Net Survival Estimates Research Articles

Cure indicators and prevalence by stage at diagnosis for breast and colorectal cancer patients: A population-based study in Italy.

People alive many years after breast (BC) or colorectal cancer (CRC) diagnoses are increasing. This paper aimed to estimate the indicators of cancer cure and complete prevalence for Italian patients with BC and CRC by stage and age. A total of 31 Italian Cancer Registries (47% of the population) data until 2017 were included. Mixture cure models allowed estimation of net survival (NS); cure fraction (CF); time to cure (TTC, 5-year conditional NS >95%); cure prevalence (who will not die of cancer); and already cured (prevalent patients living longer than TTC). 2.6% of all Italian women (806,410) were alive in 2018 after BC and 88% will not die of BC. For those diagnosed in 2010, CF was 73%, 99% when diagnosed at stage I, 81% at stage II, and 36% at stages III-IV. For all stages combined, TTC was >10 years under 45 and over 65 years and for women with advanced stages, but ≤1 year for all BC patients at stage I. The proportion of already cured prevalent BC women was 75% (94% at stage I). Prevalent CRC cases were 422,407 (0.7% of the Italian population), 90% will not die of CRC. For CRC patients, CF was 56%, 92% at stage I, 71% at stage II, and 35% at stages III-IV. TTC was ≤10 years for all age groups and stages. Already cured were 59% of all prevalent CRC patients (93% at stage I). Cancer cure indicators by stage may contribute to appropriate follow-up in the years after diagnosis, thus avoiding patients' discrimination.

Lymphoid blood cancers, incidence and survival 2005-2023: A report from the UK’s Haematological Malignancy Research Network

BackgroundPopulation-based information on cancer incidence and outcome are required to inform clinical practice and research; but contemporary data are lacking for many lymphoid cancer subtypes. MethodsSet within a socio-demographically representative UK population of ∼4 million, data are from an established UK patient cohort (N = 22,414 diagnoses). Information on incidence (crude and age-standardised) and survival (overall and net) is presented for > 40 subtypes. ResultsThe median diagnostic age was 69.9 years (interquartile range 59.1–78.3), but unlike many other cancers, lymphoid malignancies can be diagnosed at any age; different subtypes dominating at different ages. Males were more likely to be diagnosed than females (age-standardised sex rate ratio: 1.55 (95% Confidence Interval: 1.50,1.59)), and most subtypes had a male predominance, some more than three-fold (e.g. Burkitt lymphoma 3.26 (2.42, 4.40)). Five-year net survival estimates varied hugely, ranging from 97.4% (95% CI: 56.5, 99.9) in patients with hairy cell leukaemia to 31.6% (95% CI: 2.5, 69.8) in those with T-cell prolymphocytic leukaemia. No significant sex difference in survival were observed for the majority of diagnoses; one exception being classical Hodgkin lymphoma, where males had a higher mortality (Excess Mortality Ratio: 1.44 (95% CI: 1.11, 1.87)). An improvement in survival over time was observed for some, but not all, of the major diagnostic groups. ConclusionsMarked incidence and survival variations by subtype, sex and age confirm the heterogeneity of lymphoid neoplasms and highlight the importance of accurately characterising disease entities. Despite recent improvements, routine cancer registration of lymphoid neoplasms remains challenging and new issues continue to emerge; including the lack of an international consensus on classification and the recording of progressions and transformations. Furthermore, the increasing need for additional molecular and genomic information required for accurate classification is likely to impact negatively on the quality of cancer registration data, especially in low income countries.

Fair comparisons of cause-specific and relative survival by accounting for the systematic removal of patients from risk-sets

