Undergoing radiotherapy after surgery can prevent the return of breast cancer for up to 10 years, according to a study published in the journal Lancet Oncology. After this period, the chances of cancer recurrence are similar to those who have not received radiotherapy.
Radiotherapy after surgery is the standard care for women with early-stage breast cancer. Radiotherapy uses high doses of radiation to the breast to eliminate remaining cancer cells after surgical removal of the tumour.
The Scottish Breast Conservation Trial, led by the University of Edinburgh, UK, analysed results from 585 women who received treatment for early-stage breast cancer in Scotland. Half of these women received radiotherapy, and half did not. Patients continued to be followed for at least 18 years, with some cases followed for more than three decades.
After ten years, 16% of women who had radiotherapy experienced a return of their cancer in the exact location, compared with 36% of those who did not have the treatment. The results also show that radiotherapy lowered recurrence but did not improve survival rates. Average survival rates after 30 years were similar for those who received postoperative radiotherapy and those who did not – 19.2 years and 18.7 years, respectively.
The authors argue that understanding the long-term impact of radiotherapy is increasingly important, as improvements in the detection and treatment of early-stage breast cancer mean that patients are living longer.
“This 30-year study marks the longest follow-up of postoperative radiotherapy in the treatment of early-stage breast cancer. Long-term studies like this, which go beyond ten years of follow-up, are crucial to fully assess the risks and benefits of treatments,” said Dr Linda Williams from the University of Edinburgh’s Usher Institute.
“Our evidence suggests that radiotherapy protects against cancer returning in the same breast for up to 10 years. It supports the continued use of radiotherapy after breast-conserving surgery for most patients with early breast cancer. Like other anti-cancer treatments, radiotherapy loses its beneficial effects in the long term,” added Professor Ian Kunkler from the University of Edinburgh’s Institute of Genetics and Cancer.
Williams, L te al. Postoperative radiotherapy in women with early operable breast cancer (Scottish Breast Conservation Trial): 30-year update of a randomised, controlled, phase 3 trial. The Lancet Oncology, Volume 25, Issue 9, 1213 – 1221