Neoadjuvant drug therapy reduces need for mastectomy in HER2-positive breast cancer
Neoadjuvant chemotherapy plus targeted anti-HER2 therapy may reduce the need for mastectomy and lymph node removal in women with HER2-positive breast cancer, according to a study from Spain that was presented at EBCC 2018.
“We wanted to see whether the known benefits of these targeted drugs could be extended to spare women from the undesirable effects of radical surgery,” said study lead author Professor Isabel Rubio, director of the Breast Surgical Unit at Clínica Universidad de Navarra and co-chair of EBCC 2018.
“This study shows us that treating HER2-positive breast cancer with a targeted drug before surgery can mean fewer women need to undergo mastectomy and removal of several lymph nodes,” she said.
Researchers assessed data of 160 women with HER2-positive breast cancer who underwent neoadjuvant and targeted treatment at the Vall d’Hebron University Hospital in Barcelona, Spain between October 2007 and December 2016, of whom 81 percent (n=129) were candidates for mastectomy.
Biopsy samples revealed that 62.5 percent of the patients (n=100) had axillary node involvement (cN1–3) while 37.5 percent (n=60) had no regional lymph node metastasis (cN0).
Patients received neoadjuvant anthracycline and/or taxane-based chemotherapy as well as anti-HER2 medications where 71 patients were treated with trastuzumab alone, 23 with trastuzumab plus lapatinib, four with lapatinib alone, 55 with trastuzumab plus pertuzumab, and seven with trastuzumab plus neratinib prior to surgery.
Following neoadjuvant therapy, 47.2 percent of patients (n=61) only required breast conservation surgery, leading to more than half of the study population (57.5 percent) only requiring breast conservation surgery rather than mastectomy. [EBCC 2018, abstract 19]
Sentinel lymph node biopsy after neoadjuvant therapy showed that 71 percent of the patients with lymph node involvement pre-therapy achieved axillary pathologic complete response, while 95 percent of patients who had no lymph node involvement pre-treatment remained so after treatment, with 5 percent having a positive axillary node detected.
After a median follow-up of 47.09 months, five and six patients developed locoregional cancer recurrence and distant metastasis, respectively. There was no significant difference in disease-free survival or overall survival between patients on various treatments.
“Breast cancer treatments have advanced tremendously in recent years. What this means is that surgery should evolve too so that it is tailored to the individual patient and takes account of the effects of their particular treatment,” said Rubio.
“Survival rates for breast cancer are improving and research continues to look for ways to build on that success. At the same time we need to understand the needs of individual patients and the differences between individual tumours,” said Professor Robert Mansel from the Cardiff University School of Medicine in Wales, UK and chair of EBCC 2018 who was not involved in the study.
“This research provides more information on which patients are likely to benefit from radical surgery and which could be safely treated with breast conserving surgery, bringing potential benefits in patients’ quality of life,” he said.