Biopsy-verified vulvar lichen sclerosus: Incidence trends 1997-2022 and increased risk of vulvar squamous precancer and squamous cell carcinoma.

Population-based data on the epidemiology of vulvar lichen sclerosus (LS) are sparse and only few prospective studies have investigated the malignant potential of the disease. We used the nationwide Danish Pathology Registry to first assess the incidence of biopsy-verified vulvar LS in the period 1997-2022 and second to examine the incidence of vulvar high-grade squamous precancer and squamous cell carcinoma (SCC) in women with biopsy-verified vulvar LS (1978-2019) compared with that expected in the general female population. For the latter aim, we computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs). During our study period, the age-standardized incidence rate of vulvar LS increased from 5.0 (1997-1998) to 35.7 (2021-2022) per 100,000 person-years. Compared with the general female population, women with biopsy-verified vulvar LS had significantly increased rates of vulvar high-grade squamous precancer (SIR = 8.5; 95% CI: 7.2-10.0) and SCC (SIR = 16.2; 95% CI: 14.2-18.4). The SIRs of vulvar high-grade squamous precancer and SCC did not vary substantially according to length of follow-up. This nationwide and population-based study shows a 7-fold increase in the incidence of biopsy-verified vulvar LS since 1997. Data also show that women with biopsy-verified vulvar LS have 8.5 and 16 times higher than expected incidence of vulvar high-grade squamous precancer and SCC, respectively. The substantially increased incidence of vulvar high-grade squamous precancer and SCC following LS is important in relation to the clinical management and follow-up of LS patients.

Biopsy-verified vulvar lichen sclerosus and the risk of non-vulvar cancer: A nationwide cohort study.

Vulvar lichen sclerosus (VLS) is a chronic inflammatory mucocutaneous disease known to be associated with human papillomavirus-independent vulvar squamous cell carcinoma. Evidence on the association with other types of cancer, however, is sparce. We conducted a large nationwide cohort study examining the incidence of non-vulvar cancers among women with biopsy-verified VLS compared with the general female population. By using the nationwide Pathology Registry, we identified all women in Denmark with a biopsy-verified VLS diagnosis during 1978-2019 (n = 16,921). The cohort was followed up in the Danish Cancer Registry until 2022 for a subsequent non-vulvar cancer diagnosis. Standardized incidence ratios (SIRs) were computed with 95% confidence intervals (CIs) as relative risk estimates of all specific non-vulvar cancer sites. Compared with general female population rates, women with biopsy-verified VLS had decreased rates of several non-vulvar cancers, including HPV-related cancers (combined estimate: SIR = 0.5; 95% CI: 0.3-0.7), and lung (SIR = 0.6; 95% CI: 0.5-0.7), liver (SIR = 0.5; 95% CI: 0.2-0.9), and thyroid cancer (SIR = 0.5; 95% CI: 0.3-0.9). The decreased SIRs tended to sustain throughout the follow-up period following the VLS diagnosis. This large nationwide cohort study shows that women with biopsy-verified VLS may have a long-term reduced risk of developing HPV-related (cervical, vaginal, oropharyngeal, and anal) and smoking-associated cancers (lung, liver, and cervical) as well as thyroid cancer. Future studies focusing on the mechanisms behind the decreased cancer risk are needed.

Prediagnostic use of menopausal hormone therapy and long-term survival of localized epithelial ovarian cancer: The Extreme study.

Use of menopausal hormone therapy (MHT) prior to an epithelial ovarian cancer (EOC) diagnosis has been suggested to be associated with improved survival. In a recent nationwide cohort study, we found that prediagnostic long-term MHT use, especially estrogen therapy (ET), was associated with improved long-term survival in women with nonlocalized EOC. Our aim was to investigate the influence of prediagnostic MHT use on long-term survival among women with localized EOC in the same nationwide study. Our study cohort comprised all women aged 50 years or older with an EOC diagnosis in Denmark 2000-2014 (n = 2097) identified from the Extreme study. We collected information on usage of systemic ET and estrogen plus progestin therapy (EPT) from the Danish National Prescription Registry. By using pseudo-values, 5- and 10-year absolute and relative survival probabilities were estimated with 95% confidence intervals (CIs) while adjusting for histology, comorbidity, and income. Relative survival probabilities >1 indicate better survival. The 5-year absolute survival probabilities were 61% and 56%, respectively, among women who were nonusers and users of prediagnostic MHT, whereas these numbers were 46% and 41%, respectively, regarding 10-year survival. Use of MHT was not significantly associated with an improved 5- or 10-year survival in women with localized EOC (5-year relative survival probability = 0.95, 95% CI: 0.89-1.02; 10-year relative survival probability = 0.92, 95% CI: 0.84-1.02). Similar findings were seen for systemic ET or EPT use. Our findings do not suggest a positive benefit from prediagnostic MHT use on long-term survival of localized EOC.