BackgroundIn population-based cancer studies it is common to try to isolate the impact of cancer by estimating net survival. Net survival is defined as the probability of surviving cancer in the absence of any other-causes of death. Net survival can be estimated either in the cause-specific or relative survival framework. Cause-specific survival considers deaths from the cancer as the event of interest. Relative survival incorporates general population expected mortality rates to represent the other-cause mortality rate. Estimation approaches in both frameworks are impacted by the systematic removal of patients from the risk-set, commonly referred to as informative censoring in the cause-specific framework. In the relative survival framework, the Pohar Perme estimator combats the effect of this systematic removal of patients through weighting. When the two frameworks have been compared, informative censoring is rarely accounted for in the cause-specific framework. MethodsWe investigate the use of weighted cause-specific Kaplan-Meier estimates to overcome the impact of informative censoring and compared approaches to defining weights. Individuals remaining in the risk-set are upweighted using their predicted other-cause survival obtained through various model-based approaches. We also compare weights derived from expected mortality rates. We applied the approaches to US cancer registry data and conducted a simulation study. ResultsUsing weighted cause-specific estimates provides a better estimate of marginal net survival. The unweighted Kaplan-Meier estimates have a similar bias to the Ederer II method for relative survival. Weighted Kaplan-Meier estimates are unbiased and similar to the Pohar Perme estimator. There was little variation between the several weighting approaches. ConclusionIn comparisons of cause-specific and relative survival, it is important to compare “like-with-like”, therefore, a weighted approach should be considered for both frameworks. If researchers are interested in obtaining net measures in a cause-specific framework, then weighting is needed to account for informative censoring.

Improving communication of cancer survival statistics-feasibility of implementing model-based algorithms in routine publications.

Routine reporting of cancer patient survival is important, both to monitor the effectiveness of health care and to inform about prognosis following a cancer diagnosis. A range of different survival measures exist, each serving different purposes and targeting different audiences. It is important that routine publications expand on current practice and provide estimates on a wider range of survival measures. We examine the feasibility of automated production of such statistics. We used data on 23 cancer sites obtained from the Cancer Registry of Norway (CRN). We propose an automated way of estimating flexible parametric relative survival models and calculating estimates of net survival, crude probabilities, and loss in life expectancy across many cancer sites and subgroups of patients. For 21 of 23 cancer sites, we were able to estimate survival models without assuming proportional hazards. Reliable estimates of all desired measures were obtained for all cancer sites. It may be challenging to implement new survival measures in routine publications as it can require the application of modeling techniques. We propose a way of automating the production of such statistics and show that we can obtain reliable estimates across a range of measures and subgroups of patients.

'Get Data Out' Skin: national cancer registry incidence and survival rates for all registered skin tumour groups for2013-2019 in England.

Providing detailed skin cancer statistics, including incidence and survival, by tumour type and patient characteristics is important for up-to-date epidemiological information. To create a new clinically relevant consensus-based classification for registered skin tumours using tumour type and patient characteristics and to describe its application to all registered tumours in England between 2013 and 2019. Tumours with skin topographical codes (ICD-10) and morphology and behaviour (ICD-O3) were grouped together in an iterative process creating a hierarchical tree structure. The primary-level grouping partitioned skin tumours into skin cancer, melanoma in situ, extramammary Paget disease (EMPD) and tumours of uncertain malignant potential. Second-level groups splitskin cancer into keratinocyte cancer (KC), melanoma and rare cancers. The third-level group splitKC into basal cell carcinoma (BCC) and squamous cell carcinoma (cSCC). Further groups were split intogenital or non-genital, first or subsequent tumour, age, gender, stage, orNational Health Service(NHS)region. Incidence counts, Kaplan-Meier and net survival estimates and referral routes [two-week wait (TWW), general practitioner (GP), outpatient] categorisations were calculated for each grouping across all years. A total of 1 445 377 skin cancers and 49 123 precancerous lesions and undefined entities were registered in England between 2013 and 2019. Skin tumours and skin cancer incidence rates are increasing for most tumour types. The most common type of skin cancer was BCC with an incidence rate of 282.36 per 100 000 person-years (PYs) [n = 158 934, 95% confidence interval (CI) 280.98-283.76] in 2019, followed by cSCC with an incidence rate of 85.24 per 100 000 PYs (n = 47 977, 95% CI 84.48-86.00) and melanoma with 27.24 (n = 15 332, 95% CI 26.81-27.67) per 100 000 PYs. Each year approximately 1800 rare skin cancers, 1500 genital cSCCs and 100 cases of EMPD are registered. Of 15 000 melanoma cases, 120 cases of melanoma occur in individuals aged < 25 years annually. One-year and five-year overall net survival varies by tumour type. cSCC 5-year net survival (89.8%, 95% CI 88.8-90.9) was comparable to the net survival of all melanomas (89.6%, 95% CI 88.7-90.6). BCC had excellent survival (overall net survival > 100%). Patients with late-stage melanoma, Merkel cell carcinoma and genital cSCC have a 5-year net survival < 60%. Older patients received fewer TWW referrals than their younger counterparts with the same tumour type at the same location. Patients with acral lentiginous melanoma had fewer TWW referrals and more standard GP referrals than patients with common melanomas. 'Get Data Out' Skin provides detailed and up-to-date statistics on all registrable skin tumours in England, including for the first time precancerous lesions and rare subtypes of common cancers. These data can be used by clinicians, researchers and commissioners to better understand skin cancer and improve resource allocation.

