Stebbing J et al. (2006) A prognostic index for AIDS-associated Kaposi's sarcoma in the era of highly active antiretroviral therapy. Lancet 367: 1495–1502

Researchers in the UK have developed a prognostic index to predict survival in individuals with AIDS-associated Kaposi's sarcoma. Survival varies considerably between patients with this condition, and accurate prognosis is necessary to deliver appropriate treatment. To develop the model, the investigators reviewed the records of 5,873 patients, 326 of whom had Kaposi's sarcoma; they then validated the model in an independent group of 446 patients with the disease. The prognostic index uses a scale of 0–15, with 10 as the base point to avoid negative integers.

Good prognosis was associated with having Kaposi's sarcoma as the first AIDS-defining illness (−3 points on the prognostic index) and with increasing CD4+ cell count (−1 point for every 100 cells per mm3); poor prognosis was associated with age ≥50 years (+2 points) and with having an additional AIDS-associated illness (+3 points). For individuals with scores of 0, 5, 10 and 15, 1-year probability of survival was 0.993, 0.967, 0.834 and 0.378, respectively; 5-year probability of survival was 0.984, 0.918, 0.631 and 0.084, respectively. Surprisingly, gastric or pulmonary Kaposi's sarcoma, although associated with greatly reduced survival in univariate analysis, was not found to be an independent predictor of survival by multivariate analysis.

The authors recommend that patients with a poor prognosis (score >12) should receive systemic chemotherapy in addition to highly active antiretroviral therapy, whereas low-risk patients (score <5), even those with T1 disease, should receive antiretroviral treatment alone. Further research will help to determine the best approach for patients with an intermediate score.