CONTEXT: Although the increased incidence of second primary malignant neoplasms (SPMs) is a well-known late effect after non-Hodgkin’s lymphoma, no previous studies have analyzed the risk and specific types of SPMs that T-cell neoplasm (TCN) survivors are prone to.
OBJECTIVE: To evaluate the risk of SPMs in TCN survivors and to stratify the risk based on the histological subtype of TCN and latency from the time of initial TCN diagnosis.
DESIGN: Retrospective review of histologically confirmed TCNs from Surveillance, Epidemiology, and End Results (SEER) database.
SETTING: Nationwide cancer registry based study.
PATIENTS OR OTHER PARTICIPANTS: Histologically confirmed TCN patients registered in the SEER 18 database (2001-2014).
INTERVENTIONS: The SEER*Stat Multiple Primary-SIR tool was used to calculate standard incidence ratios (SIRs) and absolute excess risk (AER) for secondary malignancies. SIR and AER compares TCN patients’ subsequent cancer experience with the number of cancers that would be expected based on incidence rates for the general United States population.
MAIN OUTCOMES MEASURES: We quantified the risk of SPMs in TCN survivors, developing 2 months after the TCN diagnosis.
RESULTS: Out of 19,705 TCN patients included, 1338 patients developed a total of 1472 SPMs after a median follow up of 74 (range:1-179) months (SIR:1.66 [95%CI:1.58-1.75]; p<0.05. Patients with angioimmunoblastic and primary cutaneous T-cell lymphomas had the highest risk of developing SPMs. The risk of hematologic SPMs was higher than solid tumors [SIR:6.66 vs 1.16, p<0.05] and most common hematologic SPMs were other types of non-Hodgkin’s lymphoma, Hodgkin’s lymphoma and AML. There was an exceptionally elevated risk of AML (>100 times compared to that of general population) in patients with precursor-T-cell lymphoblastic, hepatosplenic T-cell neoplasms and NK/T-cell lymphoma (especially after 10 years latency). An increased risk of solid malignancies was noted in all TCN subtypes except angioimmunoblastic subtype.
CONCLUSIONS: TCN survivors have an increased risk of developing both solid and hematologic malignancies and the risk remained elevated even after 10 years of initial diagnosis of TCN. Our study underscores the need for more mechanistic studies analyzing altered immune surveillance, genomic alterations, and treatment effects leading to increased risk of SPMs in TCN survivors.