Grubbs, Stephen S.

Purpose Skeletal-related events (SREs) such as pathologic fracture, spinal cord compression, or the necessity for radiation or surgery to bone metastasis cause considerable morbidity, decrements in quality of life, and costs to the health care system. The results of a recent large randomized trial (Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology [CALGB/Alliance 70604]) showed that zoledronic acid (ZA) every 3 months was noninferior to monthly ZA in reducing the risks of SREs. We sought to determine the cost-effectiveness (CE) of monthly ZA, ZA every 3 months, and monthly denosumab in women with breast cancer and skeletal metastases. Methods Using a Markov model, costs per SRE avoided were calculated for the three treatments. Sensitivity analyses were performed where denosumab SRE probabilities were assumed to be 50%, 75%, and 90% lower than the ZA SRE probabilities. Quality-adjusted life-years were also calculated. The analysis was from the US payer perspective. Results The mean costs of the denosumab treatment strategy are nine-fold higher than generic ZA every 3 months. Quality-adjusted life-years were virtually identical in all the three treatment arms; hence, the optimal treatment would be ZA every 3 months because it was the least costly treatment. The sensitivity analyses showed that relative to ZA every 3 months, the incremental costs per mean SRE avoided for denosumab ranged from $162,918 to $347,655. Conclusion ZA every 3 months was more CE in reducing the risks of SRE than monthly denosumab. This analysis was one of the first to incorporate the costs of generic ZA and one of the first independent CE analyses not sponsored by either Novartis or Amgen, the makers of ZA and denosumab, respectively. ZA every 3 months is the more CE option and more reasonable alternative to monthly denosumab.

104 Background: Lymphedema (LE), a side effect of BC treatment, affects 8%–56% of women. The study tested the effectiveness of an education only vs education + exercise intervention on LE incidence in a group randomized trial (NCT00376597) of 38 cooperative group sites. Methods: Newly diagnosed women with stage I-III BC were consented and arm circumference and range of motion were measured pre-surgery. After surgery, patients (pts) were enrolled based on the randomization assignment of their treating institution, stratified by their type of node dissection (sentinel or axillary), and received either: education only: its causes, signs, symptoms and risk reduction strategies, or education + personalized exercise instruction from a physical therapist, with elastic compression garments to wear during heavy arm use and air travel. Pts completed surveys and arm measurements at baseline (BL), 12 and 18 months with the LE endpoint defined as ≥ 10% difference in limb volume at any time from BL to 18 months or physician diagnosis of LE. Cochran-Mantel-Haenszel (CMH) tests were used to compare the LE-free rate between arms, adjusted for type of biopsy. Logistic regression assessed predictors of LE. Results: 568 pts were enrolled, 45% in education only, and 55% in education + exercise, with 554 (98%) included in the analyses. Pts were on average 57.7 years, White (83%), non-Hispanic (92%) and married (62%). 47% only had sentinel node dissection, 35% had mastectomy, and 37% had chemotherapy. The LE-free rate was 58% in education only vs 55% in education + exercise (CMH p = 0.73). Predictors of LE included surgery type (lumpectomy vs mastectomy, OR = 2.22, p < 0.001) and chemotherapy (no vs yes, OR = 1.73, p = 0.02), after adjusting for BMI and type of node dissection. Only one-third wore the sleeve at least 75% of the time and only 50% did LE exercises at least weekly. Conclusions: There was no difference by intervention arm in LE incidence by 18 months. Poor adherence in the education + exercise arm may have been a factor. Additional analyses will assess quality of life, body image and knowledge about LE by arm. Further research is needed to effectively prevent LE in pts after BC surgery. Research Support: UL1TR001409; U10CA037447, UG1CA189823 Clinical trial information: NCT00376597.