Socioeconomic variation in colon cancer tumour factors associated with poorer prognosis

Understanding the impact of socioeconomic differences in colorectal cancer survival: potential gain in life-years

BACKGROUND

Colorectal cancer prognosis varies substantially with socioeconomic status. We investigated differences in life expectancy between socioeconomic groups and estimated the potential gain in life-years if cancer-related survival differences could be eliminated.

METHODS

This population-based study included 470,000 individuals diagnosed with colon and rectal cancers between 1998 and 2013 in England. Using flexible parametric survival models, we obtained a range of life expectancy measures by deprivation status. The number of life-years that could be gained if differences in cancer-related survival between the least and most deprived groups were removed was also estimated.

RESULTS

We observed up to 10% points differences in 5-year relative survival between the least and most deprived. If these differences had been eliminated for colon and rectal cancers diagnosed in 2013 then almost 8231 and 7295 life-years would have been gained respectively. This results for instance in more than 1-year gain for each colon cancer male patient in the most deprived group on average. Cancer-related differences are more profound earlier on, as conditioning on 1-year survival the main reason for socioeconomic differences were factors other than cancer.

CONCLUSION

This study highlights the importance of policies to eliminate socioeconomic differences in cancer survival as in this way many life-years could be gained.

Estimating the impact of a cancer diagnosis on life expectancy by socio-economic group for a range of cancer types in England

BACKGROUND

Differences in cancer survival exist across socio-economic groups for many cancer types. Standard metrics fail to show the overall impact for patients and the population.

METHODS

The available data consist of a population of ∼2.5 million patients and include all patients recorded as being diagnosed with melanoma, prostate, bladder, breast, colon, rectum, lung, ovarian and stomach cancers in England between 1998 and 2013. We estimated the average loss in expectation of life per patient in years and the proportion of life lost for a range of cancer types, separately by deprivation group. In addition, estimates for the total number of years lost due to each cancer were also obtained.

RESULTS

Lung and stomach cancers result in the highest overall loss for males and females in all deprivation groups in terms of both absolute life years lost and loss as a proportion of expected life remaining. Female lung cancer patients in the least- and most-deprived group lose 14.4 and 13.8 years on average, respectively, that is translated as 86.1% and 87.3% of their average expected life years remaining. Melanoma, prostate and breast cancers have the lowest overall loss. On the basis of the number of patients diagnosed in 2013, lung cancer results in the most life years lost in total followed by breast cancer. Melanoma and bladder cancer account for the lowest total life years lost.

CONCLUSIONS

There are wide differences in the impact of cancer on life expectancy across deprivation groups, and for most cancers the most affluent lose less years.

Impact of deprivation on short- and long-term outcomes after colorectal cancer surgery

Background

The aim of the study was to determine the association between short- and long-term outcomes and deprivation for patients undergoing operative treatment for colorectal cancer in the Northern Region of England.

Methods

This was a retrospective analytical study based on the Northern Region Colorectal Cancer Audit Group database for the period 1998–2002. The Index of Multiple Deprivation 2004, an area-based measure, was recalibrated and used to quantify deprivation. Patients were ranked based on their postcode of residence and grouped into five categories.

Results

Of 8159 patients in total, 7352 (90·1 per cent) had surgery; 6953 (94·6 per cent) of the 7352 patients underwent tumour resection and 4935 (67·7 per cent) of 7294 had a margin-negative (R0) resection. Deprivation was not associated with age, sex, tumour site, stage or other tumour-related factors. Compared with the most affluent group, the most deprived patients had fewer elective operations (72·9 versus 76·4 per cent; P = 0·014), more adverse co-morbidity (P < 0·001) and fewer curative resections (65·5 versus 71·2 per cent; P < 0·001). In multivariable analysis, deprivation was not an independent predictor of postoperative death (odds ratio (OR) 0·72, 95 per cent confidence interval 0·48 to 1·06; P = 0·101) but it was a predictor of curative resection (OR 1·24, 1·01 to 1·52; P = 0·042), overall survival (HR 0·83, 0·73 to 0·95; P = 0·006) and relative survival (HR 0·74, 0·58 to 0·95; P = 0·023).

Conclusion

Deprivation, both independently and by influencing other surgical predictors, impacts on short- and long-term outcomes of patients with colorectal cancer.

Does socioeconomic status influence the prospect of cure from colon cancer--a population-based study in Sweden 1965-2000

AIM OF STUDY

Differences in the survival of colon cancer patients by socioeconomic status have been demonstrated in several populations, but the underlying reasons for the differences are not well understood. By simultaneously estimating the proportion of patients cured from colon cancer and the survival times of the 'uncured' we hope to increase understanding of how socioeconomic status affects survival following a diagnosis of colon cancer.

METHODS

We conducted a population-based cohort study of 58,873 patients diagnosed with colon cancer in Sweden 1965-2000. Socioeconomic status was classified based on occupation. We fitted mixture cure models and Poisson regression models adjusted for age, sex and calendar period.

RESULTS

We observed higher excess mortality, lower proportion cured and shorter survival times among the uncured in patients from lower socioeconomic groups compared to the highest socioeconomic group. There was no evidence that the gap between the socioeconomic groups reduced over time. Farmers had the lowest odds of cure (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.75-0.95) compared to higher non-manual workers followed by self-employed (0.91, 0.81-1.03), manual workers (0.93, 0.85-1.03) and lower non-manual workers (0.98, 0.89-1.08).

