Early Evidence of the Effectiveness of the Human Papillomavirus Vaccination Program Against Anogenital Warts in Manitoba, Canada: A Registry Cohort Study.

BACKGROUND: We assessed the effectiveness of the quadrivalent human papillomavirus vaccine (qHPV) vaccination program in Manitoba, Canada, in reducing incident anogenital warts (AGWs) and to what extent effectiveness depends on age at vaccination and number of doses. METHODS: Female participants 9 years or older who received the qHPV in Manitoba between September 2006 and March 2013 (n = 31,464) through the publicly funded school-based program and a high-risk catch-up program were included. They were matched on age and area of residence to unvaccinated female participants. Information on incident AGWs was obtained from provincial administrative databases using validated algorithms. Using stratified Cox regression models, we estimate hazard ratios (HRs) for the association between qHPV and AGWs. RESULTS: For female participants vaccinated at age 18 years or younger, receipt of qHPV was associated with a 40% reduction in AGW risk (HR, 0.6; 95% confidence interval [CI], 0.4-0.8). Further adjustment for socioeconomic and medical history did not alter this estimate. For women vaccinated at age 19 years or older, we saw an increase in AGW incidence, especially among those who were sexually active (HR, 2.8; 95% CI, 2.1-3.7). Among female participants vaccinated at age 18 years or younger, risk of AGWs was lowest among those who received 3 doses, corresponding to a vaccine effectiveness of 56% (95% CI, 30%-70%). For women vaccinated at older age, risk of AGWs remained increased regardless of the number of doses. CONCLUSIONS: Women vaccinated at an older (≥19 years) age may be less protected against AGWs, particularly if sexually active before vaccine administration. Further efforts should be targeted at increasing vaccine uptake among preadolescents before the initiation of sexual activity.

Effect of changes in treatment practice on survival for cervical cancer: results from a population-based study in Manitoba, Canada.

BACKGROUND: Results from clinical trials in the 1990s led to changes in the recommended treatment for the standard therapy for stage IIB-IVA cervical cancer from radiotherapy alone to chemo-radiotherapy. We conducted the first population-based study in Canada to investigate temporal treatment patterns for cervical cancer and long-term survival in relation to these changes in the treatment guidelines. METHODS: Detailed information on stage and treatment for 1085 patients diagnosed with cervical cancer in 1984-2008 and identified from the population-based Manitoba Cancer Registry (MCR) in Canada was obtained from clinical chart review and the MCR. Factors associated with receiving guideline treatment were identified using logistic regression. All cause and cervical cancer specific survival were compared in patients who were and were not treated as recommended in the guidelines, using Cox proportional hazards models. RESULTS: The median follow-up time was 6.4 years (range: 0.05-26.5 years). The proportion of women who received guideline treatment was 79 % (95 % confidence interval [CI]: 76-81 %). However, the likelihood of being treated according to the guidelines over time was modified by age (p < 0.0001) and tumour stage at diagnosis (p = 0.002). Women who were treated according to the guidelines after the change in recommended clinical practice (1999-2008) had a significantly lower risk of death from all causes and from cervical cancer. This was driven by lower mortality rates in cases with stage IIB-IVA tumours (all causes of death: hazard ratio [HR] = 0.60, 95 % CI: 0.43-0.82, p = 0.002; cervical cancer related death: HR = 0.64, 95 % CI: 0.44-0.93, p = 0.02). CONCLUSIONS: The management of cervical cancer patients in Manitoba, Canada was in good agreement with treatment guidelines although reasons for departure from the guideline recommendations could not be examined further due to lack of data. Treatment of stage IIB-IVA cervical cancers with recommended concurrent chemo-radiotherapy, which is now standard practice, was associated with substantially increased survival, although the effect of changes in clinical practice including maintenance of haemoglobin levels on improved survival cannot be ruled out as a contributing factor.

Mammography rates for breast cancer screening: a comparison of First Nations women and all other women living in Manitoba, Canada, 1999-2008.

