Age-specific characteristics of head and neck second primary malignancies in patients treated for nasopharyngeal carcinoma: a retrospective study

This study was performed to analyse the age-specific characteristics of head and neck second primary malignancies (SPMs) in patients treated for nasopharyngeal carcinoma (NPC). The medical records of 56 NPC patients diagnosed with head and neck SPMs were reviewed retrospectively. Patients < 45 years old at NPC diagnosis were assigned to the younger group and those >= 45 years of age were assigned to the older group. The treatment of the index NPC, latency period, pathological TNM stage, survival status, and SPM subsite were analysed. Patients in the older group were found to have a shorter median latency period than those in the younger group: 8.5 years (range 3-20 years) versus 11 years (range 1-30 years) (P = 0.015). The proportion of SPMs in the jaw was significantly higher in the younger group (P = 0.002). Patients in the younger group receiving radiotherapy with chemotherapy had a shorter latency period (P = 0.003) and higher risk of developing SPMs in the jaw (P = 0.036) than those receiving radiotherapy alone. A long-term and age-dependent regular customised follow-up strategy for NPC is necessary for the prevention and early detection of head and neck second primary malignancies.