Invasive cervical cancers from women living in the United States or Botswana: differences in human papillomavirus type distribution

Genetic diversity in L1 ORF of human papillomavirus in women with cervical cancer with and without human immunodeficiency virus in Botswana and Kenya

BACKGROUND

The variation of human papillomavirus (HPV) genotypes shapes the risks of cervical cancer and these variations are not well defined in Africa. Nucleotide changes within the L1 gene, nucleotide variability, and phylogeny were explored in relation to HIV in samples from Botswana and Kenya.

METHODS

A total of 98 HPV-positive cervical samples were sequenced to identify different HPV variants. Phylogenetic inferences were used to determine HPV genotypes and investigate the clustering of sequences between women living with HIV (WLWHIV) and -women not living with HIV (WNLWHIV).

RESULTS

Out of 98 generated sequences, 83.7% (82/98) participants had high-risk (HR) HPV genotypes while 16.3% (16/98) had low-risk (LR) HPV genotypes. Among participants with HR-HPV genotypes, 47.6% (39/82) were coinfected with HIV. The prevalence of HR-HPV genotypes was statistically higher in the Botswana population compared to Kenya (p-value < 0.001). Multiple amino acid mutations were identified in both countries. Genetic diversity differed considerably among WLWHIV and WNLWHIV. The mean pairwise distances between HPV-16 between HIV and HIV/HPV as well as for HPV-18 were statistically significant. Six (6) new deleterious mutations were identified in the HPV genotypes based on the sequencing of the L1 region, HPV-16 (L441P, S343P), HPV-18 (S424P), HPV-45 (Q366H, Y365F), and HPV-84 (F458L). The majority of the patients with these mutations were co-infected with HIV.

CONCLUSIONS

Genomic diversity and different genomic variants of HPV sequences were demonstrated. Candidate novel mutations within the L1 gene were identified in both countries which can be further investigated using functional assays.

Promoter Hypermethylation Analysis of Host Genes in Cervical Cancer Patients With and Without Human Immunodeficiency Virus in Botswana

Background: Epidemics of human immunodeficiency virus (HIV) and cervical cancer are interconnected. DNA hypermethylation of host genes' promoter in cervical lesions has also been recognized as a contributor to cervical cancer progression.

Methods: For this purpose we analyzed promoter methylation of four tumor suppressor genes (RARB, CADM1, DAPK1 and PAX1) and explored their possible association with cervical cancer in Botswana among women of known HIV status. Overall, 228 cervical specimens (128 cervical cancers and 100 non-cancer subjects) were used. Yates-corrected chi-square test and Fisher's exact test were used to explore the association of promoter methylation for each host gene and cancer status. Subsequently, a logistic regression analysis was performed to find which factors, HIV status, high risk-HPV genotypes, patient's age and promoter methylation, were associated with the following dependent variables: cancer status, cervical cancer stage and promoter methylation rate.

Results: In patients with cervical cancer the rate of promoter methylation observed was greater than 64% in all the genes studied. Analysis also showed a higher risk of cervical cancer according to the increased number of methylated promoter genes (OR = 6.20; 95% CI: 3.66–10.51; P < 0.001). RARB methylation showed the strongest association with cervical cancer compared to other genes (OR = 15.25; 95% CI: 6.06–40.0; P < 0.001). Cervical cancer and promoter methylation of RARB and DAPK1 genes were associated with increasing age (OR = 1.12; 95% CI: 1.01-1.26; P = 0.037 and OR = 1.05; 95% CI: 1.00-1.10; P = 0.040). The presence of epigenetic changes at those genes appeared to be independent of HIV status among subjects with cervical cancer. Moreover, we found that cervical cancer stage was influenced by RARB (χ²= 7.32; P = 0.002) and CADM1 (χ²=12.68; P = 0.013) hypermethylation, and HIV status (χ²= 19.93; P = 0.001).

Conclusion: This study confirms the association between invasive cervical cancer and promoter gene methylation of tumor suppressing genes at the site of cancer. HIV infection did not show any association to methylation changes in this group of cervical cancer patients from Botswana. Further studies are needed to better understand the role of HIV in methylation of host genes among cancer subjects leading to cervical cancer progression.

