NEOADJUVANT CHEMOTHERAPY FOR BREAST CANCER

Patients with larger malignant tumors of the breast who undergo chemotherapy before a breast cancer operation are more likely to undergo a lumpectomy than a mastectomy, according to a study published by Killelea et al in the Journal of the American College of Surgeons.

Study investigators from Yale University School of Medicine and Yale University Comprehensive Cancer Center also determined that rates of neoadjuvant chemotherapy had increased significantly through the 5-year study period, possibly because of the FDA approval of new chemotherapy agents.

Study Background

Lead investigator general surgeon, Brigid K. Killelea, MD, MPH, FACS, called the study results “very exciting.” It is one of the largest studies to date on the use of chemotherapy before surgical treatment for breast cancer.

“We've seen data published from clinical trials showing that neoadjuvant chemotherapy results in increased lumpectomy rates, but this is one of the first studies using a large national database that reflects what is also going on in the community hospital setting,” she said.

Study Details

The researchers analyzed data from the National Cancer Data Base (NCDB), a joint program of the Commission on Cancer of the American College of Surgeons and the American Cancer Society. NCDB captures an estimated 70% of newly diagnosed cancer cases in the United States, from approximately 1,500 cancer programs accredited by the Commission on Cancer.

In all, the 5-year study involved 354,204 women diagnosed with invasive breast cancer from 2006 through 2011. Out of that group, 59,063, or 16.7%, received neoadjuvant chemotherapy.

This study did not look at overall survival among women who had neoadjuvant chemotherapy, which previously, smaller trials have found to be no different from adjuvant chemotherapy. However, it did confirm a trend that those trials had noted: higher rates of breast conservation among patients with larger tumors for those who received chemotherapy first.

Study Findings

This study found that 35% of women who had neoadjuvant chemotherapy also had breast-conservation surgery.

“One interesting thing that we saw over time was that the percentage of women that did receive neoadjuvant therapy increased, going from 13.9% in 2006 to 20.5% in 2011,” Dr. Killelea said. That’s an increase from about one in seven women in the first year of the study to one in five in the last.

Women with larger breast tumors were also more likely toward the end of the trial period to opt for neoadjuvant chemotherapy and breast-sparing lumpectomy vs mastectomy, Dr. Killelea noted. “Those who received neoadjuvant chemotherapy were 70% more likely to have a lumpectomy for tumors larger than 3 cm, leading to an increased rate of breast preservation,” she said. “In other words, those people were able to avoid a mastectomy.” This was true for tumors as large as 4 to 8 cm in diameter, study authors noted.

Benefits of Neoadjuvant Treatment

Advances in chemotherapy drugs since 2006 have made these agents more effective in treating increasingly serious forms of breast cancer, such as HER2-positive and triple-negative cancers, according to Dr. Killelea. In these patients, administering chemotherapy before the operation gives surgeons the opportunity to evaluate how the tumor will respond to treatment.

Another advantage of neoadjuvant chemotherapy is that doctors can begin treatment of cancer that has spread to the lymph nodes immediately, rather than waiting for the breast to heal after the procedure, Dr. Killelea noted.

“Going forward, it will be interesting to see whether or not the use of neoadjuvant therapy continues to rise as newer drugs and agents are being developed all the time,” Dr. Killelea said. “It will also be interesting to watch what happens to the rate of breast conservation over time. We don't know. That's why it's so important for us to have a database like NCDB.”

Dr. Killelea is the corresponding author of the Journal of the American College of Surgeons article.

For full disclosures of the study authors, visit www.journalacs.org.