria for a cancer cluster, Orloff said, which is a greater than expected number of cases of a disease in one place within a certain period of time. However, she also noted that some cases weren't counted because the patients had attended high school or college together, and then moved to another part of the country by the time they were diagnosed.
An eye melanoma is rare, affecting about 2,500 people each year in the US, or about 5 to 7 cases per 1 million people.
Melanomas are cancers of the pigment-producing cells of the body, and they are better known as a cancer of the skin. However, melanomas can occur anywhere in the body, including body parts rarely exposed to the sun, a fingernail or toenail bed, or in the eye, which is known as uveal or ocular melanoma.
While severe sunburns in childhood have been linked to skin melanomas, there is no clear link between sun exposure and eye melanomas. The American Cancer Society has more information about the causes and risk factors for melanoma.
A recent analysis didn't identify a toxic exposure in Huntersville. But the cause of ocular melanoma is unknown, which makes it hard to figure out if there is an environmental factor that's to blame.
"We don’t want to cause undue public concern," said Orloff. "If there is something remotely environmental it might have been a concern 10 years ago, but there’s no way of knowing if there is any concern now."
After analyzing local factors like potential exposures to PCBs, electromagnetic radiation, and other factors in the air and water in Huntersville, researchers did not find a link to the cases.
"Historically there have been some toxic materials released to the air and water in the area, but nothing known to have possible associations to uveal melanoma, and our analysis did not pinpoint any patterns of association," Orloff and her coauthors concluded.
"It was a very, very thorough investigation and it did not find any cause for concern, meaning any possible ongoing toxic exposure or toxic chemicals in the water or the air or the land or anything like that," said Orloff.
Auburn University has formed a task force to look at the issue, McCrary said.
Ocular melanomas can cause symptoms similar to retinal detachment, or no symptoms at all.
Some patients with ocular melanoma have symptoms similar to a detached retina — flashes of light, floaters in their visual field, and visual deficits, said Orloff. Other ocular melanoma symptoms include blurry vision or dark spots in the eye. However, some people have no symptoms at all and the condition is diagnosed during a routine eye exam. "It’s really in the back of the eye, so you really need a good dilated eye exam to see some of these," said Orloff.
People who have ocular melanoma are treated with what's called plaque radiation, and sometimes enucleation, or removal of the eye. About half of the patients have a recurrence, and the cancer often spreads to the liver.
"Once it does recur in the liver outside the eye, there is no cure," said Orloff. "There are treatments that prolong life, but the disease can definitely be life-threatening."
Materin noted that doctors at multiple centers are investigating the cases and advised people "not to panic."
"If they have a concern, they should have a dilated eye exam by an ophthalmologist, and that will give them a peace of mind," he said.