Individual frailty excess hazard models in cancer epidemiology.

Unobserved individual heterogeneity is a common challenge in population cancer survival studies. This heterogeneity is usually associated with the combination of model misspecification and the failure to record truly relevant variables. We investigate the effects of unobserved individual heterogeneity in the context of excess hazard models, one of the main tools in cancer epidemiology. We propose an individual excess hazard frailty model to account for individual heterogeneity. This represents an extension of frailty modeling to the relative survival framework. In order to facilitate the inference on the parameters of the proposed model, we select frailty distributions which produce closed-form expressions of the marginal hazard and survival functions. The resulting model allows for an intuitive interpretation, in which the frailties induce a selection of the healthier individuals among survivors. We model the excess hazard using a flexible parametric model with a general hazard structure which facilitates the inclusion of time-dependent effects. We illustrate the performance of the proposed methodology through a simulation study. We present a real-data example using data from lung cancer patients diagnosed in England, and discuss the impact of not accounting for unobserved heterogeneity on the estimation of net survival. The methodology is implemented in the R package IFNS.

Five-year cancer survival by stage at diagnosis in Canada.

Cancer survival estimates provide insights into the effectiveness of early detection and treatment. The stage of cancer at diagnosis is an important determinant of survival, reflecting the extent and spread at the time of disease detection. This work provides stage-specific, five-year survival results not previously available for Canada. Data reflect the population-based Canadian Cancer Registry death-linked analytic file covering the period from 2010 to 2017. The stage at diagnosis was determined by the Collaborative Stage Data Collection System. Five-year net survival (NS) estimates for Canada excluding Quebec were derived using the Pohar Perme estimator for the five most commonly diagnosed cancers. Except for prostate cancer, NS decreased monotonically with increased stage at diagnosis. For example, female breast cancer NS estimates were 100% (stage I), 92% (stage II), 74% (stage III) and 23% (stage IV). Apart from lung cancer, stage I NS exceeded 90% for all cancers studied. The largest sex-specific difference in NS was for lung cancer stage I (female 66%; male 56%). Stage-specific NS generally decreased with age, particularly for early-stage lung cancer. Between the 2010-to-2012 and 2015-to-2017 periods, NS improved among stage IV prostate, female breast and lung cancer cases, as well as for stage I and III lung cancer cases; however, it did not improve at any stage for colon or rectal cancer cases. The work highlights the importance of detecting cancer early, when treatment is most effective. It demonstrates some progress in stage-specific survival among top cancers in Canada and offers data to inform health policy, including screening, and clinical decisions regarding cancer treatment.

Cancer survival in Africa, central and south America, and Asia (SURVCAN-3): a population-based benchmarking study in 32 countries

