Neoadjuvant Therapy Enough for Early Stages
CancerWise - November 2008
Early-stage breast cancer patients with little or no cancer in their lymph nodes may not require post-surgery radiation if they receive chemotherapy before a mastectomy, according to results of a new study.
The findings were reported by M. D. Anderson researchers Sept. 24 at the 50th annual meeting of the American Society for Therapeutic Radiology and Oncology
Significance of results
The results could spare early stage patients from having to undergo post-mastectomy radiation that, according to the study, did not offer better results than neoadjuvant chemotherapy (chemotherapy before the primary treatment, in this case a mastectomy) and mastectomy alone.
"Radiation after surgery has been shown to benefit the survival of patients who have more advanced tumors," says Tse-Kuan Yu, M.D., Ph.D., assistant professor in M. D. Anderson's Department of Radiation Oncology. "However, administering chemotherapy prior to surgery has changed how radiation oncologists need to approach treating patients with stage 1 and 2 breast cancers."
The retrospective study, led by Yu, reviewed the cases of 427 women who underwent chemotherapy then mastectomy from 1985-2004 to observe the value of treating early-stage breast cancer with radiation therapy.
Radiation was administered to 253 women because they had more aggressive tumor features. Specifically focusing on those who did not receive radiation therapy, 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 received pre-surgery chemotherapy and were not treated with radiation:
- 20% with four or more pathologically involved lymph nodes relapsed
- 4.2% with one to three involved lymph nodes relapsed
- 1% with no involved lymph nodes relapsed
Interestingly, researchers noted that patients with zero involved lymph nodes after receiving chemotherapy prior to surgery exhibited a 1% recurrence rate.
“Our findings indicate neoadjuvant chemotherapy controlled the cancer, and patients with early-stage breast cancer and negative lymph nodes after neoadjuvant chemotherapy may not need radiation,” says the study’s senior author Thomas Buchholz, M.D., chair of M. D. Anderson’s Department of Radiation Oncology.
“Though additional research is warranted, we can begin to surmise that patients may be spared from radiation therapy if they’ve been treated with neoadjuvant chemotherapy and have fewer than three involved lymph nodes.”
By analyzing initial tumor characteristics in each patient, researchers can begin to classify which patients require post-mastectomy radiation to prevent recurrence.
To expand on these findings, M. D. Anderson researchers are planning future prospective clinical trials that would confirm whether radiation can be avoided in selected patients with early-stage breast cancer who are treated with neoadjuvant chemotherapy.
– Adapted by Darcy De Leon from an M. D. Anderson news release