Prognosis of Kaposi's sarcoma as an initial and later AIDS associated illness

The natural history of Kaposi's sarcoma (KS) as a primary presentation of AIDS has been well defined, but little is known about the prognosis of KS following a different AIDS defining illness (ADI).

Retrospective review of 852 consecutive individuals diagnosed with AIDS at Fairfield Hospital between 1984 and 1994. Demographic data, year of diagnosis, CD4 cell counts, treatment for KS and PCP prophylaxis were included in the analysis. Survival following a diagnosis of KS was evaluated, adjusting for the effects of year of diagnosis, primary or secondary KS and degree of immunodeficiency.

The overall cumulative incidence of KS by three years post ADI was 34%. Median survival for KS as an ADI (n = 130) was 20 months versus 9 months for KS subsequent to another ADI (n = 75, P < 0.001). Those with KS as an ADI had a higher CD4 count (median 90 vs. 11, P < 0.001), lower incidence of visceral disease (5 of 130 vs. 11 of 75, P = 0.032) and fewer associated AIDS related illnesses (1 vs. 2, P < 0.001). Poorer survival following diagnosis of KS was associated with a lower CD4 count at diagnosis of KS (P = 0.002), extensive cutaneous or visceral KS at diagnosis (P = 0.009 and P < 0.001 respectively) and with the number of associated AIDS related illnesses (P < 0.001). A multivariate analysis suggested that, after adjusting for these factors, there was no difference in survival between primary and secondary KS.

We found no difference in survival between primary and secondary KS after adjusting for potential confounding factors. We cannot exclude, however, that the greater incidence of visceral disease identified in secondary KS reflects an inherently more aggressive biology.