Population-based cancer survival is a key measurement of cancer control performance linked to diagnosis and treatment, but benchmarking studies that include lower-income settings and that link results to health systems and human development are scarce. SURVCAN-3 is an international collaboration of population-based cancer registries that aims to benchmark timely and comparable cancer survival estimates in Africa, central and south America, and Asia. In SURVCAN-3, population-based cancer registries from Africa, central and south America, and Asia were invited to contribute data. Quality control and data checks were carried out in collaboration with population-based cancer registries and, where applicable, active follow-up was performed at the registry. Patient-level data (sex, age at diagnosis, date of diagnosis, morphology and topography, stage, vital status, and date of death or last contact) were included, comprising patients diagnosed between Jan 1, 2008, and Dec 31, 2012, and followed up for at least 2 years (until Dec 31, 2014). Age-standardised net survival (survival where cancer was the only possible cause of death), with 95% CIs, at 1 year, 3 years, and 5 years after diagnosis were calculated using Pohar-Perme estimators for 15 major cancers. 1-year, 3-year, and 5-year net survival estimates were stratified by countries within continents (Africa, central and south America, and Asia), and countries according to the four-tier Human Development Index (HDI; low, medium, high, and very high). 1 400 435 cancer cases from 68 population-based cancer registries in 32 countries were included. Net survival varied substantially between countries and world regions, with estimates steadily rising with increasing levels of the HDI. Across the included cancer types, countries within the lowest HDI category (eg, CÔte d'Ivoire) had a maximum 3-year net survival of 54·6% (95% CI 33·3-71·6; prostate cancer), whereas those within the highest HDI categories (eg, Israel) had a maximum survival of 96·8% (96·1-97·3; prostate cancer). Three distinct groups with varying outcomes by country and HDI dependant on cancer type were identified: cancers with low median 3-year net survival (<30%) and small differences by HDI category (eg, lung and stomach), cancers with intermediate median 3-year net survival (30-79%) and moderate difference by HDI (eg, cervix and colorectum), and cancers with high median 3-year net survival (≥80%) and large difference by HDI (eg, breast and prostate). Disparities in cancer survival across countries were linked to a country's developmental position, and the availability and efficiency of health services. These data can inform policy makers on priorities in cancer control to reduce apparent inequality in cancer outcome. Tata Memorial Hospital, the Martin-Luther-University Halle-Wittenberg, and the International Agency for Research on Cancer.

Cardiovascular, bone, and metabolic health in men with castrate-resistant prostate cancer treated with androgen deprivation: a matched cohort study

Background Descriptive data on late effects associated with castrate-resistant prostate cancer (CRPC) are sparse. We aimed to define the timing and incidence of cardiovascular disease (CVD), fractures, and diabetes in a patient population with CRPC. Methods In the population-based STHLM0 cohort 1464 men with CRPC were identified and matched with three men free from prostate cancer (PC) in the Stockholm region of Sweden. Kaplan–Meier estimates of net survival were used to describe time to CVD, fracture, and diabetes. Cox regression was used to compare incidence rates (IRRs) for the respective late effects. Cumulative incidence analyses of late effects in the presence of the competing risk of death were performed to estimate absolute risks. Results The Kaplan Meier estimates demonstrated a higher net probability for CVD, fracture, and diabetes among men diagnosed with CRPC compared to the matched comparators. The IRRs were 1.94 (95% CI: 1.79–2.12) for CVD, 2.08 (95% CI: 1.70–2.53) for fracture, and 2.00 (95% CI: 1.31–3.05) for diabetes, respectively, comparing men diagnosed with CRPC to men free from PC. The cumulative incidence of CVD at 12 months of follow-up was higher in men diagnosed with CRPC compared to healthy controls regardless of age with a difference in cumulative incidence being 0.20 for men aged <65 and 0.11 for men aged >84. Conclusions In this cohort, the incidence of CVD was significantly higher among men with CRPC compared to healthy controls. Despite having this end-stage disease this finding proves that clinicians must recognize this late effect in men diagnosed with CRPC to improve preventive actions. These men did not have a higher absolute risk of fractures and diabetes after accounting for deaths due to any cause compared to healthy controls.

Measuring progress in cancer survival across Canadian provinces: Extending the cancer survival index to further evaluate cancer control efforts.

A comprehensive evaluation of progress in cancer survival for all cancer types combined in Canada has recently been accomplished. An analogous evaluation across Canadian provinces has yet to be conducted. Data from 1992 to 2017 are from the population-based Canadian Cancer Registry death-linked analytic file. Provincial cancer survival index (CSI) estimates were calculated as the weighted sum of the sex- and cancer-specific age-standardized provincial net survival estimates. Provincial sex-specific CSI estimates were calculated separately using sex-specific cancer type weights. Data availability (Quebec) and sufficiency (Prince Edward Island and the territories) issues precluded CSI calculations for all jurisdictions. For the most recent period, 2013 to 2017, the five-year CSI was highest in Ontario (64.1%) and Alberta (63.3%), and lowest in Nova Scotia (60.8%). Significant progress in the five-year CSI since the period from 1992 to 1996 was observed in each province; the largest increases occurred in Alberta (8.7 percentage points) and Ontario (8.6 percentage points). Alberta's increase improved its relative provincial ranking from eighth to second. The influence of prostate cancer on provincial changes in the CSI since the period from 2003 to 2007 varied considerably from strongly counterproductive in New Brunswick, Saskatchewan and Nova Scotia because of decreasing prostate cancer survival, to strongly productive in Manitoba. Significant progress has been made in five-year cancer survival for all cancers combined since the early 1990s in each Canadian province studied. However, the magnitude of the progress has not been uniform across the provinces, and the cancer and sex combinations that have most influenced it have varied by province and period.

