DNA index and % S phase fraction in posterior uveal melanoma: A 5 year prospective study of fresh tissue using flow cytometry

Abstract

SUMMARYIn many different solid tumours the DNA couteut of cells has been reported to be associated with malig nancy. With one exception, studies using flow cytome try to estimate cellular DNA in uveal melanoma have used archival material. We report the findings of a prospective study using fresh uveal melanoma where the DNA index (DI) and percentage of cells in S phase (%SPF) have been determined by flow cytometry in 51 patients with a minimum follow-up of 5 years. Forty one (80%) of the tumours were large, 9 (18%) were medium and only 1 was small. Eight (16%) were epithelioid tumours, 41 (80%) were mixed cell and only 2 were spindle B cell tumours. Twenty-seven tumours were diploid, of which 10 (37%) developed metastases. Of the 24 aneuploid tumours, metastases developed in 6 (25%). The median %SPF was significantly reduced in patients with diploid tumours compared with aneuploid tumours (p<O.OOOI), but there were no significant differences in %SPF between tumours associated with or without metastatic disease. The DI and %SPF were not significantly associated with the operation per formed, cell morphology, tumour size or location. Neither %SPF nor aneuploidy was associated with a poor prognosis. Our results suggest that the estimation of DI or %SPF by flow cytometry is of little value in predicting survival from uveal melanomas after a minimum follow-up of 5 years.Uveal malignant melanoma is the commonest primary ocular tumour in adults, with up to 50% of patients eventually dying from metastatic-related disease. location, tumour size, scleral or optic nerve invasion, extra-scleral spread, an epithelioid or mixed cellular composition, a lymphocytic infiltrate, and the vascu lar pattern of the tumour. 2 -5 Nuclear and nucleolar phenotypes also have prognostic value. 6 , 7Studies of DNA content of a variety of tumours have indicated that in some the presence of non diploid (aneuploid) cells carries a poor prognosis. 8 , 9 Flow cytometry studies of cellular DNA in uveal melanoma have, with one exception / o used archival material and as yet no consistent pattern of either proliferation or aneuploidy has been associated with patient survival. lO-16 We have previously reported on the DNA index (DI) and the percentage of proliferating cells in 19 posterior uveal melanomas in which no relation between cell turnover and tumour size or anatomical location could be deter mined. l O We now report the results of flow cytometry on tumours from 51 consecutive patients with a minimum follow-up of 5 years. MATERIALS AND METHODS PatientsFifty-one patients with a diagnosis of posterior uveal melanoma referred to the Ocular Oncology Unit between February 1985 and 1990 were enrolled after informed consent had been obtained. All patients were subject to a full medical examination including liver function tests, abdominal ultrasound, chest radiograph, and orbital and abdominal CT scans. None had clinical, radiological or biochemical evidence of metastatic disease at presentation. Ocular examination included visual acuity, tonome tr...

Cell Proliferation Profile of Five Human Uveal Melanoma Cell Lines of Different Metastatic Potential

“…Previous findings utilizing paraffinembedded sections have found a positive correlation between high SPF and increased mortality [14]. Although recent findings show it may be useful for determining abnormal DNA content, the measurement of SPF in uveal melanoma has not been shown to correlate with worse prognosis in recent studies of fresh tissue [15]. Our results support this finding, as none of the SPFs determined by this method correlated with the previously determined MP.…”

DNA ploidy and nuclear morphometric variables for the evaluation of melanocytic tumors in dogs and cats

“…Results of some studies indicate that DI is a valuable prognostic factor in humans, 34,35,i whereas others imply that it has little or no value in predicting the survival time. [36][37][38] The second type contains interpretative variables and is considered helpful for understanding the biological rationale behind any relationship with tumor prognosis. The PB and PI belong to this second type of variables.…”

Ploidy analysis in uveal melanoma

“…For uveal melanoma it has been shown that nuclear DNA content (ploidy) abnormalities correlate closely with survival,1-4 although conflicting results have been reported for older archival material,5 fresh tissue,6 and differences in DNA quantification techniques 7. A significant correlation between aneuploidy and epithelioid cell type has been reported2 3 8; other studies indicate similar findings,9 or contradict these findings 4.…”

“…Because of the above named restrictions, the recommended FCM ploidy classification on paraffin embedded tissue from solid tumours is diploid versus non-diploid (aneuploid) 11. Conflicting results on the prognostic value of DNA aneuploidy can be attributed to differences in methods6 7 and definition of aneuploidy (Toti et al ). Difficult areas in flow histograms, specifically high CV, high G2M phase, as well as near diploid aneuploidy and hypodiploidy can be clarified by IA,16 or in frozen tissue by FCM 11…”