Waiting more than 42 days postdiagnosis to undergo surgery could increase the risk of cancer-related mortality among patients with certain breast cancer subtypes, according to a recent study published by Salewon et al in Breast Cancer Research.
Background
Hormone receptor–positive and HER2-negative breast cancers are often initially treated with surgery. However, many factors can cause surgery delays. The diagnosis and preoperative process can take several days, and patients may have work or family obligations that further delay the surgery date. In addition, some patients may want a second opinion, and others of childbearing age may want to pursue egg preservation if their treatment plan involves chemotherapy following surgery.
“In 2022, the Commission on Cancer recommended that most [patients] with breast cancer undergo surgery within 60 days. That was a major victory, but some [patients] may need to have surgery sooner than 60 days,” noted senior study author Takemi Tanaka, PhD, Professor of Pathology at the University of Oklahoma College of Medicine. “[W]hile we want [patients] to understand the risk of delaying treatment, we also want them to have time to pursue egg preservation or get a second opinion,” she added.
Study Methods and Results
In the study, researchers assessed data from The National Cancer Institute’s Surveillance, Epidemiology, and End Results–Medicare-linked database. They discovered that the subtypes of breast cancer most affected by delayed surgery were those with the best prognoses, including hormone receptor–positive breast cancers and HER2-negative breast cancers. Although these breast cancer subtypes tend to grow more slowly, when surgery was delayed, the patients’ risk of mortality from the cancer increased exponentially.
For instance, their risk began to increase at 42 days without surgery. By 60, 90, and 120 days, the patients’ risk of mortality was 21%, 79%, and 183% higher. In contrast, hormone receptor–negative and triple-negative breast cancer subtypes, which are aggressive and invasive, changed very little during treatment delays.
“This is an important finding, because 42 days can go by very quickly, but it’s also concerning because recent studies show that both the frequency and length of delay are increasing,” stressed Dr. Tanaka.
The researchers hypothesized that these treatment delays may impact these particular breast cancer subtypes because they are slower-growing and have more room for change—unlike cancer breast subtypes that are already invasive. Further, biopsies could cause an inflammatory response that may fuel tumor growth. Prior studies demonstrated that nonsteroidal anti-inflammatory drugs suppressed inflammation in a mouse model of breast cancer following biopsy.
Research in this area has been ongoing. In a 2020 study published by Hanna et al in BMJ, investigators analyzed 34 studies on 17 types of cancers and found that treatment delays were a critical contributing factor to the risk of mortality in several types of solid tumors, notably a 6% to 8% increased risk of for each 4-week delay in treatment.
In the new study, the researchers measured whether patients died specifically from their breast cancer, whereas other studies have looked at overall survival, which includes causes of death other than cancer.
Conclusions
The findings both confirmed and built on the researchers’ previous investigation—published by Hills et al in the Annals of Surgical Oncology—showing that patients with a hormone receptor–positive breast cancer who didn’t receive surgery until 61 to 90 days following diagnosis were 18% more likely to have their tumor size upstaged compared with those who received surgery within the first 30 days following their diagnosis. There was a 47% likelihood of tumor upstaging among patients who underwent surgery beyond 90 days.
The researchers plan to launch a clinical trial to further explore how cancer treatment delays contribute to an increased risk of mortality.
Disclosure: The research in this study was supported by the U.S. Department of Defense as well as in part by the National Cancer Institute Cancer Center Support Grant and the Oklahoma Tobacco Settlement Endowment Trust contract awarded to the University of Oklahoma Health Sciences. For full disclosures of the study authors, visit breast-cancer-research.biomedcentral.com.