Trends in long-term cancer survival in Cali, Colombia: 1998-2017.

Population-based cancer survival is an indicator of the effectiveness of cancer services that reflects the survival of all cancer patients in the population, regardless of socioeconomic status and disease characteristics. Provision of an up-to-date survival estimate of patients recorded within Cali Population Cancer Registry (RPCC) in 1998-2017. As a second objective, results will be compared with those reported by the CONCORD study for cancers prioritized by the current Ten-Year Cancer Control Plan of Colombia, 2012-2021. Adult cancer cases (aged 15 to 99 years) for nine cancer types diagnosed between 1998 and 2017, with follow-up to 2018, were obtained from the RPCC. The 5-year age-standardized net survival estimates (NS) were estimated using the Pohar-Perme. The results for the period 1995- 2014 were compared with those reported by the CONCORD study for the following locations: stomach (C16), breast (C50), cervix (C53), prostate (C61), and lung (C33-34). Five-year survival estimates for breast and prostate cancers improved ten percentage points through 2007 (70.8 to 81.1 for breast and 79.9 to 90.2 for prostate) and remained stable during 2008-2017. For cervical cancer, survival estimates has remained stable for the last two decades at 53%. For stomach cancer and lung cancer, five-year NS was lower than 25% over the study period. For colorectal cancer, survival estimates increased from 37.9% in 1998-2002 to 54.8% in 2013-2017. Compared to previous 5-year survival estimates of cases diagnosed in 2010-2014, the estimates in this study are significantly higher than those obtained by CONCORD. Survival estimates of patients diagnosed in 1995-2009 showed no difference to CONCORD study. Periodic update of vital status and date of last contact reduces bias in survival estimates in population-based cancer registries with passive follow-up.

Gastric cancer incidence and mortality trends 2007-2016 in three European countries.

BACKGROUND : Increased awareness of gastric cancer risk, easy access to upper endoscopy, and high definition endoscopes with virtual chromoendoscopy may have led to the increase in early diagnosis of gastric cancer observed in recent years in Europe, which may be associated with improved survival. Currently, no data exist on the impact of early diagnosis on survival at a populational level in Europe. Our aim was to assess gastric cancer incidence, early diagnosis, and survival in northwestern and southern European countries with a low-to-moderate incidence of gastric cancer. METHODS : Data on 41 138 gastric cancers diagnosed in 2007-2016 were retrieved from national cancer registries of Belgium, the Netherlands, and northern Portugal. Age-standardized incidence and mortality rates were assessed and expressed per 100 000 person-years. Early diagnosis was defined as T1 tumors. Net survival estimates for 2007-2011 vs. 2012-2016 were compared. RESULTS : Age-standardized incidence and mortality decreased over time in Belgium, northern Portugal, and the Netherlands (relative incidence decrease 8.6 %, 4.5 %, and 46.8 %, respectively; relative mortality decrease 22.0 %, 30.9 %, and 50.0 %, respectively). Early gastric cancer diagnosis increased over time for all countries. Net 1-year survival improved significantly between the two time periods in all countries, and at 5 years in Belgium and Portugal. CONCLUSIONS : This is the first study comparing trends (2007-2016) in gastric cancer incidence and mortality in some European countries. We found an increasing proportion of T1 gastric cancers and a decrease in age-standardized mortality over time, supporting the use of secondary prevention strategies.

The cancer survival index: Measuring progress in cancer survival to help evaluate cancer control efforts in Canada.

