The role of pelvic radiotherapy in stage IV rectal cancer—still working in the dark!
Approximately 20% of patients with colorectal cancer (CRC) are found to have metastatic colorectal cancer (mCRC) at diagnosis, but only 20% of these are usually considered to be potentially resectable (de Haas 2011) (1). Early stage disease in rectal cancer confers a relatively favourable prognosis, but stage IV or metastatic disease is associated with a five-year survival of only 10–15%, despite major advances in multimodality treatment. Individual outcomes are influenced by the site and number of metastases and the specific metastatic sites involved. Patients with rectal primaries are also more likely to present with synchronous lung metastases than patients with colon cancer (Robinson 2018) (2), which then can lead to a different natural history with bone and brain metastases.