A technique used to identify risk of recurrence in breast cancer is to be adapted for use with rectal cancer, to help avoid unnecessary major surgery.
Breast cancer surgery often includes removal of nearby sentinel nodes, particular parts of the lymphatic system where cancer cells can lodge. The technique is used to determine if cancer has spread beyond the primary tumour, so that appropriate treatment can be given to reduce recurrence.
Even in early stage rectal cancer, many surgeons opt for total mesorectal excision (TME), which removes a more extensive area of the bowel, rather than the less radical transanal endoscopic microsurgery (TEM). The preference for major surgery is to ensure that all the cancer is removed and so reduce the risk of recurrence.
The new proof of concept study – supported by the HTC – will assess the feasibility of identifying and sampling sentinel lymph nodes near the rectum during TEM.
“The ultimate aim is to identify patients where major surgery can be avoided without increasing the risk of their cancer recurring,” explains Mr Chris Cunningham of the Oxford University Hospitals Colorectal Department, who leads the study. “That would obviously be better for patients, reducing the need for colostomies and improving quality of life.”
The study will use a magnetised non-radioactive tracer (Sienna+®), developed by materials technology company Endomagnetics, to define the position of sentinel lymph nodes during rectal cancer surgery. The technology has been successfully used in breast cancer patients in a UK multi-centre trial.
The first stage of the study will test whether the technology can reliably identify sentinel nodes in the mesorectum without adverse effects on patients. The second stage will be to use the technology during TEM to define sentinel nodes, which would then be removed and tested for cancer. If these feasibility trials are successful, the team plan to apply for further funding to take the technology into full clinical trials.
The idea for the study came out of a workshop run by the HTC to discuss technologies to address unmet clinical needs in rectal cancer surgery. The feasibility study will be jointly funded by Endomagnetics and the HTC, through an Engineering and Physical Sciences Research Council Impact Acceleration Award.