Blog author: Dr Kate Brain, PhD, CPsychol
Reader, Division of Population Medicine, Cardiff University and PRIME/WCRC Screening, Prevention and Early Diagnosis lead
Early cancer detection is vital to improving survival, by discovering lethal cancers at an early or pre-malignant stage when they can be treated more effectively. Lung cancer is an example of a common cancer where prognosis is poor, largely due to late diagnosis, so effective early detection strategies are critical.
The inaugural Early Detection of Cancer Conference held in Portland, Oregon on 21-24 June heralds an exciting international partnership between Cancer Research UK and the Knight Cancer Institute at Oregon Health and Science University. The purpose of the conference was to bring together world-leading scientists from across the disciplines to share expert knowledge and tackle the complex challenges of early cancer detection. Research is needed to answer key questions: what is the biology or “natural history” of early stage cancers? Why are some cancers slow-growing and others aggressive? What are the most effective technologies for precisely detecting the features of early cancer? How do we identify and target people who are at higher risk of cancer, and therefore most likely to benefit from precision early detection technologies?
A wide range of strategies for detecting cancer early was discussed, including: biomarkers (or precursors to disease) such as circulating tumour cells and fragments of DNA in bodily fluids, and nasal or breath testing to measure airway epithelial gene expression biomarkers; immunological approaches involving gut microbiology and cancer vaccines; imaging techniques such as CT scans, and smart technology, for example the “smart toilet”. In the case of lung cancer, a promising strategy is the combination of biomarkers to stratify high-risk smokers and CT screening to detect spots on the lung. However, large-scale international prospective studies are required to identify the best biomarkers for early stage or pre-malignant lung cancer and validate them in appropriate populations.
Bearing in mind there is no such thing as a perfectly accurate test, a key challenge is to find ways of accurately detecting early signs of cancer when they are present (high sensitivity, i.e. minimising the risk of “false positive” results that lead to unnecessary tests) and determining when they are not present (high specificity, i.e. avoiding over diagnosis and treatment of growths that would not cause a problem if left undetected). As well as being precise, new methods of early detection must take into account the vagaries of human behaviour. Early detection methods that are easily accessible and acceptable to those being targeted are more likely to be taken up, underlining the importance of a “whole person” approach to early detection.
The conference was thought provoking and helped to develop a common understanding among scientists from diverse backgrounds working in the field of early cancer detection. The challenge will be in choosing from the range of promising cancer risk biomarkers those that are highly sensitive and specific, and translating them into effective, equitable strategies to meet the overarching goals of earlier detection and improved cancer survivorship.