Low-dose aspirin use and risk of ovarian cancer: a combined analysis from two nationwide studies in Denmark and Sweden.

BACKGROUND: Studies on association between low-dose aspirin use and ovarian cancer risk were mostly based on self-reported medication use and few had large enough sample size to investigate the potential modification effect by ovarian cancer risk factors. METHODS: In these two nationwide nested case-control studies among the Danish and Swedish female population, 11,874 women with ovarian cancer (30-84 years old) (Denmark: 7328 diagnosed in 2000-2019, Sweden: 4546 diagnosed in 2010-2018) were randomly age- matched with 473,960 female controls (293,120 from Denmark, and 181,840 from Sweden). We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) and combined the estimates based the fixed-effect assumption. Effect modification by inflammation-related risk factors and by indication (cardiovascular disease, CVD) were also investigated. RESULTS: Ever use of low-dose aspirin was not strongly associated with the overall risk of ovarian cancer (OR = 0.97; 95%CI: 0.92-1.03). However, the association differed according to parity (nulliparous: OR = 0.80, 95%CI: 0.70-0.92; parous: OR = 1.00, 95%CI: 0.94-1.07; p-interaction = 0.0024), and according to history of CVD (no CVD: OR = 0.91, 95%CI: 0.82-1.00; ever CVD: OR = 1.05, 95%CI: 0.97-1.13; p-interaction =0.0204). CONCLUSIONS: Low-dose aspirin use was associated with a decreased ovarian cancer risk especially in nulliparous women and in women without CVD diagnosis.

PD-L1 expression in vulvar cancer: a systematic review and meta-analysis.

Programmed cell death ligand-1 (PD-L1) expression in cancer may predict clinical response to immunotherapeutic treatment with PD-1/PD-L1 inhibitors. Within the vulvar cancer field, PD-L1 expression has only been assessed by a few studies. We conducted a meta-analysis to examine the prevalence of PD-L1 positivity in vulvar cancer. PubMed, Embase, and Cochrane were searched for articles reporting on PD-L1 expression in vulvar cancer. Study selection and data extraction were performed independently by two authors. We extracted data on PD-L1 prevalence in vulvar cancer according to combined positive score (CPS) and tumour proportion score (TPS). Cutoff values for positivity were ≥1 or ≥10 for CPS and ≥1% and ≥5% for TPS. Random-effects models were used to estimate pooled PD-L1 prevalence, with 95% confidence intervals (CIs). Tests of between-study heterogeneity were evaluated by the I2 statistics. Sources of heterogeneity were explored by subgroup analyses and meta-regression. In total, 19 studies were included. Pooled PD-L1 prevalence in vulvar cancer was 83.4% (95% CI: 70.8-91.3; I2 = 80.0) and 53.9% (95% CI: 37.4-69.6; I2 = 93.0) according to CPS and TPS, respectively. Based on TPS, human papillomavirus (HPV)-associated vulvar squamous cell carcinomas (SCC) showed a lower PD-L1 prevalence (39.9%; 95% CI: 13.3-74.2) compared with HPV-independent SCC (62.6%; 95% CI: 33.7-84.6), but meta-regression showed no significant variation in PD-L1 prevalence by HPV status. PD-L1 prevalence was similar in advanced (44.9%; 95% CI: 29.8-61.1) and localized vulvar cancer (56.7%; 95% CI: 18.9-76.7). In conclusion, PD-L1 expression in vulvar cancer is frequent but between-study heterogeneity was high. Based on a subgroup of heterogenous studies, we found no strong variation in PD-L1 prevalence according to HPV status and stage.

History of autoimmune disease and long-term survival of epithelial ovarian cancer: The extreme study.

