Dr Navita Somaiah is a Clinician Scientist and Team Leader in the Division of Radiotherapy and Imaging at The Institute of Cancer Research, London (ICR), and a Clinical Oncologist in the Breast Unit at The Royal Marsden NHS Foundation Trust. Support from the NIHR Biomedical Research Centre at The Royal Marsden and the ICR (BRC) has contributed to some of her innovative research into treating breast cancer with radiotherapy. Image Could you describe your roles at The Royal Marsden and the ICR? In simple terms I’m a trained medical doctor who also carries out research. At The Royal Marsden I look after patients with breast cancer and at the ICR I conduct breast cancer research. I really enjoy the mix of responsibilities, and by bridging the gap between the lab and the clinic it means I can look at research outside of a petri dish and see how it actually affects patients. What are your research interests? I lead a translational breast radiotherapy and radiobiology team. We are investigating why tumours and normal tissues respond differently to daily doses of radiation, with the long-term aim of personalising radiotherapy dose prescriptions. I’m also interested in understanding the late side effects from radiotherapy and combining novel drugs with radiation to maximise tumour control whilst minimising normal tissue toxicity. How has the BRC supported your research? Along with KORTUC Inc, Japan, the BRC provided funding for the phase I KORTUC trial, which tested hydrogen peroxide as a novel radiation sensitiser in patients with locally advanced/recurrent breast cancer. Results suggest that a simple injection of a hydrogen peroxide solution, a common antiseptic, could boost the cancer-killing effect of radiotherapy for breast and other cancers. Following on from the successful phase I trial, I’m now leading a large-scale randomised phase II clinical trial which is underway at five UK hospitals, including The Royal Marsden, with plans to open the trial in two centres in India. If the trial proves to be effective the treatment could be a cheap and easy way to improve radiotherapy globally. Another example is the PRADA/Trans-PRADA study led by The Royal Marsden in collaboration with Imperial College London. Usually breast radiotherapy is given after surgery, meaning there is limited opportunity to really look at what effect radiation is having on the tumour and surrounding tissues. PRADA (led by Miss Fiona MacNeill, Consultant Breast Surgeon) reversed the order and explored the surgical safety of having radiotherapy before surgery, in high-risk breast cancer patients. This enabled us in Trans-PRADA, led by me, to collect novel tumour and blood samples before, during and after radiation. This will allow us to study the radiation induced changes in the tumour and immune microenvironment in order to design optimum radiotherapy plus immunotherapy trials to improve outcomes in high-risk patients. The BRC awarded us a pump priming grant to enable the collection of tissue and fund a trial coordinator for the study. What does the future hold for breast cancer radiotherapy? Our understanding of how breast cancers respond to daily doses of radiation has changed significantly over the last few decades. In a series of elegant trials led by the ICR/ The Royal Marsden, starting with the START trials in 1986 and culminating in the FAST-Forward trial in 2020, we have shown that a schedule of fewer, larger doses of radiation delivered over 1 week is as safe and effective as small daily fractions delivered over three to five weeks. One week of radiotherapy has now become standard care for patients with early breast cancer in the UK and increasingly internationally. We’re still awaiting data from the subset of patients receiving lymph node treatment in FAST-Forward, but if proven safe, it could mean we’re able to offer five radiotherapy treatments for anyone requiring breast, chest wall or axillary lymph node radiotherapy after surgery. Low-risk In women with very low-risk breast cancer, the PRIMETIME study led by the ICR (Chief Investigator, Prof Charlotte Coles, Consultant Clinical Oncologist University of Cambridge), is investigating whether radiotherapy can be safely omitted after surgery, thereby sparing side effects. Dr Anna Kirby, Consultant Clinical Oncologist, is using the UK’s first MR Linac (Magnetic Resonance Linear Accelerator) to precisely locate tumours, tailor the shape of X-ray beams in real time and accurately deliver doses of radiation to early breast tumours. High-risk/ locally advanced At the other end of the spectrum, my team is investigating novel drug plus radiation combination therapies in high-risk/locally advanced breast cancers. In collaboration with Imperial College London (as part of the CRUK Convergence Science Centre) we are also looking at how novel super-resolution ultrasound imaging and nanopore technology measuring circulating tumour DNA can significantly improve how we monitor response in patients following breast radiotherapy. We want to detect resistance to treatment or relapse early so that these patients can be offered more effective therapies. Looking forward to the future, it would be wonderful to marry biological insights and cutting-edge technology for optimal radiotherapy and be able to offer a tailored treatment for each patient.