There is evidence to suggest that location of primary colorectal tumours has an impact on prognosis and efficacy of biological agents. Studies focus on RAS WT (KRAS WT and NRAS WT) mCRC, and have identified that left sided colon cancer (LSCC) is more common than right sided colon cancer (RSCC), is observed more in males and is associated with a better prognosis. RSCC on the other hand, is observed more in females and is associated with a worse prognosis. Patients with LSCC show a better response to EGFR inhibitors, whereas those with RSCC show a better response to VEGF inhibitors. This study aims to demonstrate the differences in prescribing habits by tumour location in EU5 and US and to evaluate the impact of new clinical data on real-world treatment patterns.
Between July 2016 and January 2017, a panel of oncologists in EU5 (n = 624) and US (n = 101) were asked to report on mCRC RAS WT patients and their treatments through the submission of online de-identified record forms.
Out of 996 mCRC patients in EU5 and 821 in US, there are significantly more males with LSCC (57% & 56%) than RSCC (43% & 44%, p
1L mCRC patients with LSCC receive EGFR inhibitors more than RSCC patients, whereas RSCC patients receive VEGF inhibitors more than LSCC patients, a trend not observed in 2L+. This supports the literature when considering that ‘new clinical data’ has been a significant reason for these prescribing patterns.
Clinical trial identification
Legal entity responsible for the study
All authors have declared no conflicts of interest.