The Uganda study on HPV variants and genital cancers

Background: Genital cancers in Uganda have been the most frequently diagnosed cancer in men as well as in women since the 1950s. Genetic studies have detected HPV-16 variants of Af1 class and identified a new sub-class designated Af1-u. Objectives: The main goal of this study is to analyze the prevalence of HPV strains and HPV variants in anogenital lesions of Ugandan male and female subjects in order to possibly determine their role in the pathogenesis of such lesions and to develop an Ugandan preventive HPV vaccine program. Study design: The study is planning to enroll male and female subjects affected by genital lesions, in particular to collect 200 scrapes/biopsies from women with normal ectocervical epithelium as well as with all different degrees of ectocervical lesions (from CIN 1/LSIL to cervical carcinoma). All samples are analyzed by PCR amplification of the L1 conserved region (nt 6584–7035) and the E6/E7 genes (nt 34–880), nucleotide sequence analysis, homology and phylogenetic studies. Variant distribution studies will be followed by serological studies of prevalence and incidence in 1000 women. Preliminary Results and Conclusions: Penile cancers from the Kyadondo County have been analyzed for the presence of HPV sequences. More recently 16 ectocervical scrapes and three biopsies have been received from women attending the Nsambya Hospital and analyzed for the presence and type of HPVs. Our results, obtained by PCR and sequencing analysis, allowed the identification of HPV-16 Af1 sequences in 100% of tumor tissue and in 6.25% of scrapes. HPV 45 was identified only in one tumor together with HPV 16 infection. HPV 33 and HPV 58 were present in 20% and 40%, respectively of HPV positive benign samples. The results are showing a narrowing of the HPV pattern in more advanced lesions, suggesting that mainly HPV-16 Af1 patients are progressing to cancer.