Impact of the National Cervical Screening Programme in New Zealand by age: analysis of cervical cancer trends 1985–2013 in all women and in Māori women

Background

New Zealand is an example of a country with a well-established cytology-based screening program. New Zealand’s National Cervical Screening Programme (NCSP) commenced in 1990, and recommends three-yearly cytology-based screening for women aged 20–69 years. In 2018, the NCSP will transition to five-yearly HPV-based screening for women aged 25–69 years. The aim of this study was to assess the impact of the program to date in different groups, to provide a benchmark for the new program.

Methods

Analysis of cervical cancer trends in New Zealand by age and ethnicity over the period 1985–2013, and by morphology over the period 1997–2013, using data from the New Zealand Cancer Registry was conducted.

Results

The overall incidence of cervical cancer was 56% (95% CI 51–60%) lower in 2009–2013 than in 1985–1989, and significant reductions were observed in women aged 25–49, 50–69, and 70?+?years. Relative reductions in cervical cancer were very similar for Māori and non-Māori women aged 25–49 (50% in Māori; 52% in non-Māori) and 50–69 years (65% in Māori; 69% in non-Māori). In contrast, incidence appeared to increase after around 1996 in women aged 20–24. The increasing trend was significant for women aged 20–24 overall and for non-Māori women (p?<?0.01 in both cases).

Conclusion

There have been substantial reductions in cervical cancer among women aged 25?+?years in New Zealand since the inception of the NCSP, and these reductions are similar in Māori and non-Māori women. Cervical cancer incidence among women 20–24 years has not declined since the NCSP began, and appears to be increasing.

     

Cervical cancer screening in Korea: report on the National Cancer Screening Programme in 2008

The National Cancer Screening Programme (NCSP) began in 1999. The purpose of this report is to evaluate the results of the NCSP for cervical cancer in 2008 and to present essential evidence associated with the cervical cancer screening programme in Korea. Screening results were obtained from the National Cancer Screening Information System. Participation rates and recall rates were calculated with 95% confidence intervals (CIs). The target population of the cervical cancer screening programme in 2008 was 4,701,167 Korean women aged 30 and over, 1,208,581 of whom underwent Papanicolaou (Pap) smear tests (25.7% participation rate). The recall rate was 0.41% (95% CI, 0.40 to 0.42). Although efforts to facilitate participation and to reduce disparities in cervical cancer screening among Korean women are needed, the results do provide support for evidence-based strategies for control of cervical cancer in Korea.     

Cervical Cancer Screening Among Adult Women in China, 2010

Introduction.

Cervical cancer is one of the most commonly diagnosed cancers among women in China. The World Health Organization (WHO) recommends routine screening for cervical cancer, and the WHO Global Monitoring Framework suggests that every nation monitors cervical cancer screening. However, little information is available on cervical cancer screening behavior among women in China.

Methods.

We used data from the 2010 China Chronic Disease and Risk Factor Surveillance System that included 51,989 women aged 18 years and older. We report the proportion of women who reported ever having had a Papanicolaou (Pap) test, stratified by sociodemographic characteristics and geographic region. Multivariable logistic regression modeling was performed to adjust for potential confounders.

Results.

Overall, 21% of 51,989 women reported having ever had a Pap test. The highest proportion was reported among women aged 30–39 years (30.1%, 95% confidence interval, 26.8%–33.4%). In all geographic regions, women in rural areas were consistently less likely than women in urban areas to report having had a Pap test. Among women who reported ever having a Pap test, 82% reported having the most recent test in the past 3 years. Factors associated with reporting ever having a test were being aged 30–49 years, higher education, being married, and having urban health insurance.

Conclusion.

Our results indicate that screening programs need to be strengthened along with a more intense focus on specific demographic groups. National cervical cancer screening guidelines and comprehensive implementation strategies are needed to make screening services available and accessible to all women.

