Demographic characteristics of the 263,254 persons with AIDS included in the study are presented in . Most were male (80.1%), and the median age at AIDS onset was 36 years. Similar proportions of subjects were non-Hispanic white (39.7%) and non-Hispanic black (40.1%), and 20.2% were Hispanic. Almost half (44.8%) reported MSM and 24.8% had IDU as their mode of HIV exposure (). CD4 counts at AIDS onset were higher for subjects who contributed follow-up to the 6-10 year period than for those who contributed follow-up only to the 3-5 year period (median 144 vs. 132 cells/μL), consistent with better immune status at AIDS onset conveying longer survival. Additionally, few persons diagnosed with AIDS in 1980-1989 survived long enough to provide follow-up in the 6-10 year period. Also, some people diagnosed with AIDS in 1996-2004 did not have enough time to be followed into the 6-10 year period. As a result, most observation time in the 6-10 year period was provided by people diagnosed with AIDS in 1990-1995 ().
Demographic characteristics of persons with AIDS in the United States, 1980-2004 (N=263,254)
Risks for the three AIDS-defining cancers were significantly elevated in years 3-5 and 6-10 after AIDS onset (). KS risk was extremely high in both time periods (SIRs 5321 and 1347 respectively), and NHL risk was also elevated in both periods (SIRs 32 and 15, respectively). Likewise, risks were substantially higher than in the general population for the AIDS-defining NHL subtypes, namely diffuse large B-cell NHL, Burkitt NHL, and especially CNS NHL (). Cervical cancer risk was increased after AIDS during years 3-5 (SIR 5.6) and years 6-10 (SIR 3.6).
Cancer risk in people with AIDS for the period 3-10 years after AIDS onset
Among non-AIDS-defining cancers (), risks were elevated in both the 3-5 and 6-10 year periods for cancers of the oral cavity/pharynx, tongue, anus, liver, larynx, lung/bronchus, penis, and for Hodgkin lymphoma. Compared to the general population, risks for anal cancer were especially high (SIRs 27 in the 3-5 year period, 40 in the 6-10 year period). Among Hodgkin lymphoma subtypes, risk was most elevated for the mixed cellularity subtype (SIRs 15 in years 3-5, 17 in years 6-10). Other malignancies for which risk was increased in only one of the two periods after AIDS onset included cancers of the lip and vagina/vulva, multiple myeloma, lymphocytic leukemia, and myeloid/monocytic leukemia (). In both time periods, risk was lower than in the general population for cancers of the breast and prostate, and during years 3-5 after AIDS for kidney cancer. Overall, for all non-AIDS cancers combined, risk was significantly elevated after AIDS in both years 3-5 (SIR 1.7) and years 6-10 (SIR 1.6).
compares cancer incidence in the 3-10 years after AIDS for the pre-HAART era (1990-1995) and HAART era (1996-2006). KS incidence declined by 80% (RR 0.2, 95%CI 0.2-0.2) between the pre-HAART and HAART eras. A joinpoint model fitted to the incidence data revealed that this change corresponded to a steep decline during 1994-1997 (44.3% per year, ). Similarly, NHL incidence was 70% lower in the HAART era (RR 0.3, 95%CI 0.2-0.3) than in the pre-HAART era, and the joinpoint model indicated that this corresponded to a 36.9% annual reduction during 1995-1998 (). Declines were similar in magnitude for diffuse large B-cell NHL and CNS NHL (, ). In contrast, the change in Burkitt NHL incidence was weaker (RR 0.6, 95%CI 0.4-1.0), and cervical cancer incidence did not change significantly (RR 0.8, 95%CI 0. 5-1.2). During the HAART era, persons with AIDS continued to have significantly higher risk for all AIDS-defining cancers than people in the general population (SIRs, ).
Changes in cancer risk in the HAART era (1996-2006)
Figure 1 Incidence of selected AIDS-defining malignancies as a function of calendar year. The panels show cancer incidence during the period 3-10 years after AIDS onset, as a function of attained calendar year. The points correspond to the individual year estimates, (more ...)
Among non-AIDS-defining malignancies, anal cancer exhibited a three-fold increase in incidence between the pre-HAART and HAART eras (RR 2.9, 95%CI 2.1-4.0, ). During the HAART era, anal cancer risk remained significantly elevated relative to the general population (SIR 32). The joinpoint model for anal cancer demonstrated a 10.7% annual increase in incidence over the entire 1990-2006 period, despite a suggested decline in the most recent years (). In a separate analysis among men, anal cancer incidence increased 11.3% (95%CI 5.9%-16.8%) per year during the HAART era (1996-2006). Incidence of local anal cancer increased significantly (14.1%, 95%CI 7.3%-21.3%) among men during the same years. Regional and distant anal cancer increased annually among men during the same period (5.7%, 95%CI -1.0% to 12.9%), although this increase was not significant. There were no anal cancer cases among women prior to 1996. During 1996-2006, anal cancer increased 4.3% (95%CI -10.5% to 21.5%) per year among women.
Figure 2 Incidence of selected non-AIDS-defining malignancies as a function of calendar year. The panels show cancer incidence during the period 3-10 years after AIDS onset, as a function of attained calendar year. The points correspond to the individual year (more ...)
Hodgkin lymphoma incidence increased significantly between the pre-HAART and HAART eras (RR 2.0, 95%CI 1.3-2.9, ). The Hodgkin lymphoma joinpoint model showed a 14.1% annual increase during 1990-2000, with no significant change subsequently (). The increase in Hodgkin lymphoma incidence was most apparent for the mixed cellularity subtype. During the HAART era, risk of Hodgkin lymphoma remained significantly elevated relative to the general population (SIR 11).
Incidence of lung cancer, the most common non-AIDS-defining cancer, was marginally lower in the HAART era than in the pre-HAART era (RR 0.8, 95%CI 0.6-0.9; ). However, this decline over time was not manifest in the joinpoint model (). There were increases in the HAART era for other less common non-AIDS-defining cancers including cancers of the tongue (RR 2.9) and prostate (RR 1.6).
Overall, the incidence of all non-AIDS cancers increased 20% between the pre-HAART and HAART eras (RR 1.2, 95%CI 1.0-1.3; P=.006). This increase corresponded to a 4.3% annual increase during 1990-2006, although there was a suggestion that incidence declined in the most recent few years (). During the HAART era, people with AIDS had a 60% higher risk for non-AIDS cancers than the general population (SIR 1.6, 95%CI 1.6-1.7).