INTRODUCTION: First Nations (FN) women historically have low rates of preventive care, including breast cancer screening. We describe the frequency of breast cancer screening among FN women living in Manitoba and all other Manitoba (AOM) women after the introduction of a provincial, organized breast screening program and explore how age, area of residence, and time period influenced breast cancer screening participation. METHODS: The federal Indian Registry was linked to 2 population-based, provincial data sources. A negative binomial model was used to compare breast cancer screening for FN women with screening for AOM women. RESULTS: From 1999 through 2008, 37% of FN and 59% of AOM women had a mammogram in the previous 2 years. Regardless of area of residence, FN women were less likely to have had a mammogram than AOM women (relative rate [RR] = 0.69 in the north, RR = 0.55 in the rural south, and RR = 0.53 in urban areas). CONCLUSIONS: FN women living in Manitoba had lower mammography rates than AOM women. To ensure equity for all Manitoba women, strategies that encourage FN women to participate in breast cancer screening should be promoted.

Participation in the national cervical screening programme among women from New South Wales, Australia, by place of birth and time since immigration: A data linkage analysis using the 45 and up study.

OBJECTIVE: Equitable elimination of cervical cancer in Australia within the next decade will require high National Cervical Screening Program (NCSP) participation by all subgroups of women. The aim of this study was to examine the participation of immigrants compared to Australian-born women. METHODS: Participation in the NCSP (≥1cytology test) over a 3-year (2010-2012) and 5-year (2008-2012) period, by place of birth and time since immigration was examined using individually linked data of 67,350 New South Wales (NSW) women aged ≥45 enrolled in the 45 and Up Study. RESULTS: Three-year cervical screening participation was 77.0% overall. Compared to Australian-born women (77.8%), 3-year participation was lower for women born in New Zealand (adjusted odds ratio 0.77, 95% confidence interval 0.69-0.87), Oceania (0.67, 0.51-0.89), Middle East/North Africa (0.76, 0.60-0.97), South-East Asia (0.72, 0.60-0.87), Chinese Asia (0.82, 0.69-0.97), Japan/South Korea (0.68, 0.50-0.94), and Southern/Central Asia (0.54, 0.43-0.67), but higher for women from Malta (2.85, 1.77-4.58) and South America (1.33, 1.01-1.75). Non-English-speaking-at-home women were less likely to be screened than English-speaking-at-home women (0.85, 0.78-0.93). Participation increased with years lived in Australia but remained lower in immigrant groups compared to Australian-born women, even after ≥20 years living in Australia. Similar results were observed for 5-year participation. CONCLUSIONS: Women born in New Zealand, Oceania, and parts of Asia and the Middle East had lower NCSP participation, which persisted for ≥20 years post-immigration. The NCSP transition to primary HPV screening, and the introduction of the universal self-collection option in 2022, will offer new opportunities for increasing screening participation for these groups.

Cervical cancer incidence trends in Canada: a 30-year population-based analysis.

OBJECTIVES: To use the most recent data to update the trend in cervical cancer incidence in Canada over the 30 year period from 1978 to 2009. METHODS: Registered cases of cervical cancer and the corresponding person years for the Canadian population were retrieved from an online data repository of the International Agency on Research on Cancer and from Statistics Canada for the period 1978 to 2009. Annual age-standardized rates were estimated for all data combined and for each province separately. The ages of cases were aggregated into three groups: 25 to 39, 40 to 59, and 60 to 75 years. Joinpoint regression analysis was used to describe the trend across age groups and provinces. RESULTS: Between 1978 and 2006, the age-adjusted cervical cancer rate in Canada decreased from 20.05 to 12.66 per 100 000 females; after 2006 the rate increased. Greater reductions were observed in the older age groups. The average annual percentage change (AAPC) was -1.1% (95% CI -1.1% to 0.09%), -1.8% (95% CI -2.5% to -1.2%), and -2.6% (95% CI -3.9% to -1.4%) for age groups 25 to 39, 40 to 60, and 60 to 75, respectively. The AAPC varied between provinces, ranging from -0.22% (95% CI -1.4% to 0.9%) in Saskatchewan to -3.02% (95% CI -4.5% to -1.5%) in Newfoundland and Labrador. In Ontario the incidence of cervical cancer increased annually between 2006 and 2009. The trend in British Columbia included a significant change of slope in 1984. CONCLUSION: The incidence of cervical cancer decreased in Canada and across all provinces between 1978 and 2009. The decrease was greater in older women.

