Ontario's privacy commissioner is investigating a breach in which up to 12,000 cancer screening tests have gone missing, the Toronto Sun reports. Commissioner Ann Cavoukian announced this week that Cancer Care Ontario alerted her office on June 27 of the missing screening tests. A search for the records--which include patient name, date of birth, age, gender, health card number and screening test results--has been ongoing since then. A spokeswoman for Cancer Care Ontario said the agency is taking the matter seriously and investigating. Premier Dalton McGuinty has said the incident underscores the need for electronic health records, adding that the government treats this as "a very serious issue."