Predicting the Change in Breast Cancer Deaths in Spain by 2019: A Bayesian Approach

Using population-based data to evaluate the impact of adherence to endocrine therapy on survival in breast cancer through the web-application BreCanSurvPred

We show how the use and interpretation of population-based cancer survival indicators can help oncologists talk with breast cancer (BC) patients about the relationship between their prognosis and their adherence to endocrine therapy (ET). The study population comprised a population-based cohort of estrogen receptor positive BC patients (N = 1268) diagnosed in Girona and Tarragona (Northeastern Spain) and classified according to HER2 status (+ / −), stage at diagnosis (I/II/III) and five-year cumulative adherence rate (adherent > 80%; non-adherent ≤ 80%). Cox regression analysis was performed to identify significant prognostic factors for overall survival, whereas relative survival (RS) was used to estimate the crude probability of death due to BC (P_BC). Stage and adherence to ET were the significant factors for predicting all-cause mortality. Compared to stage I, risk of death increased in stage II (hazard ratio [HR] 2.24, 95% confidence interval [CI]: 1.51–3.30) and stage III (HR 5.11, 95% CI 3.46–7.51), and it decreased with adherence to ET (HR 0.57, 95% CI 0.41–0.59). P_BC differences were higher in non-adherent patients compared to adherent ones and increased across stages: stage I: 6.61% (95% CI 0.05–13.20); stage II: 9.77% (95% CI 0.59–19.01), and stage III: 22.31% (95% CI 6.34–38.45). The age-adjusted survival curves derived from this modeling were implemented in the web application BreCanSurvPred (https://pdocomputation.snpstats.net/BreCanSurvPred). Web applications like BreCanSurvPred can help oncologists discuss the consequences of non-adherence to prescribed ET with patients.

Long-term crude probabilities of death among breast cancer patients by age and stage: a population-based survival study in Northeastern Spain (Girona-Tarragona 1985-2004)

Background

We provide population-based long-term survival indicators of breast cancer patients by quantifying the observed survival, and the probabilities of death due to breast cancer and to other causes by age and tumor stage at diagnosis.

Methods

We included a total of 10,195 female patients diagnosed before 85 years with invasive primary breast cancer in Girona and Tarragona during the periods 1985–1994 and 1995–2004 and followed-up until December 31st 2014. The survival indicators were estimated at 5, 10, 15 and 20 years of follow-up comparing diagnostic periods.

Results

Comparing diagnostic periods: I) the probability of death due to other causes did not change; II) the 20-year survival for women diagnosed ≤ 49 years increased 13% (1995–2004 = 68%; 1985–1994:55%), whereas their probability of death due to breast cancer decreased at the same pace (1995–2004 = 29%; 1985–1994 = 42%); III) at 10 years of follow-up, decreases in the probabilities of death due to breast cancer across age groups switched from 11 to 17% resulting in a risk of death reduction of 19% after adjusting by stage. During 1995–2004, the stage-specific 10-year probabilities of death due to breast cancer switched from: 3–6% in stage I, 18–20% in stage II, 34–46% in stage III and surpassed 70% in stage IV beyond 5 years after diagnosis.

Conclusions

In our study, women diagnosed with breast cancer had higher long-term probability to die from breast cancer than from other causes. The improvements in treatment and the lead-time bias in detecting cancer in an early stage resulted in a reduction of 19% in the risk of death between diagnostic periods.

Electronic supplementary material

The online version of this article (10.1007/s12094-018-1852-1) contains supplementary material, which is available to authorized users.

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.

Reporting of Bayesian analysis in epidemiologic research should become more transparent

OBJECTIVES

The objective of this systematic review is to investigate the use of Bayesian data analysis in epidemiology in the past decade and particularly to evaluate the quality of research papers reporting the results of these analyses.

STUDY DESIGN AND SETTING

Complete volumes of five major epidemiological journals in the period 2005-2015 were searched via PubMed. In addition, we performed an extensive within-manuscript search using a specialized Java application. Details of reporting on Bayesian statistics were examined in the original research papers with primary Bayesian data analyses.

RESULTS

The number of studies in which Bayesian techniques were used for primary data analysis remains constant over the years. Though many authors presented thorough descriptions of the analyses they performed and the results they obtained, several reports presented incomplete method sections and even some incomplete result sections. Especially, information on the process of prior elicitation, specification, and evaluation was often lacking.

CONCLUSION

Though available guidance papers concerned with reporting of Bayesian analyses emphasize the importance of transparent prior specification, the results obtained in this systematic review show that these guidance papers are often not used. Additional efforts should be made to increase the awareness of the existence and importance of these checklists to overcome the controversy with respect to the use of Bayesian techniques. The reporting quality in epidemiological literature could be improved by updating existing guidelines on the reporting of frequentist analyses to address issues that are important for Bayesian data analyses.

Estimating long-term crude probability of death among young breast cancer patients: a Bayesian approach

AIMS AND BACKGROUND

Bayesian survival analysis was applied to assess the long-term survival and probability of death due to breast cancer (BC) in Girona, the Spanish region with the highest BC incidence.

