Inter-observer agreement between dermatologists and oncologists in assessing dermatological toxicities in patients with metastatic colorectal cancer treated by cetuximab-based chemotherapies: a pilot comparative study.

The aim of this study was to measure the inter-observer agreement between two teams of three dermatologists and oncologists in labelling and grading the cetuximab-induced dermatological toxicities from 98 photographs performed in a cohort of 15 patients with metastatic colorectal cancer receiving cetuximab-based chemotherapy. Kappa coefficient (κ) assessed inter-observer grading agreement. Both teams defined by the same terms eight of the 13 (62%) toxic effects reported together. Discrepancies concerned the labelling of rash desquamation, hand-foot syndrome and xerosis and the grading (different and often going in the opposite direction) of various toxicities such as paronychia, xerosis, desquamation and hand-foot syndrome (κ value less than 0.40). Acneiform eruption was recognised by both teams, but the grading allocated by oncologists was lower. Our results suggested the need for a real consensus between oncologists and dermatologists for labelling and grading these dermatological toxicities. Better training of oncologists by using a dermatological atlas would improve inter-observer agreement.