Although several studies have examined the routine use of postmastectomy radiation therapy in breast cancer patients with larger tumors and four or more positive lymph nodes, the role of postmastectomy RT for smaller tumors with one to three positive lymph nodes is unknown.
The study focused on patients with a high risk of locoregional recurrence who might benefit from postmastectomy RT for invasive breast cancer and who had tumor size less than 5 cm with one to three involved axillary lymph nodes (T1-2 N1).
Taiwan researchers retrospectively studied 544 patients with T1-2 N1 invasive breast cancer who were treated with modified radical mastectomy between April 1991 and December 2005. Of the patients, 383 did not receive radiation therapy, while 161 did.
Radiation therapy was found to reduce recurrence in patients younger than 40 years old who had T2 stage cancer with high nuclear grade, negative estrogen receptor status, and lymphovascular invasion. For 41 patients with negative estrogen receptor status and positive lymphovascular invasion, radiation therapy reduced recurrence from 40% to 13%. In addition, five-year overall survival increased from 44% to 87%, according to the researchers (Int J Radiat Oncol Biol Phys, June 1, 2010, Vol. 77:2, pp. 516-522).
"Even though the study sample size was small, we feel that the results are compelling," said lead author Po Sheng Yang, MD, a physician at Sun Yat-Sen Cancer Center in Taipei, Taiwan. "Based on this study, we strongly suggest that radiation therapy be used after mastectomy for this particular group of breast cancer patients."
By Donna Domino
AuntMinnie.com contributing writer
June 7, 2010
Long-term APBI outcomes are comparable in low-risk patients, May 31, 2010
Elderly early-stage breast cancer patients don't need RT, May 21, 2010
Mastectomy patients may underutilize radiation therapy, March 30, 2010
Women aren't told about postmastectomy radiation therapy, study shows, February 16, 2009
Postmastectomy nodal radiation unnecessary for node-negative breast cancer, September 23, 2008
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