Implications for Practice:

This study is the largest nationwide and population-based assessment of self-reported history of Pap test for cervical cancer screening in China. This article describes cervical cancer screening behavior among women and examines key demographic and geographic factors. Only one fifth of Chinese women reported having ever had a Pap test for cervical cancer screening. The results highlight the urgent need to develop national cervical cancer screening guidelines and strategies that make screening services widely available, accessible, and acceptable to all women, especially to those who reside in rural areas and those with no health insurance.     

Benefits and harms of cervical screening from age 20 years compared with screening from age 25 years

Background:

To quantify the benefits (cancer prevention and down-staging) and harms (recall and excess treatment) of cervical screening starting from age 20 years rather than from age 25 years.

Methods:

We use routine screening and cancer incidence statistics from Wales (for screening from age 20 years) and England (screening from 25 years), and unpublished data from the National Audit of Invasive Cervical Cancer to estimate the number of: screening tests, women with abnormal results, referrals to colposcopy, women treated, and diagnoses of micro-invasive (stage 1A) and frank-invasive (stage IB+) cervical cancers (under three different scenarios) in women invited for screening from age 20 years and from 25 years.

Results:

Inviting 100 000 women from age 20 years yields an additional: 119 000 screens, 20 000 non-negative results, 8000 colposcopy referrals, and an extra 3000 women treated when compared with inviting from age 25 years. Screening from age 20 years prevents between three and nine frank invasive cancers and between 0 and 23 cancers in total (depending on the scenario). A cumulative increase of nine stage IB+ cancers corresponds to an annual rate increase of 0.9 per 100 000 women aged 20–29 years.

Conclusions:

To prevent one frank invasive cancer, one would need to do between 12 500 and 40 000 additional screening tests in the age group 20–24 years and treat between 300 and 900 women.     

Reduction in interval cancer rates following the introduction of two-view mammography in the UK breast screening programme

Background:

The introduction of two-view mammography at incident (subsequent) screens in the National Health Service Breast Screening Programme (NHSBSP) has led to an increased number of cancers detected at screen. However, the effect of two-view mammography on interval cancer rates has yet to be assessed.

Methods:

Routine screening and interval cancer data were collated from all screening programmes in the United Kingdom for women aged 50–64, screened between 1 April 2003 and 31 March 2005. Interval cancer rates were compared based on whether two-view mammography was in use at the last routine screen.

Results:

The reduction in interval cancers following screening using two-view mammography compared with one view was 0.68 per 1 000 women screened. Overall, this suggests the introduction of two-view mammography at incident screen was accompanied by a 15–20% reduction in interval cancer rates in the NHSBSP.

Conclusion:

The introduction of two-view mammography at incident screens is associated with a reduction in incidence of interval cancers. This is consistent with previous publications on a contemporaneous increase in screen-detected cancers. The results provide further evidence of the benefit of the use of two-view mammography at incident screens.     

Identifying barriers to Papanicolaou smear screening in Korean women: Korean National Health and Nutrition Examination Survey 2005

Objective

This study was conducted to provide a nationwide analysis on barriers to cervical cancer screening in Korea.

Methods

Data used for this study was obtained in a survey called Korean National Health and Nutrition Examination Survey (KNHANES) 2005, which collected data from 2,590 Korean women aged older than 21 years who had not had a hysterectomy and were eligible for Papanicolaou (Pap) smears. Multivariate analysis was adopted to control each demographic factor and unhealthy behavior variable. Demographic factors included age, education, income, job and region; health-related behavior factors were defined as current smoking, obesity, hormone replacement therapy and disability.

Results

The study found that cervical cancer screening rate was significantly positively associated with income (odds ratio [OR], 1.002; 95% confidence interval [CI], 1.001 to 1.002), with education (OR, 1.324; 95% CI, 1.030 to 1.703), with job (OR, 1.420; 95% CI, 1.030 to 1.957), and with hormone replacement therapy (OR, 3.732; 95% CI, 2.354 to 5.916). Meanwhile, the age (OR, 0.977; 95% CI, 0.968 to 0.985), disability (OR, 0.358; 95% CI, 0.143 to 0.894) and smoking (OR, 0.447; 95% CI, 0.280 to 0.715) were significantly negatively associated with one''s chances to take cervical cytology.

