Highly Specific Droplet-Digital PCR Detection of Universally Methylated Circulating Tumor DNA in Endometrial Carcinoma

International audienceAbstract Background No circulating biomarker is available for endometrial carcinoma (EC). We aimed to identify DNA positions universally hypermethylated in EC, and to develop a digital droplet PCR (ddPCR) assay for detection of hypermethylated circulating tumor DNA (meth-ctDNA) in plasma from patients with EC. Methods DNA positions hypermethylated in EC, and without unspecific hypermethylation in tissue/cell types releasing circulating cell-free DNA in plasma, were identified in silico from TCGA/Gene Expression Omnibus (GEO) data. A methylation-specific ddPCR (meth-ddPCR) assay following bisulfite conversion of DNA extracted from plasma was optimized for detection of meth-ctDNA according to dMIQE guidelines. Performances were validated on a retrospective cohort (n = 78 tumors, n = 30 tumor-adjacent tissues), a prospective pilot cohort (n = 33 stage I–IV patients), and 55 patients/donors without cancer. Results Hypermethylation of zinc finger and SCAN domain containing 12 (ZSCAN12) and/or oxytocin (OXT) classified EC samples from multiple noncancer samples with high diagnostic specificity/sensitivity [>97%; area under the curve (AUC) = 0.99; TCGA/GEO tissues/blood samples]. These results were confirmed in the independent retrospective cohort (AUC = 0.99). Meth-ddPCR showed a high analytical specificity (limit of blank = 2) and sensitivity (absolute lower threshold of detection = 50 pgmethDNA/mLplasma). In the pilot cohort, meth-ctDNA was detected in pretreatment plasma samples from 9/11 and 5/20 patients with advanced and non-advanced EC, respectively. 2 of 9 patients had ctDNA detected after macroscopic complete surgery and experienced progression within 6 months. No healthy donors had any copy of hypermethylated DNA detected in plasma. Conclusions Meth-ddPCR of ZSCAN12/OXT allows a highly specific and sensitive detection of ctDNA in plasma from patients with EC and appears promising for personalized approaches for these patients

A Suggested Modification to FIGO Stage IV Epithelial Ovarian Cancer

International audienceInternational Federation of Gynecology and Obstetrics (FIGO) staging classification for stage IV epithelial ovarian cancer (EOC) separates stages IVA (pleural effusion) and IVB (parenchymal and/or extra-abdominal lymph node metastases). We aimed to evaluate its prognostic impact and to compare survival according to the initial metastatic location. We conducted a multicenter study between 2000 and 2020, including patients with a FIGO stage IV EOC. Primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS) and recurrence rates. We included 307 patients: 98 (32%) had FIGO stage IVA and 209 (68%) had FIGO stage IVB. The median OS and PFS of stage IVA patients were significantly lower than those of stage IVB patients (31 versus 45 months (p = 0.02) and 18 versus 25 months (p = 0.01), respectively). Recurrence rate was higher in stage IVA than IVB patients (65% versus 47% (p = 0.004)). Initial pleural involvement was a poor prognostic factor with a median OS of 35 months versus 49 months for patients without initial pleural involvement (p = 0.024). Patients with FIGO stage IVA had a worse prognosis than patients with FIGO stage IVB EOC. Pleural involvement appears to be relevant for predicting survival. We suggest a modification of the current FIGO staging classification

A Suggested Modification to FIGO Stage IV Epithelial Ovarian Cancer

International Federation of Gynecology and Obstetrics (FIGO) staging classification for stage IV epithelial ovarian cancer (EOC) separates stages IVA (pleural effusion) and IVB (parenchymal and/or extra-abdominal lymph node metastases). We aimed to evaluate its prognostic impact and to compare survival according to the initial metastatic location. We conducted a multicenter study between 2000 and 2020, including patients with a FIGO stage IV EOC. Primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS) and recurrence rates. We included 307 patients: 98 (32%) had FIGO stage IVA and 209 (68%) had FIGO stage IVB. The median OS and PFS of stage IVA patients were significantly lower than those of stage IVB patients (31 versus 45 months (p = 0.02) and 18 versus 25 months (p = 0.01), respectively). Recurrence rate was higher in stage IVA than IVB patients (65% versus 47% (p = 0.004)). Initial pleural involvement was a poor prognostic factor with a median OS of 35 months versus 49 months for patients without initial pleural involvement (p = 0.024). Patients with FIGO stage IVA had a worse prognosis than patients with FIGO stage IVB EOC. Pleural involvement appears to be relevant for predicting survival. We suggest a modification of the current FIGO staging classification