Appeal by employer from a decision of the' former State Industrial Board [now Workmen’s Compensation Board], reversing a decision of a referee, and determining that a carcinoma of the left breast of claimant was causally related to an accidental injury sustained by her on October 4, 1943. The decisive issue is whether a single trauma was a competent producing cause of the cancer in claimant’s breast. There is medical testimony in the affirmative. The objection that the physician, who thus testified, did not express his own> opinion is without merit. Decision affirmed, with costs to the Workmen’s Compensation Board. All concur.