Conclusion

In order to increase the rates of Korean women taking Pap test, cervical cancer screening programs will have to pay special attention to the elderly, low-income group, smokers, and the disabled.     

Cervical cancer incidence in young women: a historical and geographic controlled UK regional population study

Background:

The commencing age of cervical screening in England was raised from 20 to 25 years in 2004. Cervical cancer incidence in young women of England is increasing. It is not clear if this is due to either greater exposure to population risk factors or reduced cervical screening.

Methods:

We measured if the relative risk of cervical cancer in younger women (20–29 years) of the north-east of England (NE) differed to that of women aged 30yrs and above since 2004. We also measured average annual percentage change (AAPC) in the 3 yr moving average incidence for all age-groups. Regional screening coverage rate and population risk factors were reviewed. Comparisons were made with Wales where screening continues to commence from the age of 20 yrs.

Results:

Cervical cancer incidence in women aged 20–29 increased annually by an average of 10.3% between 2000 and 2009. The rise in women aged 30–39 was less steep (3.5%/year) but no significant rise was observed in women aged 40–49. Socioeconomic factors remained stable or improved during the time period except for the incidence of chlamydia, herpes simplex and in particular, genital warts, which increased significantly in young women. Data from Wales show similar results.

Conclusion:

The incidence of cervical cancers in young women of the NE is increasing. The rise in incidence is unrelated to the change in screening policy in 2004. Close monitoring of incidence in young women and a greater attempt to reverse the current decline in screening coverage of women aged 25–29 years are recommended.     

Current Cervical Cancer Screening Knowledge,Awareness, and Practices Among U.S. Affiliated Pacific Island Providers: Opportunities and Challenges

Background.

Cervical cancer is a leading cause of cancer mortality in nearly all U.S. Affiliated Pacific Island Jurisdictions (USAPIJ); however, most jurisdictions are financially and geographically limited in their capacity to deliver routine screening.

Methods.

We conducted a cross-sectional survey of 72 health care providers from five of the six USAPIJ in 2011 to assess knowledge, beliefs, practices, and perceived barriers regarding routine cervical cancer screening. We compared the responses of providers from jurisdictions that were funded by the Centers for Disease Control and Prevention’s National Breast and Cervical Cancer Early Detection Program (NBCCEDP) with those that were not funded.

Results.

Most providers reported cervical cancer prevention as a priority in their clinical practices (90.3%) and use the Papanicolaou test for screening (86.1%). Many providers reported knowledge of screening guidelines (76.4%); however, more than half reported that annual screening is most effective (56.9%). Providers in non-NBCCEDP-funded jurisdictions reported greater acceptance of visual inspection with acetic acid (93.9%) and self-sampling for human papillomavirus testing (48.5%) compared with NBCCEDP-funded jurisdictions (15.4% and 30.8% respectively). Providers from non-NBCCEDP-funded jurisdictions reported inadequate technological resources for screening women (42.4%), and approximately 25% of providers in both groups believed that screening was cost-prohibitive.

Conclusion.

Although cervical cancer screening is a priority in clinical practice, beliefs about annual screening, costs associated with screening, and varying levels of support for alternative screening tests pose barriers to providers throughout the USAPIJ. Further exploration of using evidence-based, lower cost, and sustainable screening technologies is warranted in addition to emphasizing timely follow-up of all positive cases.     

Characteristics and screening history of women diagnosed with cervical cancer aged 20–29 years

Background:

There was concern that failure to screen women aged 20–24 years would increase the number of cancers or advanced cancers in women aged 20–29 years. We describe the characteristics of women diagnosed with cervical cancer in England aged 20–29 years and examine the association between the period of diagnosis, screening history and FIGO stage.

Methods:

We used data on 1800 women diagnosed with cervical cancer between April 2007 and March 2012 at age 20–29 from the National Audit of Invasive Cervical Cancers.

