Elisabet Hjerpe

Genome-wide association study identifies ephrin type A receptors implicated in paclitaxel induced peripheral sensory neuropathy

Background Peripheral neuropathy is the dose limiting toxicity of paclitaxel, a chemotherapeutic drug widely used to treat solid tumours. This toxicity exhibits great inter-individual variability of unknown origin. The present study aimed to identify genetic variants associated with paclitaxel induced neuropathy via a whole genome approach. Methods A genome-wide association study (GWAS) was performed in 144 white European patients uniformly treated with paclitaxel/carboplatin and for whom detailed data on neuropathy was available. Per allele single nucleotide polymorphism (SNP) associations were assessed by Cox regression, modelling the cumulative dose of paclitaxel up to the development of grade 2 sensory neuropathy. Results The strongest evidence of association was observed for the ephrin type A receptor 4 (EPHA4) locus (rs17348202, p=1.0×10–6), and EPHA6 and EPHA5 were among the top 25 and 50 hits (rs301927, p=3.4×10–5 and rs1159057, p=6.8×10–5), respectively. A meta-analysis of EPHA5-rs7349683, the top marker for paclitaxel induced neuropathy in a previous GWAS (r2=0.79 with rs1159057), gave a hazard ratio (HR) estimate of 1.68 (p=1.4×10−9). Meta-analysis of the second hit of this GWAS, XKR4-rs4737264, gave a HR of 1.71 (p=3.1×10−8). Imputed SNPs at LIMK2 locus were also strongly associated with this toxicity (HR=2.78, p=2.0×10−7). Conclusions This study provides independent support of EPHA5-rs7349683 and XKR4-rs4737264 as the first markers of risk of paclitaxel induced neuropathy. In addition, it suggests that other EPHA genes also involved in axonal guidance and repair following neural injury, as well as LIMK2 locus, may play an important role in the development of this toxicity. The identified SNPs could form the basis for individualised paclitaxel chemotherapy.

Ovarian carcinoma cells with low levels of β-F1-ATPase are sensitive to combined platinum and 2-deoxy-d-glucose treatment

We have here examined chemopotentiating effects of glycolysis inhibitor 2-deoxy-d-glucose (DG) in two epithelial ovarian carcinoma (EOC) cell lines and 17 freshly isolated ascitic EOC cell samples, and we identify low expression of the β-F1-ATPase involved in mitochondrial ATP production as a candidate marker for sensitivity to this strategy. Although in the majority of samples, DG per se did not induce apoptosis, cotreatment with DG potentiated apoptosis and total antiproliferative effects of cisplatin and, to a lesser degree, carboplatin. In the cell lines, combination treatment with DG and cisplatin or carboplatin at noninhibitory concentrations prevented posttreatment regrowth in drug-free medium over a total of 5 days. DG per se allowed complete recuperation in drug-free medium. The more platinum-resistant a cell line was, the more sensitive it was to potentiation by DG and showed higher glucose uptake, DG-sensitive lactate production, and lower β-F1-ATPase levels. In the ascitic samples, DG reduced the median IC50 for cisplatin by 68% and, in the most sensitive samples, up to 90%, and DG-mediated potentiation correlated with low expression of β-F1-ATPase. By contrast, cisplatin sensitivity did not correlate with β-F1-ATPase levels. The findings validate targeting cancer cell glucose metabolism for potentiating platinum chemotherapy in EOC and indicate that reduced β-F1-ATPase/oxidative phosphorylation distinguishes cells that are amenable to this strategy. [Mol Cancer Ther 2009;8(7):1916–23]

Protein markers of cancer-associated fibroblasts and tumor-initiating cells reveal subpopulations in freshly isolated ovarian cancer ascites.

