The occurrence and location of a second primary malignancy (SPM) among patients with diffuse large B-cell lymphoma (DLBCL) may be affected by whether the patient had early- or advanced-stage disease at diagnosis, according to a study published in Cancer.
“Historically, hematologists consider that the risk of SPM increases 5 years after a diagnosis of DLBCL, although recent studies have suggested that patients with DLBCL may have an increased risk of SPM even in the first 5 years after diagnosis,” Ajay Major, MD, MBA, of University of Colorado School of Medicine, and colleagues. “We found that patients with early-stage disease were more likely to develop SPM in the period 0 to 5 years after diagnosis, and those with advanced-stage disease were more likely to develop SPM in the period 10 to 15 years after diagnosis.”
Major and colleagues used data on 26,038 patients with DLBCL taken from the SEER database. Patients had been diagnosed with either early-stage disease (n=14,274) or advanced-stage disease (n=11,314) between 1973 and 2010.
With a median follow-up of 13.3 years, 13.0% of patients developed SPM. The most common SPMs were leukemia and lymphoma and colorectal, pancreas, breast, and prostate SPMs
Patients with early-stage disease had a numerically, but not significantly higher, incidence of SPM than those with advanced-stage disease (14.0% vs 11.6%). However, those patients with extranodal disease at diagnosis did have a significantly increased risk for SPM (HR=1.15; 95% CI, 1.01–1.32; P=.018).
The researchers observed certain SPM patterns in each group. Patients diagnosed with early-stage disease were more likely to develop SPM in years 0 to 5, but had no increased risk for SPM in years 5 to 10. In contrast, patients with advanced disease were more likely to develop SPM in years 10 to 15, with no difference in risk beyond 15 years.
“For patients with recently diagnosed DLBCL in the current postrituximab era whose risk of SPM development is highest in the first 5 years after diagnosis, it may be prudent for survivors to undergo site-specific surveillance screening based on the period of time since diagnosis,” the researchers wrote.
Additionally, those patients with early-stage disease were more likely to develop colorectal, pancreas, breast, and male genital SPM from years 0 to 5. Those with advanced-stage disease were more likely to develop hematologic SPMs in the period from 5 to 15 years after diagnosis.
“Our current study adds to the body of literature that early stage DLBCL may have a distinct biology compared with AS DLBCL,” the researchers wrote.
Development of any SPM significantly increased the risk for death regardless of stage at diagnosis. The highest risk for death was seen in patients who had early stage disease with a SPM in the postrituximab era (HR=3.36).