After having acquired jurisdiction for review, the commissioner shall review the proceedings in question. Prior to rendering his or her decision, the commissioner may order the taking of additional evidence by an appeal tribunal to be made a part of the record in the case. Upon the basis of evidence submitted to the appeal tribunal and such additional evidence as the commissioner may order to be taken, the commissioner shall render his or her decision in writing affirming, modifying, or setting aside the decision of the appeal tribunal. Alternatively, the commissioner may order further proceedings to be held before the appeal tribunal, upon completion of which the appeal tribunal shall issue a decision in writing affirming, modifying, or setting aside its previous decision. The new decision may be appealed under RCW
50.32.070. The commissioner shall mail his or her decision to the interested parties at their last known addresses.