There was a low rate of 5-year metastasis for patients with uveal melanoma treated with either brachytherapy alone, a brachytherapy plaque with vitrectomy and silicone oil for radiation attenuation, or enucleation, according to results from a single-center cohort study that was published in Cancers.1
At a median follow-up of 4.0 months ± 3.7 months, the disease metastasis-free survival (DMFS) rate at 5 years was 80%, with the median DMFS not being reached. Eventually, 16.2% (n = 6) of patients developed metastatic disease. The study noted no intraocular failure, and at 5 years, the overall survival (OS) rate remained 100%.
One patient died from metastatic disease prior to the time of analysis. Because of this, OS was not analyzed as an end point.
“In terms of survival, our 5-year estimated survival was 100% in this cohort, whereas the Collaborative Ocular Melanoma Study for medium tumors [showed an] OS or metastasis rate [of about] 80%.2 The larger tumor group [experienced a] 60% OS rate. Our numbers were very different. This is a small study, and it’s a small sample, but even in a small cohort, we were still surprised to see our results not fall in line and be close to what we know in the reported literature,” Tara A. McCannel, MD, PhD, director of the Ophthalmic Oncology Center at the University of California, Los Angeles (UCLA) Stein Eye Institute of the David Geffen School of Medicine at UCLA, said in an interview with CancerNetwork®.
A total of 37 patients were treated by a single vitreoretinal surgical oncologist. Patient data were compiled with the IKnowMed database. Baseline uveal melanoma tumor size was used to define the tumor stage by the American Joint Committee on Cancer 8th edition, and monosomy 3 cytogenetics and GEP testing were conducted using a fine-needle aspiration at the time of testing. Patients were defined as high risk if they had monosomy 3 or a Class 2 GEP score, while those who were low risk had a Disomy 3 or Class 1A or 1B GEP score.
After treatment, patients were monitored for the development of liver metastases. If they were characterized as low risk, lactate dehydrogenase and aspartate and alanine aminotransferases were assessed, followed by examination and imaging every 6 months for 2 years. If patients were high risk, they followed similar testing as the low-risk group, except for testing every 3 months for 2 years. Those who were low risk were monitored annually, while those who were high risk were monitored every 6 months. At 5 years, patients were monitored annually with blood tests and abdominal imaging.
“The radiation plaque goes on the external part of the eye to kill the tumor. However, when we do the radiation like that, we can kill the melanoma, but what happens is that the radiation also affects healthy, non-tumor tissue in the eye. We take out the entire vitreous humor, and we fill it with a denser substance. In our case, we use silicone oil. We 1759083126 have a denser substance in the eye. The radiation will still kill the tumor, but it is attenuated or shielded, so it limits the radiation from affecting healthy tissue beyond the tumor. When the eye heals, we can take out the silicone oil and replace the content of the eye with normal saline, which gets replaced by [the patient’s] own aqueous humor,” McCannel explained.
The median patient age was 59 years, 70% of patients were male, and 90% were White and non-Hispanic. Patients were treated with either brachytherapy alone (19%), brachytherapy plaque with vitrectomy and silicone oil for radiation attenuation (73%), or enucleation (8%).
Regarding tumor stage, the mean age for those with T1 (n = 15) disease was 60.13 ± 12.66; T2 (n = 9), 65.78 ±13.17; T3 (n = 8), 57.0 ± 9.70; and T4 (n = 5), 62.2 ± 15.56. The average height and diameter were 3.01 mm ± 1.07 mm and 8.84 mm ± 2.17 mm for the T1 group, 4.03 mm ± 1.48 mm and 12.19 mm ± 1.72 mm for the T2 group, 8.97 mm ± 2.18 mm and 15.46 mm ± 1.87 mm for the T3 group, and 11.38 mm ± 2.85 mm and 19.79 mm ± 1.69 mm for the T4 group. The average progression-free survival was 6.41 years ± 4.18 years for the T1 group, 3.17 years ± 1.56 years for the T2 group, 4.37 years ± 4.03 years for the T3 group, and 1.19 years ± 0.73 years for the T4 group. Additionally, 1 patient with T2 disease died.
Reference
Rivas A, Samlowski W, McCannel TA. Unexpectedly low rate of metastasis and death among patients treated for uveal melanoma with brachytherapy, vitrectomy, and silicone oil. Cancers (Basel). 2025;17(16):2683. doi:10.3390/cancers17162683