Prevalence of Multiple Primary Squamous Cell Carcinoma of the Upper Aerodigestive Tract in an Irish Tertiary Referral Center

The elevated risk of second primary malignancy (SPM) in patients with head and neck squamous cell carcinoma (HNSCC) is well established. Despite the advances in loco regional control achieved by modern surgery and chemoradiation, survival with HNSCC has not meaningfully improved, in part due to continuing risk of development of SPMs in these patients. Our objective was to determine the prevalence of SPM among patients with HNSCC in Ireland. A retrospective study of patients diagnosed with two or more HNSCC between January 2000 and Jun 2012 was conducted in two tertiary referral centers. Out of a population of 604 patients, we identified 72patients (11.9%) with SPM. Our third primary malignancy prevalence rate was 3.0% (18 patients) while the fourth primary malignancy rate was 0.5% (3 patients). Fifty seven males and 15 females between ages of 36 to 78 (mean age 58.3 +/SD 10.01) were reviewed. The majority of the population smoked tobacco (87.5%) and consumed alcohol (76.1%).Among patients with SPM, 68% (49 patients) had metachronous lesions while 32% (23 patients) had synchronous lesions. In conclusion, multiple primary tumours in patients with an index HNSCC are relatively common in Ireland and represent a significant obstacle to improvement in survival. Our SPM rate is 11.9% in keeping with current literature. Oral cavity and oropharynx are major sites for primary and SPM, which is well documented in the literature.