Prognostic biopsy of choroidal melanoma: an optimised surgical and laboratory approach

Abstract

Background: Accurate survival prognostication for patients with uveal melanoma (UM) enables effective patient counselling and permits personalised systemic surveillance for the early detection of metastases and, in high-risk patients, enrolment in any trials of systemic adjuvant therapy. The aim of this work is to determine the success of prognostic UM tumour biopsy using an improved surgical approach and optimised sample handling workflow.

Methods: Patients with UM treated by primary radiotherapy between 2011 and 2013 and who underwent a prognostic biopsy with cytology, multiplex ligation-dependent probe amplification and/or microsatellite analysis were included. The main outcomes and measures were success of cytology and genetic studies, and surgical complications.

Results: The cohort comprised 232 patients with UM having a median age of 59 years (range, 25-82) at treatment. The median largest basal diameter was 11.4 mm (range, 4.1-20.8) and tumour height was 3.4 mm (range, 0.7-10.3). Ciliary body involvement was noted in 42 cases. Treatment consisted of Ru-106 brachytherapy in 151 cases (65%) and proton beam radiotherapy in 81 cases (35%). With improvements in surgical techniques and laboratory methods over time, cytology success increased from 92% (131/142) to 99% (89/90) and the numbers of samples with sufficient DNA for genetic testing increased from 79% (104/131) to 93% (83/89). Overall, chromosome 3 loss was noted in 64/187 (34%) cases. Surgical complications, including transient localised bleeding, vitreous haemorrhage and retinal perforation, decreased over time. Eight patients required additional surgery.

Conclusions: Improved surgical techniques and laboratory methods yielded successful cytology and genetic information in the majority of cases.

Precis: Analysis of data from 232 patients with uveal melanoma undergoing prognostic tumour biopsy demonstrated that improved surgical techniques and laboratory methods yielded successful cytology and genetic information in 99% and 89% of cases, respectively.

Keywords: MLPA; MSA; biopsy; choroidal melanoma; cytology; molecular analysis; prognostication; uveal melanoma.