Inequalities in early-onset colorectal cancer: a population-based study

Each year worldwide, almost 2 million people are diagnosed with a colorectal cancer (CRC). These cancers are typically diagnosed in people over 60. However, in recent decades, in several countries, there has been an increase in cases of CRC in people under 50. This is referred to as “early onset colorectal cancer” (EOCRC). We don’t know why this rise is happening; several explanations have been proposed. Concerningly, some people with EOCRC have more advanced cancer when they are diagnosed, and lower survival, than people who are diagnosed with CRC at an older age. Across England there is a lot of variation in CRC. People in the North are more likely to get CRC. Once diagnosed, those who live in more deprived areas have lower survival. However, we don’t know if similar differences are seen in EOCRC because there has been limited research in England. In fact there have been no studies since 2015. This 3 phase study aims to address this information gap. In phase 1, we will analyse data from national databases to examine trends over time, comparing younger (EOCRC) and older CRC patients by sex, ethnicity, deprivation, and region. We will look at numbers of new cases, the pathways people follow to diagnosis and how advanced cancers are at diagnosis. We will use the English National Cancer Registration Dataset and other linked NHS datasets to do these analyses. In Phase 2, we will assess how many people diagnosed with CRC are alive 1-year, 3-years and 5-years, comparing this between younger and older patients. In Phase 3, we will create an online toolkit to share our results with the public, healthcare professionals and NHS decision-makers. We hope the study will suggest some new ideas for the possible causes of the rise in EOCRC and help improve early diagnosis and services for people with EOCRC.