Human papillomavirus genotypes in women with invasive cervical cancer with and without human immunodeficiency virus infection in Botswana

Cervical cancer remains a significant cause of morbidity and mortality in women worldwide and is the leading cause of cancer-related death in Botswana. It is well established that women with HIV have a higher risk of persistent HPV infection leading to cervical cancer. We assessed HPV prevalence and genotype distribution in 126 tissue specimens from confirmed invasive cervical cancer cases using Abbott real-time PCR assay. Overall, 88 (69.8%) women were HIV-infected. Fifty-seven (64.8%) of the HIV-infected women had a baseline CD4⁺ count ≥350 cells/μl, and 82 (93.2%) were on antiretroviral therapy at the time of cervical cancer diagnosis. The median age of HIV-infected patients was significantly younger than that of HIV-uninfected patients (p < 0.001). HPV DNA was detected in all of 126 (100%) of tissues analyzed in our study. The HPV genotypes identified included the HPV-16 (75.4%), HPV-18 (28.6%) and other high-risk (hr) HPV genotypes (16.7%). HIV infection was positively associated with the presence of the HPV-16 genotype (p = 0.036), but not with HPV-18 or with other high-risk (hr)-HPV genotypes. Thirty-three percent of the patients had multiple hr-HPV genotypes, with higher rates in HIV-infected women. These results highlight the importance and potential impact of large-scale HPV vaccination programs covering HPV-16 and HPV-18 genotypes in countries like Botswana with high burden of HIV infection.

Performance of Two-Stage Cervical Cancer Screening With Primary High-Risk Human Papillomavirus Testing in Women Living With Human Immunodeficiency Virus

OBJECTIVE

To evaluate the performance of cervical cancer screening algorithms for women living with human immunodeficiency virus (HIV), using primary high-risk human papillomavirus (HPV) testing followed by cytology, visual inspection with acetic acid, or colposcopy.

METHODS

We conducted a prospective cohort study of women living with HIV in Botswana. All participants underwent high-risk HPV testing. Participants with positive high-risk HPV test results underwent cytology, visual inspection with acetic acid, colposcopy, and biopsy. Participants with negative high-risk HPV test results also underwent cytology. Histopathology was the reference standard for determination of preinvasive cervical disease and cervical cancer. Sensitivity, specificity, positive predictive value (PPV), negative predictive value, and likelihood ratios (LR) of high-risk HPV-based two-stage screening algorithms were calculated.

RESULTS

Among 300 women screened, 88 (29%) had a positive high-risk HPV test result, and 29 of the 88 (35%) women who tested positive for high-risk HPV had CIN 2 or higher on histopathology. High-risk HPV followed by colposcopy resulted in a sensitivity of 83%, specificity of 49%, PPV of 47%, LR+ of +1.6, and LR- of -0.4. High-risk HPV followed by visual inspection with acetic acid resulted in a reduced sensitivity of 59%, specificity of 49%, PPV of 39%, LR+ of +1.2, and LR- of -0.8. High-risk HPV testing followed by cytology also resulted in a reduced sensitivity of 62%, specificity of 77%, PPV of 60%, LR+ of +2.7, and LR- of -0.5. Stratification by HPV 16/18/45 did not improve performance of the algorithms.

CONCLUSION

In a high-risk population with HIV, high-risk HPV testing followed by colposcopy demonstrated the highest sensitivity and PPV in detecting high-grade cervical dysplasia. Allocating resources to colposcopy in resource-limited settings may be more effective than other screening strategies.

Performance of vaginal self-sampling for human papillomavirus testing among women living with HIV in Botswana

Background:

In Botswana, where HIV prevalence remains high, cervical cancer is the leading cause of cancer deaths in women. Multiple organizations recommend high-risk human papillomavirus (hr-HPV) testing as a screening tool, however, high coverage may not be feasible with provider-collected samples. We conducted the first assessment of self- versus provider-collected samples for hr-HPV testing in HIV-positive women in Botswana and report prevalence of hr-HPV and histological outcomes.

