Contribution of early detection and adjuvant treatments to breast cancer mortality reduction in Catalonia, Spain

Health utility values of breast cancer treatments and the impact of varying quality of life assumptions on cost-effectiveness

In breast cancer research, utility assumptions are outdated and inconsistent which may affect the results of quality adjusted life year (QALY) calculations and thereby cost-effectiveness analyses (CEAs). Four hundred sixty four female patients with breast cancer treated at Erasmus MC, the Netherlands, completed EQ-5D-5L questionnaires from diagnosis throughout their treatment. Average utilities were calculated stratified by age and treatment. These utilities were applied in CEAs analysing 920 breast cancer screening policies differing in eligible ages and screening interval simulated by the MISCAN-Breast microsimulation model, using a willingness-to-pay threshold of €20,000. The CEAs included varying sets on normative, breast cancer treatment and screening and follow-up utilities. Efficiency frontiers were compared to assess the impact of the utility sets. The calculated average patient utilities were reduced at breast cancer diagnosis and 6 months after surgery and increased toward normative utilities 12 months after surgery. When using normative utility values of 1 in CEAs, QALYs were overestimated compared to using average gender and age-specific values. Only small differences in QALYs gained were seen when varying treatment utilities in CEAs. The CEAs varying screening and follow-up utilities showed only small changes in QALYs gained and the efficiency frontier. Throughout all variations in utility sets, the optimal strategy remained robust; biennial for ages 40-76 years and occasionally biennial 40-74 years. In sum, we recommend to use gender and age stratified normative utilities in CEAs, and patient-based breast cancer utilities stratified by age and treatment or disease stage. Furthermore, despite varying utilities, the optimal screening scenario seems very robust.

Finding the optimal mammography screening strategy: a cost‐effectiveness analysis of 920 modelled strategies

Breast cancer screening policies have been designed decades ago, but current screening strategies may not be optimal anymore. Next to that, screening capacity issues may restrict feasibility. This cost‐effectiveness study evaluates an extensive set of breast cancer screening strategies in the Netherlands. Using the Microsimulation Screening Analysis‐Breast (MISCAN‐Breast) model, the cost‐effectiveness of 920 breast cancer screening strategies with varying starting ages (40‐60), stopping ages (64‐84) and intervals (1‐4 years) were simulated. The number of quality adjusted life years (QALYs) gained and additional net costs (in €) per 1000 women were predicted (3.5% discounted) and incremental cost‐effectiveness ratios (ICERs) were calculated to compare screening scenarios. Sensitivity analyses were performed using different assumptions. In total, 26 strategies covering all four intervals were on the efficiency frontier. Using a willingness‐to‐pay threshold of €20 000/QALY gained, the biennial 40 to 76 screening strategy was optimal. However, this strategy resulted in more overdiagnoses and false positives, and required a high screening capacity. The current strategy in the Netherlands, biennial 50 to 74 years, was dominated. Triennial screening in the age range 44 to 71 (ICER 9364) or 44 to 74 (ICER 11144) resulted in slightly more QALYs gained and lower costs than the current Dutch strategy. Furthermore, these strategies were estimated to require a lower screening capacity. Findings were robust when varying attendance and effectiveness of treatment. In conclusion, switching from biennial to triennial screening while simultaneously lowering the starting age to 44 can increase benefits at lower costs and with a minor increase in harms compared to the current strategy.

