Chemoprevention Study of Oral Cavity Squamous Cell Carcinoma
Condition: Oral Cavity; Squamous Cell Carcinoma
MeSH terms: Carcinoma; Carcinoma, Squamous Cell; Squamous Cell Carcinoma of Head and Neck
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of this study is to study the effect of 13-cis retinoic acid in preventing second
      primary malignancy in the oral cavity cancer patients after curative local treatment and to
      study the toxicity and compliance of 13-cis retinoic acid.
    

Detailed description: 
      There are more than one thousand deaths annually from head and neck cancer in Taiwan
      (excluding nasopharyngeal carcinoma) and the majority of treatment failures are related to
      recurrence of primary disease. Only patients with early-stage disease have high cure rates,
      but they remain at risk for the development of second primary tumors.

      Second primary malignancies occur at a constant annual rate of 5% to 7% in all head and neck
      cancer patients1. Furthermore, because the mortality from primary disease recurrence plateaus
      after 2 to 3 years in patients with locally advanced disease, second primary tumors become
      the major cause of late cancer mortality.

      Sporn et al defined chemoprevention as an effort to arrest or reverse premalignant cells
      during their progression to invasive malignancy2,3. The concept of chemoprevention has
      evolved to include the use of specific compounds, rather than general dietary changes, to
      prevent the development of cancer.

      Hong et al studied the effects of 13-cis retinoic acid on patients with history of head and
      neck cancers 4. After treatment of head and neck primary cancers with either radiotherapy or
      surgery or both, 103 patients were randomized to receive either adjuvant 13-cis retinoic acid
      or placebo. In an update of this trial with 55 months of follow-up, 16 patients (31%) in the
      placebo group had developed second primary tumors, whereas 7 patients (14%) in the treatment
      group had developed second primary tumors (p=0.04) 5. Betel quid chewing becomes increasingly
      popular in Taiwan. Exposure to both smoking and betel quid significantly increases the risk
      of oral cavity cancer6. The hazard of developing second primary tumors is high in this
      population, therefore, chemoprevention is worthy of trial.

      Use of 13-cis RA for chemoprevention of head and neck cancer only has been published by Hong
      et al. Their cases included a variety of head and neck cancers that are known to be not a
      homogenous group. The risk of second primary is different for different primary sites.
      Therefore, the value of 13-cis RA in chemoprevention is not conclusively addressed. In our
      proposal, only oral cavity cancer is included and the result will be more convincing. The
      result could be the basis of further chemoprevention clinical trial or guideline for clinical
      practice.
    

Intervention name(s): 13-cis Retino Acid
Intervention type(s): Drug
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single
Primary purpose: Prevention