NEW YORK (Reuters Health) – Following neoadjuvant chemotherapy, image-guided vacuum-assisted biopsy (VAB) can reliably identify a subgroup of patients with no residual disease in the breast, according to an analysis of pooled data drawn from three continents.
“Our findings support the use of a standardized assessment protocol using VAB in carefully selected patients to assess if there is residual cancer left in the breast after neoadjuvant chemotherapy,” Dr. Marios Konstantinos Tasoulis of The Royal Marsden NHS Foundation Trust in London told Reuters Health by email. “These results could inform the design of clinical trials testing the safety of omission of surgery in exceptional responders.”
In a paper in JAMA Surgery, Dr. Tasoulis and colleagues note that with improvements in treatment, especially routine use of adjuvant radiotherapy and systemic therapy, certain patients may not benefit from surgery.
To investigate further, the researchers examined data on 166 women from the U.K., South Korea and the U.S. with breast cancer who received neoadjuvant chemotherapy. Their median age was 49 years.
A total of 143 underwent VAB and 23 had core-cut biopsy before surgery. The median number of samples was six, and the overall pathological complete-response rate was 51.2%.
In the 159 women for whom data were available, the false-negative rate across the whole cohort was 18.7%. However, subgroup analysis showed that in selected patients with a complete or partial clinical response the proportion was significantly lower.
In the 76 such women who had a minimum of six VABs and residual imaging abnormality of 2 cm or less the false-negative rate was 3.2%. The negative predictive value was 97.4% and the overall accuracy was 89.5%.
In subgroups of these women who were HR positive and ERBB2 negative or HR negative and ERBB2 positive, the diagnostic accuracy was 100%.
The researchers note that a similar diagnostic protocol using a minimum of twelve 9-gauge image-guided VABs is currently being studied in a prospective clinical trial at the MD Anderson Cancer Center in Houston, Texas, to assess the safety of elimination of surgery in exceptional responders.
“If the clinical trials confirm this is a safe approach,” concluded Dr. Tasoulis, “thousands of women with breast cancer could be spared major breast and axillary surgery.”
Dr. Judy C. Boughey, a professor of surgery at Mayo Clinic, in Rochester, Minnesota, told Reuters Health by email, “The ability to identify, prior to surgery, those patients who have had eradication of disease from the breast with neoadjuvant chemotherapy, is a crucial step in the advancement of management of women with breast cancer. While some studies to date have had more disappointing results, this pooled analysis . . . identified a subset of patients (which comprised just less than half the patients) where percutaneous core needle biopsy after neoadjuvant chemotherapy was able to predict pathology findings from surgery.”
“This study provides important information to advance breast cancer (approaches) for patients treated with neoadjuvant chemotherapy to tailor their management based on response to treatment and enable the next steps towards response-dependent de-escalation of care,” said Dr. Boughey, who was not involved in the research.
SOURCE: https://bit.ly/3lOzt75 JAMA Surgery, online October 7, 2020.