Human papillomavirus genotypes in Iranian patients with cervical cancer

A meta-analysis of human papillomavirus prevalence and types among Iranian women with normal cervical cytology, premalignant lesions, and cervical cancer

In this study, all data from Iran on human papillomavirus (HPV) prevalence and types among women with normal cervical cytology, premalignant lesions, and cervical cancer were obtained and pooled. The overall HPV prevalence was found to be 9% in women with a normal cervix, 55% in atypical squamous cells of undetermined significance or atypia cases, 58% and 69% in women with low and high grade squamous intraepithelial lesions, respectively, and 81% among women with invasive cervical cancer. In all of the studied groups, HPV 16 was the most common HPV type, followed by HPV 18. In conclusion, this meta-analysis revealed that it will be beneficial if current HPV vaccines are integrated into the national vaccination programs of Iran.

A Meta-Analysis on Human Papillomavirus Type Distribution among Women with Cervical Neoplasia in the WHO Eastern Mediterranean Region

INTRODUCTION

To date, the human papillomavirus (HPV) vaccine has not been integrated into the national vaccination program of most countries of the WHO Eastern Mediterranean Region (EMRO), except for the United Arab Emirates and Libya. The knowledge of HPV genotype distribution in cervical neoplasia is valuable to predict the impact of current HPV vaccines on cancer prevention and can help the health policymakers to select the most appropriate vaccine types in their countries.

METHODS

Hence, this meta-analysis recapitulates all available data on HPV prevalence and genotypes in women with atypical squamous cells of undetermined significance (ASCUS), cervical intraepithelial neoplasia (CIN) I-III or low- and high-grade squamous intraepithelial lesions (LSIL and HSIL, respectively), and invasive cervical cancer (ICC) in EMRO countries.

RESULTS

The meta-analysis included 5,990 cases of cervical precancer and cancer. The overall HPV prevalence was 85.4, 71.3, 59.2, and 34.8% in women with ICC, CIN II-III or HSIL, CIN I or LSIL, and ASCUS, respectively. HPV 16 was the most common genotype followed by HPV 18, representing 58 and 16.5% in ICC cases, respectively.

CONCLUSION

This meta-analysis showed that the introduction of current HPV vaccines into national vaccination programs and the establishment of comprehensive screening programs in EMRO countries is beneficial by preventing 74.5% of cervical neoplasia.

Type-specific human papillomavirus prevalence in cervical intraepithelial neoplasia and cancer in Iran

In Iran, human papillomavirus (HPV) vaccination is not currently included in the national vaccination program and there are no comprehensive approaches to cervical screening program. Regional data on distribution of HPV types in women is important to predict the impact of current HPV vaccines. Although several studies on distribution of HPV types in cervical precancer and cancer have been conducted in Iran, in most of them HPV positive samples were subjected to specific-primer genotyping (mainly 16 and 18), and leaving the other HPV genotypes almost undetermined. Therefore, the present study aimed to investigate the distribution of HPV types in cervical neoplasia from West and Northwest of Iran. A total of 112 women with atypia, cervical intraepithelial neoplasia, and invasive cervical cancer were included. A PCR assay was performed in all samples to detect the presence of the HPV genome using the GP5+/6+ L1 consensus primer set. All HPV positive samples were subjected for sequencing. In overall, HPV prevalence was 20% in atypica, 44.5% in cervical intraepithelial neoplasia I, 92.3% in cervical intraepithelial neoplasia II-III, and 98.2% in invasive cervical cancer. The most frequent HPV type was HPV 16 (79.2%), which was followed by HPV types 18, 6, and 33 at the frequencies of 6.5%, 5.1%, and 2.7%, respectively. The least HPV types were found to be 31, 45, 53, 58, and 66. In conclusion, this study shows that the current HPV vaccines could have great impact to reduce the burden of cervical cancer in Iran.

Detection and Typing of Human Papilloma Viruses by Nested Multiplex Polymerase Chain Reaction Assay in Cervical Cancer

Background:

Cervical cancer is the leading cause of death from cancer in under-developed countries. Human papilloma virus (HPV) 16 and 18 are the most prevalent types associated with carcinogenesis in the cervix. Conventional Polymerase Chain Reaction (PCR), type-specific and consensus primer-based PCR followed by sequencing, Restriction Fragment Length Polymorphism (RFLP) or hybridization by specific probes are common methods for HPV detection and typing. In addition, some researchers have developed a multiplex PCR for simultaneous detection and typing of different HPVs.

Objectives:

The aim of the present study was to investigate the prevalence of HPV infection and its types in cervical Squamous Cell Carcinoma (SCC) using the Nested Multiplex PCR (NMPCR) assay.

