Libby Ellis

Population-based cancer survival trends in England and Wales up to 2007: an assessment of the NHS cancer plan for England

BACKGROUND The National Health Service (NHS) cancer plan for England was published in 2000, with the aim of improving the survival of patients with cancer. By contrast, a formal cancer strategy was not implemented in Wales until late 2006. National data on cancer patient survival in England and Wales up to 2007 thus offer the opportunity for a first formal assessment of the cancer plan in England, by comparing survival trends in England with those in Wales before, during, and after the implementation of the plan. METHODS We analysed population-based survival in 2.2 million adults diagnosed with one of 21 common cancers in England and Wales during 1996-2006 and followed up to Dec 31, 2007. We defined three calendar periods: 1996-2000 (before the cancer plan), 2001-03 (initialisation), and 2004-06 (implementation). We estimated year-on-year trends in 1-year relative survival for patients diagnosed during each period, and changes in those trends between successive periods in England and separately in Wales. Changes between successive periods in mean survival up to 5 years after diagnosis were analysed by country and by government office region of England. Life tables for single year of age, sex, calendar year, deprivation category, and government office region were used to control for background mortality in all analyses. FINDINGS 1-year survival in England and Wales improved for most cancers in men and women diagnosed during 1996-2006 and followed until 2007, although not all trends were significant. Annual trends were generally higher in Wales than in England during 1996-2000 and 2001-03, but higher in England than in Wales during 2004-06. 1-year survival for patients diagnosed in 2006 was over 60% for 12 of 17 cancers in men and 13 of 18 cancers in women. Differences in 3-year survival trends between England and Wales were less marked than the differences in 1-year survival. North-South differences in survival trends for the four most common cancers were not striking, but the North West region and Wales showed the smallest improvements during 2001-03 and 2004-06. INTERPRETATION The findings indicate slightly faster improvement in 1-year survival in England than in Wales during 2004-06, whereas the opposite was true during 2001-03. This reversal of survival trends in 2001-03 and 2004-06 between England and Wales is much less obvious for 3-year survival. These different patterns of survival suggest some beneficial effect of the NHS cancer plan for England, although the data do not so far provide a definitive assessment of the effectiveness of the plan.

Carcinoid tumors of the gastrointestinal tract: trends in incidence in England since 1971.

OBJECTIVES:The epidemiology of gastrointestinal neuroendocrine tumors (GI-NETs) is poorly understood. Recent analyses have suggested changes in the incidence and distribution of such tumors, but have generally used data sets containing small patient numbers. We aimed to define trends in the epidemiology of GI-NETs in England over a 36-year period.METHODS:We analyzed data from the national population-based cancer registry, which covers a population in excess of 50 million, over the period 1971–2006.RESULTS:In all, 10,324 cases of GI-NETs were identified. The overall incidence increased from 0.27 (per 100,000 per year) to 1.32 for men and from 0.35 to 1.33 for women. The anatomic distribution of tumors in the latest period analyzed was stomach 12%, small intestine 29%, appendix 38%, colon 13%, and rectum 8%. The largest absolute increase in incidence was seen in the appendix (from 0.03 to 0.41 in men; from 0.05 to 0.59 in women). The greatest relative increase was in gastric NETs, increasing 2,325% in men, and 4,746% in women. Overall, 48% of GI-NETs occurred in men. Sex-specific incidence rates for gastric, colonic, and rectal NETs are similar, whereas appendiceal lesions were more common in females, and small intestinal tumors in men.CONCLUSIONS:Large increases in the incidence of GI-NETs were observed, along with changes in anatomical distribution. Such changes may partly reflect changes in classification or improved detection through the increased use of endoscopy and imaging techniques. In view of the magnitude of these changes, particularly for gastric tumors, further studies to examine the underlying etiology of these changes are urgently indicated.