Objectifs : Utiliser les données les plus récentes pour offrir une mise à jour quant à la tendance pour ce qui est de l'incidence du cancer du col utérin au Canada au cours de la période de 30 ans s'étalant de 1978 à 2009. Méthodes : Les cas enregistrés de cancer du col utérin et les taux correspondants en personnes-années pour la population canadienne ont été récupérés auprès d'un dépôt de données en ligne du Centre International de Recherche sur le Cancer, ainsi qu'auprès de Statistique Canada, pour la période 1978 - 2009. Les taux annuels standardisés en fonction de l'âge ont été estimés pour l'ensemble des données et, de façon distincte, pour chacune des provinces. Les âges des cas ont été agrégés en trois groupes : 25 - 39 ans, 40 - 59 ans et 60 - 75 ans. Une analyse de régression Joinpoint a été utilisée pour décrire la tendance d'un groupe d'âge et d'une province à l'autre. Résultats : Entre 1978 et 2006, au Canada, le taux de cancer du col utérin corrigé en fonction de l'âge est passé de 20,05 à 12,66 par 100 000 femmes; après 2006, le taux a connu une hausse. Des baisses plus importantes ont été constatées au sein des groupes plus âgés. La modification annuelle moyenne en pourcentage (MAMP) était de −1,1 % (IC à 95 %, −1,1 % - 0,09 %), de −1,8 % (IC à 95 %, −2,5 % - −1,2 %) et de −2,6 % (IC à 95 %, −3,9 % - −1,4 %) pour les groupes d'âge de 25 à 39 ans, de 40 à 60 ans et de 60 à 75 ans, respectivement. La MAMP variait d'une province à l'autre, allant de −0,22 % (IC à 95 %, −1,4 % - 0,9 %) en Saskatchewan à −3,02 % (IC à 95 %, −4,5 % - −1,5 %) à Terre-Neuve-et-Labrador. En Ontario, l'incidence du cancer du col utérin a connu une hausse annuelle entre 2006 et 2009. En Colombie-Britannique, la tendance comptait une modification de pente significative en 1984. Conclusion : L'incidence du cancer du col utérin a connu une baisse, au Canada et dans toutes les provinces, entre 1978 et 2009. Cette baisse a été plus accentuée chez les femmes plus âgées.

Stage-Specific Risk of Breast Cancer among Canadian Immigrant and Non-Immigrant Women.

BACKGROUND: Breast cancer screening utilization varies across immigrant and non-immigrant populations. Recent studies have also suggested that some immigrant populations in Canada present with a higher frequency of later-stage breast cancer compared to non-immigrants. Our study aimed to augment prior research by presenting breast cancer stage distributions and stage-specific breast cancer incidence rates for immigrant and non-immigrants in British Columbia, Canada. METHODS: We utilized a population-based cohort of more than 1.3 million women built from linked administrative health and immigration data sets. Age-standardized incidence rate ratios were generated to compare immigrant and non-immigrant groups. Poisson regression was used to assess the relative frequency of later stage diagnosis among immigrant groups compared to non-immigrants. RESULTS: Indian and Chinese immigrants both showed significantly lower stage I and stage II-IV incidence rates compared to non-immigrants. However, Indian immigrants showed a higher frequency of later stage tumours at diagnosis compared to non-immigrants, while in contrast Chinese immigrants showed a lower frequency of later stage tumours. Filipino immigrants showed similar stage-specific rates and stage at diagnosis compared to non-immigrants. CONCLUSIONS: Our findings highlight a need for continued surveillance of cancer among immigrant and non-immigrant populations and inquiry into reasons for differences in stage at diagnosis across groups.

Incidence profile of four major cancers among migrants in Australia, 2005-2014.

PURPOSE: To compare the incidence profile of four major cancers in Australia by place of birth. METHODS: In this retrospective population-based cohort study, the analysis included 548,851 residents diagnosed with primary colorectum, lung, female breast, or prostate cancer during 2005-2014. Incidence rate ratio (IRR) and 95% confidence intervals (CI) were calculated for migrant groups relative to Australian-born. RESULTS: Compared with Australian-born residents, most migrant groups had significantly lower incidence rates for cancers of the colorectum, breast and prostate. The lowest rates of colorectal cancer were among males born in Central America (IRR = 0.46, 95% CI 0.29-0.74) and females born in Central Asia (IRR = 0.38, 95% CI 0.23-0.64). Males born in North-East Asia had the lowest rates of prostate cancer (IRR = 0.40, 95% CI 0.38-0.43) and females born in Central Asia had the lowest rates of breast cancer (IRR = 0.55, 95% CI 0.43-0.70). For lung cancer, several migrant groups had higher rates than Australian-born residents, with the highest rates among those from Melanesia (males IRR = 1.39, 95% CI 1.10-1.76; females IRR = 1.40, 95% CI 1.10-1.78). CONCLUSIONS: This study describes cancer patterns among Australian migrants, which are potentially helpful in understanding the etiology of these cancers and guiding the implementation of culturally sensitive and safe prevention measures. The lower incidence rates observed for most migrant groups may be maintained with continued emphasis on supporting communities to minimize modifiable risk factors such as smoking and alcohol consumption and participation in organized cancer screening programmes. Additionally, culturally sensitive tobacco control measures should be targeted to migrant communities with high lung cancer incidence rates.

