Fractures and long-term mortality in cancer patients: a population-based cohort study

Fracture Risk Prediction Using the Fracture Risk Assessment Tool in Individuals With Cancer

Importance

The Fracture Risk Assessment Tool (FRAX) is a fracture risk prediction tool for 10-year probability of major osteoporotic fracture (MOF) and hip fracture in the general population. Whether FRAX is useful in individuals with cancer is uncertain.

Objective

To determine the performance of FRAX for predicting incident fractures in individuals with cancer.

Design, Setting, and Participants

This retrospective population-based cohort study included residents of Manitoba, Canada, with and without cancer diagnoses from 1987 to 2014. Diagnoses were identified through the Manitoba Cancer Registry. Incident fractures to March 31, 2021, were identified in population-based health care data. Data analysis occurred between January and March 2023.

Main Outcomes and Measures

FRAX scores were computed for those with bone mineral density (BMD) results that were recorded in the Manitoba BMD Registry.

Results

This study included 9877 individuals with cancer (mean [SD] age, 67.1 [11.2] years; 8693 [88.0%] female) and 45 877 individuals in the noncancer cohort (mean [SD] age, 66.2 [10.2] years; 41 656 [90.8%] female). Compared to individuals without cancer, those with cancer had higher rates of incident MOF (14.5 vs 12.9 per 1000 person-years; P < .001) and hip fracture (4.2 vs 3.5 per 1000 person-years; P = .002). In the cancer cohort, FRAX with BMD results were associated with incident MOF (HR per SD increase, 1.84 [95% CI, 1.74-1.95]) and hip fracture (HR per SD increase, 3.61 [95% CI, 3.13-4.15]). In the cancer cohort, calibration slopes for FRAX with BMD were 1.03 for MOFs and 0.97 for hip fractures.

Conclusions and Relevance

In this retrospective cohort study, FRAX with BMD showed good stratification and calibration for predicting incident fractures in patients with cancer. These results suggest that FRAX with BMD can be a reliable tool for predicting incident fractures in individuals with cancer.

Increase in major osteoporotic fractures after therapy with immune checkpoint inhibitors

Background

Immune checkpoint inhibitors (ICIs) can cause severe and sometimes long-standing immune-related adverse events (irAEs). Enhanced immune activation from ICI can theoretically result in osteoclast activation, bone loss and fracture. The objective of this study was to evaluate the incidence rates of major osteoporotic fractures (MOFs) in patients with melanoma treated with ICI.

Methods

We conducted a before-after cohort study using a commercial healthcare claims dataset of adult patients with melanoma from the USA who received ICI therapy between 2011 and 2022. Incidence rates of MOF before and after ICI initiation were ascertained using International Classification of Diseases 9/10 diagnostic codes.

Results

The study cohort included 3137 patients, mean age was 68 years, of which 2010 (64%) were men. 40 (1.3%) patients had an MOF in the year before ICI initiation and 57 (1.8%) and 34 (1.8%) had an MOF in the first and second years after ICI initiation, respectively. The HR for MOF over the first year after versus the year before the first ICI dose was 1.82 (95% CI 1.24 to 2.66), and it was 1.85 (95% CI 1.12 to 2.90) over the second year. Prior fracture, older age, female sex and combination ICI therapy were associated with greater risk of MOF after ICI initiation.

Conclusion

Patients who receive ICI are at increased risk of MOF after receiving therapy. Given the plausible biological pathway, osteoporosis and osteoporotic fractures may represent a novel irAE of ICI therapy.

Fracture risk and assessment in adults with cancer

Individuals with cancer face unique risk factors for osteoporosis and fractures. Clinicians must consider the additive effects of cancer-specific factors, including treatment-induced bone loss, and premorbid fracture risk, utilizing FRAX score and bone mineral densitometry when available. Pharmacologic therapy should be offered as per cancer-specific guidelines, when available, or local general osteoporosis guidelines informed by clinical judgment and patient preferences. Our objective was to review and summarize the epidemiologic burden of osteoporotic fracture risk and fracture risk assessment in adults with cancer, and recommended treatment thresholds for cancer treatment-induced bone loss, with specific focus on breast, prostate, thyroid, gynecological, multiple myeloma, and hematopoietic stem cell transplant. This narrative review was informed by PubMed searches to July 25, 2022, that combined terms for cancer, stem cell transplantation, fracture, bone mineral density (BMD), trabecular bone score, FRAX, Garvan nomogram or fracture risk calculator, QFracture, prediction, and risk factors. The literature informs that cancer can impact bone health in numerous ways, leading to both systemic and localized decreases in BMD. Many cancer treatments can have detrimental effects on bone health. In particular, hormone deprivation therapies for hormone-responsive cancers such as breast cancer and prostate cancer, and hematopoietic stem cell transplant for hematologic malignancies, adversely affect bone turnover, resulting in osteoporosis and fractures. Surgical treatments such as hysterectomy with bilateral salpingo-oophorectomy for gynecological cancers can also lead to deleterious effects on bone health. Radiation therapy is well documented to cause localized bone loss and fractures. Few studies have validated the use of fracture risk prediction tools in the cancer population. Guidelines on cancer-specific treatment thresholds are limited, and major knowledge gaps still exist in fracture risk and fracture risk assessment in patients with cancer. Despite the limitations of current knowledge on fracture risk assessment and treatment thresholds in patients with cancer, clinicians must consider the additive effects of bone damaging factors to which these patients are exposed and their premorbid fracture risk profile. Pharmacologic treatment should be offered as per cancer-specific guidelines when available, or per local general osteoporosis guidelines, in accordance with clinical judgment and patient preferences.