Radiation after mastectomy improves overall survival in invasive breast cancer

Postmastectomy radiation therapy increased five-year overall survival by almost 50% and reduced recurrence risk by nearly 30%, according to a study in the International Journal of Radiation Oncology, Biology, Physics.

Po Sheng Yang, MD, and colleagues at the Sun Yat-Sen Cancer Center department of surgery in Taipei, Taiwan, retrospectively studied 544 patients with T1-2 N1 invasive breast cancer. The women had been treated with modified radical mastectomy between April 1991 and December 2005.

Of the patients, 383 did not receive radiation therapy and 161 did. Radiation therapy reduced the risk of recurrence from 40% to 12.5% in patients who met the following criteria:

In addition, overall survival increased from 43.7% to 87.1% in T1-2 N1 breast cancer patients with negative estrogen-receptor status and presence of lymphovascular invasion (Int J Radiat Oncol Biol Phys 77:516-522, 2010).

Surgery and radiation are common methods for treating early-stage breast cancer and preventing recurrences. While several studies have been done on the routine use of postmastectomy radiation therapy in breast cancer patients with larger tumors and four or more positive lymph nodes, the role of PMRT for smaller tumors with one to three positive lymph nodes (T1-2 N1) is not known.

A related study out of Tehran echoed these results, stating that aggressive multimodality therapy was warranted in patients with locoregional recurrence after mastectomy.

The records of 114 patients who had undergone mastectomy and adjuvant radiotherapy at the Cancer Institute of Tehran University of Medical Sciences were retrospectively reviewed between 1996 and 2008. At a median follow-up time of 84 months, 20.2% patients had disease recurrence. The cumulative recurrence-free survival (RFS) rate was 86% at 2.5 years and 82.5% at five years. The mean RFS was 4.43 months (World J Surg Oncol 8:30, 2010).