Higher incidences of osteoporosis and osteopenia are found in cancer patients, particularly in women receiving aromatase inhibitors or with chemotherapy-induced ovarian failure, or in men with prostate cancer and androgen deprivation therapy. Therefore, management of long-term bone health is emerging as an important aspect of comprehensive cancer care. Patients with cancer typically have a number of additional risk factors for osteoporosis that should prompt screening, regardless of patient age or sex. Maintaining bone health requires a broad knowledge base, including understanding underlying bone metabolism and how it is affected by both cancer itself and the drugs used to treat cancer, the effect of chemotherapy-induced menopause on bone health, bone markers and imaging techniques used to assess bone health, therapeutic strategies to maintain bone health, and treatment of bone metastases, including surgery for pathologic fractures. Multiple members of the healthcare team may need to be involved in education and care of the patient. This report summarizes discussion of these and other issues regarding bone health and cancer care from the NCCN Bone Health and Cancer Care Task Force meeting in early 2006. (JNCCN 2006;4(Suppl 2):S1-S24)
Richard L. Theriault, J. Sybil Biermann, Elizabeth Brown, Adam Brufsky, Laurence Demers, Ravinder K. Grewal, Theresa Guise, Rebecca Jackson, Kevin McEnery, Donald Podoloff, Peter Ravdin, Charles L. Shapiro, Matthew Smith, and Catherine H. Van Poznak
Seth A. Wander, Hyo S. Han, Mark L. Zangardi, Andrzej Niemierko, Veronica Mariotti, Leslie S.L. Kim, Jing Xi, Apurva Pandey, Siobhan Dunne, Azadeh Nasrazadani, Avinash Kambadakone, Casey Stein, Maxwell R. Lloyd, Megan Yuen, Laura M. Spring, Dejan Juric, Irene Kuter, Ioannis Sanidas, Beverly Moy, Therese Mulvey, Neelima Vidula, Nicholas J. Dyson, Leif W. Ellisen, Steven Isakoff, Nikhil Wagle, Adam Brufsky, Kevin Kalinsky, Cynthia X. Ma, Joyce O’Shaughnessy, and Aditya Bardia
Background: Inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6i) are widely used as first-line therapy for hormone receptor–positive metastatic breast cancer (HR+ MBC). Although abemaciclib monotherapy is also FDA-approved for treatment of disease progression on endocrine therapy, there is limited insight into the clinical activity of abemaciclib after progression on prior CDK4/6i. Patients and Methods: We identified patients with HR+ MBC from 6 cancer centers in the United States who received abemaciclib after disease progression on prior CDK4/6i, and abstracted clinical features, outcomes, toxicity, and predictive biomarkers. Results: In the multicenter cohort, abemaciclib was well tolerated after a prior course of CDK4/6i (palbociclib)-based therapy; a minority of patients discontinued abemaciclib because of toxicity without progression (9.2%). After progression on palbociclib, most patients (71.3%) received nonsequential therapy with abemaciclib (with ≥1 intervening non-CDK4/6i regimens), with most receiving abemaciclib with an antiestrogen agent (fulvestrant, 47.1%; aromatase inhibitor, 27.6%), and the remainder receiving abemaciclib monotherapy (19.5%). Median progression-free survival for abemaciclib in this population was 5.3 months and median overall survival was 17.2 months, notably similar to results obtained in the MONARCH-1 study of abemaciclib monotherapy in heavily pretreated HR+/HER2-negative CDK4/6i-naïve patients. A total of 36.8% of patients received abemaciclib for ≥6 months. There was no relationship between the duration of clinical benefit while on palbociclib and the subsequent duration of treatment with abemaciclib. RB1, ERBB2, and CCNE1 alterations were noted among patients with rapid progression on abemaciclib. Conclusions: A subset of patients with HR+ MBC continue to derive clinical benefit from abemaciclib after progression on prior palbociclib. These results highlight the need for future studies to confirm molecular predictors of cross-resistance to CDK4/6i therapy and to better characterize the utility of abemaciclib after disease progression on prior CDK4/6i.