Covariates of high-risk human papillomavirus (HPV) infections are distinct for incident CIN1, CIN2 and CIN3 as disclosed by competing-risks regression models

BACKGROUND

In addition to the oncogenic human papillomavirus (HPV), several cofactors are needed in cervical carcinogenesis, but whether the HPV covariates associated with incident (i) CIN1 are different from those of incident (ii) CIN2 and (iii) CIN3 needs further assessment.

OBJECTIVES

To gain further insights into the true biological differences between CIN1, CIN2 and CIN3, we assessed HPV covariates associated with incident CIN1, CIN2, and CIN3.

STUDY DESIGN AND METHODS

HPV covariates associated with progression to CIN1, CIN2 and CIN3 were analysed in the combined cohort of the NIS (n = 3187) and LAMS study (n = 12,114), using competing-risks regression models (in panel data) for baseline HR-HPV-positive women (n = 1105), who represent a sub-cohort of all 1865 women prospectively followed-up in these two studies.

RESULTS

Altogether, 90 (4.8%), 39 (2.1%) and 14 (1.4%) cases progressed to CIN1, CIN2, and CIN3, respectively. Among these baseline HR-HPV-positive women, the risk profiles of incident CIN1, CIN2 and CIN3 were unique in that completely different HPV covariates were associated with progression to CIN1, CIN2 and CIN3, irrespective which categories (non-progression, CIN1, CIN2, CIN3 or all) were used as competing-risks events in univariate and multivariate models.

CONCLUSIONS

These data confirm our previous analysis based on multinomial regression models implicating that distinct covariates of HR-HPV are associated with progression to CIN1, CIN2 and CIN3. This emphasises true biological differences between the three grades of CIN, which revisits the concept of combining CIN2 with CIN3 or with CIN1 in histological classification or used as a common endpoint, e.g., in HPV vaccine trials.

Longitudinal outcomes of high-risk human papillomavirus (HPV) infections as competing-risks events following cervical HPV test at baseline visit in the NIS-LAMS cohort

BACKGROUND

The complex natural history of human papillomavirus (HPV) infections following a single HPV test can be modeled as competing-risks events (i.e., no-, transient- or persistent infection) in a longitudinal setting. The covariates associated with these competing events have not been previously assessed using competing-risks regression models.

OBJECTIVES

To gain further insights in the outcomes of cervical HPV infections, we used univariate- and multivariate competing-risks regression models to assess the covariates associated with these competing events.

STUDY DESIGN AND METHODS

Covariates associated with three competing outcomes (no-, transient- or persistent HR-HPV infection) were analysed in a sub-cohort of 1,865 women prospectively followed-up in the NIS (n = 3,187) and LAMS Study (n = 12,114).

RESULTS

In multivariate competing-risks models (with two other outcomes as competing events), permanently HR-HPV negative outcome was significantly predicted only by the clearance ofASCUS+ Pap during FU, while three independent covariates predicted transient HR-HPV infections: i) number of recent (< 12 months) sexual partners (risk increased), ii) previous Pap screening history (protective), and history of previous CIN (increased risk). The two most powerful predictors of persistent HR-HPV infections were persistent ASCUS+ Pap (risk increased), and previous Pap screening history (protective). In pair-wise comparisons, number of recent sexual partners and previous CIN history increase the probability of transient HR-HPV infection against the HR-HPV negative competing event, while previous Pap screening history is protective. Persistent ASCUS+ Pap during FU and no previous Pap screening history are significantly associated with the persistent HR-HPV outcome (compared both with i) always negative, and ii) transient events), whereas multiparity is protective.

CONCLUSIONS

Different covariates are associated with the three main outcomes of cervical HPV infections. The most significant covariates of each competing events are probably distinct enough to enable constructing of a risk-profile for each main outcome.