OBJECTIVE: Patients with autoimmune disease may have impaired cancer survival. The aim was to investigate the association between autoimmune disease and ovarian cancer survival. METHODS: From the Extreme study, we included women diagnosed with epithelial ovarian cancer (EOC) in Denmark during 1990-2014 (n = 11,870). Information on exposure and covariates was retrieved from nationwide registries. Using pseudo-values, we estimated absolute and relative 5- and 10-year survival probabilities with 95% confidence intervals (CIs) for autoimmune diseases combined and for the four most common individual disorders in our study population, namely type 1 diabetes, rheumatoid arthritis, Graves' disease, and inflammatory bowel disease. RESULTS: The overall 5- and 10-year absolute survival probabilities were 35% and 24%, respectively, in women with EOC without autoimmune disease. Autoimmune diseases combined was not significantly associated with survival among women with EOC (5-year adjusted relative survival probability = 1.01, 95% CI: 0.94-1.09; 10-year adjusted relative survival probability = 0.90, 95% CI: 0.81-1.00). However, stratification by disease stage showed an impaired 10-year survival in women with autoimmune disease and a localized EOC (relative survival probability = 0.86, 95% CI: 0.76-0.97). None of the individual autoimmune diseases were statistically significantly associated with EOC survival. CONCLUSIONS: Only among women with localized EOC, there seemed to be a long-term survival loss associated with a history of autoimmune disease. In contrast, no significant association between a history of autoimmune disease and survival was observed in women with nonlocalized EOC where the survival is already low.

Paracetamol use and risk of epithelial ovarian cancer: A nationwide nested case-control study.

OBJECTIVE: To investigate whether paracetamol use is associated with a reduced risk of epithelial ovarian cancer (EOC). DESIGN: A nationwide nested case-control study. SETTING: Danish female population. POPULATION: A total of 9589 EOC cases diagnosed from 2000 to 2019 were age-matched with 383 549 randomly selected female controls using risk set sampling. METHODS: Paracetamol use, reproductive history, history of medication and history of surgery were retrieved from Danish national registers. Paracetamol use was defined as at least two prescriptions for up to 1 year before the index date, and was further classified according to recency, duration, cumulative dose and intensity of dose. MAIN OUTCOME MEASURES: Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals for the association between paracetamol and EOC risk, overall and by histological subtypes. RESULTS: 'Ever' use of paracetamol was associated with a reduced EOC risk after adjusting for potential confounding factors (OR 0.92, 95% CI 0.87-0.97). The association was only significant among recent users (OR 0.89, 95% CI 0.84-0.95). The risk declined further with the increasing level of cumulative dose and intensity; women from the group with a high cumulative dose and a high intensity had a 13% (OR 0.87, 95% CI 0.80-0.94) and 14% (OR 0.86, 95% CI 0.79-0.93) reduced risk, respectively. In the histological subtype analysis, reduced risk with 'ever' use was most pronounced for serous and clear cell tumours. CONCLUSIONS: Paracetamol use was associated with a decreased risk of EOC in a dose-response manner. Future studies are needed to validate the findings and investigate the mechanisms behind the association.

Risk of nonovarian cancer in a nationwide-based study of nearly 5000 women with borderline ovarian tumors in Denmark.

Evidence regarding cancer risk after borderline ovarian tumors (BOTs) is limited. We conducted a nationwide cohort study examining the incidence of nonovarian cancers in women with serous or mucinous BOTs compared with the general female population with up to 41 years of follow-up. Through the nationwide Pathology Registry, we identified nearly 5000 women with BOTs (2506 serous and 2493 mucinous) in Denmark, 1978 to 2018. We computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) as relative risk estimates of specific nonovarian cancers. Compared with general female population rates, women with serous BOTs had increased rates of particularly malignant melanoma (SIR = 1.9; 95% CI: 1.3-2.6), thyroid cancer (SIR = 3.0; 95% CI: 1.4-5.4) and myeloid leukemia (SIR = 3.2; 95% CI: 1.5-5.8), and women with mucinous BOTs had elevated rates of lung cancer (SIR = 1.7; 95% CI: 1.3-2.1), pancreatic cancer (SIR = 1.9; 95% CI: 1.2-2.9) and myeloid leukemia (SIR = 2.3; 95% CI: 0.9-4.7). We found no convincing association with neither breast nor colorectal cancer in women with BOTs. This is the first large nationwide study showing that women with specific types of BOTs have increased risks of several nonovarian cancers, likely due to some shared risk factors or genetic characteristics.

