Reporting of Tumour Deposits in Colorectal Cancer by Radiology and Pathology

Recent research shows that tumour deposits-small spots of cancer found near the main bowel tumour-may give doctors important information about how aggressive the cancer is and how likely it is to come back.

Doctors can find tumour deposits either:

1. When looking at scans before surgery, or 2. when examining the removed bowel tissue under the microscope after surgery.

In the past, tumour deposits were not always recorded properly. This is because older cancer-staging systems (called TNM 5) used in the UK treated these spots differently, depending on their size, and sometimes labelled them as lymph nodes even when they were not. As a result, many tumour deposits were missed in reports.

Since 2018, the UK has been using an updated staging system (called TNM 8) that gives tumour deposits their own category. This means doctors are now expected to report them separately when they are found in the tissue around the bowel.

This matters because the investigators know that patients who have tumour deposits may have a higher risk of the cancer returning or spreading. Because of this, these patients might benefit from extra treatment-such as chemotherapy or radiotherapy-on top of surgery.

However, if tumour deposits are not routinely recorded on scans or pathology reports, doctors may not realise a patient has them. This means that:

1. Patients may not get the most appropriate advice about their cancer, and 2. Patients may miss out on treatments that could help reduce the chance of the cancer returning.

This research project aims to find out two things:

1. Are tumour deposits being routinely reported on scans and pathology reports for rectal cancer since the newer TNM 8 system was introduced? And 2. Is there a link between reporting tumour deposits and another important finding called EMVI (extramural vascular invasion), which also affects cancer behaviour and treatment decisions?