Co-factors of high-risk human papillomavirus infections display unique profiles in incident CIN1, CIN2 and CIN3

In addition to oncogenic 'high-risk' human papillomaviruses (HR-HPV), several co-factors are needed in cervical carcinogenesis, but it is poorly understood whether these HPV co-factors associated with incident cervical intraepithelial neoplasia (CIN) grade 1 are different from those required for progression to CIN2 and CIN3. To gain further insights into the true biological differences between CIN1, CIN2 and CIN3, we assessed HPV co-factors increasing the risk of incident CIN1, CIN2 and CIN3. Data from the New Independent States of the Former Soviet Union (NIS) Cohort (n = 3187) and the Latin American Screening (LAMS) Study (n = 12,114) were combined, and co-factors associated with progression to CIN1, CIN2 and CIN3 were analysed using multinomial logistic regression models with all covariates recorded at baseline. HR-HPV-positive women (n = 1105) represented a subcohort of all 1865 women prospectively followed up in both studies. Altogether, 90 (4.8%), 39 (2.1%) and 14 (1.4%) cases progressed to CIN1, CIN2 and CIN3, respectively. Baseline HR-HPV was the single most powerful predictor of incident CIN1, CIN2 and CIN3. When controlled for residual HPV confounding by analysing HR-HPV-positive women only, the risk profiles of incident CIN1, CIN2 and CIN3 were unique. Completely different HPV co-factors were associated with progression to CIN1, CIN2 and CIN3 in univariate and multivariate analyses, irrespective of whether non-progression, CIN1 or CIN2 was used as the reference outcome. HPV co-factors associated with progression to CIN1, CIN2 and CIN3 display unique profiles, implicating genuine biological differences between the three CIN grades, which prompts us to re-visit the concept of combining CIN2 with CIN3 or CIN1.

Prognostic significance of topoisomerase II alpha and collagen IV immunoexpression in cervical cancer

OBJECTIVE

The immunohistochemical (IHC) expression of topoisomerase II alpha and collagen IV was studied in cervical cancer. The results of IHC expression for both markers were compared to the clinical and histological factors predicting the course of disease.

METHODS

In 114 patients with cervical cancer, treated at the Department of Gynecology and Obstetrics, University Medical Centre Ljubljana between 1995 and 1999, the tumor tissue was analyzed using standard IHC staining (IHS) procedures for topoisomerase II alpha and collagen IV. The obtained results were compared to those obtained by clinical, pathomorphological and morphometric prognostic factors, and the impact of the analyzed factors on the outcome of disease was assessed.

RESULTS

A high percentage of IHC expression of topoisomerase II alpha was present in 55.3%, and to collagen IV in 28.1% of cervical cancer patients. In the multivariate analysis the IHS intensity to collagen IV was significantly associated with lymphovascular invasion (OR = 5.906; 95% CI 2.18-15.96). Kaplan-Meier analysis showed a statistically significantly better survival in initial cervical cancer stages (p = 0.001), in tumors with a higher degree of differentiation (p = 0.049), more shallow depth of invasion (p = 0.004), smaller horizontal tumor spread (p = 0.001), in cases with no lymph node metastases (p = 0.001) and no lymphovascular space invasion (p = 0.001), in younger age groups (p = 0.001) and in women with regular menstrual cycles (p = 0.001).

CONCLUSION

IHC expression of topoisomerase II alpha and collagen IV was significantly correlated with defense reaction. A negative and weak IHC to collagen IV was a statistically significant independent predictive variable for lymphovascular invasion, related to metastatic spread in the lymph nodes. The two analyzed IHC markers indicate the existence of factors at the molecular level that might complement the assessment of cervical cancer prognosis, resulting in the appropriate choice of type and extent of treatment.

Safety of screening with Human papillomavirus testing for cervical cancer at three-year intervals in a high-risk population: experience from the LAMS study

OBJECTIVES

To assess whether human papillomavirus (HPV) testing is a safe enough approach to warrant extension of the screening intervals of baseline Papanicolaou (Pap)-/HPV- women in low-income settings.

METHODS

Of the >1000 women prospectively followed up as part of the Latin American Screening (LAMS) Study in São Paulo, Campinas, Porto Alegre) and Buenos Aires, 470 women with both baseline cytology and Hybrid Capture 2 (HC2) results available were included in this analysis. These baseline Pap-negative and HC2- or HC2+ women were controlled at six-month intervals with colposcopy, HC2 and Pap to assess the cumulative risk of incident Pap smear abnormalities and their predictive factors.

