Research summary
May 2006
Patients with early breast cancer may benefit from fewer but larger doses of radiotherapy
Summary
Giving women with early breast cancer fewer but more concentrated doses of radiotherapy as part of breast conserving treatment may be as safe and effective as the current standard treatment at reducing the risk of cancer returning, according to Cancer Research UK trial results published in the 30 May edition of Lancet Oncology.
Radiotherapy is usually given after breast conserving surgery to destroy any cancer cells that may remain and to prevent cancer from coming back in that breast.
The UK trial compared the current standard radiotherapy treatment of 25 doses over five weeks to a radiotherapy regime of 13 higher doses over the same period. The ten-year trial followed 1410 women who had a lumpectomy for early breast cancer followed by radiotherapy treatment.
The researchers found the regime of 13 higher doses may be as effective in preventing the cancer coming back as the standard treatment of 25 lower doses, without any increase in side effects.
However, researchers will await the results of further follow-up trials before confirming this strategy is more effective than the standard treatment in the long-term.
National Breast Cancer Centre comment
Current Australian clinical guidelines recommend radiotherapy after breast conserving surgery as it significantly reduces the risk of cancer coming back in the breast (local recurrence).
In Australia, radiotherapy after breast conserving surgery is usually given in 25 doses over a period of five weeks. This means women usually have radiotherapy treatment once a day, from Monday to Friday, with a rest at weekends and must travel to hospital each week day for treatment.
One of the major issues for women in Australia undergoing radiotherapy, particularly those living in rural and regional areas, is the length of time over which radiotherapy is delivered. Because radiotherapy is usually administered in major hospitals, many women from rural and regional areas are required to be away from home for the entire five-week period.
The National Breast Cancer Centre is currently awaiting the results of several international trials looking into different ways of delivering radiotherapy for women with breast cancer without compromising outcomes.
Trials underway are examining such things as the effect of administering radiotherapy directly to the breast tissue during surgery, the effect of implanting radioactive seeds into the tissue and the outcome of administering radiotherapy over a shorter time period (e.g. three weeks instead of five).
The National Breast Cancer Centre will also await with interest the results of follow-up clinical trials looking into the long-term outcomes of administering fewer but more concentrated doses of radiotherapy, as examined in the Cancer Research UK trial. This has the potential to reduce the number of visits a woman with breast cancer is required to make to hospital. However, it would not reduce the timeframe over which the radiotherapy is delivered.
It is important to note that although the Cancer Research UK trial results did not report an increase in side effects, higher doses of radiotherapy can be associated with an increased risk of tissue damage and poorer cosmetic outcomes.
Whilst any new research to improve ways of delivering radiotherapy is welcome, it will be important to evaluate both the potential benefits and any safety concerns of new radiotherapy techniques before they can be incorporated into clinical practice.
More information about radiotherapy is available on our breasthealth.com.au website.