Weil BR, et al. - Researchers evaluated the infection-related outcomes related to asplenia or impaired splenic function in survivors of childhood cancer. The risk for late infection-related mortality was significantly increased with splenectomy and splenic radiation. An increased risk was seen with even low- to intermediate-dose radiation exposure, signifying that the spleen was highly radiosensitive. Long-term follow-up guidelines ought to be impacted by these findings for survivors of childhood cancer and should lead to an avoidance or reduction of spleen-related radiation exposure whenever possible.

Methods

• Experts evaluated late infection-related mortality in 20,026 5-year survivors of childhood cancer (diagnosed < 21 years of age from 1970 to 1999; median age at diagnosis, 7.0 years [range, 0 to 20 years]; median follow-up, 26 years [range, 5 to 44 years]) using cumulative incidence and piecewise-exponential regression models to estimate adjusted relative rates (RRs).
• Splenic radiation was approximated using average dose (direct and/or indirect) to the left upper quadrant of the abdomen (hereafter, referred to as splenic radiation).

Results

• Findings suggested that within 5 years of diagnosis, 1,354 survivors (6.8%) had a splenectomy and 9,442 (46%) had splenic radiation without splenectomy.
• Authors noted the cumulative incidence of infection-related late mortality to be 1.5% (95% CI, 0.7% to 2.2%) at 35 years after splenectomy and 0.6% (95% CI, 0.4% to 0.8%) after splenic radiation, with 62 deaths.
• As per results, an independent association of splenectomy (RR, 7.7; 95% CI, 3.1 to 19.1) with late infection-related mortality was seen.
• Results demonstrated that splenic radiation was related to increasing risk for late infection-related mortality in a dose-response relationship (0.1 to 9.9 Gy: RR, 2.0; 95% CI, 0.9 to 4.5; 10 to 19.9 Gy: RR, 5.5; 95% CI, 1.9 to 15.4; ≥ 20 Gy: RR, 6.0; 95% CI, 1.8 to 20.2).
• They noted an independent association of high-dose alkylator chemotherapy exposure also with an increased risk of infection-related mortality (RR, 1.9; 95% CI, 1.1 to 3.4).