RESULTS

Of the 470 women, 324 (68.9%) were high-risk HPV (hrHPV) positive and 146 (31.1%) were negative. Having two or more lifetime sex partners (odds ratio [OR] = 2.63; 95% CI 1.70-3.51) and women using hormonal contraception (OR = 2.21; 95% CI 1.40-3.51) were at increased risk for baseline hrHPV infection. Baseline hrHPV+ women had a significantly increased risk of incident abnormal Pap smears during the follow-up. Survival curves deviate from each other starting at month 24 onwards, when hrHPV+ women start rapidly accumulating incident Pap smear abnormalities, including atypical squamous cells (ASC) or worse (log-rank; P < 0.001), low-grade squamous intraepithelial lesions (LSIL) or worse (P < 0.001) and high-grade squamous intraepithelial lesions (HSIL) (P = 0.03). Among the baseline hrHPV- women, the acquisition of incident hrHPV during the follow-up period significantly increased the risk of incident cytological abnormalities (hazard ratio = 3.5; 95% CI 1.1-11.7).

CONCLUSION

These data implicate that HPV testing for hrHPV types might be a safe enough approach to warrant extension of the screening interval of hrHPV-/Pap-women even in low-resource settings. Although some women will inevitably contract hrHPV, the process to develop HSIL will be long enough to enable their detection at the next screening round (e.g. after three years).

Self-sampling for human papillomavirus (HPV) testing as cervical cancer screening option. Experience from the LAMS study

PURPOSE

To compare Hybrid Capture II (HC2) in detecting high-risk (HR) HPV in patient-collected vaginal samples with those obtained using gynaecologist collected samples.

METHODS

Patients were submitted to Pap smears, visual inspection with acetic acid (VIA) and HC2 for hr-HPV.

RESULTS

A total of 1,081 HC2 tests for HR-HPV were performed: 770 (71.2%) samples were collected by a physician and 311 (28.8%) were self-collected by the patients. In detecting any cervical lesion, the sensitivity of HC2 collected by a physician was higher (92.86%) than that (37.5%) in the self-sampling group. Negative predictive value (NPV) was high for both, 99.69% and 93.75%, respectively. Using the CIN2 cutoff, performance of HC2 was significantly improved: 92.9% and 62.5%, respectively. HC2 specificity for any cervical lesion and for CIN2 or higher were close to 90% in both groups.

CONCLUSIONS

Self-sampled HPV testing is a powerful option to increase the detection of cervical lesions in women segregated from prevention programs.

Human papillomavirus testing as an optional screening tool in low-resource settings of Latin America: experience from the Latin American Screening study

Hybrid capture II (HC II) test for oncogenic human papillomaviruses (HPV) was carried out in a cohort of 4284 women at their first clinical visit. Overall prevalence of HPV was 17.1%, decreasing with age from 33.9% among women below 20 years to only 11.0% among those older than 41 years. HPV prevalence was significantly higher among current smokers (odds ratio [OR] = 1.31; 95% CI 1.1-1.6), in women with two or more lifetime sexual partners (OR = 1.9; 95% CI 1.6-2.4), and those women with two or more sexual partners during the past 12 months prior to examination (OR = 1.6; 95% CI 1.2-2.2). HPV detection increased in parallel with increasing cytologic abnormality, being highest in women with high-grade squamous intraepithelial lesion (P= 0.001). Specificity of the HPV test in detecting histologically confirmed cervical disease was 85% (95% CI 83.9-86.1). Sensitivity of the HPV test in detecting histologic abnormalities increased in parallel with disease severity, ranging from 51.5% for cervical intraepithelial neoplasia (CIN) 1 to 96.5% for CIN 3 and 100.0% for cancer, with respective decline of positive predictive value. These data suggest that HPV testing with HC II assay might be a viable screening tool among this population with relatively high prevalence of cervical disease.

