Contrasting Improving Rates of Cancer Survival In The Context of Life Years Lost Compared To The General Population

Abstract

In recent years, UK life expectancy (LE) has increased, as has the incidence of many common cancers. In 2014, approximately 357,000 new cases of cancer were identified in the UK, with half of all cases diagnosed in patients aged 70 or over. The therapeutic landscape associated with cancer treatment is rapidly evolving and significant increases in survival have been observed. This study aimed to quantify the improvement in survival associated with common cancer types between 1971 and 2010, relative to the general population. Published survival rates, stratified by decade, for 21 common cancers were extrapolated with piecewise exponential models using 1-year, 5-year and 10-year survival estimates, assuming a minimum annual survival hazard equivalent to that of the general population. A partitioned survival model was used to compare cancer survival estimates with published age- and sex-adjusted general population LE estimates; mean per-patient life years (LYs) lost were derived. Between 1971 and 2010, estimated age-adjusted cancer LE increased from 6.7 to 12.7 years across evaluated cancers while the age-adjusted general population LE increased from 17.2 to 22.9 years over the same period. Mean LYs lost to cancer in 1971 were 10.6, decreasing to 10.2 in 2010 driven by 62% (n=13) of evaluated cancers. In 2010, 43% of evaluated cancers exhibited a >10-year difference in LE compared to that of the general population (brain cancer was associated with a 29.4-year reduction), whilst 19% exhibited LE differences of <5 years, notably, prostate cancer and melanoma with LY differences of 0.4 and 1.7, respectively. Generally, LYs lost due to cancer have decreased in recent decades. However, this study highlights that there are still significant areas of unmet need, with several cancers seeing only marginal LE improvements.