METHODS

A Bayesian autoregressive model was implemented to compare survival indicators between the periods 1985-1994 and 1995-2004. We assessed the long-term excess hazard of death, relative survival (RS), and crude probability of death due to BC (PBC) up to 20 years after BC diagnosis, reporting the 95% credible intervals (CI) of these indicators.

RESULTS

Patients diagnosed from 1995 onwards showed lower 20-year excess hazards of death than those diagnosed earlier (RS during 1985-1994: local stage: 76.6%; regional stage: 44.9%; RS during 1995-2004: local stage: 85.2%; regional stage: 57.0%). The PBC after 20 years of BC diagnosis for patients diagnosed in 1995 and after might reach 14.4% (95% CI: 8.9%-21.2%) in local stage and 41.0% (95% CI: 36.1%-47.1%) in regional stage.

CONCLUSIONS

The method presented could be useful when dealing with population-based survival data from a small region. Better survival prospects were found in patients diagnosed after 1994, although we detected a non-decreasing long-term excess hazard of death, suggesting that these patients have higher mortality than the general population even 10 years after the diagnosis of BC.

How many new cancer patients in Europe will require radiotherapy by 2025? An ESTRO-HERO analysis

BACKGROUND

The objective of this HERO study was to assess the number of new cancer patients that will require at least one course of radiotherapy by 2025.

METHODS

European cancer incidence data by tumor site and country for 2012 and 2025 was extracted from the GLOBOCAN database. The projection of the number of new cases took into account demographic factors (age and size of the population). Population based stages at diagnosis were taken from four European countries. Incidence and stage data were introduced in the Australian Collaboration for Cancer Outcomes Research and Evaluation (CCORE) model.

RESULTS

Among the different tumor sites, the highest expected relative increase by 2025 in treatment courses was prostate cancer (24%) while lymphoma (13%), head and neck (12%) and breast cancer (10%) were below the average. Based on the projected cancer distributions in 2025, a 16% expected increase in the number of radiotherapy treatment courses was estimated. This increase varied across European countries from less than 5% to more than 30%.

CONCLUSION

With the already existing disparity in radiotherapy resources in mind, the data provided here should act as a leverage point to raise awareness among European health policy makers of the need for investment in radiotherapy.

Contribution of changes in demography and in the risk factors to the predicted pattern of cancer mortality among Spanish women by 2022

BACKGROUND

Changes in the burden of cancer mortality are expected to be observed among Spanish women. We predict those changes, in Spain, for breast cancer (BC), colorectal cancer (CRC), lung cancer (LC) and pancreatic cancer (PC) from 2013 to 2022.

METHODS

Bayesian age-period-cohort modeling was used to perform projections of the cancer burden in 2013-2022, extrapolating the trend of cancer mortality data from 1998 to 2012. We assessed the time trends of the crude rates (CRs) during 1998-2012, and compared the number of cancer deaths between the periods 2008-2012 and 2018-2022 to assess the contribution of demographic changes and changes in the risk factors for cancer.

RESULTS

During 1998-2012, CRs of cancer decreased for BC (0.3% per year) and increased for LC (4.7%), PC (2%) and CRC (0.7%). During 2013-2022, CRs might level off for CRC, whereas the time trends for the remaining cancers might continue at a similar pace. During 2018-2022, BC could be surpassed by CRC as the most frequent cause of cancer mortality among Spanish women, whereas LC could be the most common cause of cancer mortality among women aged 50-69 years (N/year=1960 for BC versus N/year=1981 for LC). Comparing 2018-2022 and 1998-2012, changes in the risk factors for cancer could contribute 37.93% and 18.36% to the burden of LC and PC, respectively, and demographic shifts - mainly due to ageing (19.27%) - will drive the burden of CRC.

CONCLUSIONS

During 2018-2022, demographic changes (ageing) and changes in risk factors could have a different impact on the lifetime risk of cancer among Spanish women.

Selecting the minimum prediction base of historical data to perform 5-year predictions of the cancer burden: The GoF-optimal method

BACKGROUND

Predicting the future burden of cancer is a key issue for health services planning, where a method for selecting the predictive model and the prediction base is a challenge. A method, named here Goodness-of-Fit optimal (GoF-optimal), is presented to determine the minimum prediction base of historical data to perform 5-year predictions of the number of new cancer cases or deaths.

METHODS

An empirical ex-post evaluation exercise for cancer mortality data in Spain and cancer incidence in Finland using simple linear and log-linear Poisson models was performed. Prediction bases were considered within the time periods 1951-2006 in Spain and 1975-2007 in Finland, and then predictions were made for 37 and 33 single years in these periods, respectively. The performance of three fixed different prediction bases (last 5, 10, and 20 years of historical data) was compared to that of the prediction base determined by the GoF-optimal method. The coverage (COV) of the 95% prediction interval and the discrepancy ratio (DR) were calculated to assess the success of the prediction.