Evaluation of visual inspection with acetic acid (VIA), Lugol's iodine (VILI), cervical cytology and HPV testing as cervical screening tools in Latin America. This report refers to partial results from the LAMS (Latin AMerican Screening) study

OBJECTIVES

To assess the performance indicators of visual inspection with acetic acid (VIA) and visual inspection with Lugol's iodine (VILI) in four Latin American centres participating in the ongoing Latin AMerican Screening (LAMS) study, in settings with moderate incidence of cervical disease and with poorly to moderately well-organized cervical cancer screening.

SETTING

Three Brazilian centres (São Paulo, Campinas and Porto Alegre) and one Argentine centre (Buenos Aires) recruited a total of 11,834 healthy women to undergo VIA, VILI, conventional Pap smear and Hybrid Capture II (HCII).

METHODS

Women who had a positive result from any of these tests were subjected to colposcopy and biopsies (if necessary), and women with high-grade cervical intraepithelial neoplasia (CIN) were properly treated. To control for verification bias, 5% of women with normal tests were referred for colposcopy, as were 20% of HCII-negative women.

RESULTS

Data on VIA (n=11,834), VILI (n=2994), conventional Pap smear (n=10,138) and HCII (n=4195) were available for test comparisons, calculating sensitivity, specificity, and positive and negative predictive values. Overall test positivity was 11.6% for VIA, 23.0% for VILI, 2.2% for Pap smear (LSIL threshold), 1.1% for Pap smear (HSIL threshold) and 17.1% for HCII. VIA was positive in 61.8% of the women with CIN 1, 57.0% of those with CIN 2, 35.0% of women with CIN 3 and in 21 of 28 (75%) of women with cancer. Approximately 10% of women with no detectable disease had an abnormal VIA. Regarding VILI, 83.3% of women diagnosed with CIN 1 and 62.5% of those with CIN 3 had an abnormal test. VILI failed to detect one of three cases of cancer. Both the sensitivity, specificity and positive predictive value of VIA and VILI in detecting CIN 2 or CIN 3 could be significantly improved depending on the combination with Pap smear or HCII (sensitivity up to 100.0% and specificity up to 99.8%).

CONCLUSIONS

The LAMS study failed to reproduce the performance figures obtained with VIA and VILI (as stand-alone tests) in some other settings, where the prevalence of cervical disease was higher. However, a combined use of VIA or VILI with the Pap test or HCII allowed specific detection of cervical abnormalities.

Comparing PAP smear cytology, aided visual inspection, screening colposcopy, cervicography and HPV testing as optional screening tools in Latin America. Study design and baseline data of the LAMS study

OBJECTIVES

This is a European Commission (EC)-funded ongoing study known as the LAMS (Latin American Screening) study, where PAP smear/liquid-based cytology and screening colposcopy were compared with i) three optional screening tools [visual inspection with acetic acid (VIA), or Lugol's iodine (VILI), cervicography] and with ii) Hybrid Capture II from a) conventional samples and from b) self-samples, in women at different risk for cervical cancer in Brazil and Argentina.

STUDY DESIGN

During 2002-2003, a cohort of 12,107 women attending four clinics: Campinas (CA), Sao Paulo (SP), Porto Alegre (PA) and Buenos Aires (BA), were interviewed for risk factors, and examined using the 8 diagnostic arms. Colposcopy was performed for women positive in any test and for 5% of women with baseline PAP-negative and 20% of HCII-negatives. All high-grade lesions (CIN2/3) were treated, and low-grade CIN are prospectively followed-up.

RESULTS

Of the 12,107 women, the following baseline data are available: epidemiological data (n=11,996), conventional PAP smears (n=10,363), LBC, SurePATH (n=320), LBC, DNA-Citoliq (n=1,346), VIA (n=12.067), VILI (n=3,061), cervicography (n=279), screening colposcopy (n=3,437), HCII conventional (n=4,710), HCII self-sampling (n=246) and cervical biopsies (n=1,524). The four sub-cohorts differ significantly in all their baseline data on the implicated risk factors of cervical cancer, consonant with their origin from regions with different cancer incidence. Around 95% of all PAP smears were negative, with slight variations in the prevalence of LSIL and HSIL between the four centers. Significant differences were found in the detection rates of abnormal findings in VIA, VILI and colposcopy between the four centers (p=0.0001). The prevalence of HPV was practically identical (16.5-18.8%) in all four cohorts (p=0.486), with no differences in the relative viral loads. Biopsy results were different depending on whether the women underwent screening colposcopy (BA) or elective colposcopy (others).