Patients and Methods:

Sixty-six samples with histologically confirmed SCC were evaluated. Total DNA was isolated by phenol–chloroform extraction and ethanol precipitation. Nested multiplex PCR was performed with first-round PCR by GP-E6/E7 consensus primers for amplification of the genomic DNA of all known mucosal HPV genotypes and second-round PCR by type-specific multiplex PCR primer cocktails.

Results:

Human papilloma virus infection was detected in 78.8% of samples, with the highest prevalence of HPV 16 (60.6%) while concurrent infections with two types was detected in 10.6%.

Conclusions:

The NMPCR assay is more convenient and easy for analysis of results, which is important for fast diagnosis and patient management, in a type-specific manner.

Human papillomaviruses-related cancers. Presence and prevention strategies in the Middle east and north African regions

Human papillomavirus (HPV) infections are estimated to be the most common sexually transmitted infections worldwide. Meanwhile, it is well established that infection by high-risk HPVs is considered the major cause of cervical cancer since more than 96% of these cancers are positive for high-risk HPVs, especially types 16 and 18. Moreover, during the last 2 decades, numerous studies pointed-out the possible involvement of high-risk HPV in several human carcinomas including head and neck, colorectal and breast cancers. The association between high-risk HPVs and cervical cancer and potentially other human malignancies would necessitate the introduction of vaccines which were generated against the 2 most frequent high-risk HPVs (types 16 and 18) worldwide, including the Middle East (ME) as well as North African countries. The presence of high-risk HPVs in the pathogenesis of human cancers in the ME, which is essential in order to evaluate the importance of vaccination against HPVs, has not been fully investigated yet. In this review, we present an overview of the existing epidemiological evidence regarding the presence of HPV in human cancers in the ME and the potential impact of vaccination against HPV infections and its outcome on human health in this region.

Prevalence of High risk Human Papillomavirus in cervical dysplasia and cancer samples from twin cities in Pakistan

INTRODUCTION

Human Papilloma Virus (HPV) is small DNA virus mostly infecting mucosa and cutaneous keratinocytes. So far, more than 200 Human papillomaviruses are known. HPV have been divided into high- and low-risk on the basis of their oncogenic potential. High risk HPV is considered to be the main etiological cause for cervical cancer.

OBJECTIVE

The current study was designed to screen the local cervical cancer patients from the twin cities of Pakistan for the occurance of high risk HPV.

METHODOLOGY

A total of 67 formalin fixed paraffin-embedded samples of cervical cancer biopsies were obtained from the government hospitals in Islamabad and Rawalpindi. Cervical cancer biopsies were examined for the presence of HPV DNA. Polymerase chain reaction (PCR) was used for the amplification of a region in the HPV-L1 gene for the general detection of the Papilloma virus and for the genotype specific detection of high risk HPV 16 and 18 using the GP5/GP6 primers and genotype specific primers, respectively.

RESULTS

HPV DNA was detected in 59 out of 67 samples analyzed. 30 samples showed the presence of HPV16 while 22 samples were positive for HPV18. HPV subtype could not be determined in 7 samples.

CONCLUSION

Our results show a strong association between HPV infection and cervical cancer among women in twin cities of Pakistan. One way to minimize the disease burden in relation to HPV infection in Pakistani population is the use of prophylactic vaccines and routine screening. An early diagnosis of HPV infection will allow better health management to reduce the risk of developing cervical cancer.

Prevalence and genotyping of high risk human papillomavirus in cervical cancer samples from Punjab, Pakistan

Cervical cancer is the third most common cause of cancer-related death in women worldwide. Infection with high-risk human papillomavirus (HPV) is established as the cause of cervical carcinoma, therefore, high risk HPV detection may have prognostic significance for the women who are at increased risk of disease progression. The paucity of data on the incidence of cervical cancer in Pakistan makes it difficult to determine disease burden. Even less information is available regarding the prevalent HPV strains in cervical specimens collected from this region. Cervical cancer is a neglected disease in Pakistan in terms of screening, prevention, and vaccination. Identification and accurate genotyping of the virus burden in cancer specimens is important to inform intervention policies for future management of HPV associated disease and to potentially stratify patients dependent on HPV status. In this study, detection and genotyping of HPV types 16 and 18 from 77 cervical specimens were carried out. Consensus primers GP5+/GP6+, which detect 44 genital HPV types, and type specific primers (TS16 and TS18) were used in conjunction with newly designed type specific primers. Using a combination of these methods of detection, a total of 94.81% (95% CI ±4.95) of cervical lesions were positive for HPV. Single infections of HPV16 were detected in 24.68% (95% CI ±9.63) of total samples and HPV18 was found in 25.97% (95% CI ±9.79) samples. Interestingly, a high proportion of samples (40.26%, 95% CI ±10.95) was positive for both HPV16 and 18, indicating a higher incidence of co-infection than previously reported for similar ethnic regions. The HPV genotype of 3.90% of HPV positive samples remained undetected, although these samples were positive with the GP5+/GP6+ primer set indicating infection with an HPV type other than 16 or 18. These data indicate that the overall incidence of high risk HPV infection in cervical cancer and intraepithelial neoplasia specimens in Punjab, Pakistan is in line with the worldwide prevalence, but that the incidence of HPV16 and 18 co-infections in our cohort is higher than that previously reported.

