Association Between Proportion of Nuclei With High Chromatin Entropy and Prognosis in Gynecological Cancers

Background: Nuclear texture analysis measuring differences in chromatin structure has provided prognostic biomarkers in several cancers. There is a need for improved cell-by-cell chromatin analysis to detect nuclei with highly disorganized chromatin. The purpose of this study was to develop a method for detecting nuclei with high chromatin entropy and to evaluate the association between the presence of such deviating nuclei and prognosis. Methods: A new texture-based biomarker that characterizes each cancer based on the proportion of high–chromatin entropy nuclei (<25% vs ≥25%) was developed on a discovery set of 175 uterine sarcomas. The prognostic impact of this biomarker was evaluated on a validation set of 179 uterine sarcomas, as well as on independent validation sets of 246 early-stage ovarian carcinomas and 791 endometrial carcinomas. More than 1 million images of nuclei stained for DNA were included in the study. All statistical tests were two-sided. Results: An increased proportion of high–chromatin entropy nuclei was associated with poor clinical outcome. The biomarker predicted five-year overall survival for uterine sarcoma patients with a hazard ratio (HR) of 2.02 (95% confidence interval [CI] = 1.43 to 2.84), time to recurrence for ovarian cancer patients (HR = 2.91, 95% CI = 1.74 to 4.88), and cancer-specific survival for endometrial cancer patients (HR = 3.74, 95% CI = 2.24 to 6.24). Chromatin entropy was an independent prognostic marker in multivariable analyses with clinicopathological parameters (HR = 1.81, 95% CI = 1.21 to 2.70, for sarcoma; HR = 1.71, 95% CI = 1.01 to 2.90, for ovarian cancer; and HR = 2.03, 95% CI = 1.19 to 3.45, for endometrial cancer). Conclusions: A novel method detected high–chromatin entropy nuclei, and an increased proportion of such nuclei was associated with poor prognosis. Chromatin entropy supplemented existing prognostic markers in multivariable analyses of three gynecological cancer cohorts.publishedVersio

Long-term oncological outcomes and recurrence patterns in early-stage cervical cancer treated with minimally invasive versus abdominal radical hysterectomy: The Norwegian Radium Hospital experience

Objective To compare long-term oncological outcomes in early-stage cervical cancer (CC) patients treated with minimally invasive radical hysterectomy (MIRH) versus abdominal radical hysterectomy (ARH), with a focus on recurrence patterns, tumor sizes, and conization. Methods This single-institution, retrospective study consisted of stage IA1-IB1 (FIGO 2009) squamous cell carcinoma, adenocarcinoma, and adenosquamous carcinoma of the cervix, who underwent radical hysterectomy between 2000 and 2017. Results Of the 582 patients included, 353 (60.7%) underwent ARH, and 229 (39.3%) MIRH. The median follow-up was 14.4 years in the ARH group and 6.1 years in the MIRH group (p < 0.0001). Among the 96 stage IA patients, only 3 (3.1%) experienced recurrence. Among stage IB1 patients, the risk of recurrence, after adjusting for standard prognostic variables, was twofold higher in the MIRH group versus the ARH group (HR 2.73, 95% CI: 1.56–4.80), and the relative difference was similar in terms of risk of cancer-specific survival (CSS) (HR 3.04, 95% CI: 1.28–7.20) and overall survival (OS) (HR 2.35, 95% CI: 1.21–4.59). In stage IB1 ≤ 2 cm patients without conization MIRH was associated with reduced time to recurrence (TTR) (HR 4.00, 95% CI: 1.67–9.57), CSS (HR 3.71, 95% CI: 1.19–11.58) and OS (HR 3.02, 95% CI: 1.24–7.34). Intraperitoneal combined recurrences accounted for 12 of 30 (40.0%) recurrences in the MIRH group but were not identified after ARH (p = 0.0001). Conclusions MIRH was associated with reduced TTR, CSS and OS versus ARH in stage IB1 CC patients. The risk of peritoneal recurrence was high, even for tumors ≤2 cm without conization

