Background and Aim: Multifaceted risk factors impair bone mass (BM) in childhood brain cancer survivors(CBCS). Aims of the study were to evaluate bone mass and it's determinant and fracture prevalence in CBCS 2(G+2), 5(G+5) or 7(G+7) years after off therapy (OT).
Methods: Seventy-three(G+2), 87(G+5) and 66(G+7)CBCS were evaluated at 12,9±4,2, 14,9±4,4 and 16,6±4,4yrs, respectively. Diagnoses were: astrocytic (G+2:n=25,G+5:n=24,G+7:n=20), embryonal (G+2:n=19,G+5:n=28,G+7:n=20), germinomas (G+2:n=13,G+5:n=18,G+7:n=12), sellar region (G+2:n=13,G+5:n=10,G+7:n=9), ependimal (G+2:n=3,G+5:n=7,G+7:n=5) tumors. Twenty-six, 37 and 27 pts, respectively, underwent CSRT in the 3 groups. Growth hormone deficiency(GHD) was diagnosed in 38(G+2), 66(G+5) and 46(G+7) pts, while hypogonadism(HH) in 15(G+2), 28(G+5) and 22(G+7)CBCS. Patients underwent height and BMI(SDS), pubertal(Tanner) and DXA(Lunar Prodigy Advance) measurements. BMD(g/cm2,Z-score), BMC(g) were obtained at the lumbar spine(L1L4=L) and the total body less head(TB); lumbar BMAD(g/cm3) was calculated; fat(FM,Kg) and lean mass(LM,Kg) were obtained.
Results: The 3 groups had similar age at diagnosis (8,0±4,2yrs), height (-0,5±1,4SDS), BMI (0,7±1,2SDS); G+7 had higher FM and LM than G+2 and G+5 (FM:P's=0,01 and 0,003 respectively; LM:P's=0,0008 and 0,03). G+2 showed a reduced LBMD and LBMC compared to G+5 and G+7 (LBMD:P's=0,009 and <0,0001; for LBMC:P's=0,03 and 0,0003, respectively) and a non-significant lower LBMDZ-score (-0,85±1,33,-0,61±1,23 and-0,74±1,31) and TBBMDZ-score (-0,72±1,09,-0,59±1,04 and-0,51±1,14). BMAD was significantly higher (P=0,03) in G+7(0,157±0,083) compared to G+2(0,135±0,021). A LBMD<-2Z-score was present in 19,2%, 11,5% and 17,7% (G+2vsG+5vsG+7) and a TBBMD<-2Z-score in 14,1%, 11,9% and 12,5% (G+2vsG+5vsG+7). G+2GHD pts had lower LBMDZ-score(P=0,01) and TBBMDZ-score(P=0,04) compared to G+5GHD pts; G+2HH pts had lower LBMDZ-score and TBBMDZ-score compared to G+5HH (P=0,009 and 0,03, respectively). TBBMDZ-score progressively increased in pts not treated with CSRT, while remained below -0.9Z-score in treated-ones. In multivariable analyses LBMDZ-score was inversely predicted by age and directly by height after correction for LM, FM, GHD, HH; TBBMDZ-score was additionally predicted by LM and GHD. Seven% CBCS in G+2(5/73), 2,3% in G+5(2/87) and 1,5% in G+7(1/66) presented fractures.
Conclusions: Older, shorter, GHD, CSRT treated and HH CBCS are at risk of decreased BM after 2 yrs OT; a low BM might persist after 5 and 7 yrs OT; the fracture prevalence remains low.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology