BYLINE: Denise Heady
A new UCLA-led study has found that a surgical technique developed to protect vision in patients with uveal melanoma, a rare cancer that arises inside the eye, may also lower the risk of the disease spreading and improve survival — a development researchers say could change the way the cancer is treated.
The study, published in the journal Cancers, followed 37 patients who were treated for uveal melanoma. Most received targeted radiation, known as plaque brachytherapy, combined with a specialized procedure that replaces the eye’s gel-like interior with silicone oil, a technique designed to shield healthy parts of the eye from radiation damage while allowing the tumor to receive the full cancer-killing dose.
Over a median follow-up of more than four years, more than 80% of patients remained free of metastatic disease, and none experienced a recurrence in the treated eye. Only 16% of patients (six) developed metastases, and one patient died from the disease. This represents a significantly lower rate than historically expected, when about 30% of patients would develop metastases, most often in the liver, and few survived beyond five years.
“Everything about uveal melanoma has always been painted with limited hope, with patients expected to lose vision and eventually die once the cancer spreads,” said Dr. Tara McCannel, director of the Ophthalmic Oncology Center at the UCLA Stein Eye Institute, an investigator in the UCLA Health Jonsson Comprehensive Cancer Center, and senior author of the study. “We know that this unique surgical technique clearly saves vision. However, we did not expect the technique to alter metastasis and mortality. And anything that improves survival in uveal melanoma is a game-changer.”
The method, pioneered at UCLA, was first reported more than a decade ago, and earlier studies showed that it reduced radiation-related vision loss. But the UCLA team and their collaborators at the University of Nevada decided to explore this further after Dr. Wolfram Samlowski, the medical oncologist who was monitoring patients in Las Vegas for metastasis, reached out to Dr. McCannel, asking why he wasn’t seeing her patients develop metastasis or die from this cancer. When they examined metastasis-free and overall survival in this group, they noticed something unexpected in the long-term outcomes: far fewer patients developed metastatic disease than historical data had predicted.
So they decided to take a closer look at the data, analyzing both clinical outcomes and genetic risk factors. They identified 37 patients with uveal melanoma, who were followed for a median of four years. Twenty-seven underwent plaque brachytherapy with vitrectomy and silicone oil placement, seven underwent brachytherapy alone, and three had their eye removed. They grouped people into high- or low-risk based on tumor genetics, tracked how long patients stayed cancer-free and how long they survived, and tested how well current prediction tools identified those at risk for metastasis.
Along with observing unexpectedly low rates of cancer metastasis and death, the team found that even patients classified as high-risk based on tumor genetics had low rates of metastasis and death. Tumor size and stage were not reliable indicators of whether the cancer spread in their cohort. Some patients with small tumors developed metastases, while many with large tumors did not. Overall, far fewer patients experienced progression or died than expected. They found that current genetic tests are effective at identifying those at low risk but less reliable in determining who is truly high risk due to the low rates of metastasis and death in their patients.
“Our study shows that combining plaque brachytherapy with vitrectomy and silicone oil not only helps patients preserve their vision but may also improve survival,” McCannel said. “Since most centers still rely on plaque brachytherapy alone to treat uveal melanoma, these findings underscore the need to adopt our vitrectomy with silicone oil approach.”
While these results highlight the potential benefits of combining vision-preserving surgical techniques with targeted radiation therapy, the researchers caution that more research is needed to determine whether the surgical technique, radiation delivery, or a combination of factors contributed to the improved outcomes and understand exactly why outcomes were so favorable. The team also emphasized the need for greater training among ocular oncologists to perform the complex retinal surgery required for silicone oil placement.
The study’s other authors are Axel Rivas of the University of Nevada and Dr. Wolfram Samlowski of Nevada Oncology Specialists in Las Vegas.