“What surprised us the most was how dramatically early reductions in chemotherapy affect survival compared to later modifications,” said Zachary Veitch, MSc, MD, FRCPC, Department of Oncology, University of Calgary, Tom Baker Cancer Centre. “This became even more apparent when patients were further separated based on chemotherapy dose cut-offs. Early dose reductions can be related to age, weight, or the number of other medical issues a patient has, such as kidney disease or diabetes, among other factors. Often the first cycle of chemotherapy can be difficult for patients, and oncologists must convey the need for maintaining initial dose intensity, while using other medications to control side effects and manage comorbidities.”
John Ward, MD, Huntsman Cancer Institute at the University of Utah, and Member, NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Panel for Breast Cancer, who was not part of the research team, agreed. “Adjuvant therapy in early-stage breast cancer leads to improved survival. When chemotherapy is part of the adjuvant treatment, it is important to give the prescribed doses. This study adds further support for the need to do so. Balancing side effects with efficacy is always a challenge. When a treatment is palliative, quality of life factors into dosing choices. When cure is the goal, as it is with adjuvant therapy, it is important to strive to give the therapy as planned. The juice is worth the squeeze.”
The study focused on data from 1,302 women with stage I-III, HER2-negative breast cancer, who were treated with adjuvant FEC-D chemotherapy between 2007 and 2014. That data came from the Alberta Cancer Registry (ACR) in Alberta, Canada. Patients received at least four cycles of FEC-D, but no more than six. The total dose was averaged across the treatments, with a value of zero percent assigned for any missed cycles.
The researchers determined that 16% of the patients received less than 85% of the total recommended dose; and that the ‘lower-dose’ group had inferior five-year disease-free survival (79.2% vs 85.9%) and inferior overall survival (80.7% vs 88.8%) compared with those who received higher cumulative doses. However, when they split the ‘lower-dose’ group into 2 cohorts based on dose reduction during cycles one-to-three versus cycles four-to-six, they found that outcomes were not compromised when dose reduction occurred only during the later cycles (which are the only cycles to include docetaxel).
“There may be a few reasons for this,” speculated Dr. Veitch. “First, the amount of docetaxel that was prescribed in the last three cycles may be higher than needed for the FEC-D regimen. Lower doses have been shown to be as effective in other standard of care chemotherapy regimens, and lower doses have been used in other countries with good outcomes. Second, the majority of cancer cells that are sensitive to chemotherapy may be killed in the first few treatments, rather than in the later treatments. Thus, reducing the dose late may not have as much of an impact.”
To read the entire study and view the corresponding data tables, visit JNCCN.org. Complimentary access to “Impact of Cumulative Chemotherapy Dose on Survival with Adjuvant FEC-D Chemotherapy for Breast Cancer” is available until November 10, 2019.
About JNCCN—Journal of the National Comprehensive Cancer Network
More than 25,000 oncologists and other cancer care professionals across the United States read JNCCN—Journal of the National Comprehensive Cancer Network. This peer-reviewed, indexed medical journal provides the latest information about best clinical practices, health services research, and translational medicine. JNCCN features updates on the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®), review articles elaborating on guidelines recommendations, health services research, and case reports highlighting molecular insights in patient care. JNCCN is published by Harborside. Visit JNCCN.org. To inquire if you are eligible for a FREE subscription to JNCCN, visit http://www.nccn.org/jnccn/subscribe.asp. Follow JNCCN on Twitter @JNCCN.
About the National Comprehensive Cancer Network
The National Comprehensive Cancer Network® (NCCN®) is a not-for-profit alliance of 28 leading cancer centers devoted to patient care, research, and education. NCCN is dedicated to improving and facilitating quality, effective, efficient, and accessible cancer care so patients can live better lives. Through the leadership and expertise of clinical professionals at NCCN Member Institutions, NCCN develops resources that present valuable information to the numerous stakeholders in the health care delivery system. By defining and advancing high-quality cancer care, NCCN promotes the importance of continuous quality improvement and recognizes the significance of creating clinical practice guidelines appropriate for use by patients, clinicians, and other health care decision-makers around the world.
The NCCN Member Institutions are: Abramson Cancer Center at the University of Pennsylvania, Philadelphia, PA; Fred & Pamela Buffett Cancer Center, Omaha, NE; Case Comprehensive Cancer Center/University Hospitals Seidman Cancer Center and Cleveland Clinic Taussig Cancer Institute, Cleveland, OH; City of Hope National Medical Center, Duarte, CA; Dana-Farber/Brigham and Women’s Cancer Center | Massachusetts General Hospital Cancer Center, Boston, MA; Duke Cancer Institute, Durham, NC; Fox Chase Cancer Center, Philadelphia, PA; Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center/Seattle Cancer Care Alliance, Seattle, WA; The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD; Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL; Mayo Clinic Cancer Center, Phoenix/Scottsdale, AZ, Jacksonville, FL, and Rochester, MN; Memorial Sloan Kettering Cancer Center, New York, NY; Moffitt Cancer Center, Tampa, FL; The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research Institute, Columbus, OH; O’Neal Comprehensive Cancer Center at UAB, Birmingham, AL; Roswell Park Comprehensive Cancer Center, Buffalo, NY; Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, MO; St. Jude Children’s Research Hospital/The University of Tennessee Health Science Center, Memphis, TN; Stanford Cancer Institute, Stanford, CA; UC San Diego Moores Cancer Center, La Jolla, CA; UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, CA; University of Colorado Cancer Center, Aurora, CO; University of Michigan Rogel Cancer Center, Ann Arbor, MI; The University of Texas MD Anderson Cancer Center, Houston, TX; University of Wisconsin Carbone Cancer Center, Madison, WI; Vanderbilt-Ingram Cancer Center, Nashville, TN; and Yale Cancer Center/Smilow Cancer Hospital, New Haven, CT.
scraped from https://www.newswise.com/articles/maintaining-full-doses-of-chemotherapy-can-be-key-for-breast-cancer-survival-according-to-new-research-in-jnccn