In Reply.—Drs Withers, Coughlin, and Douple have raised some important points.
It is clear from the text of our article that in an unselected population of patients with parotid cancer, 8% had a history of prior exposure to radiation. It was beyond the scope of this retrospective study to compare the number of patients who received radiation to the parotid area and then had parotid tumor develop, with the rate of development of parotid tumors in a nonirradiated population. However, I and my colleagues believe that if a detailed history is taken among patients with parotid carcinoma, a significant number will be found to have had exposure to radiation.
In our report, in three of the six patients parotid carcinoma was diagnosed as a second primary. Although Drs Coughlin and Douple mentioned a 10% incidence of second primary, we are sure they will agree that parotid cancer as a