Sequential evaluation of DNCB reactivity in patients with primary lung cancer. Correlation with prognosis.

Delayed hypersensitivity reactions before therapy in 137 patients with lung cancer and in 50 patients with benign thoracic lesions were evaluated by 2,4-dinitrochlorobenzene (DNCB) contact sensitization using the patch test. Ninety-eight percent (49/50) of control patients and 46 percent (62/137) of patients with lung cancer were sensitized by 250 mug of DNCB. There was an excellent correlation between the initial reactivity to DNCB and resectability. In patients with resectable lung cancer, preoperative DNCB reactivity has no prognostic value. However, an excellent correlation was found between postoperative reactivity and 2 year survival, i.e., conversion from unresponsive to responsive status was observed on sequential testing. In 15 of 74 patients with resectable disease, the conversion was noted postoperatively, and among 12 patients followed for 2 years, only two patients had died. Conversion from a reactive to nonreactive status to DNCB occurred only in the terminal stage of the disease. From these observations, we found that, in order to evaluate the afferent limb of cellular immunity in patients with lung cancer who have once expressed reactivity to DNCB, one must use some new sensitizing agents which show no cross-sensitivity with each other thereafter.