Results:

The majority of cancers (995, or 62% of those with known stage) were stage 1A. Cancer at age 20–24 years was rare (12% of those aged 20–29 years), when compared with age 25 (24%) and age 26–29 years (63%); however, cancers in women aged 20–24 years tended to be more advanced and were more often of a rare histological type. For 59% of women under age 30, the cervical cancer was screen detected, most of them (61%) as a result of their first screening test. A three-fold increase in the number of cancers diagnosed at age 25 years was seen since the start of the study period.

Conclusion:

Cervical cancer at age 20–24 years is rare. Most cancers in women under age 30 years are screen detected as microinvasive cancer.     

Factors associated with attending the National Cancer Screening Program for liver cancer in Korea

Background and Aims: The National Cancer Screening Program (NCSP) for liver cancer was initiated in 2003 in Korea. The objective of this study was to evaluate the participation rate of the program and to provide preliminary information on its results based on data collected by the NCSP in 2009. Methods: The target population of the NCSP for liver cancer in 2009 was comprised of 373,590 adults aged ≥40 years at high risk for liver cancer. Participation rates and positivity rates were assessed in this population. Multivariate logistic regression analysis was performed to determine the factors associated with participation in the NCSP for liver cancer. Results: The overall participation rate was 37.9% and 1,126 participants were positive at screening. The highest participation rates were observed in women, those in their 60s, National Health Insurance beneficiaries, and individuals positive for hepatitis B surface antigen. Positivity rates for men, those in their 70s, Medical Aid Program recipients and individuals with liver cirrhosis were the highest in the respective categories of gender, age, health insurance type, and risk factor for liver cancer. Conclusions: The participation rates of the NCSP for liver cancer are still low, despite the fact that the program targets a high-risk group much smaller than the general population. Efforts to facilitate participation and to reduce disparities in liver cancer screening among Korean men and women are needed. These results provide essential data for evidence-based strategies for liver cancer control in Korea.     

Single-visit approach of cervical cancer screening: See and Treat in Indonesia

Background:

We performed a cross-sectional study in Indonesia to evaluate the performance of a single-visit approach of cervical cancer screening, using visual inspection with acetic acid (VIA), histology and cryotherapy in low-resource settings.

Methods:

Women having limited access to health-care facilities were screened by trained doctors using VIA. If the test was positive, biopsies were taken and when eligible, women were directly treated with cryotherapy. Follow-up was performed with VIA and cytology after 6 months. When cervical cancer was suspected or diagnosed, women were referred. The positivity rate, positive predictive value (PPV) and approximate specificity of the VIA test were calculated. The detection rate for cervical lesions was given.

Results:

Screening results were completed in 22 040 women, of whom 92.7% had never been screened. Visual inspection with acetic acid was positive in 4.4%. The PPV of VIA to detect CIN I or greater and CIN II or greater was 58.7% and 29.7%, respectively. The approximate specificity was 98.1%, and the detection rate for CIN I or greater was 2.6%.

Conclusion:

The single-visit approach cervical cancer screening performed well, showing See and Treat is a promising way to reduce cervical cancer in Indonesia.     

Cervical Cancer‐Related Knowledge,Attitudes, and Practices of Health Professionals Working in Brazil's Network of Primary Care Units

Introduction.

Brazil’s national strategy for cervical cancer screening includes using the Papanicolaou (Pap) test every 3 years among women aged 25–64 years. Comprehensive primary care services are provided through a network of primary health units, but little is known about cervical cancer-related knowledge, attitudes, and practices among health professionals and coordinators working in these facilities.

Methods.

In 2011, we conducted a cross-sectional nationally representative phone survey of 1,600 primary health care units to interview one unit coordinator and one health care professional per unit (either nurse, physician, or community health worker). Responses were obtained from 1,251 coordinators, 182 physicians, 347 nurses, and 273 community health workers. Questionnaires were administered to assess health units’ characteristics and capacity for cervical cancer-related services as well as health professionals’ perceived effectiveness of the Pap test, preparedness to talk to women about cervical cancer, adherence with screening guidelines, and willingness to recommend human papillomavirus (HPV) vaccination to females.

Results.