Common matrix metalloproteinase-2 gene variants and altered susceptibility to breast cancer and associated features in Tunisian women

A role for matrix metalloproteinase polymorphisms in breast cancer development and progression was proposed, but with inconclusive results. We assessed the relation of matrix metalloproteinase-2 variants with breast cancer and related phenotypes in Tunisians. This case-control retrospective study involved 430 women with breast cancer and 498 healthy controls. Genotyping of matrix metalloproteinase-2 rs243866, rs243865, rs243864, and rs2285053 was analyzed by allelic exclusion. The minor allele frequency of rs2285053 was significantly lower in women with breast cancer cases as compared to control women; minor allele frequencies of the remaining single-nucleotide polymorphisms were similar between cases and control women. The distribution of rs243865 and rs2285053 genotypes was significantly different between breast cancer patients and control subjects. This persisted when key covariates were controlled for. None of the matrix metalloproteinase-2 variants were associated with estrogen receptor positivity, progesterone receptor positivity, or with double estrogen receptor–progesterone receptor positivity in breast cancer patients. Matrix metalloproteinase-2 rs243866, rs243865, and rs243864 were positively associated with menstrual irregularity and histological type, while rs243866 and rs2285053 were negatively associated with menarche and nodal status. In addition, rs2285053 was negatively associated with triple negativity, tumor size, distance metastasis, molecular type, and chemotherapy. Haploview analysis revealed high linkage disequilibrium between matrix metalloproteinase-2 variants. Four-locus Haploview analysis identified haplotypes GCTT and GTTC to be negatively associated with breast cancer, which remained statistically after controlling for key covariates. Matrix metalloproteinase-2 alleles and genotypes, along with four-locus haplotypes, are related to reduced susceptibility to breast cancer in Tunisian women, suggesting a protective effect.

Effectiveness of breast cancer screening policies in countries with medium-low incidence rates

Chile has lower breast cancer incidence rates compared to those in developed countries. Our public health system aims to perform 10 biennial screening mammograms in the age group of 50 to 69 years by 2020. Using a dynamic programming model, we have found the optimal ages to perform 10 screening mammograms that lead to the lowest lifetime death rate and we have evaluated a set of fixed inter-screening interval policies. The optimal ages for the 10 mammograms are 43, 47, 51, 54, 57, 61, 65, 68, 72, and 76 years, and the most effective fixed inter-screening is every four years after the 40 years. Both policies respectively reduce lifetime death rate in 6.4% and 5.7% and the cost of saving one life in 17% and 9.3% compared to the 2020 Chilean policy. Our findings show that two-year inter-screening interval policies are less effective in countries with lower breast cancer incidence; thus we recommend screening policies with a wider age range and larger inter-screening intervals for Chile.

Assessing predicted age-specific breast cancer mortality rates in 27 European countries by 2020

BACKGROUND

We assessed differences in predicted breast cancer (BC) mortality rates, across Europe, by 2020, taking into account changes in the time trends of BC mortality rates during the period 2000-2010.

METHODS

BC mortality data, for 27 European Union (EU) countries, were extracted from the World Health Organization mortality database. First, we compared BC mortality data between time periods 2000-2004 and 2006-2010 through standardized mortality ratios (SMRs) and carrying out a graphical assessment of the age-specific rates. Second, making use of the base period 2006-2012, we predicted BC mortality rates by 2020. Finally, making use of the SMRs and the predicted data, we identified a clustering of countries, assessing differences in the time trends between the areas defined in this clustering.

RESULTS

The clustering approach identified two clusters of countries: the first cluster were countries where BC predicted mortality rates, in 2020, might slightly increase among women aged 69 and older compared with 2010 [Greece (SMR 1.01), Croatia (SMR 1.02), Latvia (SMR 1.15), Poland (SMR 1.14), Estonia (SMR 1.16), Bulgaria (SMR 1.13), Lithuania (SMR 1.03), Romania (SMR 1.13) and Slovakia (SMR 1.06)]. The second cluster was those countries where BC mortality rates level off or decrease in all age groups (remaining countries). However, BC mortality rates between these clusters might diminish and converge to similar figures by 2020.

CONCLUSIONS

For the year 2020, our predictions have shown a converging pattern of BC mortality rates between European regions. Reducing disparities, in access to screening and treatment, could have a substantial effect in countries where a non-decreasing trend in age-specific BC mortality rates has been predicted.