Second primary malignancies among women with uterine sarcoma.

OBJECTIVE: Uterine sarcomas (US) are rare malignancies with unclear aetiology. Studies on uterine sarcomas in the setting of second primary malignant tumours can provide clues to aetiology and identify side effects of different treatments. METHODS: A cohort of 8606 cases of US was extracted from the data from 13 cancer registries and followed for second primary cancers within the period 1943-2000. Standardized incidence ratios (SIRs) were calculated, and Poisson regression analyses were performed. RESULTS: There were 499 cancer cases observed after a first diagnosis of US (SIR 1.26, 95%CI 1.16-1.38). SIRs were elevated for cancers of the mouth and pharynx (2.16, 95%CI 1.15-3.69), colorectum (1.60, 95%CI 1.28-1.98), lung (1.73, 95%CI 1.27-2.29), breast (1.25, 95%CI 1.05-1.49), urinary bladder (1.74, 95%CI 1.02-2.79), kidney (2.00, 95%CI 1. 24-3.06), thyroid gland (2.74, 95%CI 1.42-4.79), and soft tissue sarcoma (5.23, 95%CI 2.51-9.62). The risk of breast cancer increased along with increasing age of US diagnosis (p trend 0.040). The risk of kidney cancer increased along with decreasing age of US diagnosis (p trend 0.004) and short time since the US diagnosis (p trend 0.018). CONCLUSIONS: Our study demonstrated increased risk of certain cancers following a diagnosis of US. The elevated risk for breast cancer may indicate shared hormonal aetiology, while the increased risk of colorectal and bladder cancers after US may be caused by radiation therapy of US. The clustering of smoking-related cancers after US is worth exploring in the future.

Incidence of anogenital warts after the introduction of the quadrivalent HPV vaccine program in Manitoba, Canada.

BACKGROUND: The incidence of anogenital warts (AGW) decreased after the introduction of the quadrivalent human papillomavirus (qHPV) vaccine in multiple jurisdictions. We studied how comparing AGW incidence rates with different outcomes affects the interpretation of the qHPV vaccination program. To do this, we replicated multiple study designs within a single jurisdiction (Manitoba). METHODS: We measured the incidence rates of AGW, AGW-related prescriptions, chlamydia, and gonorrhea (the latter two as sham outcomes) between 2001 and 2017 using several clinical and administrative health databases from Manitoba. We then used incidence rate ratios (IRRs) to compare, for each outcome, the rate for the 1997-1998 birth cohort (the first cohorts eligible for the publicly funded qHPV vaccination program) and the older 1995-1996 birth cohort. RESULTS: AGW incidence in Manitoba dropped 72% (95% confidence interval 54-83%) among 16-18 year-old girls and 51% (14-72%) among boys after the introduction of the female-only qHPV vaccination program. Trends in AGW-related prescriptions were different from trends in AGW diagnoses as these prescriptions peaked shortly after the introduction of the publicly funded qHPV vaccine program. Chlamydia and gonorrhea incidence rates also decreased 12% (5-18%) and 16% (-1-30%), respectively, for 16-18 year-old girls. CONCLUSIONS: The publicly funded school-based qHPV vaccine program reduced AGW incidence in Manitoba by three-quarters in young females. AGW-related prescriptions are a poor proxy for medically attended AGW after the introduction of the publicly funded qHPV vaccination program. Different sexual habits in adolescents are, at most, responsible for a small portion of the reduction in AGW incidence.

Second malignancies after childhood noncentral nervous system solid cancer: Results from 13 cancer registries.

