A woman denied coverage for her brain cancer treatment got the go-ahead to pursue her claims against the administrator of her health benefit plan.In a written opinion last week, Chief U.S. District Judge Rebecca R. Pallmeyer declined to dismiss a lawsuit Brittany Day filed under the Employee Retirement Income Security Act against Humana Insurance Co.Day sued Humana after it denied her request for coverage for proton beam radiation therapy to treat her brain cancer. Humana determined the therapy was experimental or …