Most units conducted screening (91.9%), used home visits to conduct recruitment and outreach (83.4%), and provided follow-up to women who did not return to discuss Pap test results (88.1%). Approximately 93% of health professionals stated that Pap testing was effective in decreasing death rates from cervical cancer and 65% stated that national guidelines for cervical cancer screening are very influential; 93% of nurses and physicians reported screening women annually and 75% reported beginning to screen women younger than 25 years old. Regarding HPV vaccination, almost 90% of nurses and physicians would recommend the HPV vaccine to their females patients if it were available. A larger proportion of physicians and nurses recommended the HPV vaccine to older girls (13–18 years) and women (19–26 years and even older than 26 years) than to younger girls (12 years or younger).

Conclusion.

Although Brazil’s network of primary care units has significantly increased access to cervical cancer screening, effective strategies are needed to ensure that women get screened at the appropriate ages and intervals. Additionally, this study’s baseline data on HPV vaccination may be useful as Brazil embarks on a national HPV vaccination program in 2014.     

Exploring Knowledge,Attitudes, and Practices Related to Breast and Cervical Cancers in Mongolia: A National Population‐Based Survey

Background.

Mongolia bears the second-highest cancer burden in the world (5,214 disability-adjusted life years per 100,000 people, age standardized). To determine drivers of the growing burden of noncommunicable diseases, including breast and cervical cancers, a national knowledge, attitudes, and practices (KAP) survey was implemented in 2010.

Methods.

This paper analyzed the results of the 2010 KAP survey, which sampled 3,450 households nationally. Reflecting Mongolian screening policies, women aged 30 and older were included in analyses of questions regarding breast and cervical cancer (n = 1,193). Univariate and multivariate odds ratios (MORs) were derived through logistic regression to determine associations between demographic covariables (residence, age, education, employment) and survey responses.

Results.

This study found that 25.7% (95% confidence interval [CI]: 23.3–28.3) and 22.1% (95% CI: 19.8–24.5) of female participants aged 30 years or older self-rated their knowledge of breast and cervical cancers, respectively, as “none.” Employment and education were associated with greater awareness of both cancers and participation in screening examinations (p < .05). Clinical breast examinations were more common among rural than urban participants (MOR: 1.492; 95% CI: 1.125–1.979). Of all female participants, 17% (95% CI: 15.3–18.5) knew that cervical cancer is vaccine preventable.

Conclusion.

Our results suggest that cancer control in Mongolia should emphasize health education, particularly among lower-educated, rural, and unemployed women. The health infrastructure should be strengthened to reflect rural to urban migration. Finally, although there is awareness that early detection improves outcomes, a significant proportion of women do not engage in screening. These trends warrant further research on barriers and solutions.

Implications for Practice:

The rising burden of breast and cervical cancers, particularly in low- and middle-income countries, necessitates the development of effective strategies for cancer control. This paper examines barriers to health service use in Mongolia, a country with a high cancer burden. The 2010 national knowledge, attitude and practices survey data indicate that cancer control efforts should focus on improving health education among lower-educated, rural, and unemployed populations, who display the least knowledge of breast and cervical cancers. Moreover, the findings support the need to emphasize individual risk for disease in cancer education and ensure that the health-care infrastructure reflects Mongolia’s urbanization.     

A path for diagnosis and therapy of colon cancer: a continuous quality improvement

Objective

Prognosis of colorectal cancer strongly depends on stage at diagnosis, which can be cured in most cases at an early stage. The results were supported by different screening programmes. Few data concerning analysis of different phases of Colorectal Cancer Program were reported in literature. The aim of this study is to analyze “step by step”, from a longitudinal type, the Colorectal Cancer Program, active at our Institution, verifying compliance with standards of care.

Methods

We compared two different populations during the same period: patients referring to our Clinical Oncology Unit coming from Regional Colorectal Cancer Screening Program and the other population that was not in any Colorectal Cancer Program.