Children diagnosed with noncentral nervous system solid cancers (NCNSSC) experience several adverse late effects, including second malignant neoplasm. The aim of our study was to assess the risk of specific second malignancies after a childhood NCNSSC. Diagnosis and follow-up data on 10,988 cases of NCNSSC in children (0-14 years) were obtained from 13 registries. Standardized incidence ratios (SIRs) with 95% confidence intervals (CI) and cumulative incidence of second malignancies were computed. We observed 175 second malignant neoplasms, yielding a SIR of 4.6, 95% CI: 3.9-5.3. When considering second cancers with at least 10 occurrences, highest relative risks were found for second malignant bone tumors (SIR = 26.4, 16.6-40.0), soft tissue sarcomas (SIR = 14.1, 6.7-25.8) and myeloid leukemia (SIR = 12.7, 6.3-22.8). Significant increased risks for all malignancies combined were observed after sympathetic nervous system tumors (SIR = 11.4, 5.2-21.6), retinoblastomas (SIR = 7.3, 5.4-9.8), renal tumors (SIR = 5.7, 3.8-8.0), malignant bone tumors (SIR = 5.6, 3.7-8.2), soft tissue sarcomas (SIR = 4.7, 3.2-6.8), germ-cell, trophoblastic and other gonadal neoplasms (SIR = 2.5, 1.1-4.9), carcinomas and other malignant epithelial neoplasms (SIR = 2.2, 1.4-3.3). The highest risk of a second malignancy of any type occurred 5 to 9 years after NCNSSC (SIR = 9.9, 6.8-13.9). The cumulative incidence of second malignancies 10 years after the first neoplasm was eight times higher among NCNSSC survivors than in the general population, with the absolute difference between observed and expected cumulative incidence still increasing after 50 years of follow-up. Children who survived a NCNSSC experience a large increased risk of developing a new malignancy, even many years after their initial diagnosis.

High constant incidence rates of second primary cancers of the head and neck: a pooled analysis of 13 cancer registries.

Scanty data are available on the incidence (i.e., the absolute risk) of second cancers of the head and neck (HN) and its pattern with age. We investigated this issue using data from a multicentric study of 13 population-based cancer registries from Europe, Canada, Australia and Singapore for the years 1943-2000. A total of 99,257 patients had a first primary HN cancer (15,985 tongue, 22,378 mouth, 20,758 pharyngeal, and 40,190 laryngeal cancer), contributing to 489,855 person-years of follow-up. A total of 1,294 of the patients (1.3%) were diagnosed with second HN cancers (342 tongue, 345 mouth, 418 pharynx and 189 larynx). Male incidence rates of first HN cancer steeply increased from 0.68/100,000 at age 30-34 to 46.2/100,000 at age 70-74, and leveled off at older age; female incidence increased from 0.50/100,000 at age 30-34 to 16.5/100,000 at age 80-84. However, age-specific incidence of second HN cancers after a first HN cancer in men was around 200-300/100,000 between age 40-44 and age 70-74 and tended to decline at subsequent ages (150/100,000 at age 80-84); in women, incidence of second HN cancers was around 200-300/100,000 between age 45-49 and 80-84. The patterns of age-specific incidence were consistent for different subsites of second HN cancer and sexes; moreover, they were similar for age-specific incidence of first primary HN cancer in patients who subsequently developed a second HN cancer. The incidence of second HN cancers does not increase with age, but remains constant, or if anything, decreases with advancing age.

The reduction in colorectal cancer mortality after colonoscopy varies by site of the cancer.

