Skeletal manifestations of treatment of breast cancer on premenopausal women

Bone health assessment via digital wrist tomosynthesis in the mammography setting

Bone fractures attributable to osteoporosis are a significant problem. Though preventative treatment options are available for individuals who are at risk of a fracture, a substantial number of these individuals are not identified due to lack of adherence to bone screening recommendations. The issue is further complicated as standard diagnosis of osteoporosis is based on bone mineral density (BMD) derived from dual energy x-ray absorptiometry (DXA), which, while helpful in identifying many at risk, is limited in fully predicting risk of fracture. It is reasonable to expect that bone screening would become more prevalent and efficacious if offered in coordination with digital breast tomosynthesis (DBT) exams, provided that osteoporosis can be assessed using a DBT modality. Therefore, the objective of the current study was to explore the feasibility of using digital tomosynthesis imaging in a mammography setting. To this end, we measured density, cortical thickness and microstructural properties of the wrist bone, correlated these to reference measurements from microcomputed tomography and DXA, demonstrated the application in vivo in a small group of participants, and determined the repeatability of the measurements. We found that measurements from digital wrist tomosynthesis (DWT) imaging with a DBT scanner were highly repeatable ex vivo (error = 0.05%-9.62%) and in vivo (error = 0.06%-10.2%). In ex vivo trials, DWT derived BMDs were strongly correlated with reference measurements (R = 0.841-0.980), as were cortical thickness measured at lateral and medial cortices (R = 0.991 and R = 0.959, respectively) and the majority of microstructural measures (R = 0.736-0.991). The measurements were quick and tolerated by human patients with no discomfort, and appeared to be different between young and old participants in a preliminary comparison. In conclusion, DWT is feasible in a mammography setting, and informative on bone mass, cortical thickness, and microstructural qualities that are known to deteriorate in osteoporosis. To our knowledge, this study represents the first application of DBT for imaging bone. Future clinical studies are needed to further establish the efficacy for diagnosing osteoporosis and predicting risk of fragility fracture using DWT.

Changes in bone mineral density during 5 years of adjuvant treatment in premenopausal breast cancer patients

PURPOSE

Adjuvant treatment for breast cancer in postmenopausal women is a risk factor for bone loss. However, the association between bone mineral density (BMD) changes in premenopausal breast cancer patients and various adjuvant treatment regimens is not well characterized. In this study, we evaluated the changes in BMD according to adjuvant treatment in premenopausal women with breast cancer.

METHODS

Between 2006 and 2010, BMD data of 910 premenopausal women with breast cancer before operation and 1, 2, 3.5, and 5 years post-operation were retrospectively analyzed. The patients were divided according to the type of treatment: observation (O), tamoxifen (T), chemotherapy (C), C followed by T (C → T), and gonadotropin-releasing hormone (GnRH) agonist with T (G + T).

RESULTS

After 5 years of follow-up, BMD changes were similar between the T and O groups (all p > 0.05). Within 1 year of treatment, the C group showed the most significant BMD loss. The C → T and G + T groups showed more significant BMD loss in the lumbar spine and femur than the O and T groups (both p < 0.001, both). After 1 year of treatment, BMD loss in the lumbar spine was significantly greater in the C → T and G + T groups than in the T group; this tendency was maintained for 5 years of treatment (all p < 0.005).

CONCLUSION

Premenopausal women who received adjuvant treatment which induced menopause showed significant bone loss which lasted for 5 years. Although no significant difference was observed between the O and T groups, tamoxifen treatment during chemotherapy or GnRH agonist treatment might prevent bone loss.