Methods:

We recruited HIV-positive women ≥25 years attending an HIV clinic in Gaborone. Self- and provider-collected samples from participants were tested for hr-HPV using Cepheid GeneXpert. Women testing positive for any hr-HPV returned for colposcopy. We used unweighted κ statistics to determine hr-HPV agreement.

Results:

Thirty-one (30%) of 103 women tested positive for any hr-HPV. The most common genotypes were HPV 31/33/35/52/58. Overall agreement between self- and provider-collected samples for any hr-HPV was 92% with a κ of 0.80. Ten of the 30 hr-HPV positive women attending colposcopy had CIN 2+ (33%).

Conclusions:

In this HIV-positive population, hr-HPV prevalence was 30%, with excellent agreement between self and provider samples. Self-sampling may play an important role in screening programs in high HIV burden settings with limited resources like Botswana.

Predictors of Locally Advanced Disease at Presentation and Clinical Outcomes Among Cervical Cancer Patients Admitted at a Tertiary Hospital in Botswana

OBJECTIVES

The aim of this study was to determine predictors of locally advanced disease at presentation and clinical outcomes among cervical cancer patients in Botswana to inform interventional strategies.

METHODS

Retrospective review of 149 medical records of new cervical cancer patients was conducted between August 2016 and February 2017 at the Princess Marina Hospital. Data collected included sociodemographics, presenting symptoms, stage of disease, comorbidities, interventions, and clinical outcomes. STATA 12 was used for data analysis. Frequencies were used to describe patient demographics and clinical variables. Bivariate and multivariate binary logistic regression analyses were used to determine association between stage of disease at presentation and patient characteristics. P ≤ 0.05 was considered significant.

RESULTS

Mean age was 49.5 years. Nine (89.2%) in 10 patients had locally advanced cervical cancer (stage IB1-IVB). Two thirds (65.1%) were human immunodeficiency virus positive. Previous cervical cancer screening was low at 38.3%. Common symptoms were abnormal vaginal bleeding, low abdominal pain, and malodorous vaginal discharge reported among 75.8%, 66.4%, and 39.6% of cases, respectively. Overall, 32 (21.5%) were declared cured, 52 (34.9%) improved, and 11 (7.4%) opted for home-based care. Hospital deaths were 41 (27.5%). Major causes of death were renal failure (48.7%) and severe anemia (39%). Thirteen (8.7%) were lost to follow-up. Being unmarried (odds ratio [OR], 3.9), lack of cervical cancer screening (OR, 6.68), presentation with vaginal bleeding (OR, 7.69), and low abdominal pain (OR, 4.69) were associated with advanced disease at presentation.

CONCLUSIONS

Lack of cervical cancer screening, vaginal bleeding, low abdominal pain, and unmarried status were associated with advanced disease at presentation. We recommend scale-up of cervical cancer screening and its integration into routine human immunodeficiency virus care. Capacity building in gynecologic oncology and palliative care services is currently critical.

Prevalence of oncogenic human papillomavirus genotypes in patients diagnosed with anogenital malignancies in Botswana

BACKGROUND

Human papillomavirus (HPV) associated malignancies are the leading cause of cancer death in Botswana. We sought to determine causative HPV types in patients with anogenital malignancies in Botswana to inform vaccine strategy.

METHODS

We used formalin-fixed and paraffin-embedded (FFPE) tissue blocks from patients diagnosed with anal, penile and vulvar squamous cell carcinomas between the years, 2014 and 2016. Presence of HPV 16, 18, or other high-risk (HR) types was detected using Abbott m2000 real-time PCR platform. Tissues with other high-risk types were subsequently analysed using a multiplex qPCR assay that includes 15 validated fluorophore probes.