CONCLUSION

Four cohorts with significantly different baseline data are available, and prospective follow-up of these women permits analysis of whether variations in cervical cancer incidence in these regions is due to i) different natural history of the precursor lesions, or ii) due to different levels of exposure to the known risk factors.

Factors predicting disease outcome in early stage adenocarcinoma of the uterine cervix

CONTEXT

Adenocarcinoma (AC) and adenosquamous carcinoma (ASC) comprise the second principal histological types of cervical carcinoma. As compared with the squamous cell cancer (SCC), these lesions are far less frequent, and their epidemiology, natural history and prognostic determinants are less well understood.

OBJECTIVE

Patients with an early stage AC of the uterine cervix diagnosed in our clinic were subjected to detailed analysis for the prognostic determinants.

STUDY SUBJECTS

A series of 94 women with early stage (adenocarcinoma in situ (AIS) to IIB) cervical ACs or ASCs diagnosed and treated in our department during 1995-1999 and subsequently followed-up for a mean of 43.1 +/- 16.2 (S.D.) months.

MAIN OUTCOME MEASURES

Patients were examined by colposcopy, Papanicolaou (PAP) smear and biopsy. The stage of the disease (FIGO) and tumour histology in operative specimens were recorded, and univariate (Kaplan-Meier) and multivariate survival analysis (Cox) were run to explore the factors predicting disease outcome.

RESULTS

Mean age of the women was 44.2 +/- 2.5 (S.D.) years (range 24-81 years), which is significantly (P=0.000) lower than that (49.9 +/- 14.2) of 464 SCC patients in our material. Minority of the women (38.2%) reported any clinical symptoms, but these correlated with the stage (P=0.041). Screening history was acceptable (i.e. screening interval 3 to 4 years) in 56 women, whereas 28 (29.8%) had no previous PAP smear taken. Interpretation errors were established in 17 (23.6%) and sampling errors in 6 (8.3%) of the 72 smears available for re-screening. No colposcopic lesions were found in 29 (30.9%) women. Follow-up data were available from 72 patients, of whom the disease progressed in four (one died), whereas 68 patients are alive and well at the moment. Patient's age (P=0.000), screening history (P=0.0127), FIGO stage (P=0.001), mode of therapy (P=0.0187), and presence of co-existent squamous cell lesions (P=0.0184) were significant prognostic indicators in univariate survival analysis. Cox's multivariate survival analysis disclosed FIGO stage (P=0.001) and screening history (P=0.006) as the only significant independent predictors of the disease outcome.

CONCLUSIONS

The present data emphasise the importance of early cervical AC as a disease of younger women, making early detection of its precursors (AIS) by regular PAP smear screening mandatory in prevention of disease progression. This can only be achieved by increasing the sensitivity of the PAP smear in detecting abnormal glandular cells in asymptomatic women.

Endometriosis-associated ovarian carcinoma (EAOC): an entity distinct from other ovarian carcinomas as suggested by a nested case-control study

OBJECTIVES

Endometriosis-associated ovarian carcinoma (EAOC) has recently received increasing attention due to its suggested biological behavior, distinctive from those of usual epithelial ovarian cancer. To elucidate some of the controversies on this intriguing entity, a series of patients with EAOC were compared to ovarian carcinoma cases without concomitant endometriosis.

METHODS

To control the confounding effect of age, a nested case-control study was designed, where all 58 EAOC patients (mean age 54.5 +/- 11.5 years) were nested with four perfectly age-matched non-EAOC patients (n = 232; mean age 54.7 +/- 11.7 years) selected among 425 women representing all FIGO stages of ovarian carcinomas without endometriosis. Pertinent clinical data and results of analysis of the tumors were subjected to statistical analyses using life-table, univariate (Kaplan-Meier), and multivariate (Cox) survival techniques to disclose dissimilarities in the key biological characteristics of these two groups as well as the independent prognostic predictors of disease outcome.

