Publications

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HER3, a member of the EGFR family of receptor tyrosine kinases coded by the ERBB3 gene, plays an important role in cancer, despite its lack of intrinsic kinase activity. As with genes coding for potential heterodimeric partners of HER3, EGFR, and HER2, oncogenic mutations of ERBB3 have been explored by several studies. In this review, we discuss the evidence presenting ERBB3 somatic mutations as potential tumoral drivers. We then show that ERBB3 mutations are not uncommon in many cancer types. Finally, we present the recent results of several studies evaluating different therapeutic approaches for treating patients with oncogenic ERBB3 mutations.

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: In hormone receptor-positive breast cancer, mutations have emerged as a key mechanism of resistance to endocrine therapy. : Here, we review currently available data on mutations, regarding their functional impact, prevalence at different stages (and according to the material used: tissue-based analysis vs. liquid biopsy), prognostic impact and predictive value of resistance to aromatase inhibitors. Possible strategies to overcome this resistance by using selective estrogen receptor downregulators (such as fulvestrant) are also discussed. : mutation detection will probably become a prognostic and predictive biomarker in the future, used in clinical practice for hormone-receptor breast cancer, especially in the metastatic setting. In the future, we should expect to assess mutations, using liquid biopsy (by digital-PCR or next-generation sequencing), in the same way as other prognostic or predictive biomarkers, such as mutations in lung cancer, and possibly even have targeted-therapies against these mutations.

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The management of patients with colorectal cancer (CRC) and potentially resectable liver metastases (LM) requires quick assessment of mutational status and of response to pre-operative systemic therapy. In a prospective phase II trial (NCT01442935), we investigated the clinical validity of circulating tumor cell (CTC) and circulating tumor DNA (ctDNA) detection. CRC patients with potentially resectable LM were treated with first-line triplet or doublet chemotherapy combined with targeted therapy. CTC (Cellsearch) and Kirsten RAt Sarcoma (KRAS) ctDNA (droplet digital polymerase chain reaction (PCR)) levels were assessed at inclusion, after 4 weeks of therapy and before LM surgery. 153 patients were enrolled. The proportion of patients with high CTC counts (≥3 CTC/7.5mL) decreased during therapy: 19% (25/132) at baseline, 3% (3/108) at week 4 and 0/57 before surgery. ctDNA detection sensitivity at baseline was 91% (N=42/46) and also decreased during treatment. Interestingly, persistently detectable KRAS ctDNA (p=0.01) at 4 weeks was associated with a lower R0/R1 LM resection rate. Among patients who had a R0/R1 LM resection, those with detectable ctDNA levels before liver surgery had a shorter overall survival (p<0.001). In CRC patients with limited metastatic spread, ctDNA could be used as liquid biopsy tool. Therefore, ctDNA detection could help to select patients eligible for LM resection.

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This study was designed to monitor circulating tumor DNA (ctDNA) levels during perioperative chemotherapy in patients with non-metastatic gastric adenocarcinoma. Plasma samples were prospectively collected in patients undergoing perioperative chemotherapy for non-metastatic gastric adenocarcinoma (excluding T1N0) prior to the initiation of perioperative chemotherapy, before and after surgery (NCT02220556). In each patient, mutations retrieved by targeted next-generation sequencing (NGS) on tumor samples were then tracked in circulating cell-free DNA from 4 mL of plasma by droplet digital PCR. Thirty-two patients with a diagnosis of non-metastatic gastric adenocarcinoma were included. A trackable mutation was identified in the tumor in 20 patients, seven of whom experienced relapse during follow-up. ctDNA was detectable in four patients ( = 4/19, sensitivity: 21%; 95% confidence interval CI = 8.5⁻43%, no baseline plasma sample was available for one patient), with a median allelic frequency (MAF) of 1.6% (range: 0.8⁻2.3%). No patient with available plasma samples ( = 0/18) had detectable ctDNA levels before surgery. After surgery, one of the 13 patients with available plasma samples had a detectable ctDNA level with a low allelic frequency (0.7%); this patient experienced a very short-term distant relapse only 3 months after surgery. No ctDNA was detected after surgery in the other four patients with available plasma samples who experienced a later relapse (median = 14.4, range: 9.3⁻26 months). ctDNA monitoring during preoperative chemotherapy and after surgery does not appear to be a useful tool in clinical practice for non-metastatic gastric cancer to predict the efficacy of chemotherapy and subsequent relapse, essentially due to the poor sensitivity of ctDNA detection.

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The heterogeneity of metastatic breast cancer (MBC) necessitates novel biomarkers allowing stratification of patients for treatment selection and drug development. We propose to use the prognostic utility of circulating tumor cells (CTCs) for stratification of patients with stage IV disease.

