Progression bei analen Dysplasien
Nearly 40% of HIV-positive men with low-grade anal neoplasia may progress to high-grade neoplasia or anal cancer, according to a Spanish study presented on Wednesday at the 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in San Francisco. Younger age and shorter duration of HIV infection were risk factors for worsening disease.
Anal cancer caused by human papillomavirus (HPV) is more common among HIV-positive gay men, compared with the general population. While AIDS-defining cancers have declined since the advent of effective combination antiretroviral therapy, some studies indicate that anal cancer has become more common as people with HIV live longer.
HPV triggers abnormal cell growth including warts and neoplasia. Certain 'high-risk' or oncogenic types – in particular HPV-16 and HPV-18 – are the usual cause of anal and cervical cancer. But oncogenic HPV infection does not always result in tissue abnormalities, mild or low-grade dysplasia (abnormal tissue) does not always progress to more severe or high-grade neoplasia, and high-grade neoplasia does not always lead to cancer.
In der prospektiven Beobachtung von 163 HIV-Patienten mit gutem Immunstatus (85% auf ART) hatten 81% eine HPV-Infektion, 68% davon mit einem „Hochrisiko-Typ“ , 69% einen „Niedrigrisiko-Typ“ und 47% beide.
71% der Männer hatten leichte Veränderungen (LSIL), 3% höhergradige Veränderungen (HSIL) and 27% nicht klassifizierbare Läsionen (ASCUS).
Half of the participants underwent anoscopy by the time of analysis. Of these, 28% were normal, 47% were classified as having low-grade AIN (sometimes referred to as grade 1, as neoplasia staging terminology is not consistent), 17% were classified as having high-grade AIN (sometimes called grade 2/3) and 8% had anal cancer in situ.
The researchers calculated incidence rates of 14.9 cases per 1000 patient-months over a median of eleven months for high-grade AIN and 3.3 cases per 1000 patient-months for anal cancer.
Die Patienten wurden jährlich untersucht und nach etwa 11 Monaten war der Befund bei 33% der geringgradigen Läsionen zum Analcarcinom in Situ und 5% zum Analkarzinom. Jüngere Patienten und weniger lang HIV-Infizierte zeigten eine höhere Progressionsrate.
AIDS, Viruslast, CD4-Zahl, ART, HPV-Typ, STI, Alkohol und Rauchen waren keine unabhängigen Risikofaktoren.
