P-148: Approach to Diagnosis and Management of multiple myeloma-related bone disease in Latin America, a GELAMM survey.

Introduction: Bone disease is present in up to 80% of multiple myeloma (MM) cases. These patients are at high risk of pathological fractures and need for radiotherapy or surgical interventions, which leads to impaired quality of life and high costs for health systems.

The aim of this survey was to examine regular practices about diagnosis and management of multiple myeloma-related bone disease (MMBD) in Latin America (LA).

Methods: An anonymous online survey was distributed to hematologists in LA who treat patients with MM via social media platforms and email contact list from the Latin American Myeloma study group (GELAMM) from April 29th to May 20th, 2024. This survey had 25 multiple choice questions, including type of center and clinician’s approach to diagnosis and MMBD management. The results were descriptively analyzed.

Results: 204 responses were recorded from 168 centers in 15 Latin American countries. 57% were from public centers.

At diagnosis, 26% reported using PET-CT, 18% whole body low-dose CT, 17% X-ray, and 16% whole-spine MRI. About management, 2.5% responded they don't use any antiresorptive drugs (ARD) for MMBD. Within those who reported to use ARD, 69% employ them in all patients with MM at diagnosis, while the rest claimed using ARD only if patients have bone disease. 83% of physicians reported reinitiating ARD at relapse. 93% reported using zoledronic acid. Denosumab was accessible for 42% of participants, 60% for those in private practice and 25.5% for those in public systems. As for the duration of treatment, 73% claimed using ARD for 2 years, 14% for 1 year and 6% until progression. Regarding schedule, 50% reported using ARD monthly, 10% every 3 months, and 31% monthly the first year and then every 3 months.

For patients with Creatinine clearance < 30 mL/min, 41% would employ denosumab (56% in private centers and 28% in public hospitals) and 40% wouldn’t use any ARD.

88% executed prior dental examinations, and 58% claimed that this caused a delay for starting treatment. 20% of the participants reported not using Calcium and vitamin D supplementation, and 57% measure vitamin D plasma levels before starting treatment.

Conclusions: To our knowledge, this is the largest survey about MMBD in LA.

There are still centers that use x-ray examinations, an approach that, although no longer recommended, remains the only accessible method in some parts of the region. A large majority of physicians in LA use ARD, with zoledronic acid being the most frequent. Of importance, 31% reported using them only if patients have bone disease. The duration of treatment is usually two years, with very heterogeneous reported schedules. Physicians feel that dental examination delay initiation of ARD, a topic that should be further investigated. The use of calcium and vitamin D supplementation appear to be suboptimal, as well as vitamin D measurement.

In conclusion, this information provides useful insights of how we approach MMBD in LA and allows us to identify areas for improvement.