The risk of secondary malignancies over 30 years after the treatment of non-Hodgkin lymphoma.
BACKGROUND
Survivors of non-Hodgkin lymphoma (NHL) are at increased risk for developing secondary malignancies. For the current study, the authors quantitated this risk in a group of NHL survivors over 30 years of follow-up.


METHODS
Standardized incidence ratios (observed-to-expected [O/E] ratio) and absolute excess risk of secondary malignancies were assessed in 77,876 patients who were diagnosed with NHL between 1973 and 2001 from centers that participated in the National Cancer Institute's Surveillance, Epidemiology, and End Results Program.


RESULTS
There were 5638 patients who developed secondary malignancies, significantly more than the endemic rate (O/E, 1.14; P < .001). Overall, irradiated patients had a similar risk of secondary malignancies compared with unirradiated patients (relative risk, 1.04; 95% confidence interval, 0.98-1.10; P = .21). Irradiated patients had excess risk for sarcomas, breast cancers, and mesothelioma compared with unirradiated survivors (P < .05). Patients age <25 years at the time of their NHL diagnosis had the highest relative increased risk (no radiation: O/E, 2.1; P < .05; radiation: O/E, 4.51; P < .05). Overall, no statistical difference was observed for secondary cancer incidence between females and males (O/E, 1.12 vs. 1.15, respectively). Female survivors of NHL were less likely to develop breast cancer than the general population (O/E, 0.85; P < .05), but women age <25 years at the time of their NHL diagnosis were more likely to develop breast cancer (no radiation: O/E, 2.1; P < .05; radiation: O/E, 4.51; P < .05).


CONCLUSIONS
The overall risk of secondary malignancies was increased for NHL survivors and varied according to age at NHL diagnosis, gender, and treatment.
Tward
Jonathan D
JD
Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, Utah 84112-5560, USA. jonathan.tward@hci.utah.edu
Wendland
Merideth M M
MM
Shrieve
Dennis C
DC
Szabo
Aniko
A
Gaffney
David K
DK
D017668:Age of Onset; D000368:Aged; D005260:Female; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D017741:Survivors / Q000706:statistics & numerical data*; D013995:Time