A correlation of DNCB-induced delayed cutaneous hypersensitivity reactions and the course of disease in patients with recurrent breast cancer.

Delayed cutaneous hypersensitivity reactions to DNCB were performed before therapy in 84 patients with recurrent breast cancer. Following sensitization, a 100 microgram challenge dose was graded as a strong, weak, or negative reaction. Thirty six patients were rechallenged greater than or equal to 6 months with 109 microgram of DNCB. Patients with a strong delayed cutaneous hypersensitivity reaction to DNCB were characteried by: a significantly higher probability of surviving at 52 and 78 weeks, a longer median length of survival (strong 78 weeks, weak 43 weeks, and negative 35 weeks), and a greater probability of responding to therapy (strong 52%, weak 29%, and negative 23%). It is suggested that patients with histologic grade III tumors with a dense lymphocyte infiltrate had more frequent strong delayed cutaneous hypersensitivity reactions to DNCB than those with few lymphocytes. The correlation of DNCB skin testing with a good prognosis in this group of patients with breast cancer suggests a protective role by the immunologic defense mechanisms and warrants its further evaluation and use in the development of new therapeutic modalities.