BACKGROUND & AIMS: There are limited data on mortality from colorectal cancer (CRC) among patients who have received colonoscopy examinations. We sought to determine CRC mortality among persons undergoing colonoscopies compared with the general population. METHODS: We identified all individuals who had a colonoscopy as their first lower gastrointestinal endoscopy from April 1, 1987, to September 30, 2007 (24,342 men and 30,461 women), based on information from Manitoba's provincial physicians' billing claims database. Patients were followed until March 31, 2008, death, or migration out of the province (310,718 person-years). Individuals less than 50 years of age or more than 80 years of age at the index colonoscopy or those with prior sigmoidoscopy, inflammatory bowel disease, resective colorectal surgery, or CRC were excluded. CRC mortality after the index colonoscopy was compared with that of the general population by standardized mortality ratios (SMRs). Stratified analyses were performed to determine CRC mortality for different age groups at index colonoscopy and sex, duration of follow-up, medical specialty of the endoscopist, and site of CRC. RESULTS: There was a 29% reduction in overall CRC mortality (SMR, 0.71; 95% confidence interval [CI], 0.61-0.82], a 47% reduction in mortality from distal CRC (SMR, 0.53; 95% CI, 0.42-0.67), and no reduction in mortality from proximal CRC (SMR, 0.94; 95% CI, 0.77-1.17). The reduction in mortality from distal CRC remained significant for follow-up beyond 10 years (SMR, 0.53; 95% CI, 0.31-0.84). CONCLUSIONS: In Manitoba, colonoscopies significantly reduce mortality from CRC, but the benefit is not uniform for colorectal tumors that arise in different areas of the colon.

Risk of cervical abnormalities in women with inflammatory bowel disease: a population-based nested case-control study.

BACKGROUND & AIMS: We evaluated the risk of cervical abnormalities in women with inflammatory bowel disease (IBD) in a population-based, nested, case-control study. METHODS: Cases with abnormal Papanicolaou (Pap) smears or cervical biopsies were matched with up to 3 controls (normal Pap smears) by year of birth, year of first health care coverage, and number of Pap smears in the preceding 5 years. A diagnosis of IBD before the index date was identified from the University of Manitoba IBD Epidemiology Database. Exposures to immunosuppressant drugs and corticosteroids were determined from the provincial drug prescription database. Analyses were adjusted for socioeconomic status and exposure to oral contraceptives and nonsteroidal anti-inflammatory drugs. RESULTS: 19,692 women with cervical cytologic and/or histologic abnormalities were matched with 57,898 controls with normal Pap smears. There was no association between cervical abnormalities and ulcerative colitis (odds ratio [OR], 1.03; 95% confidence interval [CI], 0.77-1.38). The increase in risk in women with Crohn's disease was limited to those exposed to 10 or more prescriptions of oral contraceptives (OR, 1.66; 95% CI, 1.08-2.54). The combined exposure to corticosteroids and immunosuppressants was associated with increased risk of cervical abnormalities (OR, 1.41; 95% CI, 1.09-1.81). There was no interaction between the effect of IBD and corticosteroids and/or immunosuppressants. CONCLUSIONS: These findings do not support an association between IBD itself and the risk of developing cervical abnormalities. An increased risk in patients given a combination of corticosteroids and immunosuppressants should be considered in managing women with IBD.

Examining the Impact of First Nations Status on the Relationship Between Diabetes and Cancer.

Purpose: This population-based study examined the relationship between diabetes and cancer and determined if this relationship was influenced by First Nations (FN) status. Methods: In a matched case-cohort study, individuals 30-74 years of age diagnosed with diabetes during 1984-2008 in the province of Manitoba, Canada, with no cancer diagnosis before their diabetes diagnosis were matched to one diabetes-free control by age, sex, FN status, and residence. Flexible competing risk and Royston-Parmar regression models were used to compare cancer rates. Results: Overall, 72,715 individuals diagnosed with diabetes were matched to controls. In all age groups, diabetes was related to an increased risk of cancer. The relationship between diabetes and any type of cancer was not influenced by FN status (i.e., there was no interaction between the diagnosis of diabetes and people's FN status for any age group). The only significant interaction between diabetes and FN status was for kidney cancer for individuals 60-74 years of age; diabetes increased the risk of kidney cancer for all other Manitobans (AOMs) but not for FN. Conclusions: Diabetes increased the risk of cancer. The association was not modified by FN status except for kidney cancer where diabetes increased the risk for AOMs but not for FN.

Trends in Prescribing Menopausal Hormone Therapy and Bisphosphonates in Australia and Manitoba, Canada and Adherence to Recommendations.