Survival of women with cancers of breast and genital organs in Europe 1999-2007: Results of the EUROCARE-5 study

BACKGROUND

Survival differences across Europe for patients with cancers of breast, uterus, cervix, ovary, vagina and vulva have been documented by previous EUROCARE studies. In the present EUROCARE-5 study we update survival estimates and investigate changes in country-specific and over time survival, discussing their relationship with incidence and mortality dynamics for cancers for which organised screening programs are ongoing.

METHODS

We analysed cases archived in over 80 population-based cancer registries in 29 countries grouped into five European regions. We used the cohort approach to estimate 5-year relative survival (RS) for adult (⩾15years) women diagnosed 2000-2007, by age, country and region; and the period approach to estimate time trends (1999-2007) in RS for breast and cervical cancers.

RESULTS

In 2000-2007, 5-year RS was 57% overall, 82% for women diagnosed with breast, 76% with corpus uteri, 62% with cervical, 38% with ovarian, 40% with vaginal and 62% with vulvar cancer. Survival was low for patients resident in Eastern Europe (34% ovary-74% breast) and Ireland and the United Kingdom [Ireland/UK] (31-79%) and high for those resident in Northern Europe (41-85%) except Denmark. Survival decreased with advancing age: markedly for women with ovarian (71% 15-44years; 20% ⩾75years) and breast (86%; 72%) cancers. Survival for patients with breast and cervical cancers increased from 1999-2001 to 2005-2007, remarkably for those resident in countries with initially low survival.

CONCLUSIONS

Despite increases over time, survival for women's cancers remained poor in Eastern Europe, likely due to advanced stage at diagnosis and/or suboptimum access to adequate care. Low survival for women living in Ireland/UK and Denmark could indicate late detection, possibly related also to referral delay. Poor survival for ovarian cancer across the continent and over time suggests the need for a major research effort to improve prognosis for this common cancer.

Breast cancer mortality trends in Italy by region and screening programme, 1980-2008

OBJECTIVES

To describe trends in breast cancer mortality in 14 Italian regions representing 90% of the Italian population, and in the country overall, in relation to the diffusion of organized or opportunistic breast cancer screening programmes. Settings : Breast cancer mortality figures from 1980-2008 in Italy and 14 Italian regions were retrieved from the National Statistics Institute.

METHODS

Estimated annual percent change (EAPC) was calculated for three time-periods (1980-1989, 1990-1999, 2000-2008). To estimate the age-adjusted and age-specific EAPC, trends in mortality based on annual data were examined using a log-linear regression model, and the year of death as a regressor variable.

RESULTS

In the period 1980-1989 an increasing trend was observed in Italy overall (EAPC = +1.1%; 95% confidence interval [95%CI]: + 0.9%; + 1.3%) and in the 14 regions. In the second decade a decreasing trend was recorded both overall in Italy (EAPC = -1.6%; 95CI:-1.8%;-1.4%) and in all the regions. Between 2000-2008 a slightly decreasing trend was observed in Italy overall (EAPC = -0.8%; 95%CI:-1.0%;-0.5%). A steeper and earlier decrease compared with the rest of Italy was observed in 1990-1999 in Liguria (EAPC = -3.1%; 95%CI:-4.0%,-2.1%), Lombardy (EAPC = -2.3%; 95%CI:-2.8%;-1.9%), and Tuscany (EAPC = -3.0%; 95%CI:-3.7%;-2.2%), mainly due to the 55-64 age-group. There were significant EAPCs between -4.1% and -3.7% in these three regions, 2.5-3.0 times greater than in the rest of Italy (EAPC = -1.4%).

CONCLUSIONS

This earlier decline in three Italian regions could be partially attributable to local organized screening programmes implemented earlier than in the rest of Italy, and to opportunistic screening that became more common in 1990s.

