[Possible value of variations in the serum alkaline DNAse activity in the prognosis of cancers of the upper respiratory-digestive tract treated by chemotherapy].

Variations in serum alkaline DNase activity before and repeatedly after standardized chemotherapy were examined in patients with head and neck carcinomas. The enzyme activity was measured by way of a modified spectrophotometric method. No variations of such activity observed in patients without therapeutic response or with minor response could be considered as a marker of primary or acquired resistance to chemotherapy. Distinct variations in serum alkaline DNase activity (a steep decrease after therapy followed a few weeks later by a regain of values higher than the initial value) correspond to complete or partial positive responses. Such observations of the variations in enzyme activity in relation to individual initial values measured before therapy could be considered as a reliable prognostic test for the therapy of many head and neck carcinomas.