Respondents and non-respondents did not differ significantly in terms of clinical characteristics or treatments: age at diagnosis (p = 0.0490); age at time of survey (p = 0.1015); time since diagnosis (p = 0.7607); AJCC stage (p = 0.2673); tumor grade (p = 0.3391); hormone receptor status (p = 0.1408); HER2 status (p = 0.5709); tumor triple negative status (p = 0.2479); menopausal status at diagnosis (p = 0.8060); Charlson comorbidity index (p = 0.2336); chemotherapy (p = 0.1477); radiotherapy (p = 0.4795); endocrine therapy (p = 0.5772). This evidence concerns the gene ERBB2 and neoplasm.