Are second primary head and neck cancers with previous hematological malignancy more aggressive than de novo head and neck cancers?

Objectives: Secondary solid tumors can occur after the treatment of hematological malignancies and are associated with a poor prognosis. We evaluated the survival outcomes of patients with second primary head and neck cancers according to the site of cancer origin, type of hematological malignancy, and age. Materials and methods: We enrolled all patients who underwent surgery for second primary head and neck cancer and were previously treated for hematological malignancy between 1997 and 2020. We analyzed the survival outcomes of patients with second primary head and neck cancer, and compared them with 3126 de novo head and neck cancer patients diagnosed during the same period at our hospital. Results: The 5-year overall survival (OS) rate was significantly worse for second primary head and neck cancer patients than de novo cancer patients (52.0 % and 77.9 %, respectively; p = 0.04) and those results were similarly observed in second primary oral cavity cancer (33.3 % and 75.7 %, respectively; p < 0.01). Patients with myelodysplastic syndrome and acute myeloid leukemia showed significantly worse 5-year OS rate than those with other types of hematological malignancies (p = 0.036). Multivariate analysis showed that bone marrow transplantation (BMT) was a risk factor for the recurrence of head and neck cancers (odds ratio = 6.635, p = 0.042). Conclusion: Patients with second primary head and neck cancer, particularly of the oral cavity, had a worse prognosis than patients with de novo head and neck cancer. BMT predicts recurrence in second primary head and neck cancer patients.