Socioeconomic inequalities in cancer survival in England after the NHS cancer plan

Background:Socioeconomic inequalities in survival were observed for many cancers in England during 1981–1999. The NHS Cancer Plan (2000) aimed to improve survival and reduce these inequalities. This study examines trends in the deprivation gap in cancer survival after implementation of the Plan.Materials and method:We examined relative survival among adults diagnosed with 1 of 21 common cancers in England during 1996–2006, followed up to 31 December 2007. Three periods were defined: 1996–2000 (before the Cancer Plan), 2001–2003 (initialisation) and 2004–2006 (implementation). We estimated the difference in survival between the most deprived and most affluent groups (deprivation gap) at 1 and 3 years after diagnosis, and the change in the deprivation gap both within and between these periods.Results:Survival improved for most cancers, but inequalities in survival were still wide for many cancers in 2006. Only the deprivation gap in 1-year survival narrowed slightly over time. A majority of the socioeconomic disparities in survival occurred soon after a cancer diagnosis, regardless of the cancer prognosis.Conclusion:The recently observed reduction in the deprivation gap was minor and limited to 1-year survival, suggesting that, so far, the Cancer Plan has little effect on those inequalities. Our findings highlight that earlier diagnosis and rapid access to optimal treatment should be ensured for all socioeconomic groups.

Socio-economic disparities in access to treatment and their impact on colorectal cancer survival

BACKGROUND Significant socio-economic disparities have been reported in survival from colorectal cancer in a number of countries, which remain largely unexplained. We assessed whether possible differences in access to treatment among socio-economic groups may contribute to those disparities, using a population-based approach. METHODS We retrospectively studied 71 917 records of colorectal cancer patients, diagnosed between 1997 and 2000, linked to area-level socio-economic information (Townsend index), from three cancer registries in UK. Access to treatment was measured as a function of delay in receipt of treatment. We assessed socio-economic differences in access through logistic regression models. Based on relative survival < or =3 years after diagnosis, we estimated excess hazard ratios (EHRs) of death for different socio-economic groups. RESULTS Compared with more affluent patients, deprived patients had poorer survival [EHR = 1.20; 95% confidence interval (CI) 1.16-1.25], were less likely to receive any treatment within 6 months [odds ratio (OR) = 0.87, 95% CI 0.82-0.92] and, if treated, were more likely to receive late treatment. No disparities in survival were detected among patients receiving treatment within 1 month from diagnosis. Disparities existed among patients receiving later or no treatment (EHR = 1.30; 95% CI 1.22-1.39), and persisted after adjustment for age and stage at diagnosis (EHR = 1.15; 95% CI 1.08-1.24). CONCLUSIONS Tumour stage helped explain socio-economic disparities in colorectal cancer survival. Disparities were also greatly attenuated among patients receiving early treatment. Aspects other than those captured by our measure of access, such as quality of care and patient preferences in relation to treatment, might contribute to a fuller explanation.

How many deaths would be avoidable if socioeconomic inequalities in cancer survival in England were eliminated? A national population-based study, 1996–2006

AIM Inequalities in survival between rich and poor have been reported for most adult cancers in England. This study aims to quantify the public health impact of these inequalities by estimating the number of cancer-related deaths that would be avoidable if all patients were to have the same cancer survival as the most affluent patients. METHODS National Cancer Registry data for all adults diagnosed with one of 21 common cancers in England were used to estimate relative survival. We estimated the number of excess (cancer-related) deaths that would be avoidable within three years after diagnosis if relative survival for patients in all deprivation groups was as high as the most affluent group. RESULTS For patients diagnosed during 2004-2006, 7122 of the 64,940 excess deaths a year (11%) would have been avoidable if three-year survival for all patients had been as high as in the most affluent group. The annual number of avoidable deaths fell from 8435 (13%) a year for patients diagnosed during 1996-2000. Over 60% of the total number of avoidable deaths occurred within six months after diagnosis and approximately 70% occurred in the two most deprived groups. CONCLUSION The downward trend in the annual number of avoidable deaths reflects more an improvement in survival in England overall, rather than a narrowing of the deficit in cancer survival between poor and rich. The lack of any substantial change in the percentage of avoidable excess deaths highlights the persistent nature of the deficit in survival between affluent and deprived groups.

Cancer incidence, survival and mortality: explaining the concepts.

Cancer incidence, survival and mortality are essential population‐based indicators for public health and cancer control. Confusion and misunderstanding still surround the estimation and interpretation of these indicators. Recurring controversies over the use and misuse of population‐based cancer statistics in health policy suggests the need for further clarification. In our article, we describe the concepts that underlie the measures of incidence, survival and mortality, and illustrate the synergy between these measures of the cancer burden. We demonstrate the relationships between trends in incidence, survival and mortality, using real data for cancers of the lung and breast from England and Sweden. Finally, we discuss the importance of using all three measures in combination when interpreting overall progress in cancer control, and we offer some recommendations for their use.

