Fifty-seven DCIS specimens and 10 normal breast specimens were examined for HPR1 expression using immunohistochemical staining. Twenty-seven arbitrarily selected specimens were also examined for HS deposition by immunofluorescence staining, confirming HPR1 activity. Patient medical records were obtained to explore a possible association between biologic potential using Van Nuys Prognostic Index (VNPI) and HPR1 expression.