The return of
breast cancer remains a persistent anxiety, even when the control examinations follow one another without warning. Many women still wonder if, ten years after the end of treatment, the risk of recurrence is not increasing again.
A large Dutch study provides reassuring elements: when
radiotherapy is adjusted to individual risk after chemotherapy and surgery, local relapses remain very rare, even after ten years of follow-up. This tailor-made approach questions the dose of rays really necessary.
Recurrence of breast cancer after ten years: what the study shows
These results come from the team of Dr Fleur Mauritz, oncologist in training at the Maastro Institute, in the Netherlands. She recalls that, for many patients, chemotherapy precedes surgery and already makes it possible to reduce the tumor and the cells which have begun to spread throughout the body.
The RAPCHEM registry study followed 848 women treated between 2011 and 2015 in 17 Dutch centers. All had a tumor of less than 5 centimeters with one to three affected lymph nodes before treatment; the researchers wanted to know if we could reduce the radiotherapy in those whose nodes responded well to chemotherapy, without increasing the risk of local recurrence.
Radiotherapy adapted to the risk of lymph nodes
After chemotherapy and surgery, patients were divided into three risk groups based on the presence or absence of remaining cancer cells in the lymph nodes. Low-risk women received limited radiation to the breast after conservative surgery, or no radiation after mastectomy, while those at intermediate risk kept radiation to the breast or chest wall, and high-risk patients were treated to nearby lymph nodes as well.
Of the 838 participants with complete ten-year follow-up, only 24 experienced recurrence in the breast, chest wall or lymph nodes, or 2.9% in total (2.4% in the low-risk group, 3.2% in the intermediate group and 2.8% in the high-risk group). “The results of our study show that tailoring the extent of radiotherapy based on the effectiveness of chemotherapy to treat cancer in the lymph nodes leads to very low and reassuringly low recurrence rates in the breast and surrounding area. In a selected group of patients, we observe very low recurrence rates even when we omit radiotherapy completely.“, explained Dr Fleur Mauritz, cited by the European Organization for Research and Treatment of Cancer (EORTC).
Fewer rays, without increased risk for the patient
For Professor Isabel Rubio, head of breast surgical oncology at Clínica Universidad de Navarra, these data support the idea of modulating rays according to the risk of each woman, in order to avoid both overtreatment and undertreatment, while limiting long-term side effects.
The authors emphasize that most patients underwent an axillary dissection, a less common procedure today, and that the study did not directly compare a group with and without radiotherapy. An American randomized trial has yet to confirm these results, but these long-term figures are already fueling the thinking of the French teams on a
radiotherapy more personalized, decided in a multidisciplinary meeting for each file.