Background: Cyclin-dependent kinase (CDK) 4/6 inhibitors are now the standard of care for hormone receptor–positive (HR+), HER2-negative (HER–) metastatic breast cancer (MBC). However, guidelines are lacking regarding their optimal sequencing with other available agents. This study examines physician practice patterns and treatment outcomes of palbociclib and subsequent therapies in a real-world setting. Methods: A retrospective chart review was conducted for consecutive patients with MBC who received palbociclib between February 2015 and August 2017 at the Alvin J. Siteman Cancer Center. Kaplan-Meier method was used to generate time-to-event curves and estimate median progression-free survival (mPFS). Log-rank test was used to compare differences. Results: A total of 200 patients, with a median age of 59.4 years and a follow-up of 19.5 months, were included. Palbociclib was most frequently combined with letrozole (73.5%), followed by fulvestrant (25%), anastrozole (1%), and tamoxifen (0.5%). Most patients received palbociclib in the endocrine-resistant setting (n=42, n=50, and n=108 in the first-, second-, and subsequent-line settings, respectively), and the fraction of patients receiving palbociclib as first- or second-line therapy increased in recent months (P=.0428). mPFS was 20.7, 12.8, and 4.0 months with palbociclib administered in the first-, second-, and subsequent-line settings, respectively (P<.0001). Incidences of grade 3/4 neutropenia (41.5%) and dose reductions (29%) were comparable to reports in the literature. Among patients whose disease progressed on palbociclib (n=104), the most frequent next-line treatment was capecitabine (n=21), followed by eribulin (n=16), nab-paclitaxel (n=15), and exemestane + everolimus (n=12). mPFS with hormone therapy alone or in combination with targeted agents (n=32) after first-, second-, and subsequent-line palbociclib was 17.0, 9.3, and 4.2 months, respectively (P=.04). mPFS with chemotherapy (n=70) was not reached, 4.7, and 4.1 months after first-, second-, and subsequent-line palbociclib, respectively (P=.56). Conclusions: Palbociclib is effective for HR+/HER2– MBC in real-world practice. Hormone therapy alone or in combination with targeted agents remains an effective option after palbociclib progression.
Jing Xi, Aabha Oza, Shana Thomas, Foluso Ademuyiwa, Katherine Weilbaecher, Rama Suresh, Ron Bose, Mathew Cherian, Leonel Hernandez-Aya, Ashley Frith, Lindsay Peterson, Jingqin Luo, Jairam Krishnamurthy and Cynthia X. Ma
Hinda Boutrid, Maryam Lustberg, Jeffrey Vandeusen, Sagar Sardesai, Daniel Stover, Robert Wesolowski, Mathew Cherian, Julie Stephens, Marilly Palettas, Evan Morgan, Mohmoud Kassem, Michael Berger, Craig A. Vargo, Bhuvaneswari Ramaswamy and Nicole Williams
Background: Invasive lobular carcinoma (ILC) accounts for 5%–15% of all invasive breast cancer cases. ILC has the propensity for distant late recurrence with widespread metastatic disease. To our knowledge, there is limited data on the clinical outcomes and treatment strategies of metastatic ILC. This retrospective study evaluates the overall survival (OS) and progression-free survival (PFS) in the metastatic ILC population at a single institution, focusing on first line treatment received in the metastatic setting. Methods: A retrospective chart review was performed on patients (Pts) diagnosed with metastatic ILC diagnosed at The Ohio State University Comprehensive Cancer Center between January 1, 2004 and December 31, 2014 using an IRB approved protocol. Patient demographics, clinical characteristics, and treatment modalities were summarized with descriptive statistics. OS (time from metastasis to death or last known follow-up) and PFS (time from diagnosis of metastasis to progression) were compared between types of first-line treatment: endocrine therapy (ET), chemotherapy (chemo), chemo followed by ET, ET plus CDK 4/6 inhibitor, or other treatments. OS and PFS estimates were generated using Kaplan Meier methods and compared using Log-rank tests. Results: 60 female pts were included in this study. The median age was 59 years (24–78). 45 (75%) pts were postmenopausal, 44 (73%) ER+/PR+, 14 (23%) ER+/PR-, and 2 (3%) ER-PR-, 28 (47%) with only bone metastases, 19 (32%) with visceral and bone metastases, and 13 (22%) with liver metastases. Twenty-eight (47%) pts received first line ET therapy, 12 (20%) received ET + CDK 4/6 inhibitor, 7 (12%) received chemo alone, 4 (7%) received chemo followed by ET, and 9 (15%) received other types of first line therapy. The median OS was 3.0 years, and the median PFS was 1.4 years. No difference in the Kaplan-Meier curves was found between first-line treatment groups in OS or PFS (OS: P=.247; PFS: P=.436). Discussion: ILC is a histologically distinct disease from invasive ductal cancer. It has been previously shown that invasive lobular cancer may not be as sensitive to adjuvant chemotherapy. We showed that in the metastatic setting there was no difference in PFS and OS among first line treatment groups. ET remains preferred treatment option; however, based on our data, chemotherapy can be considered in patient with metastatic ILC in the appropriate clinical context such as visceral crisis.