Reference MicroRNAs for RT-qPCR Assays in Cervical Cancer Patients and Their Application to Studies of HPV16 and Hypoxia Biomarkers

MicroRNA (miRNA) expressions in tumor biopsies have shown potential as biomarkers in cervical cancer, but suitable reference RNAs for normalization of reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays in patient cohorts with different clinicopathological characteristics are not available. We aimed to identify the optimal reference miRNAs and apply these to investigate the potential of miR-9-5p as human papilloma virus (HPV) 16 biomarker and miR-210-3p as hypoxia biomarker in cervical cancer. Candidate reference miRNAs were preselected in sequencing data of 90 patients and ranked in a stability analysis by RefFinder. A selection of the most stable miRNAs was evaluated by geNorm and NormFinder analyses of RT-qPCR data of 29 patients. U6 small nuclear RNA (RNU6) was also included in the evaluation. MiR-9-5p and miR-210-3p expression was assessed by RT-qPCR in 45 and 65 patients, respectively. Nine candidates were preselected in the sequencing data after excluding those associated with clinical markers, HPV type, hypoxia status, suboptimal expression levels, and low stability. In RT-qPCR assays, the combination of miR-151-5p, miR-152-3p, and miR-423-3p was identified as the most stable normalization factor across clinical markers, HPV type, and hypoxia status. RNU6 showed poor stability. By applying the optimal reference miRNAs, higher miR-9-5p expression in HPV16- than HPV18-positive tumors and higher miR-210-3p expression in more hypoxic than less hypoxic tumors were found in accordance with the sequencing data. MiR-210-3p was associated with poor outcome by both sequencing and RT-qPCR assays. In conclusion, miR-151-5p, miR-152-3p, and miR-423-3p are suitable reference miRNAs in cervical cancer. MiR-9-5p and miR-210-3p are promising HPV16 and hypoxia biomarkers, respectively

Prognostic value of the diversity of nuclear chromatin compartments in gynaecological carcinomas

Statistical texture analysis of cancer cell nuclei stained for DNA has recently been used to develop a pan-cancer prognostic marker of chromatin heterogeneity. In this study, we instead analysed chromatin organisation by automatically quantifying the diversity of chromatin compartments in cancer cell nuclei. The aim was to investigate the prognostic value of such an assessment in relation to chromatin heterogeneity and as a potential supplement to pathological risk classifications in gynaecological carcinomas. The diversity was quantified by calculating the entropy of both chromatin compartment sizes and optical densities within compartments. We analysed a median of 281 nuclei (interquartile range (IQR), 273 to 289) from 246 ovarian carcinoma patients and a median of 997 nuclei (IQR, 502 to 1452) from 791 endometrial carcinoma patients. The prognostic value of the entropies and chromatin heterogeneity was moderately strongly correlated (r ranged from 0.68 to 0.73), but the novel marker was observed to provide additional prognostic information. In multivariable analysis with clinical and pathological markers, the hazard ratio associated with the novel marker was 2.1 (95% CI, 1.3 to 3.5) in ovarian carcinoma and 2.4 (95% CI, 1.5 to 3.9) in endometrial carcinoma. Integration with pathological risk classifications gave three risk groups with distinctly different prognoses. This suggests that the novel marker of diversity of chromatin compartments might possibly contribute to the selection of high-risk stage I ovarian carcinoma patients for adjuvant chemotherapy and low-risk endometrial carcinoma patients for less extensive surgery

Mitochondrial Function of CKS2 Oncoprotein Links Oxidative Phosphorylation with Cell Division in Chemoradioresistant Cervical Cancer

