Vivian Mak

Variation in incidence of breast, lung and cervical cancer and malignant melanoma of skin by socioeconomic group in England

BackgroundCancer incidence varies by socioeconomic group and these variations have been linked with environmental and lifestyle factors, differences in access to health care and health seeking behaviour. Socioeconomic variations in cancer incidence by region and age are less clearly understood but they are crucial for targeting prevention measures and health care commissioning.MethodsData were obtained from all eight English cancer registries for patients diagnosed between 1998 and 2003, for all invasive cases of female breast cancer (ICD-10 code C50), lung cancer (ICD-10 codes C33-C34), cervical cancer (ICD-10 code C53), and malignant melanoma of the skin (ICD-10 code C43). Socioeconomic status was assigned to each patient based on their postcode of residence at diagnosis, using the income domain of the Index of Multiple Deprivation 2004. We analysed the socioeconomic variations in the incidence of breast, lung and cervical cancer and malignant melanoma of the skin for England, and regionally and by age.ResultsIncidence was highest for the most deprived patients for lung cancer and cervical cancer, whilst the opposite was observed for malignant melanoma and breast cancer. The difference in incidence between the most and the least deprived groups was higher for lung cancer patients aged under 65 at diagnosis than those over 65 at diagnosis, which may indicate a cohort effect. There were regional differences in the socioeconomic gradients with the gap being widest for lung and cervical cancer in the North (North East, North West and Yorkshire and Humberside) and for malignant melanoma in the East and South West. There were only modest variations in breast cancer incidence by region. If the incidence of lung and cervical cancer were decreased to that of the least deprived group it would prevent 36% of lung cancer cases in men, 38% of lung cancer cases in women and 28% of cervical cancer cases. Incidence of breast cancer and melanoma was highest in the least deprived group, therefore if all socioeconomic groups had incidence rates similar to the least deprived group it is estimated that the number of cases would increase by 7% for breast cancer, 27% for melanoma in men and 29% for melanoma in women.ConclusionNational comparison of socioeconomic variations in cancer incidence by region and age can provide an unbiased basis for public health prevention and health commissioning. Decreasing inequalities in incidence requires the integration of information on risk factors, incidence and projected incidence but targeted public health interventions could help to reduce regional inequalities in incidence and reduce the future cancer burden.

The epidemiology and survival of extrapulmonary small cell carcinoma in South East England, 1970-2004.

BackgroundExtrapulmonary small cell carcinoma (EPSCC) is a rare cancer and few studies describe its epidemiology. Our objectives were to compare the incidence and survival of EPSCC in South East England with small cell carcinoma of the lung (SCLC), to determine the most common anatomical presenting sites for EPSCC and to compare survival in EPSCC by disease stage and site of diagnosis.MethodsWe used data from the Thames Cancer Registry database for South East England between 1970 and 2004 to determine the incidence, most common anatomical sites, and survival by site, and stage of EPSCC. 1618 patients registered with EPSCC were identified. We calculated the age-standardised incidence rate for EPSCC using the European standard population and compared this to that for SCLC. We calculated survival using the Kaplan-Meier method for EPSCC and SCLC, and reported 3-year survival for different EPSCC anatomical sites and disease stages.ResultsThe incidence of EPSCC was much lower than for SCLC, similar in males and females, and stable throughout the study period, with incidence rates of 0.45 per 100,000 in males and 0.37 in females during 2000–2004. In general, patients with EPSCC had a better 3-year survival (19%) than SCLC (5%). The most common anatomical sites for EPSCC were oesophagus (18%), other gastrointestinal (15%), genitourinary (20%), head and neck (11%), and breast (10%). Breast EPSCC had the best 3-year survival (60%) and gastrointestinal EPSCC the worst (7%).ConclusionThis study suggests that EPSCC has a stable incidence and confirms that it presents widely, but most commonly in the oesophagus and breast. Site and extent of disease influence survival, with breast EPSCC having the best prognosis. Further studies using standardised diagnosis, prospective case registers for uncommon diseases and European cancer registries are needed to understand this disease.

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.

Lung cancer incidence and survival in England: an analysis by socioeconomic deprivation and urbanization.

Introduction: Most previous studies have investigated either socioeconomic deprivation or urbanization in relationship to lung cancer incidence or survival. We investigated the association between socioeconomic deprivation, urbanization, and lung cancer incidence and survival in England. Methods: We extracted data on patients diagnosed with lung cancer (ICD-10 C33-C34) between 2003 and 2007 and who were resident in England. We assigned each patient to an urbanization score and to a socioeconomic quintile based on their postcode of residence. We calculated age-specific and age-standardized incidence rates (per 100,000 European standard population) by urbanization, sex, and socioeconomic deprivation group. We used Kaplan-Meier survival analysis to compare the survival of patients from urban and rural areas by socioeconomic deprivation. Results: A high proportion of urban areas in England were classified as deprived and rural areas were mostly affluent. The incidence of lung cancer was higher in urban areas than in rural areas. In the more affluent areas, the incidence of lung cancer in urban and rural areas was very similar. Survival from lung cancer was slightly higher in affluent areas than in deprived areas. Survival from lung cancer in urban and rural areas was similar across all socioeconomic deprivation quintiles. Conclusions: The difference in incidence between urban and rural areas can be explained by the differences in the distribution of socioeconomic deprivation quintiles in the two urbanization categories. When socioeconomic deprivation is taken into account, little difference is seen between both the incidence and survival of lung cancer in urban and rural areas.