A comprehensive evaluation of progress in cancer survival for all cancer types combined has not previously been conducted for Canada. The cancer survival index (CSI) is superior to age standardization in measuring such progress. Data are from the population-based Canadian Cancer Registry, record-linked to the Canadian Vital Statistics Death database. CSI estimates for both sexes combined were calculated as the weighted sum of the sex- and cancer-specific age-standardized net survival estimates. Sex-specific CSI estimates were calculated separately using sex-specific cancer type weights. From the 1992-to-1994 period to the 2015-to-2017 period, the five-year CSI increased 8.6 percentage points to 63.7%. It increased by 8.9 percentage points to 61.8% among males, and by 8.2 percentage points to 65.8% among females. The contribution of a cancer and sex combination to change in the CSI over time is a function of its assigned weight and changes in its age-standardized net survival. Female breast was the most influential cancer and sex combination, contributing 10.1% to the overall increase, followed by prostate (8.2%) and female lung (7.3%). The increase in the index since the 2005-to-2007 period was most impacted by lung cancer among both females (11.1%) and males (9.4%). While prostate cancer survival increased over the entire study period, it has recently decreased, resulting in a counterproductive 8.1% contribution since the 2005-to-2007 period. Steady progress has been made in overall cancer survival in Canada since the early 1990s. Female breast cancer has contributed the most to this progress overall, but more recently female lung cancer has been the most influential.

Hemodialysis vs Peritoneal Dialysis: Comparison of Net Survival in Incident Patients on Chronic Dialysis in Colombia.

Background:In the area of nephrology, the practical application of relative survival methodologies can provide information regarding the impact of outcomes for patients with kidney failure on dialysis compared with what would be expected in the absence of this condition.Objective:Compare the net survival of hemodialysis (HD) and peritoneal dialysis (PD) patients in a cohort of incident patients on chronic dialysis in Colombia, according to the dialysis therapy modality.Design:Observational, analytic, historical cohort.Setting:Renal Therapy Services (RTS) clinic network across Colombia.Patients:Patients over 18 years old with chronic kidney disease, incidents in dialytic therapy, which reached day 90 of therapy. Recruitment took place from January 1, 2008, to December 31, 2013, with a follow-up until December 31, 2018. The final cohort for analysis corresponds to a total of 12 508 patients, of which 5330 patients (42.6%) began HD and 7178 patients (57.4%) began PD.Measurements:Demographic, socioeconomic, and clinical variables were measured.Methods:Analyses were conducted according to the treatment assigned (PD or HD) at the time of the inception of the cohort and another approach of analysis was done with a subsample of those patients who never changed the initial modality. To calculate expected survival, life tables were constructed for Colombia for the years 2006 to 2018. Net survival estimates were made using the Pohar Perme estimator. The comparison of the net survival curves was done using the method developed by Pavlič and Perme, the log-rank type.Results:Net survival at 5 years compared with the general population was estimated at 0.53 (95% confidence interval 0.52-0.54) in the dialysis cohort. In intention-to-treat analyses of 7178 patients on PD and 5330 patients on HD, by global and Pohar-Perme methods, survival (expressed as a ratio of survival in patients on dialysis to survival in an age-, sex- and geographic-matched general Colombian population) was higher in patients on HD than in those on PD. In year 1, net survival by Pavlov-Perme on PD was 0.79 (95% confidence intervals [CI] 0.78 - 0.80) and on HD 0.85 (95% CI 0.84 - 0.86); in year 5, 0.36 (95% CI 0.34 – 0.38) and 0.57 (95% CI 0.55 – 0.59) for PD and HD respectively.Limitation:There may be imbalances among the populations analyzed (HD vs PD), in which one or more variables other than the type of therapy may influence the survival of the patients. In Colombia there are marginal levels of underreporting of demographic data in some subpopulations that may affect life-tables construction.Conclusion:An important difference was observed in terms of survival between the dialysis population and the population of reference without dialysis. Statistically significant differences were found in net survival between HD and PD, net survival was higher in patients on HD than in those on PD.

Burden of malignant melanoma in Ukraine in 2002-2013: incidence, mortality and survival.

