Immune deficiency and risk for malignancy among persons with AIDS.

BACKGROUND

People with AIDS have an elevated risk for cancer. We studied the relationship between cancer risk and AIDS-related immunosuppression as measured by CD4 count at AIDS onset.

METHODS

We linked records from AIDS and cancer registries in 11 US regions (1990-1996). We studied 82,217 (86.6%) adults who had a CD4 count measured at AIDS onset and survived into the follow-up period. We calculated standardized incidence ratios (SIRs) for AIDS-defining (Kaposi sarcoma [KS], non-Hodgkin lymphoma [NHL] and cervical cancer) as well as non-AIDS-defining cancers in the 2 years after AIDS onset. For each cancer, the change in SIRs across CD4 counts (0-49 cells/mm3, 50-99 cells/mm3, 100-199 cells/mm3, and > or =200 cells/mm3) was modeled using Poisson regression.

RESULTS

The SIRs for KS, NHL, and cervical cancer were 258, 78, and 8.8, respectively. For each fall of 100 CD4 cells/mm3, RRs were 1.36 (95% CI: 1.29-1.43) for KS and 1.48 (95% CI: 1.37-1.59) for NHL. Among NHL subtypes, the association with lower CD4 counts was strongest for immunoblastic lymphoma (RR =1.64, 95% CI: 1.37-1.96, per decline of 100 CD4 cells/mm3) and central nervous system lymphoma (RR = 2.29, 95% CI: 1.95-2.69). The SIR for cervical cancer did not vary with CD4 count (p =.74). For non-AIDS-defining cancers (overall SIR = 2.1), neither the combined risk nor the risk of specific types was associated with declining CD4 counts.

CONCLUSION

SKS and NHL risk increased with level of immunosuppression at AIDS onset. Risks for other cancers, including cervical cancer, were unrelated to CD4 counts. Elevated risks for non-AIDS cancers may be a result of lifestyle factors.