Comparison of provider-assessed and patient-reported outcome measures of acute skin toxicity during a Phase III trial of mometasone cream versus placebo during breast radiotherapy: the North Central Cancer Treatment Group (N06C4).
OBJECTIVE
Considerable interobserver variability exists among providers and between providers and patients when measuring subjective symptoms. In the recently published Phase III N06C4 trial of mometasone cream vs. placebo to prevent radiation dermatitis, the primary provider-assessed (PA) endpoint, using the Common Toxicity Criteria for Adverse Events (CTCAE), was negative. However, prospectively planned secondary analyses of patient-reported outcomes (PROs), using the Skindex-16 and Skin Toxicity Assessment Tool (STAT), were positive. This study assesses the relationship between PA outcomes and PROs.


METHODS
Pearson correlation coefficients were calculated to compare the three tools. Statistical correlations were defined as follows: <0.5, mild; 0.5-0.7, moderate; and >0.7, strong.


RESULTS
CTCAE dermatitis moderately correlated with STAT erythema, and CTCAE pruritus strongly correlated with STAT itching. CTCAE pruritus had a moderate correlation with Skindex-16 itching. Comparing the 2 PRO tools, Skindex-16 itching correlated moderately with STAT itching. Skindex-16 burning, hurting, irritation, and persistence all showed the strongest correlation with STAT burning; they showed moderate correlations with STAT itching and tenderness.


CONCLUSIONS
The PRO Skindex-16 correlated well with the PRO portions of STAT, but neither tool correlated well with CTCAE. PROs delineated a wider spectrum of toxicity than PA measures and provided more information on rash, redness, pruritus, and annoyance measures compared with CTCAE findings of rash and pruritus. PROs may provide a more complete measure of patient experience than single-symptom, PA endpoints in clinical trials assessing radiation skin toxicity.
Neben-Wittich
Michelle A
MA
Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA.
Atherton
Pamela J
PJ
Schwartz
David J
DJ
Sloan
Jeff A
JA
Griffin
Patricia C
PC
Deming
Richard L
RL
Anders
Jon C
JC
Loprinzi
Charles L
CL
Burger
Kelli N
KN
Martenson
James A
JA
Miller
Robert C
RC
D001943:Breast Neoplasms / Q000532:radiotherapy*; D003142:Communication; D003879:Dermatologic Agents / Q000627:therapeutic use*; D004890:Erythema / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D000068656:Mometasone Furoate; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011244:Pregnadienediols / Q000627:therapeutic use*; D011446:Prospective Studies; D011537:Pruritus / Q000209:etiology / Q000517:prevention & control; D011788:Quality of Life; D011855:Radiodermatitis / Q000150:complications / Q000517:prevention & control*; D016896:Treatment Outcome
D003879:Dermatologic Agents; D011244:Pregnadienediols; D000068656:Mometasone Furoate