RESULTS

A total of 126 tissue specimens, comprising of 21 anal (9 males, 12 females), 31 penile and 74 vulvar were studied. Ninety-three (73.8%) patients had their HIV status documented in the records while the rest did not. Eighty-three (83) out of 93 were HIV positive, a prevalence of 89.4% (95% CI: 81-94). HPV was detected in 68/126 (54%) tissues, of which 69% (95% CI: 54-79) had HPV 16 only, 28% (95% CI: 19-40) had other hr.-HPV types and 2.9% (95% CI, 3.5-10.1) were co-infected with HPV 16 and other hr.-types. Other high-risk types detected included HPV 26, 31, 33, 35, 39, 45, 51, 52, 66 and 68. HPV 18 was not detected. Multiple-type HPV infection was detected in 44 of 47 (93.6%) HIV positive participants co-infected with HPV. In HIV-negative individuals, only HPV 16 was detected.

CONCLUSION

In our study, anogenital carcinomas were associated with HPV 16 and other hr.-HPV types besides HPV 16 and 18. HIV co-infected patients had multiple hr.-HPV types detected whereas in HIV-negative patients only HPV 16 was detected. Our study suggests that multivalent vaccines may be more suitable in this setting, especially for HIV-infected individuals.

Invasive cervical cancers in the United States, Botswana and Kenya: HPV type distribution and health policy implications

BACKGROUND

More deaths occur in African women from invasive cervical cancer (ICC) than from any other malignancy. ICC is caused by infection with oncogenic types of human papillomavirus (HPV). Co-infection with the human immunodeficiency virus (HIV) accelerates the natural history of ICC, and may influence the HPV type distribution. Because HPV vaccines are available, this malignancy is theoretically preventable, but the vaccines are largely type-specific in protection against infection. Data on specific HPV types causing ICC in African women is limited, and many studies utilized swab samples rather than actual cancer tissue. A previous study using archived, ICC tissue from women in Botswana identified an unusual HPV type distribution. A similar study was therefore performed in a second sub-Saharan country to provide additional information on the HPV type distribution in ICC.

METHODS

Archived, formalin-fixed, paraffin-embedded ICCs were acquired from women in the United States, Kenya, or Botswana. DNA was extracted and HPV genotyping performed by Roche Linear Array. HIV sequences were identified in ICCs by PCR.

RESULTS

HPV types 16 or 18 (HPV 16/18) were identified in 93.5 % of HPV-positive ICCs from the U.S., 93.8 % from Kenya, and 61.8 % from Botswana (p < 0.0001). Non-HPV 16/18 types were detected in 10.9 % of HPV-positive cancers from the U.S., 17.2 % from Kenya, and 47.8 % from Botswana (p < 0.0001). HIV was detected in 2.2, 31.5, and 32.4 % from ICCs from the U.S., Kenya, or Botswana, respectively (p = 0.0002). The distribution of HPV types was not significantly different between HIVinfected or HIV-uninfected women. The percentages of ICCs theoretically covered by the bivalent/quadrivalent HPV vaccines were 93.5, 93.9, and 61.8 % from the U.S., Kenya and Botswana, respectively, and increased to 100, 98, and 77.8 % for the nanovalent vaccine.

CONCLUSIONS

HPV 16/18 caused most ICCs from the U.S. and western Kenya. Fewer ICCs contained HPV 16/18 in Botswana. HIV co-infection did not influence the HPV type distribution in ICCs from African women from the two countries. Available HPV vaccines should provide protection against most ICCs in the U.S. and Kenya. The recently developed nanovalent vaccine may be more suitable for countries where non-HPV 16/18 types are frequently detected in ICC.

Effect of HIV Infection on Human Papillomavirus Types Causing Invasive Cervical Cancer in Africa

OBJECTIVES

HIV infection is known to worsen the outcome of cervical human papillomavirus (HPV) infection and may do so differentially by HPV type.

DESIGN

Twenty-one studies were included in a meta-analysis of invasive cervical cancers (ICC) among women infected with HIV in Africa.

METHOD

Type-specific HPV DNA prevalence was compared with data from a similar meta-analysis of HIV-negative ICC using prevalence ratios (PR).

