The rationale for this study is that there’s been increasing attention to the really unfortunate incidence of earlier onset colorectal cancer and really gastrointestinal cancers more broadly. There has been a declining incidence in colorectal cancer overall, however, we’ve seen this very concerning increase in the early onset version of colorectal cancer, in other words the type that is discovered before a patient is 50 years old.

There has been a lot of attention, again, on early onset colorectal cancer but we designed the study to look more broadly. So we included the range of gastrointestinal cancers, including stomach, oesophageal, as well as colorectal, to begin to ask questions about the pattern of early onset gastrointestinal cancer versus average onset. We took a particular interest in social determinants of the burden of early onset disease because there have been signals that this is an important part of this epidemic.

Could you outline the methodology?

This was a retrospective observational cohort study that leveraged secondary data emanating from the US Oncology Network. The study was derived from structured data generated in the electronic health record. Again, this is a very efficient way to study large populations quickly, so this is real-world data that is principally used for clinical purposes, of course, but we make secondary use of that data to ask interesting research questions. Essentially we categorised the gastrointestinal cancers as early onset – below age 50 – or over age 50, and then mostly just in descriptive analyses – how are these patients different with respect to race, ethnicity and particularly stage at diagnosis is a really important factor for prognosis of these patients.

What did you find?

We found some really sobering findings around the burden of early onset gastrointestinal cancers, I should say, that are consistent with other trends we’ve seen for colorectal cancer at large. In particular we see an uneven distribution with respect to race and ethnicity, so we see an over-representation of black patients in particular in the early onset group of gastrointestinal cancers. We also see a really concerning difference in the burden of stage at diagnosis. So there was a roughly 10 percentage point increase in the prevalence of advanced stage of disease at diagnosis among the early onset group versus the average onset group.

What impact could these findings have?

This work continues to shed light on the burden of early onset tumours in general, colorectal but also more broadly for gastrointestinal cancers. Our work is really focussed on characterising patients once they are in the medical oncology system but I think the biggest impact of this work needs to be earlier upstream. So it needs to be informing public health initiatives and activities among the general population, raising awareness of screening, attempting to reduce diagnostic delay, that I think is happening. I suspect it’s happening more often in the early onset patients and may be leading to that more advanced stage of disease at diagnosis.