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Human papillomavirus (HPV) is found in 90% of squamous cell carcinomas of the anal canal (SCCA). We investigated the clinical validity of HPV circulating tumor DNA (ctDNA) detection in patients enrolled in the Epitopes-HPV02 trial that demonstrated the efficacy of docetaxel, cisplatin, and 5-FU as first-line chemotherapy in advanced SCCA.

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Droplet digital polymerase chain reaction (ddPCR) is a highly sensitive quantitative polymerase chain reaction (PCR) method based on sample fractionation into thousands of nano-sized water-in-oil individual reactions. Recently, ddPCR has become one of the most accurate and sensitive tools for circulating tumor DNA (ctDNA) detection. One of the major limitations of the standard ddPCR technique is the restricted number of mutations that can be screened per reaction, as specific hydrolysis probes recognizing each possible allelic version are required. An alternative methodology, the drop-off ddPCR, increases throughput, since it requires only a single pair of probes to detect and quantify potentially all genetic alterations in the targeted region. Drop-off ddPCR displays comparable sensitivity to conventional ddPCR assays with the advantage of detecting a greater number of mutations in a single reaction. It is cost-effective, conserves precious sample material, and can also be used as a discovery tool when mutations are not known a priori.

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Disseminated tumor cells (DTCs) collect in the bone marrow and indicate micrometastatic spread. We previously reported that DTCs could be a predictive factor for the efficacy of regional node irradiation (internal mammary nodes [IMNs]/supra- and infraclavicular nodes [SCNs]). In this article, we report the long-term results (>10 years) on the impact of DTC status in early stage breast cancer.

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Recent technological developments enable the detection and quantification of circulating tumour DNA in the blood, with potentially major clinical implications, particularly for cancers treated with curative intent. Circulating tumour DNA has a potential impact before, during and after treatment. If limitations of this approach remain, requiring further development, it is important to know the principles and applications in view of the potential impact on the clinical practice. In this review, we will discuss the current detection methods, then the place of circulating tumour DNA in oncology and more particularly in radiotherapy.

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Chemoradiotherapy (CRT) is the current standard of care for patients diagnosed with locally advanced anal squamous cell carcinoma (ASCC), but some patients develop local and/or distant relapse during follow-up. This study was designed to monitor human papillomavirus (HPV) circulating tumor DNA (ctDNA) levels during CRT in patients with ASCC. We analyzed samples from patients with HPV16- or HPV18-positive locally advanced ASCC. Blood samples were collected before and after CRT. HPV16 or HPV18 ctDNA detection was performed by droplet digital-PCR. HPV ctDNA was detected before CRT in 29 of 33 patients with stages II-III ASCC [sensitivity: 88%; 95% confidence interval (CI), 72-95]; ctDNA positivity rate was associated with tumor stage (64% and 100% in stages II and III, respectively; = 0.008). Among ctDNA-positive patients at baseline, ctDNA levels were higher in N than in N tumors (median 85 copies/mL, range = 8-9,333 vs. 32 copies/mL, range = 3-1,350; = 0.03). ctDNA detection at baseline had no significant prognostic impact. After CRT, three of 18 (17%) patients displayed residual detectable HPV ctDNA; ctDNA detection after CRT was strongly associated with shorter disease-free survival ( < 0.0001). This is the first proof-of-concept study assessing the prognostic value of ctDNA after CRT in locally advanced ASCC. In most patients, HPV ctDNA can be detected before CRT and becomes undetectable during CRT. In this study, we show that residual ctDNA levels after CRT are associated with very poor outcome. .

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Considerable interest surrounds the use of immune-checkpoint inhibitors in patients with solid tumours following the demonstration of the impressive clinical efficacy of anti-programmed cell death protein 1 and anti-programmed cell death 1 ligand 1 antibodies in several tumour types. However, the emergence of unexpected tumour response patterns, such as pseudoprogression or hyperprogression, might complicate the management of patients receiving these agents. Analysis of circulating tumour DNA (ctDNA) has been shown to have prognostic value by enabling the detection of residual proliferating disease in the adjuvant setting and estimation of tumour burden in the metastatic setting, which are key stratification biomarkers for use of immune-checkpoint inhibition (ICI). Furthermore, examinations of ctDNA for genetic predictors of responsiveness to immunotherapy, such as mutations, tumour mutational load, and microsatellite instability provide a noninvasive surrogate for tumour biopsy sampling. Proof-of-concept reports have also demonstrated that quantitative changes in ctDNA levels early in the course of disease are a promising tool for the assessment of responsiveness to ICI that might complement standard imaging approaches. Other applications of this technology are also currently under investigation, such as early detection of resistance to immunotherapy and characterization of mechanisms of resistance. The aim of this Review is to summarize available data on the application of ctDNA in patients receiving immunotherapy and to discuss the most promising future directions.

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We conducted a meta-analysis in nonmetastatic breast cancer patients treated by neoadjuvant chemotherapy (NCT) to assess the clinical validity of circulating tumor cell (CTC) detection as a prognostic marker.

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