Distribution and survival outcomes of primary head and neck hematolymphoid neoplasms in older people: a population-based study

Primary head and neck hematolymphoid neoplasms (PHNHLN) are defined as a series of hematolymphoid system-derived neoplasms which primarily emanate in head and neck region. Due to the rarity and absence of symptomatic specificity, PHNHLN is easily neglected. The objective of this study is to investigate demographics, pathological subtype distribution, anatomical location, survival outcomes and prognostic factors of PHNHLN among older patients aged ≥ 60. The individual patient information in our study was derived from Surveillance, Epidemiology and End Results database. Descriptive epidemiological methods were used to analyze the distribution of histologic subtypes and primary anatomical sites. Kaplan–Meier survival curves and log-rank test were conducted to evaluate the effect of variables on the prognosis. Cox hazard regression was conducted to identify the independent prognostic factors. The male-to-female ratio in most pathological subtypes was close to 1:1. The most common pathological subtype was diffuse large B-cell lymphoma. The most commonly involved sites outside the lymph nodes were salivary glands, especially parotid gland, followed by tonsil, thyroid gland and tongue. The prognosis of mature T- and NK-cell non-Hodgkin lymphoma (NHL) was bleaker than Hodgkin lymphoma, mature B-cell NHL and plasma cell neoplasm. Age at diagnosis, presence of second primary malignancy (SPM), pathological subtype, Ann-Arbor stage, chemotherapy and radiation were independent prognostic factors of overall survival. Our study comprehensively reported the subtype distribution, anatomical sites and survival outcomes of PHNHLN among older patients, improving understanding of this rare group of cancer entities.