Patients diagnosed with iris, ciliary body or choroidal melanoma of high-risk tumour cytogenetics (monosomy 3>/= 20% of cells), were treated with adjuvant low-dose dacarbacine (DTIC) and interferon –alpha-2b (IFNA-2b), following primary treatment (enucleation, brachytherapy or resection). DTIC was given intravenously at 850mg/sqm on days one and 28. IFNA-2b was given at three million units subcutaneously three times a week for 24 weeks, starting at week nine. Five-year survival data was analysed, with a total of 33 patients (22%) in the treatment group, and 29 (19%) in the observation group. The five-year metastasis free (MFS) rate was 64% +/-9% for the treated group and 33% +/-10% for the observation group (p=0.05). Five-year overall survival (OS) rate was 66% +/- 9% in the treated group and 37% +/-10% in the observation group (p=0.02). However, when corrected for differences in age, tumour size and initial treatment, survival between treated and observation groups was no longer significant (MFS: p=0.56, OS: p=0.92). The authors concluded that differences of the treated and observation groups in baseline tumour features (e.g. age, tumour size), and relatively small size of the study, can influence results interpretation.