Diffuse Large B-Cell Lymphoma Survivorship: Risk of Second Malignancies in Long Term Survivors

Background: Survivors of Diffuse Large B-Cell Lymphoma (DLBCL) are at increased risk of subsequent malignancies secondary to their genetic makeup, environmental and treatment factors. Specific data on the long term risk of subsequent malignancies are underreported in the literature. Most oncologists release patients to be followed by their general physicians at five years. We studied the incidence rates of all second malignancies in survivors of DLBCL five years after their initial diagnosis.

Methods: We analyzed data from the Surveillance, Epidemiology and End Results 9 database, Nov 2014 Sub {1973-2012} to determine the risk of second malignancies in five year survivors of DLBCL. For our analysis we included only patients with initial diagnosis between 1992 and 2007 as there was a change in classification in 1992 and this will also give at least 5 year of follow up for all patients. With these criteria we had 10,905 patients and 58,192 patient years of follow up. The risk of subsequent malignancies is reported as a standardized incidence ratio (observed incidence [O]/expected incidence [E]).

Results: After five years from diagnosis of DLBCL, patients have the highest risk of a second cancer of Hodgkin's Lymphoma (O/E: 11.23; CI: 7.19-16.70; N=24). The risk of recurrence of Non-Hodgkin's Lymphoma also remains high after 5 years with an O/E ratio of 2.07 (CI: 1.63-2.59; N=76), with Extranodal NHL being at an especially high risk (O/E: 2.99; CI: 2.10-4.12; N=37). Survivors of DLBCL are also at high risk of Acute Non-Lymphocytic Leukemia (O/E: 4.38; CI: 3.03-6.12; N=34). There is also a high risk of Laryngeal cancer (O/E: 1.96; CI: 1.01-3.42; N=12). Furthermore, patients are also at a high risk of Cancer of the Colon excluding the Rectum (O/E: 1.28; CI: 1.01-1.58; N=82) and Anal Cancer (O/E: 3.26; CI: 1.41-6.42; N=8).

Conclusion: There are several second malignancies that long term survivors of DLBCL are at increased risk of, even after 5 years. This information may help physicians effectively monitor survivors of DLBCL for any second cancers.