Endocrine sequelae of hematopoietic stem cell transplantation: Effects on mineral homeostasis and bone metabolism

Increased risk of hip and major osteoporotic fractures in 8463 patients who have undergone stem cell transplantation, a Swedish population-based study

In this retrospective cohort study of adult stem cell transplanted patients (n = 8463), a significant increased risk of both MOF and hip fractures was seen compared with the Swedish population and occurred in mean more than 2 years after stem cell transplantation.

PURPOSE

To explore the risk for osteoporotic fracture in patients who have undergone hematopoietic stem cell transplantation (HSCT) compared with the Swedish population.

METHODS

The risk of osteoporotic fractures was determined in a retrospective population cohort study of adult (≥ 18 years) Swedish patients (n = 8463), who were transplanted with HSCT 1997-2016 and compared with all adults living in Sweden during the same period.

RESULTS

In the total study group (n = 8463), 90 hip fractures (1.1% both in males and females) and 361 major osteoporotic fractures (MOF) (3.2% in men and 6.0% in women) were identified. In the total study population, the ratio of observed and expected number of hip fracture for women was 1.99 (95% CI 1.39-2.75) and for men 2.54 (95% CI 1.91-3.31). The corresponding ratio for MOF in women was 1.36 (CI 1.18-1.56) and for men 1.61 (CI 1.37-1.88). From 2005 onwards, when differentiation in the registry between allo- and auto-HSCT was possible, the observed number of hip fracture and MOF in allo-HSCT (n = 1865) were significantly increased (observed/expected hip fracture 5.24 (95% CI 3.28-7.93) and observed/expected MOF 2.08 (95% CI 1.63-2.62)). Fractures occurred in mean 2.7 (hip) and 2.5 (MOF) years after allo-HSCT. Graft-versus-host disease (GVHD) was not associated with an increased risk of fracture.

CONCLUSION

Patients who underwent HSCT had an increased risk of both hip and major osteoporotic fracture compared with the Swedish population and occurred in 4.3% of patients. GVHD was not statistically significantly associated with fracture risk.

Randomized controlled trial of pre-transplant zoledronate versus observation for prevention of bone loss in allogeneic hematopoietic cell transplantation

Background

Approximately half of allogeneic hematopoietic cell transplantation (HCT) recipients experience significant bone loss in the early post-HCT period. Only recently have international guidelines started recommending early screening. However, the guidance for intervention remains conservative. In this study, we sought to evaluate the efficacy of pre-transplant prophylactic zoledronate in preventing early bone loss in allogeneic HCT recipients.

Methods

This was an open-label, investigator-initiated, phase 2 randomized controlled trial (RCT) of prophylactic zoledronate versus observation to prevent bone loss in allogeneic HCT recipients. Recipients aged ≥ 18 years of age were included after informed consent and randomized to prophylactic zoledronate 4 mg pre-HCT or observation in a 1:1 ratio. The primary outcome of the study was bone mineral density (BMD) loss at the femoral neck (FN), total hip (TH), and lumbar spine (LS), as assessed using dual-energy X-ray absorptiometry (DXA) on day+100 post-HCT. The secondary outcomes included BMD loss on day+365 and Z scores on day+100 and day+365 at the FN, TH, and LS sites.

Results

The trial was terminated because the interim analysis showed a significant benefit in the intervention arm, with 50% planned recruitment. A total of 40 patients were randomized to the zoledronate and control arms. Both arms were matched for age, sex, diagnosis, pre-HCT steroid exposure, body mass index, human leukocyte antigen (HLA) match, and conditioning intensity. The grade 2-4 acute graft versus host disease (GVHD) incidences were comparable. The primary endpoint of BMD loss at FN and TH at day+100 was significant (5.62% vs. -6.78%, p = 0.009, -1.59 vs. -3.98, p = 0.016, respectively). There was no difference in the secondary endpoint of BMD loss on day+365 compared to that on day+100 or baseline at any BMD site. There was no difference in the Z-scores at any site on day+100 or day+365.

Conclusions

Prophylactic zoledronate prevented early bone loss on day+100. The indicated preemptive zoledronate beyond day+100 in recipients prevented further bone loss. Patients receiving prophylactic zoledronate may benefit from a supplementary dose of the indicated preemptive zoledronate.

Unveiling the mechanisms and challenges of cancer drug resistance

Cancer treatment faces many hurdles and resistance is one among them. Anti-cancer treatment strategies are evolving due to innate and acquired resistance capacity, governed by genetic, epigenetic, proteomic, metabolic, or microenvironmental cues that ultimately enable selected cancer cells to survive and progress under unfavorable conditions. Although the mechanism of drug resistance is being widely studied to generate new target-based drugs with better potency than existing ones. However, due to the broader flexibility in acquired drug resistance, advanced therapeutic options with better efficacy need to be explored. Combination therapy is an alternative with a better success rate though the risk of amplified side effects is commonplace. Moreover, recent groundbreaking precision immune therapy is one of the ways to overcome drug resistance and has revolutionized anticancer therapy to a greater extent with the only limitation of being individual-specific and needs further attention. This review will focus on the challenges and strategies opted by cancer cells to withstand the current therapies at the molecular level and also highlights the emerging therapeutic options -like immunological, and stem cell-based options that may prove to have better potential to challenge the existing problem of therapy resistance. Video Abstract.