Editorial

By Professor Adrian L Harris
Editor-in-Chief

In the last five years, cancer therapy has been revolutionised by the effective introduction of immunotherapies.
In particular, antibodies that block cytotoxic T-lymphocyte-associated protein 4 [CTLA-4] or Programmed death-ligand 1 [PDL1 ] and so reduce signals that inhibit T cell function, have proved efficacious in producing complete regressions that are maintained for years, in melanoma and other tumours, for example bladder cancer and non-small cell lung cancer.
Additionally, the emerging success, in end-stage patients, of chimeric antigen receptor T cells has produced remarkable responses even in patients with end-stage disease, who have failed multiple other therapies. These two important ways of harnessing immunotherapy have led to it being called the 'fifth pillar' of cancer treatment. There remain many other mechanisms and pathways to be considered in optimising these treatments, selecting patients for therapy, predicting response and so improving the current results.
This collection of papers covers these areas, including reviews of the pathways of immune modulation for cancer therapy, detection of tumour antigens by mRNA analysis in blood, directions of immunotherapy with selective targeting agents such as HER2, the role of inflammatory micro environment, generation of suitable tumour infiltrating lymphocytes, predictive and prognostic biomarkers for response, and improvement of vaccination approaches.
Further investigation in parallel with therapeutic trials will be needed to optimise the outcomes, to use agents selectively and to understand resistance mechanisms.

The recent exciting results with antibodies against signalling molecules that suppress T cell responses, show improved survival and responses in tumour types not consider to be targets for immunotherapy previously. Immunotherapy has become rapidly established as a mainline therapy and this collection of articles combines basic, translational, clinical and review papers that provide a current analysis and background to the field.