7 Recommendations for further research
7.1 The following research is recommended in the context of people with oestrogen receptor positive (ER+), lymph node negative (LN−) or human epidermal growth factor receptor 2 negative (HER2−) early breast cancer.
7.2 MammaPrint: research is recommended on the clinical validity of the test in people that are representative of the population in England. In particular, information on how the test reclassifies people when compared with current practice in England and their risk of distant recurrence would be useful. Research into the clinical utility of the test is also recommended; in particular, evidence of the impact of the test on clinical decision-making in England and robust data on its ability to predict the benefit of chemotherapy.
7.3 Oncotype DX: research is recommended on the clinical utility of the test, including robust evidence on the impact of Oncotype DX on clinical decision-making in England (containing consideration of informal approaches compared with a formal algorithm for combining the Oncotype DX score with clinicopathological variables) and its ability to predict the benefit of chemotherapy. As part of the adoption of Oncotype DX by the NHS, the Committee encourages the collection of clinical utility and any other useful data by the health system, potentially by a multicentre audit.
7.4 The Committee noted that the MINDACT study is being conducted on MammaPrint and the TAILORx study is being conducted on Oncotype DX. The Committee encourages the availability of data showing the risk of distant recurrence of patients in these trials using tools representative of current practice adopted by the NHS (for example, Nottingham Prognostic Index [NPI] and Adjuvant! Online). Researchers should be mindful of the evolving breast cancer practice in England. For example, the emergence of the PREDICT tool; although a new tool at present, this may be more widely used in the future.
7.5 IHC4: research into the analytical validity (reliability and reproducibility) of the complete IHC4 test is recommended (an algorithm combining 4 markers and classical clinical and pathological variables), particularly within the NHS and when performed in local laboratories. Studies to confirm the prognostic ability and to determine the impact of IHC4 on clinical decision-making in England and, ideally, to predict the benefit of chemotherapy are recommended.
7.6 Mammostrat: research on the analytical validity (reliability and reproducibility) of the test is recommended. Research on the clinical utility of the test is also recommended. In particular, evidence of how the test reclassifies people's risk when compared with current practice in England, evidence on the impact of Mammostrat on clinical decision-making in England, and its ability to predict the benefit of chemotherapy.