Somatic Variants in DNA Damage Response Genes in Ovarian Cancer Patients Using Whole-exome Sequencing.

BACKGROUND/AIM: Several clinical trials have investigated homologous recombination deficiency and BRCA1/2 status to select ovarian cancer patients for treatment with poly(ADP-ribose) polymerase-inhibitors (PARPi), but less attention has been given to other DNA-damage response (DDR) pathways. Therefore, we investigated somatic single/multiple nucleotide variants and small insertions/deletions in exonic and splice-site regions of 356 DDR genes to examine whether genes other than BRCA1/2 are altered. MATERIALS AND METHODS: Whole-exome sequencing data from eight high-grade serous adenocarcinoma (HGSC) and four clear cell carcinoma (oCCC) patients were analyzed. RESULTS: Forty-two variants (pathogenic, likely pathogenic or variants of uncertain significance) in 28 genes from DDR pathways were identified. Seven out of nine TP53 variants were previously described in The Cancer Genome Atlas Ovarian Cancer; other variants were found in 23 out of 28 unique genes, whereas no variants were reported in FAAP24, GTF2H4, POLE4, RPA3, and XRCC4. CONCLUSION: As the identified variants were not only limited to well-known TP53, BRCA1/2, and HR-associated genes, our study might contribute to the better understanding of which DDR pathways potentially influence disease progression. Moreover, they may display a potential role as biomarkers to predict platinum-based chemotherapy or PARPi treatment response or disease progression, as differences in disrupted DDR pathways were observed between patients with long and short overall survival in HGSC and oCCC groups.

Identification of Stably Expressed Reference microRNAs in Epithelial Ovarian Cancer.

BACKGROUND/AIM: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression and have been associated with the development of various cancers, including epithelial ovarian cancer (EOC). Accurate quantification of miRNA levels is important for determining their role in tumorigenesis and as biomarkers. Currently, U6 is widely used as a normalization control when investigating miRNAs in EOC; however, its variable expression across cancers has been reported. As only a few studies have been published to date on the identification of endogenous miRNA controls in EOC, our aim was to identify stable miRNAs based on global microarray profiling of 197 EOC patients and verify their stability in external datasets. MATERIALS AND METHODS: We collected miRNA-microarray data from four datasets: the in-house "Pelvic Mass", and three public datasets with primary EOC patients: The Cancer Genome Atlas, GSE47841, and GSE73581. The expression stability of endogenous control candidates was evaluated by their coefficient of variation. RESULTS: All miRNA results in the used cohorts were produced by either Affymetrix or Agilent technologies, which show similar intra-platform patterns. Nonetheless, a clear difference in a cross-platform comparison was observed. We identified hsa-miR-92b-5p and hsa-miR-106b-3p as stable candidates shared between four datasets. Moreover, we investigated the stability performance of eight miRNAs that have been previously reported as stable endogenous controls in EOC and various performance was observed in four datasets. CONCLUSION: The selection of suitable endogenous miRNA normalization controls in EOC remains to be resolved, as variability in miRNA performance between platforms might have a crucial impact on the biological interpretation of data.

Differences in regional diagnostic strategies and in intended versus actual first-line treatment of patients with advanced ovarian cancer in Denmark.

BACKGROUND: Triage of patients with ovarian cancer to primary debulking surgery (PDS) or neoadjuvant chemotherapy (NACT) is challenging. In Denmark, the use of NACT has increased, but substantial differences in the use of NACT or PDS exist among centers. We aimed to characterize the differences between intended and actual first-line treatments in addition to the differences in the triage process among the centers and to evaluate the different diagnostic modalities and the clinical aspects' influence in the triage process. MATERIALS AND METHODS: From 4 centers, forms containing data about the diagnostic process and intended treatment were prospectively collected and merged with data from the Danish Gynecological Cancer Database and medical records. RESULTS: Of the 671 completed forms, 540 patients had stage IIIC or IV epithelial ovarian cancer. Of the 238 (44%) referred to PDS, 91% received PDS and 4% never had debulking surgery. Of the 288 patients (53%) referred to NACT, 44% were never debulked. Fourteen patients (3%) were referred to palliative treatment. The use of different imaging modalities, diagnostic laparoscopy, and laparotomy varied significantly among the centers. Diagnostic surgical procedures were considered to be most influential in the triage process. Regardless of the intended first-line treatment or center, the tumor size and dissemination was the most influential clinical aspect. CONCLUSIONS: In Denmark, substantial differences exist between intended and actual first-line treatments as well as in the diagnostic process and use of NACT, calling for further discussion on diagnostic strategy and therapeutically approach for patients with advanced ovarian cancer.

Does neoadjuvant chemotherapy impair long-term survival for ovarian cancer patients? A nationwide Danish study.

OBJECTIVE: In Denmark, the proportion of women with ovarian cancer treated with neoadjuvant chemotherapy (NACT) has increased, and the use of NACT varies among center hospitals. We aimed to evaluate the impact of first-line treatment on surgical outcome and median overall survival (MOS). METHODS: All patients treated in Danish referral centers with stage IIIC or IV epithelial ovarian cancer from January 2005 to October 2011 were included. Data were obtained from the Danish Gynecological Cancer Database, the Danish National Patient Register and medical records. RESULTS: Of the 1677 eligible patients, 990 (59%) were treated with primary debulking surgery (PDS), 515 (31%) with NACT, and 172 (10%) received palliative treatment. Of the patients referred to NACT, 335 (65%) received interval debulking surgery (IDS). Patients treated with NACT-IDS had shorter operation times, less blood loss, less extensive surgery, fewer intraoperative complications and a lower frequency of residual tumor (p < 0.05 for all). No difference in MOS was found between patients treated with PDS (31.9 months) and patients treated with NACT-IDS (29.4 months), p = 0.099. Patients without residual tumor after surgery had better MOS when treated with PDS compared with NACT-IDS (55.5 and 36.7 months, respectively, p = 0.002). In a multivariate analysis, NACT-IDS was associated with increased risk of death after two years of follow-up (HR: 1.81; CI: 1.39-2.35). CONCLUSIONS: No difference in MOS was observed between PDS and NACT-IDS. However, patients without residual tumor had superior MOS when treated with PDS, and NACT-IDS could be associated with increased risk of death after two years of follow-up.