According to SEER data, more than 260,000 women were diagnosed with breast cancer in the United States in 2016, most of whom were diagnosed with early-stage (stage I or II) disease. For this demographic, the National Comprehensive Cancer Network Clinical Practice Guidelines (NCCN Guidelines) in Oncology recommend standard imaging with bilateral mammography and ultrasound and, in some cases, breast MRI—the NCCN Guidelines for Breast Cancer do not recommend chest CT scans in patients asymptomatic for distant metastases. Regardless, many asymptomatic patients undergo chest CT.
A recent study conducted by researchers at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine, led by Barbara Dull, MD, further confirmed the recommendations of the NCCN Guidelines panel. The study is published in the June issue of Journal of the National Comprehensive Cancer Network.
Using data from a prospective database, Dull and colleagues studied records of more than 3,300 patients diagnosed with early-stage breast cancer between 1998 and 2012 and found that 11% of patients with stage I and more than 36% of patients with stage II breast cancer underwent chest CT within 6 months of diagnosis, despite NCCN Guidelines recommendations. Of these 683 patients, only nine were diagnosed with pulmonary metastases. However, benign pulmonary nodules were discovered in 175 patients.
"The overwhelming majority of nodules found in this study's patient population classified as false positive results," Dull says. "Not only do the costs of the chest CT and subsequent imaging and work-up put a cost constraint on the already burdened health care system, but the psychological impact of such results on a patient and their family is enormous."
"I hope patients and their physicians are reassured by findings like these," added Amy E. Cyr, MD, corresponding author of the study. "Chest CT and other staging studies are of extremely low yield for identifying metastases in patients with early-stage breast cancer, and even for the 1.3% of patients in our cohort ultimately diagnosed with pulmonary disease, many were not diagnosed because of that original CT scan, but were instead diagnosed on scans as long as two years after diagnosis, suggesting even lower utility. Unfortunately, for the 26.9% of patients with positive CT scans (the vast majority of which were false positives), the subsequent evaluation needed not only raises health care costs and anxiety, but also has the potential to delay oncologic treatment."
The NCCN Guidelines recommendations for patients with early-stage breast cancer are reinforced by other leading organizations in oncology, including the American Society of Clinical Oncology, European Society for Medical Oncology, and Britain's National Institute for Health and Clinical Excellence.
According to the study, patients who underwent staging chest CT were generally younger and more likely to have unfavorable tumor markers. However, there were no statistical differences between patients diagnosed with metastases and those with false positive results.
"Even with numerous guidelines and recommendations, staging studies are routinely performed in patients with stage I and II breast cancer. Despite NCCN recommendations, many patients with asymptomatic early-stage breast cancer continue to undergo chest CT as part of their initial evaluation. Adherence to the NCCN Guidelines and other evidence-based recommendations will spare patients unnecessary testing and, in an era of increasing health care costs, also curb excessive spending," Dull says.
The NCCN Guidelines are the recognized standard for clinical policy in cancer care and are often the most thorough and most frequently updated clinical practice guidelines available in any area of medicine.
"Notwithstanding the publicized potential risks of radiation exposure and the disputable value of chest CT in early-stage breast cancer, referring clinicians still order it, not infrequently, based on anecdotal cases, concerns regarding legal ramifications, or to satisfy insistent patients. At all stages of cancer care, including at presentation, during neoadjuvant or adjuvant therapy, and with advanced disease, evidence-based guidelines are needed to help direct treating physicians and their patients in selecting appropriate and indicated imaging studies," says Pamela J. DiPiro, MD, Dana-Farber/Brigham and Women's Cancer Center.
Source: National Comprehensive Cancer Network