Clinical and translational pharmacology of drugs for the prevention and treatment of bone metastases and cancer-induced bone loss

Bone disease is a frequent event in cancer patients, both due to cancer spread to bone and to cancer therapies. Bone is the organ most frequently affected by metastatic disease when considering the two most frequent cancers in the Western world (breast and prostate cancers). Bone metastases can have a substantial detrimental effect on patients' quality of life, as well as significant morbidity due to complications collectively known as skeletal-related events (SREs), which include hypercalcaemia, pathological fractures, spinal cord compression, and need of radiotherapy or surgery to the bone. These have been successfully mitigated with the development of bone-targeted agents (BTAs; bisphosphonates and denosumab), focused on inhibiting osteoclast activity. The potential direct antitumour effect of bisphosphonates, as well as the impact of osteoclast inhibition with subsequent decrease in bone metabolism, have also propelled investigation on the role of BTAs in preventing cancer relapse in bone. In this review, the authors aimed to discuss the role of BTAs in the treatment and prevention of bone metastases, as well as their potential value in preventing cancer treatment-induced bone loss (CTIBL). The review will focus on breast and prostate cancers, with the aim of providing the most relevant clinical data emerging from bench to bedside translational research in the field of cancer-induced bone disease.

Osteoporosis in premenopausal women

PURPOSE OF REVIEW

The scope of this review was to review the newest developments in the context of the existing knowledge on premenopausal bone fragility. Fragility fractures are common in postmenopausal women and men and diagnostic criteria for osteoporosis have been agreed and multiple pharmacological treatments have been developed over the last 25 years. In premenopausal women, fragility fractures and very low bone mass are uncommon and osteoporosis in premenopausal women has therefore attracted much less interest.

RECENT FINDINGS

Recent studies have highlighted that lifestyle and dietary habits affect premenopausal bone mass. Bone mass may be improved by sufficient intake of calcium and vitamin D together with increased physical activity in premenopausal women with idiopathic osteoporosis. If pharmacological treatment is needed, teriparatide has been demonstrated to efficiently increase bone mass; however, no fracture studies and no comparative studies against antiresorptive therapies have been conducted. Pregnancy affects bone turnover and mass significantly, but pregnancy-associated osteoporosis is a rare and heterogeneous condition.

SUMMARY

The diagnosis of osteoporosis should only be considered in premenopausal women with existing fragility fractures, diseases or treatments known to cause bone loss or fractures. Secondary causes of osteoporosis should be corrected or treated if possible. The women should be recommended sufficient intake of calcium and vitamin and physical activity. In women with recurrent fractures or secondary causes that cannot be eliminated, for example glucocorticoid or cancer treatment, pharmacological intervention with bisphosphonates or teriparatide (not in the case of cancer) may be considered.

Femur fracture classification in women with a history of breast cancer

Purpose

Women with breast cancer are at increased risk for femur fracture. Contributing factors include estrogen deficiency, cancer-related therapies, or direct bone involvement. This study examines fracture subtypes in women with prior breast cancer experiencing a femur fracture.

Methods

Women age ≥50 years old with a history of invasive breast cancer who experienced a femur fracture were identified during 2005–2012. Fracture site was classified by hospital diagnosis (for hip) and/or radiologic findings (for femoral diaphysis), with subtype classification as pathologic, atypical or fragility fracture. Clinical characteristics were ascertained using health plan databases and disease registries.

Results

There were 802 women with prior breast cancer who experienced a femur fracture. The mean age at fracture was 80.5±9.6 years, with most fractures (93.8%) occurring in the hip and only 6.2% in the femoral diaphysis. However, diaphyseal fractures accounted for 23.6% of fractures in younger women (age ≤65 years). Pathologic fractures comprised 9.6% of total fractures (56.0% of diaphyseal fractures) and accounted for half the fractures in younger women. An atypical fracture pattern was seen in 1% of all femur fractures and 16.0% of diaphyseal fractures, with prior bisphosphonate exposure in all atypical fracture cases.

Conclusion

Most femur fractures in women with prior breast cancer occurred in the hip. Among younger women and those experiencing diaphyseal fractures, a larger proportion were pathologic and some were found to be atypical. Further studies should examine risk factors for femur fracture in women with breast cancer with specific attention to fracture subtype and pharmacologic exposures.

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This study examines femur fracture subtypes in women with prior breast cancer.

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Most fractures occurred in the hip, with fewer occurring in the femoral diaphysis.

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Fractures occurring in the femoral diaphysis were more likely to be pathologic.

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Fractures were also more likely to be pathologic in younger women.

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One in six diaphyseal femur fractures was classified as an atypical femur fracture.