Oral & Faecal Microbiota Analysis in Patients With Rectal Cancer Requiring Pre-operative Therapy Before Surgery, & Correlation With Response

Rectal cancer is a common pathology which is treated by a multimodal approach. Those tumours in the rectum that are locally advanced are treated with neoadjuvant chemoradiotherapy before an operation. This aims to reduce the size of the tumour and increase the change of a complete resection. The degree of shrinkage of a rectal cancer to pre-operative treatment is influenced by the immune system. In some other cancers there is evidence that the bacteria living in our mouth \& in the large bowel influence the way the body responds a cancer. In this study patients with rectal cancer requiring radiotherapy before surgery will be asked to give samples of saliva \& bowel motions before chemoradiotherapy \& again before surgery. These samples will have the type and number of bacteria analysed, as well as levels of key metabolic products of these bacteria. The results will be compared with the response, as assessed by the pathologist using standard criteria, of the rectal to the radiotherapy.

Sex

All

Minimum age

18 Years

Maximum age

100 Years

Inclusion Criteria:

* Adult patients with a locally advanced rectal cancer (defined as CRM threatening on MRI scans) in whom neoadjuvant chemoradiotherapy has been offered before consideration of curative resection
* must be able to consent to inclusion in project

Exclusion Criteria:

* Anyone who does not consent for inclusion
* Any non rectal adenocarcinoma
* Early rectal cancers that do not require neoadjuvant therapy
* Patients presenting as an emergency with an obstructing rectal cancer requiring an early resection
* Patients who are treated with short course radiotherapy alone rather than long course chemoradiotherapy