Time trends in prevalence of p16 positivity and combined HPV/p16 positivity in a large cohort of Danish vulvar cancer patients.

Vulvar cancer is rare, but causes substantial morbidity in affected patients. A subset of vulvar cancers is caused by high-risk human papillomavirus (hrHPV), which primarily exerts its oncogenic effect through upregulation of tumor suppressor protein p16. Tumors positive for both hrHPV and p16 (double positive) are assumed to be HPV-driven, but only few large studies have investigated the combined prevalence of hrHPV and p16 positivity in vulvar cancer over time. In this Danish cross-sectional study, we assessed the prevalence of p16 positivity and double positivity for hrHPV and p16 in a large sample of vulvar squamous cell carcinomas (VSCCs) diagnosed during 1990 to 2017. In a nationwide register, we identified VSCCs from 13 hospitals across Denmark, and collected archival tumor tissue for hrHPV testing with INNO-LiPA and immunohistochemical p16 staining. We calculated the prevalence of hrHPV, p16 positivity and double positivity according to time, age and histological subtype and evaluated time trends through estimated annual percentage changes. We included 1278 VSCCs. Overall, 35.0% (95% confidence interval [CI]: 32.4-37.6) were positive for p16 and 31.0% (95% CI: 28.4-33.5) were positive for both hrHPV and p16. The prevalence of p16 positivity and double positivity increased over time, both in women aged ≤59 and ≥60 years. The double positive prevalence was higher in nonkeratinizing (60.7%) and warty/basaloid VSCCs (67.5%) than in keratinizing (16.1%) and verrucous VSCCs (5.0%). These results indicate that approximately one-third of vulvar cancers were caused by hrHPV infection, supporting a substantial preventive potential of the HPV vaccine.

Risk of ovarian cancer after salpingectomy and tubal ligation: Prospects on histology and time since the procedure.

OBJECTIVE: Recent theories propose that most epithelial ovarian cancer (EOC), depending on histological type, originate from other gynecological tissues and involve the ovary secondarily. According to these theories, any protective effect of salpingectomy and tubal ligation may vary by histological type. The study aim was to examine the association between salpingectomy and tubal ligation, respectively, and risk of EOC, with a focus on associations specific for histological types. METHODS: We identified EOC cases and matching controls in national registries and gathered information on surgical procedures and potential confounders. Conditional logistic regression was used to estimate odds ratio (OR) with 95% confidence interval (CI) of EOC related to salpingectomy and tubal ligation, respectively, overall and stratified by histological type. Furthermore, we investigated the association according to timing of the procedures. RESULTS: Our study comprised 16,822 EOC cases. Each case was matched with 40 controls. There was an overall EOC risk reduction after unilateral (OR = 0.73; 95% CI: 0.60-0.87) and bilateral salpingectomy (OR = 0.46; 95% CI: 0.31-0.67). A slight risk reduction was seen among women with previous tubal ligation (OR = 0.91; 95% CI: 0.83-0.99). For salpingectomy, the risk reduction increased with increasing time since the surgical procedure and was only present among women younger than 50 years at salpingectomy. Unilateral and bilateral salpingectomy was associated with a risk reduction for most histological types. CONCLUSION: The association between previous salpingectomy and reduced risk of several histological subtypes of EOC supports the suggested theories about the site of origin of EOC and may be of clinical importance.

Long-term survival of nonlocalized epithelial ovarian cancer among women using menopausal hormone therapy prior to diagnosis: The extreme study.