RESULTS

The results showed that (i) models using the prediction base selected through GoF-optimal method reached the highest COV and the lowest DR and (ii) the best alternative strategy to GoF-optimal was the one using the base of prediction of 5-years.

CONCLUSIONS

The GoF-optimal approach can be used as a selection criterion in order to find an adequate base of prediction.

Opposite trends in the consumption of manufactured and roll-your-own cigarettes in Spain (1991-2020)

OBJECTIVE

The aim of this study is to describe trends in the consumption of manufactured and roll-your-own cigarettes between 1991 and 2012 in Spain, and to project these trends up to 2020.

METHODS

We estimated daily consumption per capita during 1991-2012 using data on sales of manufactured cigarettes (20-packs) and rolling tobacco (kg) from the Tobacco Market Commission, and using data of the Spanish adult population from the National Statistics Institute. We considered different weights (0.5, 0.8 and 1 g) to compute the number of rolled cigarettes per capita. We computed the annual per cent of change and assessed possible changes in trends using joinpoint regression, and projected the consumption up to 2020 using Bayesian methods.

RESULTS

Daily consumption per capita of manufactured cigarettes decreased on average by 3.0% per year in 1991-2012, from 7.6 to 3.8 units, with three trend changes. However, daily consumption per capita of roll-your-own cigarettes increased on average by 14.1% per year, from 0.07 to 0.92 units of 0.5 g, with unchanged trends. Together, daily consumption per capita decreased between 2.9% and 2.5%, depending on the weight of the roll-your-own cigarettes. Projections up to 2020 indicate a decrease of manufactured cigarettes (1.75 units per capita) but an increase of roll-your-own cigarettes (1.25 units per capita).

CONCLUSIONS

While the consumption per capita of manufactured cigarettes has decreased in the past years in Spain, the consumption of roll-your-own cigarettes has increased at an annual rate around 14% over the past years. Whereas a net decrease in cigarette consumption is expected in the future, use of roll-your-own cigarettes will continue to increase.

Cancer incidence and mortality projections up to 2020 in Catalonia by means of Bayesian models

PURPOSE

To predict the burden of cancer in Catalonia by 2020 assessing changes in demography and cancer risk during 2010-2020.

METHODS/PATIENTS

Data were obtained from Tarragona and Girona cancer registries and Catalan mortality registry. Population age distribution was obtained from the Catalan Institute of Statistics. Predicted cases in Catalonia were estimated through autoregressive Bayesian age-period-cohort models.

RESULTS

There will be diagnosed 26,455 incident cases among men and 18,345 among women during 2020, which means an increase of 22.5 and 24.5 % comparing with the cancer incidence figures of 2010. In men, the increase of cases (22.5 %) can be partitioned in three components: 12 % due to ageing, 8 % due to increase in population size and 2 % due to cancer risk. In women, the role of each component was 9, 8 and 8 %, respectively. The increased risk is mainly expected to be observed in tobacco-related tumours among women and in colorectal and liver cancers among men. During 2010-2020 a mortality decline is expected in both sexes.

CONCLUSION

The expected increase of cancer incidence, mainly due to tobacco-related tumours in women and colorectal in men, reinforces the need to strengthen smoking prevention and the expansion of early detection of colorectal cancer in Catalonia.

Time trends of cancer incidence and mortality in Catalonia during 1993-2007

PURPOSE

To describe time trends of cancer in Catalonia, Spain, during the period 1993-2007.

METHODS/PATIENTS

Data have been provided by two population-based cancer registries, Girona and Tarragona, and the Catalan mortality registry. Cancer incidence in Catalonia has been estimated through modeling methods using data from these health structures.

RESULTS

During 2003-2007, there were 20,042 cancer cases and 9,842 deaths per year among men and 13,673 new cancer cases and 5,882 deaths among women. The most frequent incident cancers among men were prostate (N = 4,258), lung (N = 3,021), colorectal (N = 3,007) and bladder (N = 2,238), whereas among women they were breast (N = 3,907), colorectal (N = 2,088), corpus uteri (N = 734) and lung (N = 527). During 1993-2007, age-standardized incidence rates (ASIRs) rose 1.2 % per year among men [prostate (6.3 %), testis (5.7 %), kidney (2.9 %), liver (2.2 %) and colorectal (2.1 %)]. ASIRs decreased for stomach (-2.9 %), oral cavity and pharynx (-2.8 %), larynx (-2.7 %) and esophagus (-2 %). Among women, ASIRs only rose for lung (5.2 %), kidney (3.1 %), oral cavity and pharynx (2.6 %) and thyroid (1.6 %). ASIRs decreased for corpus uteri (-2.3 %), stomach (-1.7 %) and ovary (-1.6 %). Cancer mortality decreased -1.3 % per year among men and -2.1 % among women during the same period.

CONCLUSION

Among men, the decrease of incidence/mortality of tobacco-related tumors was related to a reduction of smoking prevalence. Among women, the stabilization of breast cancer incidence and the rise of lung cancer incidence are similar to that observed in most European regions. These results allow assessing the effectiveness of public health strategies and they pose new frontiers for cancer control in Catalonia.