Introduction: Over one million people in the United States are either living with or in remission from a hematologic malignancy– including leukemia, lymphoma, and myeloma. Previous studies have demonstrated increased risk for certain second primary neoplasms in survivors of hematologic malignancies, including a case series showing increased risk of head and neck cancer after Hodgkin’s Lymphoma. However, research specifically on the risk of head and neck solid tumors in patients with prior hematologic malignancies is very limited.
Methods: Data on 30,939,656 veterans was gathered from the Veteran’s Health Administration (VHA) Corporate Data Warehouse (CDW). Patients were included if their birthdate was between 1/1/1910 and 12/31/1969. Outpatient problem lists were queried for diagnoses of hematologic and associated malignancies, and solid head and neck cancers using ICD codes. Age at cancer diagnosis and months of survival following diagnosis were calculated. Demographic information such as race and sex were included, as well as limited available data on alcohol and tobacco use from the outpatient problem list. Chi-square, t-test, and binary logistic regression analyses were conducted with a p value <0.05 indicating statistical significance.
Results: A total of 207,322 cases of hematologic malignancy that did not follow a prior diagnosis of head and neck cancer, as well as 113,995 cases of head and neck cancer were identified in this cohort. In patients with a hematologic malignancy diagnosis, the rate of head and neck cancer was 0.65%, versus 0.37% in patients with no prior hematologic malignancy – a relative risk of 1.79 (p<0.0001). Subsites of head and neck cancer were analyzed, and prior hematologic malignancy was a risk factor for oral cavity, oropharynx, salivary gland, nasopharynx, nasal cavity / accessory sinus, larynx, and thyroid tumors (p<0.0001 for all). Relative risk for development of head and neck cancer after hematologic malignancy for each site ranged from lower in laryngeal tumors (1.31) to higher in salivary gland (2.81), nasopharynx (2.84), and nasal cavity / accessory sinus tumors (3.03). On multivariate analysis, with race, sex, tobacco use, and alcohol use included, prior hematologic malignancy remained a significant risk factor for all aforementioned subsites except larynx. For several subsites, prior hematologic malignancy was also associated with shorter survival times – from 10 months (oral cavity) to 20 months (salivary gland and larynx) less than patients with no previous hematologic malignancy.
Conclusions: In a study of over 30 million veterans, prior diagnosis of hematologic or associated malignancy was associated with an increased risk of solid head and neck cancers in a range of subsites. Additionally, patients with prior hematologic malignancy had shorter survival times for several head and neck cancer subsites. Further investigation into the risks of specific hematologic malignancies is warranted.