Patterns of repeated anal cytology results among HIV-positive and HIV-negative men who have sex with men.

BACKGROUND

Men who have sex with men (MSM) are at increased risk for anal cancer. In cervical cancer screening, patterns of repeated cytology results are used to identify low- and high-risk women, but little is known about these patterns for anal cytology among MSM.

METHODS

We analyzed Multicenter AIDS Cohort Study (MACS) data for MSM who were offered anal cytology testing annually (HIV-positive) or every 2 years (HIV-negative) for 4 years.

RESULTS

Following an initial negative (normal) cytology, the frequency of a second negative cytology was lower among HIV-positive MSM with CD4 ≥ 500 (74%) or CD4 < 500 (68%) than HIV-negative MSM (83%) (p < 0.001). After an initial abnormal cytology, the frequency of a second abnormal cytology was highest among HIV-positive MSM with CD4 < 500 (70%) compared to CD4 ≥ 500 (53%) or HIV-negative MSM (46%) (p = 0.003). Among HIV-positive MSM with at least three results, 37% had 3 consecutive negative results; 3 consecutive abnormal results were more frequent among CD4 < 500 (22%) than CD4 ≥ 500 (10%) (p = 0.008).

CONCLUSIONS

More than one-third of HIV-positive MSM have consistently negative anal cytology over three years. Following abnormal anal cytology, a repeated cytology is commonly negative in HIV-negative or immunocompetent HIV-positive men, while persistent cytological abnormality is more likely among HIV-positive men with CD4 < 500.