Author: Hibba Quhill (United Kingdom)
Co-authors: Hibba Quhill, Joanna M Jefferis, Ian G Rennie, Sachin Salvi, Anna T Gavin, Paul Rundle
Purpose
Incidence of uveal melanoma is 1·3 - 8·6 per million in European populations (EUROCARE, 2007), with incidence increasing at higher geographical latitudes. The incidence in Ireland though is notably higher at 9.5 per million. The incidence of uveal melanoma in Northern Ireland (NI) which shares a land border with Ireland, has not been previously reported, but might be expected to be similar or greater than in Ireland given its higher latitude. Survival rates in uveal melanoma have remained stable despite advancements in detection and treatment, with around 30% mortality at 5 years. Within Europe, broad geographic variation was described, with published survival rates from the UK (England and Wales) being the highest. Ireland’s data are awaited. The purpose of this study was threefold: 1) to investigate the incidence of uveal melanoma in NI; 2) to investigate clinical outcomes including recurrence and metastatic rates of patients from NI treated at Sheffield Ocular Oncology Service and 3) to determine the survival rates from uveal melanoma of those patients.
Setting/Venue
A collaborative study between Sheffield Ocular Oncology Service, Royal Hallamshire Hospital, Sheffield, United Kingdom, and the Northern Ireland Cancer Registry (NICR), Belfast, UK.
Methods
To identify incidence data: Anonymised data from NICR were analysed alongside population data from NISRA (Northern Ireland Statistics and Research Agency) to identify the incidence of uveal melanoma in NI. To identify clinical outcomes: Patients with uveal melanoma from NI treated in Sheffield were identified from Sheffield Ocular Oncology Database and pertinent patient data collected from case notes review. Data collected included patient demographics at diagnosis, the site and laterality of the melanoma, basis of diagnosis, tumour dimensions, stage of the primary tumour, date and type of treatment, any tumour recurrence or metastases, and any further treatments. To identify survival data: Information including the date and cause of death, and information on systemic metastases of patients with uveal melanoma treated in Sheffield was collected from NICR in October 2020.
Results
Based on the anonymised NICR data, the incidence of uveal melanoma in NI was 6.9 (95% confidence interval 6.1 – 7.8) over the period from 1999 – 2019. 182 patients from Northern Ireland were diagnosed with uveal melanoma in Sheffield, from 1998 to May 2020 (date of database interrogation), 80 fewer cases than was identified on reviewing the population-based database in the NICR. Data were available for all patients in the Sheffield cohort. All patients were diagnosed clinically , with only 50 patients having histological confirmation of diagnosis. No patients had evidence of metastatic disease at diagnosis. Of those patients treated, 74% received globe sparing treatment, while recurrence of the primary tumour occurred in 7.6%. The median follow-up duration of the cohort was 79·5 months, during which, 27 (14·8%) patients developed systemic metastases from their melanoma, detected a median of 23.0 months following initial treatment of melanoma in Sheffield. As of October 2020, 43 (23·6%) patients had died, 135 (74.2%) were alive and mortality status was unknown for 4 patients (2.2%). The all-cause 5-year survival across all Northern Irish patients treated in Sheffield was 83.9%.
Conlusions
With an incidence of 6.9 per million, the rate of uveal melanoma in NI is much lower than in Ireland, and more in keeping with those published from the rest of the UK and northern Europe. Given the ethnic similarities and that Ireland and NI share the same landmass, we had expected the incidence rate for uveal melanoma to be similar in these two countries. The discrepancy may be due to the Irish data only covering 5 years, in contrast with this study and others which span decades. Given the rarity of uveal melanoma, random variation may have accounted for the difference in incidence over a short period of time. Northern Irish patients treated in Sheffield had excellent clinical outcomes: three quarters of patients were treated with globe-sparing treatments, with low recurrence rates and an all-cause 5-year survival rate of over 80%. This study adds to the body of evidence regarding uveal melanoma on the island of Ireland, in the UK, and Europe as a whole, by presenting data that has not been published before. Given the rarity of uveal melanoma, population-based studies are necessary to complete the picture but further study from more centres is needed.
Financial Disclosure
The authors have no financial relations or conflicts of interest
Comments
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