Anal neoplasia grade linked with genetic changes

In HIV-positive and negative men with anal intraepithelial neoplasia (AIN), the likelihood of chromosomal changes is directly associated with the disease’s histologic grade, according to a report published in the March 1st issue of the Journal of Acquired Immune Deficiency Syndromes.

Using comparative genomic hybridisation, Dr. Joel M. Palefsky and colleagues, from the University of California at San Francisco, assessed the presence and characteristics of genetic change in AIN samples from 19 HIV-positive and 11 HIV-negative men.

The researchers found that the proportion of samples with genetic changes increased significantly as the histologic grade increased. Genetic changes were identified in 0% of AIN 1 samples, 29% of AIN 2 samples, and 56% of AIN 3 samples. This correlation was also noted in subjects with multiple lesions of different grades.

The most common change was a gain in DNA copy number mapped to chromosome arm 3q. This alteration is also the most common change in cervical cancer, suggesting a common molecular pathway for these two disease entities, the investigators note.

“Given the frequency of [the chromosome 3q] change in cervical cancer and anal cancer, further genetic analyses are needed to identify candidate oncogenes in this region,” the researchers point out. “Further studies are also needed to determine whether changes in this region may be useful markers for progression to cancer and whether HIV-positive individuals are at higher risk of genetic changes than HIV-negative individuals.”