The Department does not hold the data requested for individual hospitals. Hospitals have been the main users of Tarceva (Erlotinib) with low usage by primary care trusts (PCTs). In the period September 2005 to June 2006, hospitals in at least 25 of the 28 former strategic health authorities had used Tarceva. In the period September 2005 to December 2006, six of the former 303 PCTs had prescribed the drug. To provide details of individual PCTs could potentially disclose the identity of the patients involved as prescribing has, so far, been minimal.