Secondary Primary Cancers in Nodular Lymphocyte Predominant Hodgkin’s Lymphoma

Background: Nodular Lymphocyte Predominant Hodgkin’s Lymphoma (NLPHL) is an uncommon subtype of Hodgkin’s Lymphoma. The risk for secondary primary cancers is not well understood.

Methods: The Surveillance Epidemiology and End Results (SEER) database was used to identify cases of NLPHL diagnosed up to 12/31/2011. The Standardized Incidence Ratio (SIR) was calculated as the ratio of observed to expected cases of secondary primary malignancies based on incidence data in the general United States population. The latency exclusion period from the date of diagnosis was 60 months. We also investigated for possible modifying effects of gender, age at diagnosis (20-39 years of age and ≥ 40 years of age), use of radiation therapy, and latency periods (5-10 years and >10 years) after initial diagnosis of NLPHL.

Results: A total 947 cases of NLPHL were present in the database. Secondary primary cancer cases occurred in 64 cases with 36 (56.3%) solid tumors and 28 (43.8%) hematological malignancy cases. Radiation was administered in 38 (59.4%) of secondary primary cancer cases. Females had an increased risk of Non-Hodgkin’s Lymphoma (NHL) (SIR: 13.86, p<0.05), “All Solid Tumors” (SIR: 1.89, p<0.05), Colon and Rectum (SIR: 4.39, p<0.05), and Urinary System (SIR: 2.01, p<0.05) tumors. Comparatively, males had an increased risk of NHL (SIR: 26.02, p<0.05) exclusively. The risk of developing NHL (SIR: 60.23, p<0.05), and “All Solid Tumors” (SIR: 2.47, p<0.05) was increased in individuals between 20-39 years of age. Whereas, increased risk of Urinary System (SIR: 3.78, p<0.05), and NHL (SIR: 12.59, p<0.05) were observed in the ≥ 40 years of age cohort. NHL (SIR: 21.0, p<0.05), “All Solid Tumors” (SIR: 1.65, p<0.05), and Colon and Rectum (SIR: 3.68, p<0.05) tumor risk was increased in cases treated with radiation therapy, while NHL (SIR: 21.0, p<0.05) was the only significantly increased secondary malignancy in non-radiated cases. Latency period of >10 years, after the initial diagnosis, was associated with increased risk of “All Solid Tumors” (SIR: 2.62, p<0.05), Thyroid cancer (SIR: 16.64, p<0.05), and NHL (SIR: 35.68, p<0.05).

Conclusion: NLPHL is associated with an increased risk of secondary primary cancers, both solid and hematological malignancies. Thyroid cancer and NHL were the most frequent tumors observed in patients ten years after initial NLPHL diagnosis. Radiation treatment for NLPHL increased the risk for solid tumors, including colorectal cancer. Further research is necessary to clarify optimal surveillance technique in patients after treatment of NLPHL.