p16 INK4a and Ki67 expression in normal, dysplastic and neoplastic uterine cervical epithelium and human papillomavirus (HPV) infection

Cellular cycle proteins like the p16(INK4a) and the Ki67 proliferation nuclear antigen have been used as oncogenicity cellular markers. The E6 and E7 oncoproteins interact with tumor suppressor genes p53 and pRb, culminating with the p16(INK4a) overexpression. The objective of this study was to evaluate the presence of HPV-DNA in 174 cervical biopsies and correlate the different histological grades with the p16(INK4a) and Ki67 immunohistochemical expression (IHC). A cross-sectional study that enrolled a total of 174 women who underwent uterine cervical biopsies between February 2003 and December 2006, in southern Brazil, was performed. Cervical smear samples were analyzed for the presence of HPV-DNA through polymerase chain reaction (PCR), and biopsy samples were examined for p16(INK4A) and Ki67 expression through IHC techniques. The presence of HPV-DNA was observed in 89% of the tested patients, among which 52% were positive for high-risk (HR) viral types [16, 18 and 31]. Regarding p16(INK4a), an expression of 69% was observed, being expressed in 100% of the high-grade squamous lesions (HSIL) and HR-HPV-DNA positives. Ki67 expression was associated with the lesion grade, being more expressive in the most severe lesions (p<0.001). p16(INK4A) and Ki67 markers coexpression was present in 86% of the samples (p<0.001), being 100% among those positive to HR-HPV-DNA with HSIL (p<0.001). The results suggest an association between the presence of HR-HPV infection and the p16(INK4a) and Ki67 expression and which is even stronger among women with HSIL.

High-Risk HPVs and Human Carcinomas in the Syrian Population

Human papillomavirus (HPV) infection is the most common sexually transmitted infection; persistent infection with high-risk types of HPV present a major risk factor for the initiation and progression of a variety of human carcinomas including cervical, colorectal, head, and neck (HN) as well as breast carcinomas. A huge number of studies investigated and reported the incidence of high-risk HPVs in these cancers worldwide particularly in the developed countries; therefore, two HPV prophylactic vaccines against the two most frequent high-risk HPV types (16 and 18) have been developed and used worldwide. However, there are very limited studies about the prevalence of HPVs in the developing countries especially in Africa and some states of the Middle East. In this mini review, we outline the presence of high-risk HPVs in human cervical, colorectal, HN as well as breast cancers in the Syrian population, which was recently explored for the first time by a Canadian/Syrian group.

Epidemiology of cervical cancer and human papilloma virus infection among Iranian women - analyses of national data and systematic review of the literature

BACKGROUND

Few studies have evaluated the epidemiology of cervical cancer in low risk Muslim countries, where the prognosis of cervical cancer is poor and which lack an organized cervical screening program. We studied incidence and mortality rates of cervical cancer and the prevalence of high risk human papilloma virus (HPV) infection in the Islamic Republic (I.R.) of Iran.

METHODS

We analyzed national cancer and mortality registration data and estimated age-standardized incidence (ASR) and mortality (ASMR) rates and age-specific patterns of cervical cancer. Furthermore, based on a systematic review we estimated prevalence of HPV infection in Iran.

RESULTS

The mean cervical cancer ASR was 2.5 per 100,000 in pathology-based cancer registries. However, ASRs were almost double in the population-based cancer registry and reached 6 per 100,000. The mean cervical cancer ASMR for Iran was 1.04 per 100,000. The mortality to incidence ratio was 42%. The cervical cancer incidence rate increased after age 30 and peaked between ages 55 and 65. The prevalence of HPV infection was 76% in cervical cancer patients and 7% among healthy Iranian women. Of the HPV types isolated, HPV 16 (54%), 18 (14%), and 31 (6%) were the most commonly detected in Iranian cervical cancer patients.

CONCLUSIONS

An organized prevention program is needed to fight against cervical cancer in Iran and other low incidence countries. We suggest a screening program starting after age 30 and with at least three screenings tests over each woman's lifetime. With a reservation on cost-effectiveness issue, available HPV vaccine will prevent HPV infection and cervical cancer in Iran.