Osteoprotegerin expression in triple-negative breast cancer cells promotes metastasis

Osteoprotegerin (OPG) is a secreted member of the tumor necrosis factor (TNF) receptor superfamily that has been well characterized as a negative regulator of bone remodeling. OPG is also expressed in human breast cancer tissues and cell lines. In vitro studies suggest that OPG exerts tumor-promoting effects by binding to TNF-related apoptosis inducing ligand (TRAIL), thereby preventing induction of apoptosis. However, the in vivo effect of OPG expression by primary breast tumors has not been characterized. We knocked down OPG expression in MDA-MB-231 and MDA-MB-436 human breast cancer cells using shRNA and siRNA to investigate impact on metastasis in the chick embryo model. We observed a reduction in metastasis with OPG knockdown cells. We found that lowering OPG expression did not alter sensitivity to TRAIL-induced apoptosis; however, the OPG knockdown cells had a reduced level of invasion. In association with this we observed reduced expression of the proteases Cathepsin D and Matrix Metalloproteinase-2 upon OPG knockdown, indicating that OPG may promote metastasis via modulation of protease expression and invasion. We conclude that OPG has a metastasis-promoting effect in breast cancer cells.

Budget impact analysis of switching to digital mammography in a population-based breast cancer screening program: a discrete event simulation model

Objective

To assess the budgetary impact of switching from screen-film mammography to full-field digital mammography in a population-based breast cancer screening program.

Methods

A discrete-event simulation model was built to reproduce the breast cancer screening process (biennial mammographic screening of women aged 50 to 69 years) combined with the natural history of breast cancer. The simulation started with 100,000 women and, during a 20-year simulation horizon, new women were dynamically entered according to the aging of the Spanish population. Data on screening were obtained from Spanish breast cancer screening programs. Data on the natural history of breast cancer were based on US data adapted to our population. A budget impact analysis comparing digital with screen-film screening mammography was performed in a sample of 2,000 simulation runs. A sensitivity analysis was performed for crucial screening-related parameters. Distinct scenarios for recall and detection rates were compared.

Results

Statistically significant savings were found for overall costs, treatment costs and the costs of additional tests in the long term. The overall cost saving was 1,115,857€ (95%CI from 932,147 to 1,299,567) in the 10^th year and 2,866,124€ (95%CI from 2,492,610 to 3,239,638) in the 20^th year, representing 4.5% and 8.1% of the overall cost associated with screen-film mammography. The sensitivity analysis showed net savings in the long term.

Conclusions

Switching to digital mammography in a population-based breast cancer screening program saves long-term budget expense, in addition to providing technical advantages. Our results were consistent across distinct scenarios representing the different results obtained in European breast cancer screening programs.

An assessment of existing models for individualized breast cancer risk estimation in a screening program in Spain

Background

The aim of this study was to evaluate the calibration and discriminatory power of three predictive models of breast cancer risk.

Methods

We included 13,760 women who were first-time participants in the Sabadell-Cerdanyola Breast Cancer Screening Program, in Catalonia, Spain. Projections of risk were obtained at three and five years for invasive cancer using the Gail, Chen and Barlow models. Incidence and mortality data were obtained from the Catalan registries. The calibration and discrimination of the models were assessed using the Hosmer-Lemeshow C statistic, the area under the receiver operating characteristic curve (AUC) and the Harrell’s C statistic.

Results

The Gail and Chen models showed good calibration while the Barlow model overestimated the number of cases: the ratio between estimated and observed values at 5 years ranged from 0.86 to 1.55 for the first two models and from 1.82 to 3.44 for the Barlow model. The 5-year projection for the Chen and Barlow models had the highest discrimination, with an AUC around 0.58. The Harrell’s C statistic showed very similar values in the 5-year projection for each of the models. Although they passed the calibration test, the Gail and Chen models overestimated the number of cases in some breast density categories.

Conclusions

These models cannot be used as a measure of individual risk in early detection programs to customize screening strategies. The inclusion of longitudinal measures of breast density or other risk factors in joint models of survival and longitudinal data may be a step towards personalized early detection of BC.