Postoperative Radiation Best for Lymph Node-Positive Breast Cancer Patients

Postoperative radiotherapy benefits for women with between one and three positive lymph nodes are confirmed

medwireNews: Radiotherapy significantly improves survival and reduces the risk of recurrence in women undergoing breast cancer surgery who have between one and three positive lymph nodes, meta-analysis confirms.

The 10-year recurrence and 20-year mortality results for 8,135 women treated between 1964 and 1986 were presented this week at the 9th European Breast Cancer Conference in Glasgow in the UK, and simultaneously published in The Lancet.

Overall, 3,786 patients with axillary dissection to at least level I and II and either no positive lymph nodes or one, two, three, or four or more positive lymph nodes participated in 14 trials of radiation to the chest wall, supraclavicular and/or axillary fossa, and internal mammary chain.

The 1,314 women with between one and three positive lymph nodes who underwent axillary dissection and received radiotherapy had a significantly reduced risk of locoregional recurrence, overall recurrence (rate ratio [RR]=0.68) and breast cancer-specific mortality (RR=0.80), compared with women who were not treated with radiation.

And analysis of data for 1,133 of the women with one to three positive nodes showed a benefit of radiotherapy even when patients were also receiving systemic cyclophosphamide, methotrexate and fluorouracil, or tamoxifen, again with a significant reduction in the risk of locoregional recurrence, overall recurrence (RR=0.67) and breast cancer mortality (RR=0.78).

Data for 1,722 patients showed radiation was also beneficial for women with four or more positive lymph nodes, with regard to locoregional recurrence, overall recurrence (RR=0.79) and breast cancer morality (RR=0.87), report presenting author Paul McGale, from the Clinical Trial Service Unit in Oxford, UK, and fellow Early Breast Cancer Trialists’ Collaborative Group researchers.

By contrast, radiotherapy had no significant impact on the risk of recurrence or breast-cancer survival for women undergoing axillary dissection with no positive lymph nodes, the researchers say.

Writing in a press release, Paul McGale noted the significant advances in breast cancer care since the trials included in the meta-analysis were initiated, including improvements in screening, radiotherapy, surgery, lymph node staging and systemic treatment.

“[The] absolute benefits from post-mastectomy radiotherapy today may be smaller than those we have reported here,” he admitted.

“But the proportional benefits from radiotherapy are likely to be at least as big.”

References

Early Breast Cancer Trialists’ Collaborative Group. Effect of radiotherapy after mastectomy and axillary surgery on 10-year recurrence and 20-year breast cancer mortality: meta-analysis of individual patient data for 8135 women in 22 randomised trials. Lancet 2014; Advance online publication 19 March. doi:10.1016/S0140-6736(14)60488-8

Radiotherapy after mastectomy benefits women with breast cancer that has spread to just a few lymph nodes. Press release from 9th European Breast Cancer Conference; Glasgow, UK (19–21 March 2014). Page visited last time 20 March, 2014.

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