Which factors influence the development of a second head and neck cancer? Are there new factors that could be used to identify patients at greatest risk for the development of a second primary malignancy?
Background: Multiple malignancies of the upper aerodigestive tract are commonly encountered. The patient’s susceptibility may be influenced by mutation-induced chromosomal fragility, and gene aberrations such as P53 may play a role.
Study design: Researchers followed a group of 96 consecutive patients who were treated between 1987-1991 with irradiation therapy for squamous cell carcinoma. Eligibility required that the patient had adequate tissue available. All patients had been followed for at least six years. Suspicious new primaries were biopsied. The definition of a second primary required that it be at least 2 cm from the index tumor or at least three years after the index tumor. Tissue was assessed with the bleomycin test for chromosomal fragility and microsatellite analysis.
This is a single-institution, retrospective study of tissue available from previously treated patients. Genetic analysis, as well as polymerase chain reaction (PCR) and single-strand confirmation, polymorphism analysis, and nucleotide sequence analysis were employed.
Setting: Cohort study at a single institution.
Synopsis: During the follow-up, 27 of 96 enrolled patients (28.1%) developed a second primary tumor, with a mean time of onset at 5.8 years. P53 gene status was not statistically significant in predicting the incidence of second primaries. Chromosomal fragility was found in 47% of patients overall. Microsatellite instability was identified in 34.9% of all patients.
Overall, the statistical risk for second primary tumor was increased in patients with persistent smoking after treatment. T stage greater than 2, chromosomal fragility, and microsatellite instability were associated with second primary tumor.
Bottom line: Head and neck oncologists continue to struggle with understanding the etiology of second primary squamous cancer. This study does not solve the dilemma.
Citation: Deganello A, Gitti G, Mannelli G, Meccariello G, Gallo O. Risk factors for multiple malignancies in the head and neck. Otolaryngol Head Neck Surg. 2013;149:105-111.