This study retrospectively evaluated the melanoma-specific mortality among patients who underwent a biopsy for posterior uveal melanoma.
Researchers retrospectively reviewed the clinical and histopathologic records of Danish patients diagnosed with choroidal or ciliary body melanoma between 1985 and 2016. Of the 1,637 patients identified, 567 underwent transvitreal-retinochoroidal biopsy as part of their primary treatment regimen. Biopsies were followed by enucleation or brachytherapy. Exclusion criteria included patients who did not undergo treatment, lack of documented tumor characteristics, history of extensive intraocular surgery and those who had metastatic disease at presentation.
Clinical characteristics, all-cause and melanoma-specific mortality were compared between those that were biopsied at initial diagnosis and those who were not.
The baseline characteristics of biopsy versus no-biopsy patients were significantly different. Those who underwent biopsy were younger, had smaller tumors and lower American Joint Committee of Cancer stage (all P<0.001). Follow-up time also differed because biopsied patients were diagnosed later than patients who did not undergo the procedure.
During follow-up, 166 biopsied patients and 434 non-biopsied patients died from uveal melanoma metastases. The risk of melanoma-specific mortality was consistently similar between groups, even after adjusting for age, tumor size and AJCC stage.
As noted above, the baseline characteristics significantly differed between groups (i.e., age, tumor size and AJCC stage). In addition, there was a surveillance bias towards the biopsy group. Patients who underwent biopsy were followed at the university hospital whereas the non-biopsied group was mostly cared for at community hospitals. Lastly, this is a retrospective review without randomization.
This is the first study with sufficient sample size and follow-up period to examine the risk of potential iatrogenic dissemination of tumor cells during biopsy. This study found a similar all-cause and melanoma-specific mortality when comparing biopsied and non-biopsied patients, suggesting that an intraocular biopsy can be safely performed if necessary.