Does long-term treatment with Doxil^® predispose patients to oral cancer?

We present a possible adverse reaction related to long-term use of Doxil^® in female patients. We believe that long-term use of Doxil^® may predispose female patients to oral squamous cell carcinoma. The patients in this report were not exposed to the common risk factors related to oral cancer formation such as smoking or alcohol consumption. Both patients were 59-year-old females. The first patient was diagnosed in 2001 with stage IIIC ovarian cancer. Seven years following treatment with Doxil ^®, she was diagnosed with stage III squamous cell carcinoma of the right maxilla. The second patient was diagnosed with Kaposi's sarcoma with evidence of spread to the lungs. Four years following treatment with Doxil ^® she was diagnosed with stage I squamous cell carcinoma of the left maxilla. A literature review did not reveal any report on Doxil ^® and predisposition to oral cancer; however, we found an abstract that was presented at the last annual meeting of the American Society of Clinical Oncology (ASCO) by Cannon et al. When we combine the data from Cannon et al. and the data presented here, a total of six female patients developed an epithelial carcinoma of the oral cavity following long-term treatment with Doxil^®. We believe that a large-scale study should be initiated on patients that were treated with Doxil^® for more than 3 years, since these patients might be at risk for developing secondary cancer of the oral cavity.