HPV types and variants among cervical cancer tumors in three regions of Tunisia

Abstract

Cervical cancer is the second most common cancer among Tunisian women, and the incidence rates vary by region. Three Tunisian registries report age-standardized rates of 6.3/105 in the central region, 5.4/105 in the north, and 2.7/105 in the south. High-risk human papillomavirus (HPV) types and their variants differ in carcinogenic potential and geographic distribution. The HPV type and variant distribution could be a factor in the differing rates between regions of Tunisia. Tumor tissue was collected from 142 Tunisian cervical cancer patients. Demographic and reproductive characteristics of the patients were abstracted from cancer registry and hospital records. HPV type and variant analyses were performed using PCR-based Luminex and dot-blot hybridization assays. Eighty-three percent of tumors were infected with at least one HPV type. European variants of HPV16/18 were the most prevalent in tumors from all three regions, with all HPV18 infections and 64% of HPV16 infections being of European lineage. A higher frequency of HPV16 was present in Northern Tunisia (80%) than in Central (68%) or Southern Tunisia (50%) (P = 0.02). HPV18/45 was significantly more common in adenocarcinomas (50%) than in squamous cell carcinomas (11%) (P = 0.004). Frequent infection with European HPV variants most likely reflects the history of European migration to Tunisia. In addition to the importance of understanding the variants of HPV in Tunisia, behavioral and cultural attitudes towards screening and age-specific infection rates should be investigated to aid the development of future vaccination and HPV screening programs and policies.

Type-Specific Human Papillomavirus Distribution in Invasive Squamous Cervical Carcinomas in Tunisia and Vaccine Impact

“…Missaoui et al report (Missaoui et al, 2010) shows using PCR technique and consensus GP5/GP6 primers, that HPV 16 is the most frequent detected genotype (47.6%) in the samples isolated from their patients. HPV 16 and 18 were also the most reported genotypes in a series of 146 cases collected in the Tunisian cancer Institute (KrennHrubec et al, 2011). Our results also show that multiple infections were seen in 51.7 % of cases and were mainly mixing HPV 16,18,35 and 45 and less frequently HPV 59,40,66,73 and 58.…”

Human Papillomavirus 16 Non-European Variants Are Preferentially Associated with High-Grade Cervical Lesions

“…An increased risk of developing high-grade CIN/cancer was observed in association of HPV16 non-European variants in several studies in the world [22], [32], [45], [59]–[63]. In addition, a number of reports in Brazil have described the presence of HPV16 variants in cervical samples and/or in association with different grades of lesions [37]–[43].…”

Human papillomavirus genotypes and HPV-16 variants distribution among Tunisian women with normal cytology and squamous intraepithelial lesions

“…The first molecular studies published results on the HPV infection among women with normal cervical cytology having different lifestyle practices [20, 21]. Recently, HPV type and variants distribution have been assessed in cervical tumor tissues from Tunisian patients [24]. However, there are insufficient data on the risk factors for HPV infection and cervical intraepithelial lesions.…”

“…Our results showed that the rate of HPV-16 E variant was higher among NIL women than SIL women (88.2% and 81.8%, respectively) whereas, non-European variants were high among SIL women compared to NIL women (18% and 12%, respectively). KrennHrubec et al, observed that among cervical cancer cases collected from the center of Tunisia, a prevalence rate was of 61% for the HPV-16 E variant and of 40% for the non-European variants [24]. Non-European variants were also reported to be frequently observed among cervical cancer cases from Morocco [40].…”