Prediagnostic use of menopausal hormone therapy (MHT) has been suggested to be associated with improved survival of epithelial ovarian cancer (EOC). We investigated the potential long-term survival benefit of prediagnostic MHT use in women ≥50 years with nonlocalized EOC using the Extreme study including all women in Denmark registered with nonlocalized EOC during 2000 to 2014 (N = 3776). We obtained individual-level information on prediagnostic use of systemic estrogen therapy (ET) and estrogen plus progestin therapy (EPT) from the National Prescription Registry and estimated absolute and relative 5- and 10-year survival probabilities with 95% confidence intervals (CIs) using pseudo-values, taking into account histology, comorbidity, income and residual disease. Among women not having used prediagnostic MHT, 5- and 10-year absolute survival probabilities were 19% and 11%, respectively. Compared to MHT nonusers, prediagnostic systemic ET use for 3 to 4 years and ≥ 5 years was associated with 1.43 (95% CI: 1.01-2.02) and 1.22 (95% CI: 0.96-1.55) times higher 5-year survival probabilities, respectively. Ten-year survival probabilities were also increased but not statistically significantly. Among prediagnostic EPT users, increased 5-year (1.14, 95% CI: 0.85-1.53) and 10-year (1.38, 95% CI: 0.91-2.08) survival probabilities were observed after use for 3 to 4 years compared to MHT nonuse, whereas EPT use for ≥5 years was not associated with long-term survival of nonlocalized EOC. Our findings may suggest a better long-term survival of nonlocalized EOC in women having used long-term prediagnostic ET. However, the statistical precision of our results did not allow firm conclusions and more studies are needed.

Changes in HPV prevalence in Danish women with vulvar cancer during 28 years - A nationwide study of >1300 cancer cases.

OBJECTIVE: A substantial proportion of vulvar cancers are caused by high-risk human papillomavirus (hrHPV), but hrHPV prevalence in vulvar cancer has mainly been investigated in smaller studies which did not evaluate time trends. Our aim was to assess hrHPV prevalence in >1300 Danish vulvar cancers diagnosed during 1990-2017, including changes in hrHPV prevalence over time. METHODS: In a nationwide pathology register, we identified women diagnosed with vulvar cancer at thirteen hospitals from all Danish regions. Archival tumor tissue was collected from local repositories and, upon pathology review, sent to a central laboratory for HPV testing using INNO-LiPA. We calculated hrHPV prevalence according to time, age and histology, and evaluated the overall and age-specific estimated annual percentage change (EAPC). RESULTS: We included 1308 vulvar cancer cases, with a median age of 72 years at diagnosis. The overall hrHPV prevalence was 52.0% (95% CI: 49.3-54.7). HPV types 16/18 were found in 39.6% of cases, whereas nine-valent HPV (9vHPV) vaccine types 16, 18, 31, 33, 45, 52, and 58 were found in 50.8%. The hrHPV prevalence showed an increasing trend over time, with an EAPC of 0.35% (95% CI: 0.00-0.71). The hrHPV prevalence was higher in younger women throughout the study period, and increasing trends over time were seen in both older (age ≥ 60) and younger (age < 60) women. The hrHPV prevalence was higher in non-keratinizing (71.0%) and warty/basaloid (78.0%) carcinomas than in keratinizing (39.4%) and verrucous (36.4%) carcinomas. CONCLUSIONS: Our results indicate that the 9vHPV vaccine could potentially prevent a substantial proportion of vulvar cancers in Denmark.

One-Dose Human Papillomavirus Vaccination and the Risk of Genital Warts: A Danish Nationwide Population-based Study.

BACKGROUND: Increasing evidence suggests that 1-dose human papillomavirus (HPV) vaccination may protect significantly against HPV-related disease. We provide nationwide, real-world data on the risk of genital warts (GWs) after <3 vaccine doses. METHODS: All Danish women born in 1985-2003 were identified, and individual-level vaccination data were retrieved. The cohort was followed up for first occurrence of GWs until 31 December 2016. Using Poisson regression, we calculated incidence rates (IRs) of GWs per 100 000 person-years and IR ratios (IRRs) with corresponding 95% confidence intervals (CIs) for GWs, according to vaccination status, age at first dose, and calendar time. RESULTS: The cohort comprised 1 076 945 girls and women, of whom 485 408 were vaccinated. For girls initiating vaccination at age 12-14 years and 15-16 years, 1-dose vaccine effectiveness (VE) was 71% (IRR = 0.29; 95% CI, .22-.38) and 62% (0.38; .29-.49), respectively, compared with unvaccinated girls. In the same age groups, 2-dose VE was 78% (IRR, 0.22; 95% CI, .18-.26) and 68% (0.32; .26-.38), respectively. After 2009, the IRRs for 3 versus 1 dose and 2 versus 1 dose increased towards unity over calendar time, being 0.69 (95% CI, .57-.84) and 0.86 (.68-1.08) in 2016, respectively. CONCLUSIONS: In this study, 1 or 2 doses of quadrivalent HPV vaccine was associated with substantial protection against GWs in girls vaccinated at age ≤16 years. The 1-dose VE approached that of 3 or 2 doses over calendar time, probably reflecting the impact of herd protection.

