Biography and research overview
Dr Navita Somaiah is a clinician scientist at The Institute of Cancer Research, London, and a clinical oncologist at The Royal Marsden. She is the first recipient of a prestigious Clinician Scientist Fellowship at the ICR.
Dr Somaiah is investigating biomarkers of sensitivity to fraction size in curative radiotherapy.
Radiotherapy is widely used in the treatment of cancer and is typically delivered in small daily doses (fractions) with the aim of sparing normal tissues relative to cancers. However, recent clinical trials led by investigators at the ICR and The Royal Marsden confirm important exceptions to this generalisation. Breast and prostate cancer, for example, are more sensitive to fraction size than previously thought, leading to increasing interest in hypofractionation (use of fractions >2Gy).
Dr Somaiah investigates cell and molecular determinants of sensitivity to radiotherapy fraction size. Her research has shown that loss of sensitivity to fraction size is associated with use of homologous recombination to repair radiation induced DNA double-strand breaks in the S/G2 phase of the cell cycle. The molecular determinants of fractionation sensitivity including DNA repair capacity and cell cycle regulation are subject to genetic and epigenetic modifications, which can be heterogeneous even in a ‘single’ disease like breast cancer. Against this background, she aims to identify biomarkers of fraction size sensitivity for evaluation in clinical trials testing individualisation of fraction size.
Another key aspect of Dr Somaiah’s research is to investigate the modifying effects of small molecule inhibitors of DNA repair, cell cycle checkpoints and growth factor signalling on fractionation responses. The aim of this is to test how combining biological and radiation therapies is expected to change the fractionation sensitivity of tumour and normal tissues. The ultimate aim will be to improve the therapeutic index by selecting individualised dose prescriptions.