The hopes of an oncological radiotherapist
Dr Youlia Kirova, radiothérapeute au département de Radiothérapie de l'Institut Curie.
What are today's challenges in oncological radiotherapy?
A combination of several therapies is generally required to fight a tumor and resistance to treatment. However this can increase the number of side effects. In the past we were concerned mainly with patient recovery. As cancer prognoses have improved, we now think increasingly about the long-term effects of treatments, to improve patients' quality of life. It is with this in mind that we recently published a study for the retrospective evaluation of toxicity caused by combining radiotherapy with anti-HER2 (trastuzumab, pertuzumab in particular) frequently used in HER2 breast cancer. No major harmful side effect was found, in particular with trastuzumab. But other studies must be conducted on a larger number of patients to draw conclusions on the actual consequences of this type of combination, particularly with the new anti-HER2 molecules, such as pertuzumab and TDM1.
Combinations can also be beneficial in some cases. Which ones are beneficial?
Our priority must be above all to halt the cancer without causing complications. This goal is achieved with new radiation techniques combined with new targeted molecules. For example, we have already shown that the combination of some of them (such as lenalidomide and bortezomide) with a highly sophisticated radiotherapy such as tomotherapy, can increase survival without progression in patients suffering from solitary plasmacytoma, a rare bone tumor.
For breast cancer, we are very hopeful about the use of PARP inhibitors combined with radiotherapy in breast cancer patients. The underlying idea of this combination is to prevent the repair of damage caused by rays in the tumor cells, and thus lead to their destruction. Clinical trials are in progress. In the long term, the hope is that we will be able to offer this therapeutic strategy before surgery to patients with triple-negative breast cancer, to increase the use of conservative surgery and improve the prognosis. But we need to remain vigilant and continue short- and long-term monitoring.
More generally, what other major innovations are you working on?
A broad field of research also aims to increase the number of indications and locations in proton therapy, a highly precise form of radiotherapy. Proton therapy limits radiation of healthy tissue as far as possible, and is perfectly suited to treating certain tumors for which side effects must be reduced to a minimum. Our efforts are focused on two indications, namely breast cancer and Hodgkin's disease. A breast cancer patient was recently successfully treated using proton therapy. We are now awaiting financing to carry out a phase-3 clinical trial. Similarly, a patient with Hodgkin's disease was treated, making Institut Curie the leader in proton therapy for this indication. We hope to be able to conduct a phase-2 clinical trial.
Dr Youlia Kirova is an oncological radiotherapist, head of senology and hematology research within the Department of Oncological Radiotherapy.