CONCLUSION

Patients from lower socioeconomic groups in Sweden experience worse survival following a diagnosis of colon cancer. Differences exist in both the cure proportion and the survival time of the uncured, suggesting that socioeconomic differences cannot be attributed solely to lead time bias.Although this study has furthered our understanding of socioeconomic differences in survival, more detailed studies are required in order to identify, and subsequently remove, the underlying reasons for the differences.

Trends and variation in the management of oesophagogastric cancer patients: a population-based survey

Background

Previous evidence indicates potential variation in the quality of care of cancer patients. We aimed to examine whether recent changes in the treatment of oesophagogastric cancers have been distributed equally among different patient subgroups.

Methods

We analysed population-based cancer registry data about the treatment patterning of oesophagogastric cancer (other than oesophageal squamous cell carcinoma) during 1995-2006.

Results

There were 14,077 patients aged ≥40 years (69% men). There was only limited information on stage, and no information on co-morbidity status. During successive triennia, curative surgery use decreased from 28% to 20% (p < 0.001) whilst chemotherapy use increased from 9% to 30% (p < 0.001). Use of palliative surgery and of radiotherapy increased significantly but modestly (7% to 10%, and 9% to 11%, respectively). In multivariable logistic regression adjusting for age group, gender, diagnosis period and tumour type, curative surgery and chemotherapy were used less frequently in more deprived patients [per increasing deprivation group Odds Ratio (OR) = 0.96, 95% Confidence Interval (CI) 0.93-0.99, and OR = 0.90, 95%CI 0.87-0.93, respectively, p < 0.001 for both)]. Chemotherapy was also used less frequently in women (OR = 0.76, p < 0.001).

Conclusions

During the study period, curative surgery decreased by a third and chemotherapy use increased by more than three-fold, reflecting improvements in the appropriateness and quality of management, but chemotherapy use, in particular, was unequal, both by socioeconomic status and gender.

Pronostic des cancers colorectaux et inégalités socio-économiques

It is well established that socio-economic status is a major prognostic factor for many cancers, including colorectal cancer. The aims of this review are (i) to report epidemiological data showing how socio-economic status influences colorectal cancer survival, (ii) to attempt to describe the mechanisms underlying these survival inequalities, and (iii) to assess their impact on survival of colorectal cancer.

Origins of socio-economic inequalities in cancer survival: a review

BACKGROUND

Cancer survival is known to vary by socio-economic group. A review of studies published by 1995 showed this association to be universal and resilient to the many different ways in which socio-economic status was determined. Differences were most commonly attributed to differences in stage of disease at diagnosis.

MATERIALS AND METHODS

A review of research published since 1995 examining the association of cancer survival with socio-economic variables.

RESULTS

An association between socio-economic status and cancer survival has continued to be demonstrated in the last decade of research. Stage at diagnosis and differences in treatment have been cited as the most important explanatory factors. Some research has evaluated the psychosocial elements of this association.

CONCLUSIONS

Socio-economic differences in cancer survival are now well documented. The explanatory power of stage at diagnosis, although great, should not detract from the evidence of differential treatment between social groups. Neither factor can completely explain the observed socio-economic differences in survival, however, and the importance of differences in tumour and patient factors should now be quantified.

Absence of socioeconomic variation in survival from colorectal cancer in patients receiving surgical treatment in one health district: cohort study

OBJECTIVE

To examine whether there is an association between patient deprivation status and survival from colorectal cancer among patients receiving treatment of the same type and quality.

PATIENTS AND METHODS

A survival study was conducted of all colorectal cancer patients diagnosed between 1991 and 1997 who received surgery either in the NHS district general hospital or the private hospital of one UK health district. The five-year survival rates, both all cause and colorectal cancer specific, were calculated for subgroups defined by patient age, gender, stage and deprivation status using Kaplan-Meier curves. Cox proportional hazards models were used to examine the influence of deprivation on five-year survival after adjusting for age, gender and stage.

RESULTS

There were 603 consecutive colorectal patients during the study period. Five-year all-cause and colorectal cancer-specific survival rates were 41% and 53%, respectively. There was no association between deprivation status and stage at diagnosis (P = 0.308). Multivariable proportional hazards modelling (adjusting for gender, age and tumour stage) demonstrated no association between deprivation status and survival.

CONCLUSION

In this single district study, no relationship between patient socioeconomic status and survival from colorectal cancer could be demonstrated. Consistency in the type and quality of treatment offered to patients by the same clinical teams may have been responsible for the equitable survival outcomes.

Trends and socioeconomic inequalities in cancer survival in England and Wales up to 2001

We examined national trends and socioeconomic inequalities in cancer survival in England and Wales during the 1990s, using population-based data on 2.2 million patients who were diagnosed with one of the 20 most common cancers between 1986 and 1999 and followed up to 2001. Patients were assigned to one of five deprivation categories (from 'affluent' to 'deprived') using characteristics of their electoral ward of residence at diagnosis. We estimated relative survival up to 5 years after diagnosis, adjusting separately in each deprivation category for background mortality by age, sex and calendar period. We estimated trends in survival and in the difference in survival between deprivation categories ('deprivation gap') over the periods 1986-90, 1991-95 and 1996-99. We used period analysis to examine likely survival rates in the near future. Survival improved for most cancers in both sexes during the 1990s, and appears likely to continue improving for most cancers in the near future. The deprivation gap in survival between rich and poor was wider for patients diagnosed in the late 1990s than in the late 1980s. Increases in cancer survival in England and Wales during the 1990s are shown to be significantly associated with a widening deprivation gap in survival.