Topical chemoprevention of oral cancer with tretinoin "biofilm".
BACKGROUND
Oral cancer is a common malignancy. Chemoprevention is a promising treatment strategy but it produces systemic toxic effects. Topical application of chemopreventive agents is an attractive alternative that reduces toxic effects. This study is based on the hypothesis that topical application of mucosal adhesive film (MAF), as a means to deliver tretinoin, is effective and safe for oral cancer chemoprevention.


METHODS
Randomized animal study conducted at the Boston University School of Medicine.


METHODS
This study uses the hamster cheek-pouch model to test efficacy and safety of the MAF/tretinoin patch for oral cancer prevention. The oral mucosa of 36 hamsters was painted with dimethylbenzanthracene to produce premalignant lesions. The 36 hamsters were divided into 3 groups of 12 hamsters each as follows: (1) control, no treatment; (2) systemic tretinoin (5.0 mg/kg per day, intraperitoneally); and (3) topically applied MAF/tretinoin patch (0.45 mg tretinoin/cm2, once daily). Treatments continued for 40 days.


METHODS
Tumor growth and burden were measured over time. The duration of MAF patch retention on mucosa and local tissue reaction to the treatment were also evaluated.


RESULTS
The patch stayed on the mucosa for at least 5 hours with no evidence of inflammatory or other adverse reactions from the treated tissue. There was a significant difference in the tumor growth measurement between the control and systemic tretinoin groups (P<.001), and between the control and MAF patch groups (P<.001).


CONCLUSIONS
This is the first study, to our knowledge, to use a polymer MAF technique for oral cancer prevention. The MAF/tretinoin patch is safe and effective for such chemoprevention in the hamster model.
Wang
Zhi
Z
Department of Otolaryngology-Head and Neck Surgery, Boston Medical Center/Boston University School of Medicine, Boston, Mass, USA. zwang@bu.edu
Polavaram
Raju
R
Fuentes
Cesar F
CF
Shapshay
Stanley M
SM
D000287:Administration, Topical; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D006224:Cricetinae; D008297:Male; D009061:Mouth Mucosa / Q000187:drug effects; D009062:Mouth Neoplasms / Q000517:prevention & control*; D014212:Tretinoin / Q000008:administration & dosage*
D000970:Antineoplastic Agents; D014212:Tretinoin