Results

Considering patients from the Regional Colorectal Cancer Screening Program (19 patients, corresponding to 24.0% of the general case study), 3 (15.8%) were deceased and 16 (84.2%) were alive without evidence of the disease (NED). Concerning patients that are not coming from Regional Colorectal Cancer Screening Program (61 patients, corresponding to 76.0% of the general case study), 9 (14.8%) were deceased, 43 (70.5%) were NED, 8 (13.1%) were alive with metastases and 1 (1.6%) was lost during follow-up (PFU).

Conclusions

On the basis of this experience, we concluded for high-quality care for both populations. Any critical point should be carefully analyzed in order to implement quality of care.     

Cervical cancer in the screening era: who fell victim in spite of successful screening programs?

Objective

To compare profiles of a prescreening and screening cohort of women with cervical cancer regarding histopathology and clinical variables in order to identify those remaining at risk despite successful screening programs. By analyzing these profiles we hope to improve future screening methods.

Methods

The prescreening and screening cohorts consisted of 5,046 and 1,174 women, respectively, treated for cervical cancer at the Department of Gynecological Oncology at Radiumhemmet, Karolinska University Hospital, during the periods 1944-1957 and 1990-2004.

Results

Mean age increased from 48.9 years to 55.3 years in the cohorts treated 1944-1957 and 1990-2004, respectively. The percentage of patients older than 69 years was 5.4% and 27.3% in the prescreening and screening period, respectively. A shift towards earlier stages at diagnosis, a reduction of squamous cervical cancer and an increase of adenocarcinoma were observed in the screening cohort. The percentage of adenocarcinoma was about 6 times higher among younger patients. Cases of stump cancer and cervical cancer associated with pregnancy have declined. Eighty-seven women in the screening cohort had a history of treatment for in situ carcinoma by conization; 28% of these cases developed cervical cancer within one year after conization.

Conclusion

The profile changed in the screening era indicating a need to refine screening for improved detection of in older women. This study, one of the largest clinical series of cervical cancer, provides an important baseline with which later studies can be compared to evaluate the effects of human papillomavirus vaccine and other important changes in this field.     

Interval cancers in the NHS breast cancer screening programme in England, Wales and Northern Ireland

Background:

The United Kingdom NHS Breast Screening Programme was established in 1988, and women aged between 50 and 70 are routinely invited at three yearly intervals. Expected United Kingdom interval cancer rates have been calculated previously, but this is the first publication from an exercise to collate individual-based interval cancer data at a national level.

Methods:

Interval cancer case ascertainment is achieved by the regular exchange of data between Regional Breast Screening Quality Assurance Reference Centres and Cancer Registries. The present analysis includes interval cancers identified in women screened between 1st April 1997 and 31st March 2003, who were aged between 50 and 64 at the time of their last routine screen.

Results:

In the periods >0–<12 months, 12–<24 months and 24–<36 months after a negative screen, we found overall interval cancer rates and regional ranges of 0.55 (0.43–0.76), 1.13 (0.92–1.47) and 1.22 (0.93–1.57) per 1000 women screened, respectively. Rates in the period 33–<36 months showed a decline, possibly associated with early re-screening or delayed presentation.

Conclusions:

Interval cancer rates were higher than the expected rates in the 24-month period after a negative screen, but were similar to published results from other countries. Increases in background incidence may mean that the expected rates are underestimated. It is also possible that, as a result of incomplete case ascertainment, interval cancers rates were underestimated in some regions in which rates were less than the expected.     

50 years of screening in the Nordic countries: quantifying the effects on cervical cancer incidence

Background:

Nordic countries'' data offer a unique possibility to evaluate the long-term benefit of cervical cancer screening in a context of increasing risk of human papillomavirus infection.

Methods:

Ad hoc-refined age-period-cohort models were applied to the last 50-year incidence data from Denmark, Finland, Norway and Sweden to project expected cervical cancer cases in a no-screening scenario.

Results:

In the absence of screening, projected incidence rates for 2006–2010 in Nordic countries would have been between 3 and 5 times higher than observed rates. Over 60 000 cases or between 41 and 49% of the expected cases of cervical cancer may have been prevented by the introduction of screening in the late 1960 s and early 1970 s.