Inequalities in the incidence of cervical cancer in South East England 2001–2005: an investigation of population risk factors

BackgroundThe incidence of cervical cancer varies dramatically, both globally and within individual countries. The age-standardised incidence of cervical cancer was compared across primary care trusts (PCTs) in South East England, taking into account the prevalence of known behavioural risk factors, screening coverage and the deprivation of the area.MethodsData on 2,231 cases diagnosed between 2001 and 2005 were extracted from the Thames Cancer Registry, and data on risk factors and screening coverage were collated from publicly available sources. Age-standardised incidence rates were calculated for each PCT using cases of squamous cell carcinoma in the screening age group (25–64 years).ResultsThe age-standardised incidence rate for cervical cancer in South East England was 6.7 per 100,000 population (European standard) but varied 3.1 fold between individual PCTs. Correlations between the age-standardised incidence rate and smoking prevalence, teenage conception rates, and deprivation were highly significant at the PCT level (p < 0.001). However, screening coverage was not associated with the incidence of cervical cancer at the PCT level. Poisson regression indicated that these variables were all highly correlated and could not determine the level of independent contribution at a population level.ConclusionThere is excess disease burden within South East England. Significant public health gains can be made by reducing exposure to known risk factors at a population level.

Histological subtype of lung cancer in relation to socio-economic deprivation in South East England

BackgroundPrevious studies have found differences in the histological subtypes of lung cancers affecting males and females. Our objective was to investigate trends in the incidence of histological subtypes of lung cancer in males and females in relation to socio-economic deprivation in South East England.MethodsData on 48,031 males and 30,454 females diagnosed with lung cancer between 1995 and 2004 were extracted from the Thames Cancer Registry database. Age-standardised incidence rates for histological subtypes were calculated for each year, using the European standard population. Using the Income Domain of the Multiple Index of Deprivation 2004, patients diagnosed between 2000 and 2004 were classified into quintiles of socio-economic deprivation based on their postcode of residence. Age-standardised rates for each histological subtype were then calculated for each deprivation quintile. A Poisson regression model was fitted to the data for males and females separately to test the hypothesis that the relationship between socio-economic deprivation and adenocarcinoma was less strong than for other subtypes.ResultsIn males all specific histological subtypes except adenocarcinoma declined in incidence. Squamous cell carcinoma remained the most common specific subtype and large cell carcinoma the least common. In females squamous cell carcinoma was initially most common, but its incidence declined slightly and that for adenocarcinoma increased. In both sexes the overall age-standardised incidence rate of lung cancer increased with increasing deprivation. However, these trends were less strong for adenocarcinoma than for the other subtypes in both males (p < 0.001) and females (p = 0.003).ConclusionThe temporal trends and distribution of histological subtypes of lung cancer in males and females are similar to that reported from other western populations. In both males and females, adenocarcinoma was less strongly related to deprivation than other subtypes. This may be because its development is less strongly linked to individual smoking history.

The effect of economic deprivation on oesophageal and gastric cancer in a UK cancer network.

Aims:  The National Health Service (NHS) Cancer Plan aims to eliminate economic inequalities in healthcare provision and cancer outcomes. This study examined the influence of economic status upon the incidence, access to treatment and survival from oesophageal and gastric cancer in a single UK cancer network.

Using funnel plots to explore variation in cancer mortality across primary care trusts in South-East England

BACKGROUND In 2004, the English government set a target to reduce the difference in cancer mortality in those aged under 75 between spearhead primary care trusts (PCTs) and all others by 6% in 2010. METHODS We used mortality data for 2002-04 to calculate the age-standardized cancer mortality rates in 11 spearhead and 65 non-spearhead PCTs in South-East England. We calculated the ratio of each rate to that for England and Wales overall, and plotted these within funnel plots. RESULTS Age-standardized cancer mortality ratios for males varied widely. The 11 spearhead PCTs had the highest mortality and six fell outside three standard deviations of the distribution of the funnel. Removing mortality due to lung cancer greatly reduced this variation and caused the outliers to shift down within the normal range. Ratios for females showed less variation, although those for spearheads were higher. One high outlier was unaffected by removing mortality due to lung cancer, other smoking-related cancers or breast cancer. CONCLUSION Current variation in PCT cancer mortality is materially influenced by past patterns of smoking in men but less so in women. Effective smoking cessation policies should decrease inequalities in male cancer mortality, but will take time and be less effective in decreasing female inequalities.

Trends in the epidemiology of head and neck cancer in London

Head and neck cancers [HNCs] are biologically heterogeneous tumours. The objectives of this study were to describe trends in incidence of HNCs amongst London residents by sex, age, anatomical site, deprivation and ethnicity.

Survival from twenty adult cancers in the UK and Republic of Ireland in the late twentieth century

AbstractBackground International studies have shown that cancer survival was generally low in the UK and the Republic of Ireland compared to western and northern European countries, but no systematic comparative analysis has been performed between the UK countries and the Republic of Ireland. Methods Population‐based survival for 20 adult malignancies was estimated for the UK and the Republic of Ireland. Data on adults (15–99 years) diagnosed between 1991 and 1999 in England, Scotland, Wales, Northern Ireland (1993–99) and the Republic of Ireland (1994–99) were analysed. All cases were followed up until the end of 2001. Relative survival was estimated by sex, period of diagnosis and country, and for the nine regions of England. Predicted survival was estimated using the hybrid approach. Results Overall, cancer survival in UK and Republic of Ireland improved during the 1990s, but there was geographic variation in survival across the UK and Republic of Ireland. Survival was generally highest in Ireland and Northern Ireland and lowest in England and Wales. Survival tended to be higher in Scotland for cancers for which early detection methods were in place. In England, survival tended to be lower in the north and higher in the south. Conclusions The geographic variations in survival seen across the UK and Republic of Ireland are narrower than between these countries and comparable European countries. Artefact is likely to explain some, but not all of the differences across the UK and Republic of Ireland. Geographic differences in stage at diagnosis, co‐morbidity and other clinical factors may also be relevant. List of Tables, 9