Treatments affecting splenic function as a risk factor for valvular heart disease in Childhood Cancer Survivors: A DCCSS-LATER study.

PURPOSE: Splenectomy might be a risk factor for valvular heart disease (VHD) in adult Hodgkin lymphoma survivors. As this risk is still unclear for childhood cancer survivors (CCS), the aim of this study is to evaluate the association between treatments affecting splenic function (splenectomy and radiotherapy involving the spleen) and VHD in CCS. METHODS: CCS were enrolled from the DCCSS-LATER cohort, consisting of 6,165 five-year CCS diagnosed between 1963 and 2002. Symptomatic VHD, defined as symptoms combined with a diagnostic test indicating VHD, was assessed from questionnaires and validated using medical records. Differences in the cumulative incidence of VHD between CCS who received treatments affecting splenic function and CCS who did not were assessed using the Gray test. Risk factors were analyzed in a multivariable Cox proportional hazards model. RESULTS: The study population consisted of 5,286 CCS, with a median follow-up of 22 years (5-50 years), of whom 59 (1.1%) had a splenectomy and 489 (9.2%) radiotherapy involving the spleen. VHD was present in 21 CCS (0.4%). The cumulative incidence of VHD at the age of 40 years was significantly higher in CCS who received treatments affecting splenic function (2.7%, 95% confidence interval (CI) 0.4%-4.9%) compared with CCS without (0.4%, 95% CI 0.1%-0.7%) (Gray's test, p = 0.003). Splenectomy was significantly associated with VHD in a multivariable analysis (hazard ratio 8.6, 95% CI 3.1-24.1). CONCLUSIONS AND IMPLICATIONS: Splenectomy was associated with VHD. Future research is needed to determine if CCS who had a splenectomy as part of cancer treatment might benefit from screening for VHD.

The Value of IgM Memory B-Cells in the Assessment of Splenic Function in Childhood Cancer Survivors at Risk for Splenic Dysfunction: A DCCSS-LATER Study.

Background: Childhood cancer survivors (CCS) who received radiotherapy involving the spleen or total body irradiation (TBI) might be at risk for splenic dysfunction. A comprehensive screening test for examining splenic dysfunction is lacking. Objective: We investigated whether IgM memory B-cells could be used to assess splenic dysfunction in CCS who received a splenectomy, radiotherapy involving the spleen, or TBI. Methods: All CCS were enrolled from the DCCSS-LATER cohort. We analyzed differences in IgM memory B-cells and Howell-Jolly bodies (HJB) in CCS who had a splenectomy (n = 9), received radiotherapy involving the spleen (n = 36), or TBI (n = 15). IgM memory B-cells < 9 cells/µL was defined as abnormal. Results: We observed a higher median number of IgM memory B-cells in CCS who received radiotherapy involving the spleen (31 cells/µL, p=0.06) or TBI (55 cells/µL, p = 0.03) compared to CCS who received splenectomy (20 cells/µL). However, only two CCS had IgM memory B-cells below the lower limit of normal. No difference in IgM memory B-cells was observed between CCS with HJB present and absent (35 cells/µL vs. 44 cells/µL). Conclusion: Although the number of IgM memory B-cells differed between splenectomized CCS and CCS who received radiotherapy involving the spleen or TBI, only two CCS showed abnormal values. Therefore, this assessment cannot be used to screen for splenic dysfunction.