What extent of radiation therapy is standard?

Evidence based radiation oncology: Breast cancer

PURPOSE

Radiotherapy is, similar to surgery, a local treatment. In the case of breast cancer, it is generally given after conservative or after more extensive, tumour and patient adapted, surgery. The target volumes can be the breast and/or the thoracic wall and/or the regional lymph node areas. The integration and the extent of radiotherapy as part of the comprehensive treatment of the breast cancer patient, including the amount of surgery and the sequencing with the systemic treatments, has to be well discussed with all medical specialists involved in treating breast cancer on a multidisciplinary basis. Guidelines for the appropriate prescription and execution of radiotherapy are of utmost importance. However, individualisation based on the individual patients' and tumours' characteristics should always be envisaged.

MATERIALS AND METHODS

Based on a review of the literature the level of evidence that is available for the indications for radiotherapy is summarised, as well as the main clinical questions that are unanswered today. An overview of the recent and ongoing clinical trails in breast cancer will highlight some of the current ongoing debates.

CONCLUSIONS

In the case of breast cancer, radiotherapy, given after as well conservative as extensive risk-adapted surgery, significantly reduces the risk of local and regional recurrences. Especially for patients with an intermediate to high absolute risk for local recurrences, a positive influence on overall survival has been shown, notably when appropriate radiotherapy techniques are used. Most important is that the best results that we can offer to our breast cancer patients for all clinical endpoints (local and regional control; quality of life; cosmetic results; survival) can be obtained by a multidisciplinary and patient-oriented approach, involving all those involved in the treatment of breast cancer patients.

Radiothérapie prophylactique des aires ganglionnaires dans le cancer du sein

In breast cancer patients, the incidence of involvement of the regional lymph nodes and the risk for developing a locoregional recurrence are highly influenced by several prognostic factors. A meta-analysis of the EBCTCG showed a reduction of about 70% of the locoregional recurrence rate with radiotherapy for all patients, independent of age, characteristics of the tumour or the administration of systemic treatment. At the same time, this meta-analysis confirmed that radiotherapy can lead to an increased risk for developing contralateral breast cancer and to an increase in the risk of non-breast cancer related mortality, mainly due to cardiac and pulmonary toxicity. Because of this, the net effect of regional radiotherapy will be strongly influenced by the individual risk factors of the patients and by the quality of the technical aspects of the radiotherapy. The thin line between the benefits of elective regional lymph node irradiation and the possible late toxicity for patients with early stage breast cancer is currently the subject of several prospective randomised trials, the results of which will only become available in several years. Moreover, recent developments in the field of novel prognostic factors will open completely new ways to be explored, which might give us new tools for estimating the individual benefit/risk ratio for every single patient.