"Radiation after surgery has been shown to benefit the survival of patients who have more advanced tumors," said lead researcher Tse-Kuan Yu. "However, administering neoadjuvant chemotherapy prior to surgery has changed how radiation oncologists need to approach treating patients with stage one and two breast cancers."
The retrospective study reviewed the cases of 427 women who underwent neoadjuvant chemotherapy and mastectomy from 1985 to 2004 to observe the value of treating early-stage breast cancer with RT. Of the 427 women, radiation was administered to 253 due to more aggressive tumor features. Those who received radiation more commonly had four or more pathologically involved lymph nodes or lymphovascular invasion.
Specifically focusing on those who did not receive RT, researchers looked at whether each patient's breast cancer relapsed over the course of five years to determine if radiation contributed to preventing its return. Of the group of patients who were not treated with radiation, 20 percent of those with four or more pathologically involved lymph nodes after pre-surgery chemotherapy relapsed compared to 4.2 percent of those with one to three involved lymph nodes. Patients with zero involved lymph nodes after receiving chemotherapy prior to surgery exhibited a zero percent recurrence rate.
"Our findings indicate neoadjuvant chemotherapy controlled the cancer and radiation would have been unnecessary for patients with early-stage breast cancer and negative lymph nodes after neoadjuvant chemotherapy," said Thomas Buchholz, the study's senior author. Additional research is warranted though, he adds.
MEDICA.de; Source: University of Texas M. D. Anderson Cancer Center