DNA ploidy pattern in choroidal melanoma: correlation with survival. A flow cytometry study on archival material

Abstract

Background/aims-ParaYn embedded samples have provided an important source of material for retrospective cytofluorimetric studies, useful in establishing the predictive value of DNA content measurements. The aim of this study was to investigate the incidence and type of aneuploidy in choroidal malignant melanomas (CMM) and the significance in the clinical outcome (median follow up 55 months). Methods-DNA content was quantified by flow cytometry in 61 CMM from archival material. Non-tumour ocular tissue was used as the reference diploid standard. Cases in which the coeYcient of variation (CV) of the diploid peak was >8% were excluded. The CMM were classified as spindle A, spindle B, mixed spindle and epithelioid, epithelioid, and necrotic. Results-The frequency of the aneuploid DNA pattern was 38%. Necrotic tumours showed a worse clinical outcome independent of the ploidy pattern. Spindle A tumours were found to be diploid. Spindle B and mixed tumours showed a prevalent diploid and near diploid aneuploid pattern (DI <1.3), yet aneuploidy was not correlated with a worse prognosis. The epithelioid tumours were prevalently diploid. However, 83% of the aneuploid tumours were hypodiploid (DI <0.95), and showed the worst prognosis. Conclusion-These results indicate that increasing DNA abnormalities in CMM, especially in the epithelioid histotype, were associated with an increasing mortality. (Br J Ophthalmol 1998;82:1433-1437 Choroidal malignant melanoma (CMM) is the most common primary intraocular malignancy in adults. The estimated 15 year survival rate after detection of the tumour is 53%.

Karyotype aberrations and gene mutations characteristics correlated it with UM prognosis

“…Most of patients with uveal melanoma displayed the karyotypes were near-normal (diploid) with few nonrandom chromosomal changes like monosomy 3 and a gain of chromosome 8q [7], but some researches showed the karyotype would display polyploidy with a prevalence of 13% to 18% based on DNA content [11,12].…”