RESULTS

When compared in a case-control design with four perfectly age-matched non-EAOC patients nested to each EAOC case, the patients with EAOC proved to: (1) have a lower stage disease (both FIGO and TNM) (P = 0.000), (2) show a completely different distribution of histological subtypes (significant overpresentation of endometrioid and clear cell carcinomas) (P = 0.0001), (3) have predominantly lower grade lesions (P = 0.029), (4) be devoid of any primary residual tumor (P = 0.0001), and, most importantly (5) have demonstrated a significantly better overall survival (47/58 versus 126/232; OR 2.89, 95% CI 1.56-5.34, P = 0.0001). This better survival was evident (a) in all age groups and (b) for all histological subtypes, but (c) not explained by a better stage-specific survival in any FIGO stage. The two series also differed in their significant prognostic predictors in Kaplan-Meier and Cox analyses. In the EAOC group, the most significant (P = 0.0001) predictors of OS in univariate analysis were age, histological type, observation time for endometriosis, and distribution of endometriosis. In the non-EAOC group, such significant predictors were age, residual tumor, and type of therapy. In the multivariate (Cox) model, age and FIGO stage were the only two significant independent prognostic factors shared by these two series. In addition, histological type and type of therapy proved to be significant independent predictors in the non-EAOC series.

CONCLUSIONS

These data suggest that EAOC deviates from the non-EAOC in many of its key biological characteristics. The implications of these data in the diagnosis, treatment policy, and prognostication still require confirmation by further studies, however.

Relationship between endometriosis and ovarian cancer

PURPOSE

To investigate the occurrence of ovarian cancer (OC) arising in ovarian endometriosis (OE) diagnosed in our laboratory, and the relation of the disease to patient age.

METHODS

Histopathological reports were reviewed in cases of endometriosis and ovarian cancer diagnosed between 1982 and 1989 and in 1997. The occurrence of OE and OC was studied in relation to patient age.

RESULTS

Of the 796 OE cases, 36 (4.5%) ovarian cancers were found in the eight-year period, and of the 216 OC cases 36 (16.7%) were associated with OE; 12 patients (1.7%) were under 50 years old and 24 (22.9%) were over 50. In 1997 there were 168 cases of OE, and 4 cases were associated with OC. Of the 60 OC cases 4 cases arose in endometriosis. Two patients were over 50 and two under 50.

CONCLUSION

In our report the occurrence of OC arising in OE was most influenced by patient age, the extent of sampling and the consistency of histologic reports about the presence of endometriosis in ovarian adenocarcinoma.

Detection of human papillomaviruses (HPV-16,18) in cervical smears by in situ hybridization

The rate of human papillomaviruses (HPV) 16 and 18 infections were measured in 109 women with histologically or cytologically determined lesions of the uterine cervix and in 42 healthy women. Cervical swabs were taken as the source of the target viral DNA. In situ hybridization with biotinylated probes was used. HPV-16 was the predominant type in patients and in healthy women. The percentage of positive cases was the highest in cervical cancer patients: 43.3% in squamous cell carcinoma and 33.3% in adenocarcinoma followed by cervical intraepithelial neoplasia (CIN), III, II (21.4%), CIN I (14.3%) and low grade squamous intraepithelial lesions (13.6%). HPV-18 type was detected in a lower percentage in the three groups of patients. In healthy women HPV-16 was determined in 12% and HPV-18 in 4.8%. We believe that the described noninvasive method of obtaining clinical material should be the method of choice for estimating papillomavirus infections in patients and in the general population. Our results are in agreement with suggestions that HPV genotype could be an important prognostic indicator in cervical carcinoma.

[Role of team work in preventing the birth of abnormal children]

In diagnosing and preventing the birth of abnormal children the authors stress the necessity of team work of different specialists and their centralisation at the University complex or hospitals. The results of such a team work organised at the Division of Medical Genetics, Department of Gynecology and Obstetrics in Ljubljana and their experience in detecting some of monogenic, chromosome, and etiologically unknown disorders are presented, as well as the results of the follow-up of certain cases. The value of team work in genetic counselling is also pointed out.