Antiretroviral therapy reduces the incidence of pre-cancerous cervical lesions in HIV-positive women, South African investigators reported in the online edition of AIDS. Their study also showed that HIV therapy was associated with a regression of pre-existing lesions.
"Our results indicate that compared to non-HAART [highly active antiretroviral therapy]-users, HIV-infected women on HAART are more than twice as likely to exhibit regression of cervical lesions," the authors wrote. "HAART users with baseline normal cervical smears are significantly less likely to suffer from incident abnormalities in subsequent cervical smears."
Cervical cancer has been classified as an AIDS-defining illness since 1993. Most diagnoses involve HIV-positive women in resource-limited settings, especially sub-Saharan Africa.
The malignancy is caused by high-risk strains of human papilloma virus. This sexually transmitted infection can cause pre-cancerous cell changes in the cervix and other anogenital sites.
Incidence of the other AIDS-defining cancers - non-Hodgkin's lymphoma and Kaposi's sarcoma - has fallen significantly since the introduction of effective antiretroviral therapy. This treatment has also been associated with the regression of disease associated with these cancers.
Determining the benefits
However, the benefits of HIV therapy regarding prevention of cervical cancer are less clear. To establish a better understanding of its potential benefits, an international team of investigators designed a study involving 1 123 HIV-positive women in Soweto, South Africa, who had at least two cervical smears between 2003 and 2009.
Their research had two aims: to compare the incidence of abnormal cervical smears in women with normal results at baseline according to the use or non-use of HIV therapy; and to assess the association between HIV treatment and the regression/progression of cervical lesions.
The patients had a mean baseline age of 33 years. Their mean body mass index (BMI) was 26.8. Smoking - a risk factor for cervical cancer - was reported by 15% of women. Symptoms of a sexually transmitted infection were detected in 18% of women when they entered the study, at which time 75% of participants had a current sexual partner.
Only 2% of individuals were taking HIV therapy at baseline, a further 17% starting treatment during follow-up.
The number of cervical smears per patient ranged from two to seven with an average of three. The median interval between consecutive smears varied from 181 to 2343 days, the median interval being 421 days.
Taking antiretroviral therapy reduced the risk of incident cervical lesions.
Women who had a normal cervical smear at baseline were 38% less likely to develop an abnormality if they were taking HIV therapy (p = 0.001).
A low CD4 cell count was associated with an increased risk of developing abnormal cells. This was irrespective of treatment with antiretroviral drugs. Incident lesions were twice as likely to be detected in women with a CD4 cell count below 200cells/mm3 compared to women with a CD4 cell count above 500 cells/mm3(p = 0.001). Smoking was also associated with an increased risk of new cervical disease (p = 0.05).
There was some evidence that antiretroviral treatment was associated with a reduced risk of the progression of cervical lesions. After taking into account other possible risk factors, the investigators found that HIV therapy reduced the risk of progression by 20%. However, this fell short of significance (95% CI, 0.56-1.13;p =0.20).
In contrast, HIV treatment was associated with the regression of lesions. The odds of regression were over twice as high for individuals taking antiretroviral therapy (OR =2.61; 95% CI, 1.75-3.89; p < 0.001).
"We found that women on HAART were more than twice as likely than non-HAART users to demonstrate regression in consecutive smears," conclude the authors. "In addition, we found that among those women with a baseline normal smear, those on HAART were significantly less likely to develop an abnormality in the future."
Source: Health Systems Trust
Reference: Adler DH et al. Increased regression and decreased incidenceof HPV-related cervical lesions among HIV-infected women on HAART. AIDS 26,online edition. DOI: 10. 1097/QAD.0b013e32835536a3, 2012.