Owing to its advantages over prior relevant technologies, massive parallel or next-generation sequencing (NGS) is rapidly evolving, with growing applications in a wide range of human diseases. The burst in actionable molecular alterations in many cancer types advocates for the practicality of using NGS in the clinical setting, as it permits the parallel characterization of multiple genes in a cost- and time-effective way, starting from low-input DNA. In advanced clinical practice, the oncological management of colorectal cancer requires prior knowledge of KRAS, NRAS, and BRAF status, for the design of appropriate therapeutic strategies, with more gene mutations still surfacing as potential biomarkers. Tumor heterogeneity, as well as the need for serial gene profiling due to tumor evolution and the emergence of novel genetic alterations, have promoted the use of liquid biopsies—especially in the form of circulating tumor DNA (ctDNA)—as a promising alternative to tissue molecular analysis. This review discusses recent studies that have used plasma NGS in advanced colorectal cancer and summarizes the clinical applications, as well as the technical challenges involved in adopting this technique in a clinically beneficial oncological practice.

Introduction: During the coronavirus disease 2019 (COVID-19) pandemic, the Gustave Roussy Cancer Center introduced teleconsultation via telephone, as an alternative to face-to-face consultation to reduce patient hospital visits. This study was designed to assess patient and doctor satisfaction with this modality of care in oncology patient care during the period of the pandemic and beyond. Methods: We designed two questionnaires based on validated scores to assess satisfaction from teleconsultation in patients (EORTC OUT-PATSAT 35 and Telemedicine Satisfaction Questionnaire [TSQ] scores) and doctors (Telehealth Usability Questionnaire [TUQ]), and anxiety levels in both groups (anxiety section of the Hospital Anxiety and Depression Scale [HADS], HADS-A). These were electronically sent to patients and doctors with experience of at least one remote consultation during the first wave of the COVID-19 pandemic. Results: 239 patients and 32 doctors were eligible for the analyses. In the patient group, the mean satisfaction scores were 79.5 (SD 18.1) and 74.92 (SD 15.3) for EORTC OUT-PATSAT 35 and TSQ, respectively. In the doctor group, the mean satisfaction scores were 67.1 (SD 12.7) and 64.9 (SD 13.9) for TUQ and TUQ for Skype for Business, respectively. 65.7% of patients and 81.2% of doctors had no/low anxiety. Univariable analyses in patients showed correlation of the EORTC OUT-PATSAT 35 and TSQ scores with anxiety and gender, with lower mean scores in women compared to men. Multivariable analysis showed correlation of the EORTC OUT-PATSAT 35 and TSQ scores to anxiety in both patients and doctors. Conclusions: Teleconsultation via telephone is an acceptable modality of care for oncology patients, with high satisfaction from its implementation during the pandemic reported by patients and doctors. This was consistent across responder groups with different characteristics. An individualized approach to patients should be implemented for the safe and effective use of teleconsultation in oncology beyond the pandemic.

The detection of actionable mutations in tumor tissue is a prerequisite for treatment customization in patients with metastatic colorectal cancer (mCRC). Analysis of circulating tumor DNA (ctDNA) for the identification of such mutations in patients’ plasma is an attractive alternative to invasive tissue biopsies. Despite having the high analytical sensitivity required for ctDNA analysis, digital polymerase chain reaction (dPCR) technologies can only detect a very limited number of hotspot mutations, whilst a broader mutation panel is currently needed for clinical decision making. Recent advances in next-generation sequencing (NGS) have led to high-sensitivity platforms that allow screening of multiple genes at a single assay. Our goal was to develop a small, cost- and time-effective NGS gene panel that could be easily integrated in the day-to-day clinical routine in the management of patients with mCRC. We designed a targeted panel comprising hotspots in six clinically relevant genes (KRAS, NRAS, MET, BRAF, ERBB2 and EGFR) and validated it in a total of 68 samples from 30 patients at diagnosis, first and second disease progression. Results from our NGS panel were compared against plasma testing with BEAMing dPCR regarding the RAS gene status. The overall percent of agreement was 83.6%, with a positive and negative percent agreement of 74.3% and 96.2%, respectively. Further comparison of plasma NGS with standard tissue testing used in the clinic showed an overall percent agreement of 86.7% for RAS status, with a positive and negative percent agreement of 81.2% and 92.8%, respectively. Thus, our study strongly supports the validity and efficiency of an affordable targeted NGS panel for the detection of clinically relevant mutations in patients with mCRC.