Post-brachytherapy initial tumour regression rate correlates with metastatic spread in posterior uveal melanoma

Abstract

Aim: To confirm the prognostic value of post-brachytherapy initial tumour regression rate in posterior uveal melanoma. Methods: A prospective, comparative, observational cohort study was carried out on 147 eyes (147 patients) with choroidal melanoma (mean age 61 years) treated with Ru-106 brachytherapy. Observation procedure: Patients were followed clinically and ultrasonically every 6.7 (SD 0.3) months (1001 examinations). On average each patient was examined 5.8 times (mean follow up 9.6 (3.7) years). The echographic parameters included tumour base size, height, internal reflectivity, regularity, vascularity, and extrascleral extension. The clinical follow up included ocular examination and periodic metastatic screening (liver function tests and liver imaging). Main outcome measures were risk of liver metastasis in correlation with the post-brachytherapy initial tumour regression rate. Results: At brachytherapy the mean tumour height was 5.2 mm (range 2.2-11.8 mm). After brachytherapy 142 tumours (96.6%) responded by a decrease in height. The initial height regression rate was 6.1% (0.8%) per month in patients who later developed metastasis v 4.3% (0.4%) per month in those who did not. Tumours higher than 6 mm, tumours with an internal reflectivity smaller than 50%, and tumours with an initial rate of height regression larger than 0.7 mm/month (10% per month) had higher 5 year melanoma related mortality. Kaplan-Meier survival analysis and the multivariate Cox proportional hazards model showed a significant role for tumour height and initial tumour regression rate on patients' survival. Conclusion: This study confirms that post-brachytherapy initial tumour regression rate has a prognostic value.

Tumor Cell Plasticity in Uveal Melanoma

“…It is well known from clinical studies that patients whose tumors respond immediately and rapidly to brachytherapy are significantly more likely to die of metastatic melanoma than patients whose tumors respond much more slowly. 55 Therefore, relative successes in treating planktonic malignancies such as the leukemias compared with solid malignancies may be related in part to the generation of vasculogenic mimicry patterns now documented 3 in a wide variety of solid cancers.…”

Does choroidal melanoma regression correlate with chromosome 3 loss after ruthenium brachytherapy?

“…Kaiserman et al 2 reported a correlation between metastatic death and tumour regression after ruthenium-106 plaque radiotherapy.…”

Uveal Melanoma Regression after Brachytherapy: Relationship with Chromosome 3 Monosomy Status

“…It has been previously reported that a higher rate of regression following radiation therapy in uveal melanoma correlated with an increased risk of metastasis [8,9,10]. With the advent of genetic testing, monosomy 3 and gene expression profiling are now considered as more reliable prognostic indicator for metastatic potential in uveal melanoma [11,12,13,14].…”

“…The rate of regression of the uveal melanoma following brachytherapy as a prognostic factor for metastasis has been an issue of great interest and debate. Rapid regression of uveal melanoma following brachytherapy has been reported as an independent risk factor for metastasis [8,9,10]. …”