CDK regulatory subunit 2 (CKS2) has a nuclear function that promotes cell division and is a candidate biomarker of chemoradioresistance in cervical cancer. The underlying mechanisms are, however, not completely understood. We investigated whether CKS2 also has a mitochondrial function that augments tumor aggressiveness. Based on global gene expression data of two cervical cancer cohorts of 150 and 135 patients, we identified a set of genes correlated with CKS2 expression. Gene set enrichment analysis showed enrichment of mitochondrial cellular compartments, and the hallmarks oxidative phosphorylation (OXPHOS) and targets of the MYC oncogene in the gene set. By in situ proximity ligation assay, we showed that CKS2 formed complex with the positively correlated MYC target, mitochondrial single-stranded DNA binding protein SSBP1, in the mitochondrion of cervix tumor samples and HeLa and SiHa cervical cancer cell lines, indicating a role in mitochondrial DNA (mtDNA) replication and thereby OXPHOS. CDK1 was found to be part of the complex. Flow cytometry analyses of HeLa cells showed cell cycle regulation of the CKS2-SSBP1 complex consistent with mtDNA replication activity. Moreover, repression of mtDNA replication and OXPHOS by acute hypoxia decreased CKS2-SSBP1 complex abundance and expression of MYC targets. By immunohistochemistry, cytoplasmic CKS2 expression was found to add to the prognostic impact of nuclear CKS2 expression in patients, suggesting that the mitochondrial function promotes tumor aggressiveness. Our study uncovers a novel link between regulation of cell division by nuclear pathways and OXPHOS in the mitochondrion that involves CKS2 and promotes chemoradioresistance of cervical cancer

DCE-MRI - Derived Measures of Tumor Hypoxia and Interstitial Fluid Pressure Predict Outcomes in Cervical Carcinoma

Purpose: The poor outcome of locally advanced cervical cancer has been associated with extensive hypoxia and high interstitial fluid pressure (IFP) in the primary tumor. In the present study, measures of tumor hypoxia and IFP were provided using dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) and related to the treatment outcomes. Methods and Materials: The data from 54 cervical cancer patients treated with concurrent cisplatin-based chemoradiotherapy were studied. A low-enhancing tumor volume (LETV) and peritumoral fluid flow velocity (v0) were used as measures of tumor hypoxia and IFP, respectively. Results: Poor disease-free survival and overall survival were associated with large LETV and high v0. The multivariate analysis results suggested that the prognostic power of v0 and LETV is independent of established clinical prognostic factors and that the prognostic power of v0 is strong compared with that of LETV. The outcomes was especially poor for patients with a high v0 combined with a large LETV and especially good for those with a low v0 combined with a small LETV, with 5-year disease-free survival and overall survival of 13% versus 100%, respectively. Conclusions: The outcome of locally advanced cervical carcinoma seems to be influenced strongly by the tumor IFP and to a lesser extent by tumor hypoxia. DCE-MRI might have the power to provide important biomarkers for the outcome of cervical cancer

Clinical Outcome of Patients with High-Risk Endometrial Carcinoma after Treatment with Chemotherapy only

Objectives: Adjuvant treatment of high-risk endometrial cancer (EC) is still controversial. Several studies have tried to clarify the best treatment strategy, and guidelines have been made, but no study to date has shown a survival benefit for radiation over chemotherapy. We aimed to evaluate the outcome of high-risk EC patients treated with adjuvant chemotherapy only in a population where the routine administration of adjuvant radiotherapy was omitted. Methods: This is a retrospective study including 230 EC patients with International Federation of Gynecology and Obstetrics stage I type II, stage Ib type I/G3, stage II, and IIIc treated at Oslo University Hospital between 2005 and 2012. Standard treatment was hysterectomy, bilateral salpingo-oophorectomy and at least pelvic lymphadenectomy followed by adjuvant chemotherapy. Results: Of the 230 high-risk patients, standard treatment was given to 146 patients (63.5%): 60 patients in stage I, 10 patients in stage II, and 76 patients in stage IIIc. Only 10% of patients with stage I disease relapsed, with 3.3% locoregional relapses and 6.7% distant relapses. Recurrence rate in stage IIIc was 39.5%, with 7.9% isolated vaginal and 31.6% distant relapses. The 3-year disease-free survival was 92% for stage I, 80% for stage II, and 60% for stage IIIc disease. In the total population, 55 patients had International Federation of Gynecology and Obstetrics stage Ia, 43 Ib, 42 stage II, and 90 stage IIIc disease. Recurrence rate in the total population was 29.6%, with 9.6% isolated vaginal recurrences, 1.7% recurrences located in the pelvis, and 18.3% distant recurrences. Conclusions: Patients with high-risk EC have acceptable vaginal/pelvic control rates after adjuvant chemotherapy. However, prognosis remains poor for patients with stage IIIc disease, also after chemotherapy

