According to an article recently published in the journal Cancer, patients with nasopharyngeal cancer have an increased risk of second cancers in the upper aerodigestive tract.
The nasopharynx is the area above the soft palate (roof of the mouth) and behind the nose. Nasopharyngeal cancer is considered a type of head and neck cancer. Approximately 40,000 people in the U.S. are diagnosed with head and neck cancer every year.
Radiation therapy is a common form of treatment for cancers of the head and neck. However, researchers have been concerned that radiation to affected tissues may cause long-term side effects, including the development of another cancer.
Researchers from China recently conducted a clinical study to evaluate the effects of treatment among patients with nasopharyngeal cancers. This study included 326 patients with nasopharyngeal cancer that had not spread to distant sites in the body. These patients were treated between 1994 and 1995. All patients received radiation therapy as part of their treatment regimen.
At nearly six years follow-up, the following results were reported:
- 5.2% of patients developed subsequent tumors (SPTs) that were not associated with cancer spread from their initial cancer.
- 64.7% of these patients developed the SPTs in the upper aerodigestive tract (areas such as the lip, tongue, major salivary glands, gums and nearby oral cavity tissues, floor of the mouth, tonsils, all parts of the throat and other oral regions, nasal cavity, accessory sinuses, middle ear, and larynx (voice box).
- Only 21.4% of the SPTs that occurred less than five years from treatment occurred within the area where radiation was delivered.
- All of the SPTs that occurred greater than five years from treatment occurred within the area where radiation was delivered.
The researchers concluded that patients with nasopharyngeal cancers have an increased risk of developing cancers of the upper aerodigestive tract. Cancers that occurred greater than five years after radiation therapy all developed within the site of radiation delivery. Patients diagnosed with nasopharyngeal cancer should speak with their physician regarding screening measures for subsequent cancers.
Reference: Kong L, Lu J, Hu C, et al. The Risk of Second Primary Tumors in Patients with Nasopharyngeal Carcinoma after Definitive Radiotherapy. Cancer. 2006; 107:1287 – 1293.