Delayed cutaneous hypersensitivity reactions to DNCB were performed before therapy i n 84 patients with recurrent breast cancer. Following sensitization, a lW+g challenge dose was graded as a strong, weak, or negative reaction. Thirty six patients were rechallenged 2 6 months with 100 +g of DNCB. Patients with a strong delayed cutaneous hypersensitivity reaction to DNCB were characteried by: a significantly higher probability of surviving a t 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 5296, weak 29%, and negative 23%). I t is suggested that patients with histologic grade I11 tumors with a dense lymphocyte infiltrate had more frequent strong delayed cutaneous hypersensitivity reactions to DNCB than those with few lymphocytes. T h e 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.
Cancer 37:16961700, 1976. UTANEOUS DELAYED HYPERSENSITIVITY RE-C actions t o 2,4 dinitrochlorobenzene (DNCB)* are positive in 95% of normal people,',? whereas the frequency of reactions are diminished in paticnts with cancer.' Patients with resectable cancer are more likely to react than those with more advanced disease.?