The malignant melanoma (MM) incidence rates were increasing and later stabilizing in many regions of the world, while in South-Eastern Europe incidence rates are uniformly increasing and mortality rates are higher. To describe burden of MM in Ukraine in terms of incidence, mortality and survival by sex, age and stage for the period 2002-2013and compare with European countries. Database of the National Cancer Registry of Ukraine was used to extract MM incidence cases; number of MM deaths was obtained from the official mortality statistics. Age-standardised and age-specific incidence and mortality rates were calculated by sex, age groups (15-39, 40-59and 60+); estimated annual percent of change was used to describe trends. Proportions of new cases by stage of disease and calendar period (2002-2007vs 2008-2013) were compared as well as net survival estimates. In Ukraine, MM was more common in females (age-standardised 5.3per 100,000in 2013; annual percent of change 3.5%) than in males (5.1per 100,000; 4.1%); around 50% of them diagnosed in the age group 60+. The observed increase in proportion of new cases with early stage (I-II) was due to stage II cases. The slight increase in mortality rates in males or stability in females were not accompanied with increase of survival. Net MM survival was consistently lower comparing to European countries. More resources should be targeted to increase the capacity of healthcare in diagnostics and treatment of malignant melanoma, but also in promoting healthcare and education in Ukraine.

Exploring the impact of cancer registry completeness on international cancer survival differences: a simulation study

BackgroundData from population-based cancer registries are often used to compare cancer survival between countries or regions. The ICBP SURVMARK-2 study is an international partnership aiming to quantify and explore the reasons behind survival differences across high-income countries. However, the magnitude and relevance of differences in cancer survival between countries have been questioned, as it is argued that observed survival variations may be explained, at least in part, by differences in cancer registration practice, completeness and the availability and quality of the respective data sources.MethodsAs part of the ICBP SURVMARK-2 study, we used a simulation approach to better understand how differences in completeness, the characteristics of those missed and inclusion of cases found from death certificates can impact on cancer survival estimates.ResultsBias in 1- and 5-year net survival estimates for 216 simulated scenarios is presented. Out of the investigated factors, the proportion of cases not registered through sources other than death certificates, had the largest impact on survival estimates.ConclusionOur results show that the differences in registration practice between participating countries could in our most extreme scenarios explain only a part of the largest observed differences in cancer survival.

Progression of incidence and estimate of net survival from papillary thyroid cancers diagnosed between 2008 and 2016 in France

BackgroundAfter several decades of increasing incidence of papillary thyroid cancer (PTC), a change in this trend has been recently observed, particularly in the United States. This is attributed to the impact of new guidelines for the management of thyroid disease. The objective of this study was to describe the recent situation in France in terms of incidence and survival, taking account of tumor size. MethodsData from the FRANCIM network cancer registries, covering around 25% of the French metropolitan population, were analyzed. Distribution according to tumor size was determined in terms of frequency, trends in incidence and spatial distribution for the period 2008–2016. Analysis of net survival considered gender, age and tumor size. ResultsCancers of size≤5mm were predominant in patients diagnosed between 55 and 74 years of age. Incidence of≤5mm tumors in women and of 5–10mm tumors in men began declining in the early 2010s. Incidence of 10–20mm and 20–40mm tumors in men increased significantly throughout the period 2008–2016. For both men and women, the incidence of the largest tumors (>40mm) also increased, but not significantly. The spatial distribution of incidence showed great heterogeneity. Net survival was generally high, although decreasing with age and tumor size. ConclusionThe recent epidemiological situation in France is consistent with the hypothesis of recent progress in medical management of thyroid pathologies. Variations in incidence should be monitored for both small (<10mm) and larger tumors, and notably>40mm tumors. Net survival is generally high, although decreasing with age and tumor size.

Estimation of age-standardized net survival, even when age-specific data are sparse

BackgroundAge-standardization is vital in international comparison studies of cancer patient survival, but standard approaches can fail to produce estimates in the case of sparsity. MethodsThe purpose of this paper is to demonstrate that using a standardization pre-weighting approach is a viable alternative approach for external age-standardization in population-based cancer data and performs well in cases of sparsity. We further de;1;scribe how the pre-weighting approach to age-standardization can be coupled with the Pohar Perme estimator in both a cohort and period analysis setting. For period analysis, we compare approaches for defining the internal age distribution. We use SEER public use data to illustrate our approach and estimate survival for Connecticut and by race to create a scenario with sufficient sparsity. ResultsThe pre-weighting approach gives comparable estimates to traditional age-standardization in cases with sufficient data and produces estimates throughout follow-up in cases of sparsity when a traditional approach would fail. ConclusionInternational comparison studies and other national population-based survival studies that need to age-standardize estimates for comparability purposes should adopt the Pohar Perme estimator with pre-weighting. This approach avoids issues of non-estimation in the case of sparsity and will allow more consistent comparisons across the produced estimates.