The association of reproductive factors with risk of non-epithelial ovarian cancer and comparison with serous ovarian cancer.

OBJECTIVE: To examine the association between reproductive factors and risk of non-epithelial ovarian cancer and to compare the associations with those in serous ovarian cancer. METHODS: From the Danish Cancer Registry, we identified all ovarian cancer cases (≥20 years old at diagnosis) of germ cell (n = 188), sex cord-stromal (n = 116), or serous (n = 4854) histology during 1982-2016. For each case, 15 age-matched female controls were selected with risk set sampling. Reproductive history was obtained from nationwide registries. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between reproductive factors and the three ovarian cancer types. RESULTS: Compared with nulliparity, ever giving birth was associated with increased odds for germ cell tumors (OR = 1.28, 95% CI: 0.85-1.93) and decreased odds for sex cord-stromal (OR = 0.74, 95% CI: 0.44-1.26) and serous tumors (OR = 0.70, 95% CI: 0.64-0.76). Infertility decreased odds for germ cell tumors (OR = 0.63, 95% CI: 0.23-1.76) but increased odds for sex cord-stromal tumors (OR = 2.20, 95% CI: 0.89-5.43) and serous tumors (OR = 1.97, 95% CI: 1.69-2.30). Finally, use of oral contraceptives decreased the odds for all three tumor types (germ cell: OR = 0.50, 95% CI: 0.29-0.87; sex cord-stromal: OR = 0.40, 95% CI: 0.13-1.22; serous: OR = 0.50, 95% CI: 0.40-0.62). CONCLUSIONS: Reproductive factors affected the risk of sex cord-stromal and serous ovarian cancer similarly with decreased risk associated with parity and use of oral contraceptives. Oral contraceptives also seemed to decrease the risk of germ cell tumors, whereas parity was associated with increased risk.

Prognostic impact of socioeconomic status on long-term survival of non-localized epithelial ovarian cancer ꟷ The Extreme study.

OBJECTIVE: To examine the influence of socioeconomic status (SES) on long-term survival of non-localized ovarian cancer. METHODS: All women in Denmark with a first diagnosis of non-localized epithelial ovarian cancer 1982-2007 were identified in the Cancer Registry and/or the Pathology Registry and followed up until December 2017. The survival probability was estimated after respectively 5 and 10 years, using so-called pseudo observations, and analyzed according to education, income, and marital status defined from nationwide registries. RESULTS: The study cohort included 6486 women, and the estimated 5- and 10-year survival probabilities were 21.4% and 12.7%, respectively. Compared to women with short education, the 5-year survival probability was 7% higher for women with medium (relative survival probability = 1.07, 95% CI: 0.97, 1.19) and long education (relative survival probability = 1.07, 95% CI: 0.93, 1.24). Compared with married women, the 5-year survival probability for divorced women/widower was slightly lower (0.85, 95% CI: 0.69, 1.04) and for unmarried women slightly higher (1.08, 95% CI: 0.94, 1.23). Finally, the probability of being alive 5 years after diagnosis was 1.09 times higher (95% CI: 0.95, 1.24) for medium-income women and 1.23 times higher (95% CI: 1.08, 1.41) for high-income women compared with low-income women. Similar patterns were observed for 10-year survival. CONCLUSIONS: Non-localized ovarian cancer patients have a poor prognosis. Our data suggest that among Danish women with advanced ovarian cancer, higher personal income is associated with slightly higher probability of long-term survival, whereas education and marital status did not affect the probability of long-term survival.

Borderline ovarian tumors in Denmark 1997-2018: Time trends in incidence by histology, age and educational level.