RESULTS

HPV detection was similar in 770 HIV-positive (91.2%) and 3846 HIV-negative (89.6%) ICC, but HIV-positive ICC harbored significantly more multiple HPV infections (PR = 1.75, 95% confidence intervals: 1.18 to 2.58), which were significantly more prevalent in ICC tested from cells than from biopsies. HPV16 was the most frequently detected type in HIV-positive ICC (42.5%), followed by HPV18 (22.2%), HPV45 (14.4%), and HPV35 (7.1%). Nevertheless, HIV-positive ICC were significantly less frequently infected with HPV16 than HIV-negative ICC (PR = 0.88, 95% confidence intervals: 0.79 to 0.99). Other high-risk types were significantly more prevalent in HIV-positive ICC, but only for HPV18 was there a significantly higher prevalence of both single and multiple infections in HIV-positive ICC. Increases for other high-risk types were primarily accounted for by multiple infections. The proportion of HPV-positive ICC estimated attributable to HPV16/18 (71.8% in HIV positive, 73.4% in HIV negative) or HPV16/18/31/33/45/52/58 (88.8%, 89.5%) was not affected by HIV.

CONCLUSIONS

HIV alters the relative carcinogenicity of HPV types, but prophylactic HPV16/18 vaccines may nevertheless prevent a similar proportion of ICC, irrespective of HIV infection.

Lack of Associations between TNF-αPolymorphisms and Cervical Cancer in Thai women

The risk of developing cervical cancer in women infected with human papillomavirus (HPV) may be influenced by an individual's genetic susceptibility. Published data linking single nucleotide polymorphisms (SNPs) in the tumor necrosis factor-alpha (TNF-?) promoter region at positions -308G>A (rs1800629) and -238G>A (rs361525) to cervical cancer risk have been inconclusive. In this study, we examined 251 cervical specimens and classified them into two groups according to their cytological findings: 121 cancer cases and 130 controls (low-grade squamous intraepithelial lesion and normal cytology). All specimens were typed by PCR and sequencing for TNF-αpromoter -308G>A (rs1800629) and -238G>A (rs361525). The genotype distribution of SNPs in either rs1800629 or rs361525 did not significantly demonstrate higher frequency in the cancer group (p=0.621 and p=0.68, respectively). Based on these results, neither the TNF-αpromoter -308G>A (rs1800629) nor the -238G>A (rs361525) polymorphism presents a major risk factor for cervical cancer among Thai women. Larger studies are necessary to elucidate possible genetic mechanisms influencing cervical cancer development.

Genotypic distribution of human papillomavirus (HPV) and cervical cytology findings in 5906 Thai women undergoing cervical cancer screening programs

Background

Cervical cancer is the major cause of morbidity and mortality in Thai women. Nevertheless, the preventive strategy such as HPV vaccination program has not been implemented at the national level. This study explored the HPV prevalence and genotypic distribution in a large cohort of Thai women.

Methods

A hospital-based cervical cancer screening program at Chulabhorn Hospital, Bangkok and a population-based screening program at a rural Pathum Thani Province were conducted using liquid-based cytology and HPV genotyping.

Results

Of 5906 women aged 20–70 years, Pap smear was abnormal in 4.9% and the overall HPV prevalence was 15.1%, with 6.4% high-risk (HR), 3.5% probable high-risk (PR), and 8.4% low-risk (LR) HPV. The prevalence and genotypic distribution were not significantly different between the two cohorts. Among HR-HPV genotypes, HPV52 was the most frequent (1.6%), followed by HPV16 (1.4%), HPV51 (0.9%), HPV58 (0.8%), HPV18 (0.6%), and HPV39 (0.6%). Among LR-HPV genotypes, HPV72 and HPV62 were the most frequent while HPV6 and HPV11 were rare. HPV infection was found to be proportionately high in young women, aged 20–30 years (25%) and decreasing with age (11% in women aged >50). The more severe abnormal cytology results, the higher positivity of HR-HPV infection was observed.

Conclusions

In conclusion, HPV52, HPV16, and HPV51 were identified as the most common HR-HPV genotypes in Thai women. This study contributes genotypic evidence that should be essential for the development of appropriate HPV vaccination program as part of Thailand’s cervical cancer prevention strategies.