Understanding Molecular Testing Uptake Across Tumor Types in Eight Countries: Results From a Multinational Cross-Sectional Survey

Abstract

QUESTION ASKED: Does variation in molecular testing exist among Asian and Western European countries across a number of tumor types (namely, breast, colorectal, gastric, non-small-cell lung cancer [NSCLC], and melanoma)? SUMMARY ANSWER: Statistically significant differences in uptake of molecular testing were determined among countries for NSCLC, gastric, and colorectal cancers, with China having the lowest uptake of molecular testing overall. However, for breast cancers, for which HER2 testing is more established and there is a high incidence in all countries, uptake was generally consistently high, showing promise for the future. Use of HER2 testing for gastric cancers was lower in some European countries compared with Japan and South Korea, which can be attributable to the incidence of cancer in these countries. Likewise, in the case of melanoma, the rate of BRAF testing was greater in European countries. POTENTIAL BIAS AND CONFOUNDING FACTORS: The cross-sectional survey design is a major limitation of our findings and the original questionnaire was not designed for our research purpose. For these reasons, we could only report at a high level the differences between countries and not in-depth findings on possible other reasons for variations. We tried to limited bias in our analyses; however, biases involved in questionnaire delivery and completion were beyond our control. REAL-LIFE IMPLICATIONS: Variations in molecular testing may be attributed to differences in incidence of certain cancers or genetic mutations present in different populations of patients: a high incidence may prompt investment in better treatments for that cancer. This approach may seem logical for a country; however , the approach disadvantages the individual patient with a "rare" cancer for that country. We have demonstrated with the example of breast cancer that consistency between countries is attainable. There is an urgent need to improve access for patients to both molecular testing and targeted treatments in countries where incidence of a tumor type is not high. Our findings can guide future policy to enable equitable access internationally. abstract PURPOSE The growth in understanding of molecular biology and genomics has augmented the development of targeted cancer treatments; however, challenges exist in access to molecular testing, an essential precursor to treatment decision-making. We used data from a cross-sectional survey to evaluate the differences in uptake of molecular testing, METHODS Using the aggregated results of a questionnaire developed and distributed to clinicians by IQVIA, including treatment details and investigations undertaken for patients, we compared proportions of patients receiving molecular testing and targeted treatment by cancer type for the United Kingdom,. We used multivariable logistic regression methods to understand the effect of country on the odds of receiving a molecular test. RESULTS There was a total of 61,491 cases. Across countries and cancer types, uptake rates for molecular testing ranged between 2% and 98%, with the greatest differences seen in gastric cancers (range, 23% to 70%), and significant variations were observed for both European and Asian countries. China consistently demonstrated a significantly reduced uptake for all molecular tests assessed; however; uptake of drug treatment in gastric cancers after testing positive for the human epidermal growth factor receptor 2 gene was higher than in some European countries (China, 85%; European range, 8% to 66%). The uptake of epidermal growth factor receptor gene testing was greater in some Asian countries relative to the United Kingdom, where incidence of lung cancer is higher (Japan: odds ratio, 3.1 [95% CI, 2.6 to 3.8]; South Korea: odds ratio, 2.7 [95% CI, 2 to 3.4]). CONCLUSION We have highlighted inequity in access to molecular testing and subsequent treatments across countries, which warrants improvements.