INTRODUCTION: After some decades with an increasing incidence of borderline ovarian tumors, more recent studies have observed that the incidence rate seems to be leveling off or declining. In this study, we describe the incidence of borderline ovarian tumors in Denmark 1997-2018 by histology, age at diagnosis and educational level. MATERIAL AND METHODS: All borderline ovarian tumors registered in the Danish Pathology Registry during 1997-2018 were identified and individual-level educational information was retrieved from nationwide registers. Age-standardized incidence rates were estimated according to histology, age at diagnosis and educational level. To investigate incidence trends over time, the average annual percentage change and corresponding 95% confidence intervals (CIs) were estimated using Poisson regression. RESULTS: We identified 3927 women with borderline ovarian tumors during the study period, of which 1997 (50.9%) were serous and 1743 (44.4%) were mucinous. The age-standardized incidence rate of serous borderline ovarian tumors did not change significantly over calendar time (average annual percentage change = -0.13, 95% confidence interval [CI] -1.13 to 0.88). For mucinous tumors, the age-standardized incidence rate was also relatively stable during the first half of the study period, followed by a decrease from 2.56 to 1.25 per 100 000 person-years between 2007-2011 and 2017-2018. Over the entire study period, the incidence rate of mucinous borderline tumors declined on average by 2.91% (95% CI -4.24 to -1.51) per year. The incidence of both types of borderline ovarian tumors seemed to be highest among women with a low educational level. Over calendar time, the incidence of mucinous tumors decreased in all educational groups, whereas the incidence of serous tumors decreased exclusively in women with a high educational level. Time trends did not differ markedly by age at diagnosis. CONCLUSIONS: In Denmark, the incidence of serous borderline ovarian tumors was stable during 1997-2018, whereas the incidence of mucinous borderline ovarian tumors decreased. The incidence rates of both types of borderline ovarian tumors tended to be highest among women with a low educational level throughout the study period.

Time trends in the incidence and survival of vaginal squamous cell carcinoma and high-grade vaginal intraepithelial neoplasia in Denmark - A nationwide population-based study.

OBJECTIVE: To describe trends in incidence of high-grade vaginal intraepithelial neoplasia (VaIN) and vaginal squamous cell carcinoma (SCC) in Denmark. For vaginal SCC, we also examine 5-year relative survival and mortality. METHODS: All high-grade VaIN cases diagnosed 1997-2017 and vaginal SCCs during 1978-2017 were identified in two high-quality nationwide registers. Age-standardized incidence rates and average annual percentage change (AAPC) were assessed. For vaginal SCC, 5-year relative survival was calculated, and Cox regression was applied to study the effect of selected characteristics on mortality. RESULTS: Altogether, 831 cases of high-grade VaIN and 721 vaginal SCCs were identified. The age-standardized incidence rate of high-grade VaIN showed no clear trend over time. However, when we stratified by age and divided the study period according to HPV vaccine licensure in Denmark (2006), the incidence of high-grade VaIN decreased significantly by 15.6% per year (95% CI: -23.2, -7.3%) after 2007 onwards among the youngest women (<30 years). For vaginal SCC, the incidence decreased from 0.5 (1978-1982) to 0.3 (2013-2017) per 100,000 woman-years. The 5-year relative survival improved over time and was 67.9% (95% CI: 54.9, 84.1%) in the most recent time period. Mortality was significantly associated with calendar year, age, and stage at diagnosis. CONCLUSIONS: The overall incidence of high-grade VaIN showed no clear trend over time, but a significant decline was observed in women younger than 30 years after HPV vaccine licensure. The incidence of vaginal SCC was reduced by approximately 50% and survival after vaginal SCC improved over time.

Use of antidepressants and risk of epithelial ovarian cancer.

