LAUSR

Abstract Background Several lines of evidence suggest that the gut microbiome represents a novel biomarker in the era of immuno-oncology. Therefore, the prospective collection of fecal samples is now routinely included in clinical trials and acts as a new challenge for research nurses. However, little is known about patient compliance in the collection process. The objective of this study was to assess enrolment and compliance rates for fecal sample collection. Methods Fecal samples were prospectively collected in two academic institutions, University of Montreal Hospital and Gustave Roussy Cancer Center, using the International Human Microbiome Standards SOP Version 3 in the following groups: (1) patients with advanced non-small cell lung cancer (NSCLC) amenable to immune checkpoint inhibitors and (2) patients with early-stage NSCLC or renal cell carcinoma (RCC) at a pre-operative stage. Informed and written consent were obtained by research nurses and patient baseline characteristics were collected. Upon consent, a white opaque polypropylene pot with an anaerobic generator bag was provided to the patient, along with a document to explain the self-collection technique. Enrolment (signing of consent) and compliance (returning the sample) rates were analysed using a Chi-squared method. Results A total of 267 patients were eligible for the study and 252 (94%) patients with a median age of 64 agreed to sign the consent form. The enrolment rate in the study reached 96% (175/183) in patients receiving immunotherapy compared to 92% (77/84) in patients with early stage cancers undergoing surgical resection who did not receive immunotherapy (p = 0.01). Overall patient compliance was 81% (204/252). Importantly, compliance was significantly higher in the pre-immunotherapy setting (94%, 164/175) versus the pre-operative group (52%, 40/77) (p = 0.01). Furthermore, regardless of the cancer stage, women (82% or 77 patients) were more compliant than men (80% or 127 patients) (p = 0.02). Conclusions New tools to increase compliance and assist patients in sample collection should be developed, especially for male patients diagnosed with early stage disease who are undergoing surgery. Legal entity responsible for the study Bertrand Routy. Funding Montreal Cancer Institute. Disclosure All authors have declared no conflicts of interest.