Conclusions:

Our study suggests that screening programmes might have prevented a HPV-driven epidemic of cervical cancer in Nordic countries. According to extrapolations from cohort effects, cervical cancer incidence rates in the Nordic countries would have been otherwise comparable to the highest incidence rates currently detected in low-income countries.     

Breast and cervical cancer screening behaviours among colorectal cancer survivors in Nova Scotia

Purpose

We analyzed patterns and factors associated with receipt of breast and cervical cancer screening in a cohort of colorectal cancer survivors.

Methods

Individuals diagnosed with colorectal cancer in Nova Scotia between January 2001 and December 2005 were eligible for inclusion. Receipt of breast and cervical cancer screening was determined using administrative data. General-population age restrictions were used in the analysis (breast: 40–69 years; cervical: 21–75 years). Kaplan–Meier and Cox proportional hazards models were used to assess time to first screen.

Results

Of 318 and 443 colorectal cancer survivors eligible for the breast and cervical cancer screening analysis respectively, 30.1% [95% confidence interval (ci): 21.2% to 39.0%] never received screening mammography, and 47.9% (95% ci: 37.8% to 58.0%) never received cervical cancer screening during the study period. Receipt of screening before the colorectal cancer diagnosis was strongly associated with receipt of screening after diagnosis (hazard ratio for breast cancer screening: 4.71; 95% ci: 3.42 to 6.51; hazard ratio for cervical cancer screening: 6.83; 95% ci: 4.58 to 10.16).

Conclusions

Many colorectal cancer survivors within general-population screening age recommendations did not receive breast and cervical cancer screening. Future research should focus on survivors who meet age recommendations for population-based cancer screening.     

Parameter estimates for invasive breast cancer progression in the Canadian National Breast Screening Study

Background:

The aim of screening is to detect a cancer in the preclinical state. However, a false-positive or a false-negative test result is a real possibility.

Methods:

We describe invasive breast cancer progression in the Canadian National Breast Screening Study and construct progression models with and without covariates. The effect of risk factors on transition intensities and false-negative probability is investigated. We estimate the transition rates, the sojourn time and sensitivity of diagnostic tests for women aged 40–49 and 50–59.

Results:

Although younger women have a slower transition rate from healthy state to preclinical, their screen-detected tumour becomes evident sooner. Women aged 50–59 have a higher mortality rate compared with younger women. The mean sojourn times for women aged 40–49 and 50–59 are 2.5 years (95% CI: 1.7, 3.8) and 3.0 years (95% CI: 2.1, 4.3), respectively. Sensitivity of diagnostic procedures for older women is estimated to be 0.75 (95% CI: 0.55, 0.88), while women aged 40–49 have a lower sensitivity (0.61, 95% CI: 0.42, 0.77). Age is the only factor that affects the false-negative probability. For women aged 40–49, ‘age at entry'', ‘history of breast disease'' and ‘families with breast cancer'' are found to be significant for some of the transition rates. For the age-group 50–59, ‘age at entry'', ‘history of breast disease'', ‘menstruation length'' and ‘number of live births'' are found to affect the transition rates.

Conclusion:

Modelling and estimating the parameters of cancer progression are essential steps towards evaluating the effectiveness of screening policies. The parameters include the transition rates, the preclinical sojourn time, the sensitivity, and the effect of different risk factors on cancer progression.     

Age-specific risk of breast cancer in women with neurofibromatosis type 1

Background:

Young women with neurofibromatosis type 1 (NF1) are reported to have a higher risk of breast cancer than others, and this might have implications for screening programmes. Our aim was to calculate this risk.

Methods:

An all-England linked data set of hospital admissions and deaths was analysed to determine age-specific rates of breast cancer in women with NF1 and controls.

Results:

The age-specific excess risk of breast cancer, comparing the NF1 cohort with the control cohort, was elevated 6.5-fold (95% confidence interval 2.6–13.5) in women aged 30–39 years. There was a 4.4 (2.5–7.0) times higher risk among women aged 40–49.

Conclusions:

Women with NF1 develop breast cancer at younger ages than the general population.