BackgroundIn ovarian cancer, massive intraperitoneal dissemination is due to exfoliated tumor cells in ascites. Tumor-initiating cells (TICs or cancer stem cells) and cells showing epithelial-mesenchymal-transition (EMT) are particularly implicated. Spontaneous spherical cell aggregates are sometimes observed, but although similar to those formed by TICs in vitro, their significance is unclear.MethodsCells freshly isolated from malignant ascites were separated into sphere samples (S-type samples, n=9) and monolayer-forming single-cell suspensions (M-type, n=18). Using western blot, these were then compared for expression of protein markers of EMT, TIC, and of cancer-associated fibroblasts (CAFs).ResultsS-type cells differed significantly from M-type by expressing high levels of E-cadherin and no or little vimentin, integrin-β3 or stem cell transcription factor Oct-4A. By contrast, M-type samples were enriched for CD44, Oct-4A and for CAF markers. Independently of M- and S-type, there was a strong correlation between TIC markers Nanog and EpCAM. The CAF marker α-SMA correlated with clinical stage IV. This is the first report on CAF markers in malignant ascites and on SUMOylation of Oct-4A in ovarian cancer.ConclusionsIn addition to demonstrating potentially high levels of TICs in ascites, the results suggest that the S-type population is the less tumorigenic one. Nanoghigh/EpCAMhigh samples represent a TIC subset which may be either M- or S-type, and which is separate from the CD44high/Oct-4Ahigh subset observed only in M-type samples. This demonstrates a heterogeneity in TIC populations in vivo which has practical implications for TIC isolation based on cell sorting. The biological heterogeneity will need to be addressed in future therapeutical strategies.

HSP60 predicts survival in advanced serous ovarian cancer.

Objective Heat shock protein 60 (HSP60) plays an essential role in malignant cell survival. We evaluated the prognostic and treatment predictive value of HSP60 in advanced ovarian cancer. Methods Fresh tumor samples were prospectively collected from 123 patients undergoing primary surgery for suspected advanced ovarian cancer. Of these, 57 fulfilled the eligibility criteria, that is, International Federation of Gynecology and Obstetrics stage IIC-IV, serous/endometrioid tumors, platinum-based chemotherapy, and specimens with 50% tumor cells or greater. Heat shock protein 60 mRNA and protein expression was determined by real-time polymerase chain reaction and immunohistochemistry. We estimated the association between HSP60 and overall survival (OS) and platinum-free interval (PFI) by Cox proportional hazards models and its relationship with treatment response by Fisher’s exact test. Median follow-up was 60 months. Results High HSP60 mRNA expression was associated with shorter OS (hazard ratio [HR], 3.4; 95% confidence interval [CI], 1.3–8.5) and PFI (HR, 3.3; 95% CI, 1.5–7.2). Likewise, high HSP60 protein expression was associated with shorter OS (HR, 3.2; 95% CI, 1.5–7.1) and PFI (HR, 2.6; 95% CI, 1.3–5.3). Median survival for patients with high HSP60 protein expression was 31 months compared with 55 months for low expression cases (P = 0.016). The impact on OS and PFI was even stronger in the subgroup of grade 3 serous tumors. All patients with low HSP60 levels responded to first-line chemotherapy. Conclusion Heat shock protein 60 may identify groups of advanced serous ovarian cancer with different prognosis and treatment response.

Metabolic markers and HSP60 in chemonaive serous solid ovarian cancer versus ascites.

Objective Metabolic pathway alterations in cancer are thought to be dependent upon tumor type–specific oncogenic activation and local nutrient and oxygen supply during disease progression. In serous ovarian cancer, the typical peritoneal spread of disease is caused by shedding of tumor cells into the abdominal cavity, often along with ascites formation. Not much is known about the metabolic features of these detached serous tumor cells. In this study, we investigate the messenger RNA (mRNA) expression of GAPDH (glycolytic glyceraldehyde 3-phosphate dehydrogenase) and PKM2 (pyruvate kinase isoform M2), ATP5B (mitochondrial β-F1-ATPase), and heat shock protein 60 in matched serous solid tumor and corresponding ascites. Materials/Methods Fresh samples from solid tumor and corresponding ascites were prospectively collected from 40 patients undergoing primary surgery for suspected advanced ovarian cancer. Of these, 25 met the study eligibility criteria, that is, stage IIC to IV disease of the serous (24) or endometrioid (1) subtype with solid and ascites specimens containing 50% or more tumor cells and with good quality and quantity mRNA yield. All but 2 patients (92%) had type II disease. GAPDH, PKM2, ATP5B, and HSP60 mRNA expressions were assessed by real-time polymerase chain reaction. For each marker, the mRNA expression in solid tumor was pairwise compared with the corresponding expression in ascites using the Wilcoxon matched pairs signed rank sum test. Results In contrast to our hypothesis, the mRNA expression of analyzed metabolic markers and HSP60 did not significantly differ between matched solid tumor and malignant ascites. Conclusions Our results indicate that further expression changes in genes related to glycolysis or oxidative phosphorylation are not a prerequisite for serous cancer cell survival after detachment.

