Clinical Biochemistry

The performance of Carbohydrate Antigen 125-Thomsen-nouveau and anti-Müllerian hormone combined with CA125, Human epididymis protein 4 and Risk of Malignancy Algorithm in diagnosis for patients with Epithelial ovarian cancer

We examined the blood concentrations of Carbohydrate Antigen 125-Thomsen-nouveau (CA125-Tn) and anti-Müllerian hormone (AMH) in epithelial ovarian cancer (EOC) patients to evaluate their potential diagnostic utility together with CA125, human epididymis protein 4 (HE4) and Risk of Malignancy Algorithm (ROMA). 50 healthy subjects, 45 EOC patients, 22 patients with borderline ovarian tumors (BOT), 21 patients with benign ovarian tumor (BET) and 45 patients with chocolate cyst of ovary (CCO) were studied. Blood levels of CA125, HE4, CA125-Tn and AMH were measured, and the ROMA value was calculated. We compared the differences in the levels of these biomarkers among groups. Additionally, a total of 10 testing strategies were established for comparison to maximize the diagnostic value. The levels of CA125, HE4, CA125-Tn and ROMA value were significantly higher in EOC group compared with either the disease control (DC) group (BOT group, BET group and CCO group) or healthy control (HC) group (p < 0.001). In addition, they had better discriminatory performance with an area under the receiver operator characteristic curve (AUC) 0.93; 0.93; 0.93; 0.85, respectively (p < 0.001) compared with the AUC value of AMH 0.67 (p < 0.001). Among all 10 testing strategies, both single-positive of ROMA and double-positive of any 2 markers showed better Youden index (0.82, 0.79, respectively) and kappa value (κ) (0.82, 0.81, respectively). CA125-Tn and AMH can be treated as useful biomarkers of EOC when combined with CA125, HE4 and ROMA, because when any two biomarkers of them are positive, the value of EOC diagnosis is maximized.

Identification of germline pathogenic variants in DNA damage repair genes by a next-generation sequencing multigene panel in BRCAX patients

Approximately 5-10% of breast carcinomas have been related to hereditary conditions and are attributable to pathogenic variants in the BRCA1 and BRCA2 genes, which is referred to as hereditary breast and ovarian cancer (HBOC) syndrome. The inclusion of additional genes that can be related to HBOC syndrome is under intense evaluation due to the high proportion of patients with HBOC criteria who do not present pathogenic mutations in BRCA genes, named BRCAX, despite having high clinical suspicion of hereditary cancer. The main aim is to identify new potentially pathogenic gene variants that may contribute to HBOC to improve the efficiency of routine diagnostic tests in this hereditary condition. A retrospective cohort of 77 HBOC BRCAX patients was analyzed by next-generation sequencing using a targeted multigene panel composed of 25 genes related to hereditary cancer and deficiencies in DNA repair pathways. We found 9 variants in 7 different genes, which were confirmed by automated sequencing. Six variants were classified as pathogenic or likely pathogenic. Three of them were located in the PALB2 gene, one in the BRIP1 gene, one in the BARD1 gene and 1 in the RAD50 gene. In addition, three variants of uncertain significance (VUS) were detected in the TP53, CHEK2, and CDH1 genes. We identified that 8% of BRCAX patients were carriers of pathogenic variants in genes other than BRCA1 and BRCA2. Therefore, wide gene panels, including clinically actionable genes, should be routinely used in the screening of HBOC in our population. We observed differences from other studies in the prevalence of mutated genes, most likely due to differences in the selection criteria of the probands and in the population analyzed. The high incidence of deleterious variant detection in PALB2 supports its significant role in breast cancer susceptibility and reinforces its inclusion in the HBOC genetic diagnostic process.

Hook effect although rare, still exists

The hook effect occurs when extremely high concentrations of an analyte in the sample, saturate the antibodies used in the method, leading to falsely low results. We describe a case observed with the Atellica IM 1600 (Siemens) analyzer for the measurement of human chorionic gonadotropin (β-HCG) in serum of a pregnant woman at the thirteenth week of pregnancy. The β-HCG result was inconsistent with the gestational age and helped us to highlight the hook effect and supported the clinical diagnosis of vesicular mole in the patient. The same sample was also analyzed using the Alinity-i Total β-hCG kit (Abbott), and the authors highlight how differences between diagnostic kits can significantly affect the analytical result. In cases of discrepancies between laboratory data and clinical findings, it is essential to consult with laboratory specialists to rule out analytical interferences. To minimize the risk of the hook effect, we modified the analytical procedure and submitted a report to Siemens European Support.