Health Systems Performance and Cancer Outcomes

Do the characteristics of health systems influence cancer outcomes? Although caveats are required when undertaking international comparisons of both health systems and cancer outcomes, observed differences cannot solely be explained by data problems or economic development. Health systems can influence cancer outcomes through three mechanisms: coverage, innovation, and quality of care. First, in countries where population coverage is incomplete, patients may find certain services excluded or face substantial copayments or deductibles. Second, there are variations in the rate at which innovative treatments are introduced, reflecting in particular the need for publicly funded health systems to compare costs and benefits of increasingly expensive treatments given demands for other treatments. Third, systematic differences in quality of care (early diagnosis, timely and equitable access to specialist care, and existence of systematic coordination between these activities) may lead to variations in cancer outcomes.

Multivariable flexible modelling for estimating complete, smoothed life tables for sub-national populations.

BackgroundThe methods currently available to estimate age- and sex-specific mortality rates for sub-populations are subject to a number of important limitations. We propose two alternative multivariable approaches: a relational model and a Poisson model both using restricted cubic splines.MethodsWe evaluated a flexible Poisson and flexible relational model against the Elandt-Johnson approach in a simulation study using 100 random samples of population and death counts, with different sampling proportions and data arrangements. Estimated rates were compared to the original mortality rates using goodness-of-fit measures and life expectancy. We further investigated an approach for determining optimal knot locations in the Poisson model.ResultsThe flexible Poisson model outperformed the flexible relational and Elandt-Johnson methods with the smallest sample of data (1%). With the largest sample of data (20%), the flexible Poisson and flexible relational models performed comparably, though the flexible Poisson model displayed a slight advantage. Both approaches tended to underestimate infant mortality and thereby overestimate life expectancy at birth. The flexible Poisson model performed much better at young ages when knots were fixed a priori. For ages 30 and above, results were similar to the model with no fixed knots.ConclusionsThe flexible Poisson model is recommended because it derives robust and unbiased estimates for sub-populations without making strong assumptions about age-specific mortality profiles. Fixing knots a priori in the final model greatly improves fit at the young ages.

The impact of life tables adjusted for smoking on the socio-economic difference in net survival for laryngeal and lung cancer

Background:Net survival is a key measure in cancer control, but estimates for cancers that are strongly associated with smoking may be biased. General population life tables represent background mortality in net survival, but may not adequately reflect the higher mortality experienced by smokers.Methods:Life tables adjusted for smoking were developed, and their impact on net survival and inequalities in net survival for laryngeal and lung cancers was examined.Results:The 5-year net survival estimated with smoking-adjusted life tables was consistently higher than the survival estimated with unadjusted life tables: 7% higher for laryngeal cancer and 1.5% higher for lung cancer. The impact of using smoking-adjusted life tables was more pronounced in affluent patients; the deprivation gap in 5-year net survival for laryngeal cancer widened by 3%, from 11% to 14%.Conclusions:Using smoking-adjusted life tables to estimate net survival has only a small impact on the deprivation gap in survival, even when inequalities are substantial. Adjusting for the higher, smoking-related background mortality did increase the estimates of net survival for all deprivation groups, and may be more important when measuring the public health impact of differences or changes in survival, such as avoidable deaths or crude probabilities of death.

Full dates (day, month, year) should be used in population-based cancer survival studies.

Accurate survival estimates are essential for monitoring cancer survival trends, for health care planning and for resource allocation. To obtain precise estimates of survival, full dates (day, month and year) rather than partial dates (month and year) are required. In some jurisdictions, however, cancer registries are constrained from providing full dates on the grounds of confidentiality. The bias resulting from the use of partial dates in the estimation and comparison of survival makes it impossible to determine precisely the differences in the risk of death from cancer between population groups or in successive calendar periods. Important operational arguments also exist against the use of incomplete dates for survival analysis, including increased workload for cancer registry staff and the introduction of avoidable complexity for quality control of survival data. Cancer survival is one of the most widely known outputs produced by population‐based cancer registries, and it is a crucial metric for the comparative effectiveness of health services. The bodies that set data access guidelines must take a more balanced view of the risks and benefits of using full dates for the estimation of cancer survival.