Extramural Venous Invasion in Rectal Cancer

Extramural venous invasion (EMVI), where cancer spreads into veins outside the rectum, is a sign of poor prognosis (lower chance of survival) in rectal cancer. MRI scans can detect this ( and when seen on MRI it is called mrEMVI). Most patients with advanced rectal cancer (including those with mrEMVI) will be treated with chemotherapy and radiotherapy before surgery to try to increase their chance of cure. Another MRI scan after this treatment is done to assess how the tumour has responded and whether the treatment has been successful. It is possible to see on the second MRI scan whether the mrEMVI has disappeared or responded to treatment, but it is unclear whether this makes a difference to survival. This study aimed to show that if mrEMVI improves after treatment, it leads to better outcomes, and that it can be used as a reliable marker to guide treatment.

62 patients were included in the study. For 35 patients whose mrEMVI showed significant improvement after treatment (more than 50% fibrosis), 88% were still cancer-free after 3 years, with only 9% having a recurrence. However, for 27 patients with poor improvement (less than 50% fibrosis), only 46% remained cancer-free after 3 years, with 44% having a recurrence.

This study confirmed that if mrEMVI improves significantly after treatment, patients tend to have better long-term survival without cancer. Those who show poor improvement could potentially be considered for more aggressive treatments.

Pelican supported this study with a grant of £10,000