Low-Dose Isotretinoin Does Not Reduce Subsequent Tumors in Head and Neck Cancers
According to an article recently published in the Journal of the National Cancer Institute, therapy with low-dose isotretinoin (13-cis-retinoic acid) does not reduce the rate of developing subsequent cancers in patients with head and neck cancer.
Approximately 40,000 people in the U.S. are diagnosed with head and neck cancer every year.
Cancers of the head and neck comprise several types of cancers affecting the nasal cavity and sinuses, oral cavity, nasopharynx (upper part of throat, behind ear), oropharynx (middle part of throat, including soft palate, base of tongue, and tonsils), and other sites throughout the head and neck. In 2005 the American Cancer Society estimated that 11,000 people would die from head and neck cancer.
Patients with early head and neck cancer, or cancer that has not spread far from its site of origin, may be susceptible to developing another cancer (second primary tumor) in the head and neck area or in another area in the body. Research continues in an effort to reduce these patients’ risk of developing a second primary tumor.
Isotretinoin is a derivative of vitamin A. Results from studies evaluating high doses of isotretinoin have produced some encouraging results. These results prompted researchers from several medical institutions in the U.S. and Canada to conduct a trial to evaluate low doses of isotretinoin in patients with early head and neck cancer.
This trial included 1,190 patients with early head and neck cancer who had been treated with surgery and/or radiation therapy. Patients were then treated with low-dose isotretinoin for 3 years or placebo (inactive substitute) for 3 years.
Patients treated with isotretinoin did not have better outcomes than those treated with placebo:
- There was no significant difference between the rate of developing second primary tumors in either group of patients.
- There was no significant difference in survival between the two groups of patients.
- Patients who were current or former smokers had a higher rate of second primary tumors than patients who had not smoked; the lung and oral cavity were the most common sites.
- Patients who were current smokers had a higher rate of death than former smokers and never-smokers.
The researchers concluded that low-dose isotretinoin does not reduce the risk of developing second primary tumors or improve survival in patients with early head and neck cancer.
Reference: Khuri F, Lee J, Lippman S, et al. Randomized Phase III Trial of Low-dose Isotretinoin for Prevention of Second Primary Tumors in Stage I and II Head and Neck Cancer Patients. Journal of the National Cancer Institute. 2006; 98: 441-450.