Background: Recommendations for using menopausal hormone therapy (MHT) and bisphosphonates for postmenopausal osteoporosis management have changed over time. After the release of the Women's Health Initiative (WHI) trial results in 2002, new evidence on risks and benefits of MHT became available, and newer guidelines generally specify that MHT should not be prescribed for prevention of chronic disease, including osteoporosis. This raises the question of whether bisphosphonate prescribing changed over time to compensate for the decrease in MHT use. Materials and Methods: We examined trends in dispensed prescriptions in Australia (national) and Canada (province of Manitoba) in relation to prescribing recommendations. Administrative data were used to describe dispensing patterns and changes for persons of all ages from 1996 to 2008, and for women aged 50 to ≥80 years from 2003 to 2008 in Australia and 1996 to 2008 in Canada. Results: In both geographic settings, MHT dispensing increased 1996-2001, peaked in 2001, and declined substantially thereafter (67% reduction in MHT prescriptions for Australia; 64% reduction for Manitoba, Canada to 2008). From 2003 to 2008, the number of MHT prescriptions declined among all age groups in both settings, with the highest declines among women in their 50s. Concurrently, bisphosphonate dispensing increased until 2005 (2001-2005: 260% increase in the number of prescriptions in Australia; 125% increase in Manitoba) and stabilized thereafter, in both settings. Annual bisphosphonate dispensing rates increased 4.1-10.9% for women in their 70s and 80s in Australia and Manitoba during the period studied. Conclusions: Based on dispensed prescriptions data, more recent guidelines for MHT and bisphosphonates use for postmenopausal osteoporosis, which were updated during the study period (and are still consistent with the current guidelines), appear to have been broadly adhered to in both settings.

Twenty-year trends in the incidence and prevalence of diagnosed anogenital warts in Canada.

BACKGROUND: A vaccine has recently been licensed in many countries that protects against the human papillomavirus types 6, 11, 16, and 18. Types 6 and 11 account for approximately 90% of anogenital warts (AGWs). We describe the 20-year trends in the incidence and prevalence of AGWs in Manitoba, Canada. METHODS: We used linked population-based hospital and physician databases for Manitoba for 1984 to 2004. Cases were identified using tariff (billing) and ICD codes. A case was considered to be incident if it was preceded by a 12-month interval free period of AGWs care. Otherwise, it was deemed to be prevalent. An episode was considered over once a 12-month interval had elapsed without an AGW claim. RESULTS: Approximately 25,000 Manitobans were diagnosed with AGWs between 1985 and 2004. The annual age-standardized incidence rates peaked in 1992 (men, 149.9/100,000; women 170.8/100,000). In recent years, the rates have been increasing again, particularly for men. The male:female incidence rate ratio increased from 0.76 in 1985 to 1.25 in 2004. The highest incidence rate tended to be in those aged 20 to 24 years. Trends in prevalence were similar. Prevalence in 2004 was 165.2/100,000 for men and 128.4/100,000 for women. CONCLUSIONS: These population-based findings suggest that AGWs are a substantial burden to Manitobans and that their pattern has changed over time, with incidence and prevalence becoming higher in men than women. Monitoring the future trends in AGWs will provide an early marker of the effectiveness and duration of protection of human papillomavirus vaccination at a population level.

Breast cancer incidence by country of birth among immigrant women in British Columbia, Canada.

INTRODUCTION: Breast cancer rates vary internationally and between immigrant and non-immigrant populations. We describe breast cancer incidence by birth region and country in British Columbia, Canada. METHODS: We linked population-based health and immigration databases for a population with >1.29 million immigrants to assess breast cancer incidence among immigrant and non-immigrant women. We report age-standardized incidence ratios (SIRs) by birth region and country using non-immigrant women as the standard. RESULTS: SIRs varied widely by both birth country and region. Low rates were found for South (SIR = 0.52, 95% CI: 0.47,0.59) and East Asian (SIR = 0.75, 95% CI: 0.72,0.79) women and a higher rate for Western Europeans (SIR = 1.15, 95% CI: 1.01,1.30). CONCLUSION: There is considerable variation in SIRs across some of British Columbia's largest immigrant populations and several demonstrate significantly different risk profiles compared to non-immigrants. These findings provide unique data to support breast cancer prevention and control.

Risk of second primary cancer among patients with head and neck cancers: A pooled analysis of 13 cancer registries.