Combining imaging- and gene-based hypoxia biomarkers in cervical cancer improves prediction of chemoradiotherapy failure independent of intratumour heterogeneity

Background Emerging biomarkers from medical imaging or molecular characterization of tumour biopsies open up for combining the two and exploiting their synergy in treatment planning of cancer patients. We generated a paired data set of imaging- and gene-based hypoxia biomarkers in cervical cancer, appraised the influence of intratumour heterogeneity in patient classification, and investigated the benefit of combining the methodologies in prediction of chemoradiotherapy failure. Methods Hypoxic fraction from dynamic contrast enhanced (DCE)-MR images and an expression signature of six hypoxia-responsive genes were assessed as imaging- and gene-based biomarker, respectively in 118 patients. Findings Dichotomous biomarker cutoff to yield similar hypoxia status by imaging and genes was defined in 41 patients, and the association was validated in the remaining 77 patients. The two biomarkers classified 75% of 118 patients with the same hypoxia status, and inconsistent classification was not related to imaging-defined intratumour heterogeneity in hypoxia. Gene-based hypoxia was independent on tumour cell fraction in the biopsies and showed minor heterogeneity across multiple samples in 9 tumours. Combining imaging- and gene-based classification gave a significantly better prediction of PFS than one biomarker alone. A combined dichotomous biomarker optimized in 77 patients showed a large separation in PFS between more and less hypoxic tumours, and separated the remaining 41 patients with different PFS. The combined biomarker showed prognostic value together with tumour stage in multivariate analysis. Interpretation Combining imaging- and gene-based biomarkers may enable more precise and informative assessment of hypoxia-related chemoradiotherapy resistance in cervical cancer. Funding Norwegian Cancer Society, South-Eastern Norway Regional Health Authority, and Norwegian Research Council

Salvage radiation for pelvic relapse after surgically treated endometrial cancer

(1) Background: This study evaluated the clinical outcome after salvage radiotherapy for first pelvic relapse after endometrial cancer (EC). (2) Methods: This multicenter retrospective study included EC patients with first central pelvic relapse without lymph node involvement treated with curative intent. Progression-free (PFS) and overall survival (OS) were calculated with the Kaplan–Meier method and possible predictive factors for risk of relapse and mortality were identified using the Cox model. (3) Results: We included 139 patients with median EQD2 (Equivalent Dose in 2 Gy fractions) to the clinical target volume of 70.0 Gy. During follow up of median 6.66 years, 39.6% patients developed a second relapse. Risk group classification at primary diagnosis based on histology, grading and FIGO stage and how the pelvic tumor boost was administered were independently associated with PFS and OS. Five-year OS was 68% (95% CI (59–75)) for the whole cohort. Five-year OS was 88% (95% CI (75–94)), 72% (95% CI (55–84)) and 38% (95% CI (15–60)) for the stage I low-, intermediate- and high-risk group, respectively. (4) Conclusions: The majority of central pelvic recurrences in RT-naive EC women can be successfully salvaged with radiotherapy. However, survival in patients with high-risk disease remains poor and warrants a more individualized approach to optimize outcome