Research consistently demonstrates that individuals residing in socioeconomically deprived areas experience worse cancer outcomes compared to their less deprived counterparts, both in the UK and internationally. Despite improvements in overall cancer survival over the past 25 years in England, socio-economic inequalities persist, highlighting a need for targeted interventions. While previous research has examined survival and mortality probabilities, these measures don't fully capture the societal burden of these disparities. This study aims to quantify this burden using the Number of Life-Years Lost (NLYL) due to cancer, a readily communicable metric that translates to societal and economic costs. The researchers hypothesize that socio-economic deprivation is significantly associated with increased NLYL due to cancer and aim to identify specific cancer types and patient subgroups most affected, informing public health policy and resource allocation.

Existing literature reveals that socio-economic inequalities in cancer outcomes are only partially explained by factors such as cancer awareness, comorbidities, and tumor stage. Variations in cancer screening uptake and patient management contribute significantly to these disparities. However, the translation of these epidemiological findings into effective policy interventions has been suboptimal. Previous studies have used survival or mortality probabilities to describe socio-economic inequalities, but these metrics do not fully represent the societal impact. Alternative measures like the crude probability of death from cancer and NLYL offer more comprehensive assessments of the burden of disease.

This population-based study utilized data from the National Cancer Registry of England, encompassing over 1.2 million patients diagnosed with one of the 23 most common cancers between January 1, 2010, and December 31, 2014. The patients were followed up to December 31, 2015. Socio-economic deprivation was determined using the income domain of the English Index of Deprivation. A non-parametric approach was employed to estimate the NLYL within 3 years of diagnosis, stratified by sex, age, and deprivation level. The relative survival framework allowed researchers to disentangle cancer-related deaths from deaths due to other causes, even without cause-of-death information. The study also calculated the crude probability of death from cancer (CPr) within 3 years.

The study revealed considerable variation in NLYL across different cancer types, age groups, and deprivation levels. The largest socio-economic inequalities were observed in adults under 45 years old with poor-prognosis cancers (e.g., lung, pancreatic, oesophageal). In this age group, the most deprived patients experienced up to 6 additional months of life-years lost within 3 years compared to the least deprived. For cancers with moderate or good prognoses, socio-economic inequalities tended to widen with age. Lung cancer consistently emerged as a major contributor to NLYL across all age groups and deprivation levels, particularly among the most deprived, accounting for a substantial proportion of total life-years lost. Other cancers showing significant disparities included pancreatic cancer in younger adults, bladder cancer in young women, and laryngeal cancer in young men. These disparities were frequently associated with cancers linked to smoking. There were also notable inequalities in cervical cancer, highlighting the need to improve screening uptake and HPV vaccination coverage, especially among younger women in deprived areas. The most deprived patients lost 1.5 times more NLYL than the least deprived (0.98 years vs. 0.67 years within 3 years).

The findings underscore the significant societal and economic impact of socio-economic inequalities in cancer outcomes, particularly in younger working-age adults. The increased NLYL in this group has substantial implications for reduced workforce productivity and economic contribution. The observed disparities, especially in cancers linked to tobacco use, suggest the influence of modifiable risk factors and access to healthcare. While some inequalities may be attributed to late diagnosis, the study highlights the potential impact of suboptimal care, such as delayed treatment or difficulties navigating complex cancer pathways. These factors are likely exacerbated in more deprived populations, who may experience challenges related to access to specialized healthcare facilities and social support. The study's use of NLYL provides a more impactful and easily communicable metric than traditional survival measures, strengthening its value for policy-making and resource allocation decisions.

This study demonstrates significant socio-economic inequalities in cancer-related life-years lost, particularly among younger adults with poor-prognosis cancers. These inequalities highlight the urgent need for cancer policies to integrate an explicit focus on equity and to consider the structural factors contributing to these disparities. Future research should investigate the underlying mechanisms driving these inequalities and evaluate the effectiveness of interventions aimed at reducing them. Targeted interventions focusing on improving early detection, treatment access, and patient navigation within a universal healthcare system are crucial to mitigate the health and economic burden of these disparities.

The study's reliance on routinely collected data limits the ability to fully explore all potential causal mechanisms. While the relative survival framework accounted for competing risks of death, unmeasured confounders could influence the results. The three-year time horizon might underestimate the long-term effects of socio-economic inequalities on cancer survival. The study focuses primarily on income deprivation as a measure of socio-economic status, which does not fully capture the complexity of socio-economic factors.