Antidepressants are widely prescribed among women to treat depression and anxiety disorders, but studies of their effects on gynecological cancer risk are sparse. We assessed associations between various antidepressants and risk of epithelial ovarian cancer. By using Danish nationwide registers, we identified all women (cases) aged 30-84 years with incident epithelial (serous, endometrioid, clear cell or mucinous) ovarian cancer during 2000-2011 (n = 4,103) and matched each case to 20 population controls (n = 58,706) by risk-set matching. Data on drug use (including tricyclic and related antidepressants, selective serotonin reuptake inhibitors, other antidepressants, and potential confounder drugs), medical and reproductive history and socioeconomic parameters, were obtained from nationwide registries. We used conditional logistic regression models to estimate adjusted odds ratios (ORs) and two-sided 95% confidence intervals (CIs) for epithelial ovarian cancer associated with antidepressive drug use. Compared with non-use, use of selective serotonin reuptake inhibitors was associated with a decreased risk of ovarian cancer (OR, 0.85; 95% CI, 0.74-0.96), whereas the associations for other antidepressants were close to unity [tricyclic and related antidepressants: OR, 0.99 (95% CI, 0.78-1.26); other antidepressants: OR, 1.05 (95% CI, 0.76-1.46)]. For individual types of SSRI, reduced ORs were observed for citalopram OR, 0.78 (95% CI, 0.66-0.93), paroxetine 0.79 (95% CI, 0.56-1.12) and sertraline 0.80 (95% CI, 0.60-1.08). Among postmenopausal women, the inverse association was restricted to users of menopausal hormone therapy. In conclusion, use of selective serotonin reuptake inhibitors was associated with a decreased risk of epithelial ovarian cancer; thereby implying potential chemopreventive properties of these drugs.

Parity, infertility, oral contraceptives, and hormone replacement therapy and the risk of ovarian serous borderline tumors: A nationwide case-control study.

OBJECTIVE: Few studies have examined the risk of an ovarian serous borderline tumor (SBT) associated with parity, infertility, oral contraceptives (OCs), or hormone replacement therapy (HRT), which was the study aim. METHODS: This nationwide case-control study included all women with an SBT diagnosis in Denmark, 1978-2002. SBTs were confirmed by centralized expert pathology review. For each case, 15 age-matched female controls were randomly selected using risk-set sampling. Cases and controls with previous cancer (except for non-melanoma skin cancer) and controls with bilateral oophorectomy or salpingo-oophorectomy were excluded. Conditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: We found a strongly decreased risk of SBTs among parous women which decreased with increasing number of children (p<0.01). Older age at first birth also decreased the SBT risk (p=0.03). An increased SBT risk was associated with infertility (OR=3.31; 95% CI: 2.44-4.49), which was present both among parous and nulliparous women. HRT use increased the SBT risk (OR=1.32; 95% CI: 1.02-1.72), whereas OC use decreased the risk (OR=0.40; 95% CI: 0.26-0.62). CONCLUSIONS: Our nationwide study with expert histopathologic review of all SBTs showed that parity, infertility, use of HRT, and use of OCs, respectively, were strongly associated with the risk of SBTs. This is the first study to report a strong and significantly decreased SBT risk associated with OC use and a significantly increased risk with infertility, and HRT use. This supports that SBTs and serous ovarian cancer share similar risk factors.

Significant Reduction in the Incidence of Genital Warts in Young Men 5 Years into the Danish Human Papillomavirus Vaccination Program for Girls and Women.

BACKGROUND: Denmark introduced the quadrivalent human papillomavirus vaccine into the vaccination program for 12- to 15-year-old girls in 2008 to 2009. In 2012, the program was supplemented with a catch-up program for women aged up to 27 years. We evaluated the effectiveness of the Danish vaccination program on the nationwide incidence of genital warts (GWs), after the second catch-up by including information on both hospital treatments and on self-administered treatment with podophyllotoxin. Genital wart incidence was investigated in both sexes; however, the main focus was on potential herd protection of men. METHODS: Incident cases of GWs were identified from the Danish National Patient Register and through redemptions of prescription for podophyllotoxin in the Danish National Prescription Registry in 2006 to 2013. Age-specific incidence rates (IRs) were assessed, and estimated annual percentage change (EAPC) was calculated by Poisson regression. RESULTS: Genital wart incidence was either stable or increased in both sexes in 2006 to 2008. After introduction of the vaccination program, GW incidence decreased significantly in women aged 12 to 35 years and men aged 12 to 29 years, with rapid decrease among 16- to 17-year-olds (IRwomen, from 1071 to 58 per 100,000 person-years [EAPC, -55.1%; 95% confidence interval, -58.7 to-51.2]; IRmen, from 365 to 77 per 100,000 person-years [EAPC, -36.6%; 95% confidence interval, -40.5 to -32.5] in 2008-2013). CONCLUSIONS: We found a significantly decreasing incidence of GWs in women up to 35 years of age after the start of the human papillomavirus vaccination program. A similar pattern was observed for men aged 12 to 29 years, indicating substantial herd protection.