Endocrine Abstracts

Background: Neuroendocrine tumors awareness is developing. Carcinoid syndrome and hormonal overproduction may be controlled with somatostatin analogues in majority of cases. However, due to unspecific symptomatology in early stages of disease, majority of cases are diagnosed when process is disseminated. Co-morbidities and coexisting diseases are present in most of patients. Bone loss may be accelerated by metastizing tumor, peptides secreted or decreased absorption of vitamin D and calcium.

Aim was to investigate zolendronic acid effectiveness in preventing of bone loss not related to metastases.

Group: Eight patients with carcinoid syndrome due to GEP-NET, with no metastases to bones at octreoscan and strontium scyntygraphy, on stable therapy with octreotide LAR (n=6) or lanreotide AutoGel (n=2), with excluded multiple endocrine neoplasia and deficit of vitamin D.

Intervention: Zolendronic acid 5 mg i.v. given every 12 months, DXA of lumbar spine and femoral neck and history of fractures to assess intervention effectiveness.

Results: Overall L2–L4 BMD did not changed significantly (0.876 SD 0.113 vs 0.911 SD 0.134; T_score −1.6 SD 0.8 −1.4 SD 0.9) during first year and second year of observation. Femoral neck BMD increased during first year in 5 out of 8 and trend was significant during 2nd year (n=6; 0.814 SD 0.134 vs 0.947 SD 0.098 P=0.03; T_score −1.7 SD 0.7 vs −1.1 SD 0.5 P=0.05). Two patients were excluded from further observation due to disease progression and bone metastases detection. No fractures were recorded in whole group.

Conclusions: Zolendronic acid 5 mg given yearly may be useful to treat concomitant osteoporosis in patients with neuroendocrine tumors during disease stabilization on somatostatin analogue therapy.