Survival trends for primary liver cancer, 1995–2009: analysis of individual data for 578,740 patients from 187 population-based registries in 36 countries (CONCORD-2)

Background: Primary liver cancer is the fifth most common cancer world-wide, and the second most common cause of death from cancer, with an estimated 841,100 new cases and 781,500 deaths each year. Hepatocellular carcinoma (HCC) accounts for 60–80% of cases, and cholangiocarcinoma 10–40%. We examined global trends in survival for both these sub-types of liver cancer, by country, age, sex and calendar period. Methods: Data on 1,005,032 adults (aged 15–99 years) diagnosed with a primary, invasive malignant neoplasm of the liver or intrahepatic bile ducts between 1995 and 2009 were provided by 243 population-based cancer registries in 60 countries. Analysis was restricted to patients for whom the diagnosis of a primary malignancy had been confirmed by histological or cytological examination, or assignation of a specific morphology code, and to registries from which survival estimates were considered reliable. We estimated both five-year net survival and conditional five-year net survival, for patients who survived to the first anniversary of diagnosis. Funnel plots were used to examine international variation in survival and variation by age and morphology. Results: Data on 578,740 patients from 187 registries in 36 countries were included after quality control. For patients diagnosed during 2004–2009, the pooled estimate of age-standardised five-year net survival for liver cancer was 14.8% (range, 4.4–23.7%), higher than for patients diagnosed during 1995–2000 (11.0%). Survival for patients diagnosed with HCC during 2004–2009 (pooled estimate 17.4%, range 7.7–25.5%) was higher than for those with cholangiocarcinoma (8.4%, range 3.7–16.0%). Survival for patients diagnosed during 2004–2009 was higher in Canada, Italy, Japan, Taiwan and Korea (21.2–23.7%) than the pooled estimate for patients diagnosed some 10 years earlier (1995–2000; 11.0%). Conditional survival in 2004–2009 was also higher in New Zealand, Canada, Taiwan, Korea, and China (42.0–52.7%) than the pooled estimate for 1995–2000 (33.2%). Conclusions: Survival from primary cancers of the liver has increased, but it remains poor in most countries we have examined. International variation in survival highlights the potential to improve outcomes, but prevention must also remain a priority. There is a need for continued and expanded surveillance of survival, especially in low- and middle-income countries, to assess the impact of interventions in policy and treatment. Greater consistency in registration practice and coding of liver cancer would reduce the variation in data quality and further improve the comparability of survival estimates.

Correcting for misclassification and selection effects in estimating net survival in clinical trials

BackgroundNet survival, a measure of the survival where the patients would only die from the cancer under study, may be compared between treatment groups using either “cause-specific methods”, when the causes of death are known and accurate, or “population-based methods”, when the causes are missing or inaccurate. The latter methods rely on the assumption that mortality due to other causes than cancer is the same as the expected mortality in the general population with same demographic characteristics derived from population life tables. This assumption may not hold in clinical trials where patients are likely to be quite different from the general population due to some criteria for patient selection.MethodsIn this work, we propose and assess the performance of a new flexible population-based model to estimate long-term net survival in clinical trials and that allows for cause-of-death misclassification and for effects of selection. Comparisons were made with cause-specific and other population-based methods in a simulation study and in an application to prostate cancer clinical trial data.ResultsIn estimating net survival, cause-specific methods seemed to introduce important biases associated with the degree of misclassification of cancer deaths. The usual population-based method provides also biased estimates, depending on the strength of the selection effect. Compared to these methods, the new model was able to provide more accurate estimates of net survival in long-term clinical trials.ConclusionFinally, the new model paves the way for new methodological developments in the field of net survival methods in multicenter clinical trials.