How well does the MESTT correlate with CTCAE scale for the grading of dermatological toxicities associated with oral tyrosine kinase inhibitors?

BACKGROUND: Dermatological toxicities associated with tyrosine kinase inhibitors (TKIs) are commonly graded using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE). A new tool has been proposed by the Multinational Association for Supportive Care in Cancer (MASCC), namely the MASCC EGFRI Skin Toxicity Tool (MESTT), as a class-specific grading system. This study was designed to assess the correlation between the severity grading of the dermatological toxicities associated with TKIs using the NCI-CTCAE v4.0 and the MESTT. PATIENT AND METHODS: One hundred patients were interviewed at the National Cancer Centre Singapore with the criteria of being on erlotinib, gefitinib, lapatinib, sorafenib, or sunitinib over 2 weeks and manifested dermatological toxicities. Dermatological toxicities were graded using CTCAE and MESTT 1, respectively, by a single observer. Spearman's correlation test was performed on the results.
RESULTS: Sixty-five patients (65%) experienced papulopustular rash, 72 patients (72%) had pruritus, 85 patients (85%) had xerosis, 33 patients (33%) experienced nail changes, and 24 patients (24%) had alopecia. There was significant positive correlation between the two grading systems for all investigated dermatological toxicities, namely rash (r = 0.734), pruritus (r = 0.917), xerosis (r = 0.635), and paronychia (r = 0.611) at 99% confidence level.
CONCLUSION: Good correlation was observed between the scales, but there is a tendency for the MESTT tended to report higher toxicity grades for rash, xerosis, and paronychia. The MESTT was also found to be more useful to grade rash specific to TKIs and had similar usefulness for grading other studied toxicities.