Cancer-treatment-induced bone loss, part 1

The pathophysiology, frequency, sequelae, diagnosis, and treatment of cancer-treatment-induced bone loss (CTIBL) are discussed.

CTIBL is a long-term complication associated with cancer therapies that can directly or indirectly affect bone metabolism. Although CTIBL can occur in any patient receiving a cancer therapy known to cause bone loss, CTIBL is most common in patients with breast or prostate cancer who receive chemotherapy, hormone therapy, or surgical castration, as these can cause hypogonadism and induce bone loss. CTIBL causes bone fragility and an increased susceptibility to fractures; therefore, prevention, early diagnosis, and treatment of CTIBL are essential to decrease the risk of fracture. Bone loss occurs more rapidly and tends to be more severe in patients with CTIBL compared with those with normal age-related bone loss. Fractures of the hip, vertebra, and wrist are the fractures most commonly associated with bone loss. CTIBL is diagnosed by measuring bone mass using bone densitometry. Treatment of CTIBL consists of changing diet and lifestyle such as optimizing calcium and vitamin D intake, exercising, modifying behaviors known to increase the risk of CTIBL and pharmacologic therapy with hormone replacement therapy (HRT), selective estrogen-receptor modifiers (SERMs), calcitonin, or a bisphosphonate.

Early identification and treatment of CTIBL are essential to prevent fractures. Patients should be instructed to optimize calcium and vitamin D intake, exercise regularly, and modify lifestyle behaviors known to cause bone loss. Patients with CTIBL should be treated with an oral or i.v. bisphosphonate; SERMs or HRT may be an option in some patients if contraindications do not exist.