The objective of the study was to assess the risk of second primary cancers (SPCs) following a primary head and neck cancer (oral cavity, pharynx and larynx) and the risk of head and neck cancer as a SPC. The present investigation is a multicenter study from 13 population-based cancer registries. The study population involved 99,257 patients with a first primary head and neck cancer and contributed 489,855 person-years of follow-up. To assess the excess risk of SPCs following head and neck cancers, we calculated standardized incidence ratios (SIRs) by dividing the observed numbers of SPCs by the expected number of cancers calculated from accumulated person-years and the age-, sex- and calendar period-specific first primary cancer incidence rates in each of the cancer registries. During the observation period, there were 10,826 cases of SPCs after head and neck cancer. For all cancer sites combined, the SIR of SPCs was 1.86 (95% CI = 1.83-1.90) and the 20-year cumulative risk was 36%. Lung cancer contributed to the highest proportion of the SPCs with a 20-year cumulative risk of 13%. Excess second head and neck cancer risk was observed 10 years after diagnosis with lymphohaematopoietic cancers. The most common SPC following a first primary head and neck cancer was lung cancer. However, the highest excess of SPCs was in the head and neck region. These patterns were consistent with the notion that the pattern of cancer in survivors of head and neck cancer is dominated by the effect of tobacco smoking and alcohol drinking.

Risk of second primary cancer among esophageal cancer patients: a pooled analysis of 13 cancer registries.

BACKGROUND: The objective of this study is to assess the risk of second primary cancers following a first primary esophageal cancer as well as the risk of esophageal cancer as a second primary, following first primary cancers of other sites. METHODS: The present investigation is a multicenter study of 13 population-based cancer registries in Europe, Australia, Canada, and Singapore. To assess excess occurrence of second cancers after esophageal cancers, we calculated standardized incidence ratios (SIR) by dividing the observed numbers of second cancers by the expected number of cancers calculated from the accumulated person-years and the age-, sex-, calendar period-, and registry-specific first primary cancer incidence rates. RESULTS: During the study period, 959 cases of second primary cancers occurred after an initial esophageal cancer, resulting in a SIR of 1.15 (95% confidence interval, 1.08-1.22). Second primary stomach cancers were associated with first primary esophageal adenocarcinomas (SIR, 2.13; 95% confidence interval, 1.26-3.37) and second primary cancers of the oral cavity and pharynx (6.68; 5.33-8.26), stomach (1.53; 1.14-2.01), larynx (3.24; 1.88-5.18), lung (1.55; 1.28-1.87), kidney (1.88; 1.18-2.85), and thyroid (2.92; 1.18-6.02) were associated with first primary squamous cell carcinomas of the esophagus. An excess of esophageal cancer as a second primary were observed following first primary cancers of the aerodigestive tract, female breast, cervix, testis, bladder, Hodgkin's lymphoma, and non-Hodgkin lymphoma. CONCLUSION: We observed associations of esophageal cancer with second primary head and neck cancers and lung cancer regardless of years of follow-up, which may suggest that common risk factors play a role in multiple tumor development.

Breast screening participation and retention among immigrants and nonimmigrants in British Columbia: A population-based study.

Breast cancer screening programs operate across Canada providing mammography to women in target age groups with the goal of reducing breast cancer mortality through early detection of tumors. Disparities in breast screening participation among socio-demographic groups, including immigrants, have been reported in Canada. Our objectives were to: (1) assess breast screening participation and retention among immigrant and nonimmigrant women in British Columbia (BC), Canada; and (2) to characterize factors associated with screening among screening-age recent immigrant women in BC. We examined 2 population-based cohorts of women eligible for breast screening participation (537 783 women) and retention (281 052 women) using linked health and immigration data. Breast screening rates were presented according to socio-demographic and health-related variables stratified by birth country. Factors associated with screening among recent immigrant women were explored using Poisson regression. We observed marked variation in screening participation across birth country cohorts. Eastern European/Central Asian women showed low participation (37.9%) with rates from individual countries ranging from 35.0% to 49.0%. Participation rates for immigrant women from the most common birth countries, such as China/Macau/Hong Kong/Taiwan (45.7%), India (44.5%), the Philippines (45.9%), and South Korea (39.0%), were lower than the nonimmigrant rates (51.2%). Retention rates showed less variation by birth country; however, some disparities between immigrant and nonimmigrant groups persisted. Associations between screening indicators and study factors varied considerably across immigrant groups. Primary care physician visits were consistently positively associated with screening participation; this variable was also the only predictor associated with screening within each of the groups of recent immigrants. Our study provides unique data on both screening participation and retention among Canadian immigrant women compiled by individual country of birth. Our results are further demonstration that screening disparities exist among immigrant populations as well as in comparison with nonimmigrant women.