Data quality in the Swedish Quality Register of Gynecologic Cancer – a Swedish Gynecologic Cancer Group (SweGCG) study

Abstract Aim: The aim of this study is to evaluate the quality of data on endometrial (EC) and ovarian, fallopian tube, peritoneal, abdominal or pelvic cancers (OC) registered in the Swedish Quality Register of Gynecologic Cancer (SQRGC). Method: A random sample of 500 patients was identified in the SQRGC and their medical charts were reviewed for re-abstraction of 31 selected core variables by an independent validator. The data in the SQRGC and the re-abstracted data were compared. The data were collected from 25 hospitals evenly distributed throughout Sweden. The main outcomes were comparability, timeliness, completeness and validity. Coverage was compared with the National Cancer Register (NCR). Timeliness was defined as the speed of registration i.e. when patients were registered in the SQRGC relative to date of diagnosis. Internationally accepted coding systems for stage, grading and histologic type were used ensuring a high degree of comparability. Correlations were estimated using Pearson’s correlation coefficient and Cohen´s kappa coefficient. Results: The completeness was 95%. The timeliness was 88–91% within 12 months of diagnosis. The median degree of agreement between re-abstracted data and data in the SQRGC was 82.1%, with a median kappa value of 0.73 for ordinate variables and a median Pearson’s correlation coefficient of 0.96. The agreements for the type of surgery were 76% (95% CI 70–81%; kappa 0.49) and type of primary treatment 90% (95% CI 87–94%; kappa 0.85) in OC and in EC 88% (95% CI 84–93%; kappa 0.84). The agreements for the FIGO stage were in OC and EC 74% (95% CI 68–80%; kappa 0.69) and 87% (95% CI 82–91%; kappa 0.79), respectively. Conclusions: The data in the Swedish Quality Register for Gynecologic Cancer are of adequate quality in order to be used as a basis for research and to evaluate possible differences in treatment, lead times and treatment results.

Lymph node metastases as only qualifier for stage IV serous ovarian cancer confers longer survival than other sites of distant disease – a Swedish Gynecologic Cancer Group (SweGCG) study

Abstract Background: The International Federation of Gynecology and Obstetrics (FIGO) ovarian cancer staging system includes no sub-stage for lymph nodes (LN) as only distant disease manifestation. We explore the prognostic implication of LN as only stage IV classifier in serous ovarian cancer. Method: This is a nation-wide, population-based study on 551 women with serous stage IV cancers diagnosed between 2009–2014. We compare overall survival (OS) in women with LN as only distant metastatic site to those with pleural metastases only and to patients with other/multiple stage IV manifestations. Cox regression models were used for uni- and multivariable estimations. Results: Of 551stage IV cases, distant metastatic site was registered in 433. Median OS for women with LN (n = 51) was 41.4 months, compared to 25.2 and 26.8 months for patients with pleural (n = 195) or other/multiple (n = 187) distant metastases (p = .0007). The corresponding five-year survival rates were 32, 11 and 22%, respectively. Multivariable analyzes confirmed shorter survival for women with pleural (HR 2.99, p = .001) or other/multiple distant sites (HR 2.67, p = .007), as compared to LN cases. LN only patients lived 9.1 months longer after primary than after interval surgery, but this difference was not significant (p = .245). Conclusion: Women with stage IV serous ovarian cancer having lymph nodes as only distant metastatic site live longer than other stage IV patients.

Cardiophrenic lymph node resection in advanced ovarian cancer: surgical outcomes, pre- and postoperative imaging

Abstract Objective: To evaluate the accuracy of preoperative imaging in the diagnosis of cardiophrenic lymph node (CPLN) metastases and to report perioperative outcomes after resection of CPLN at the time of cytoreductive surgery for advanced epithelial ovarian cancer (EOC). Furthermore, to assess clearance of CPLN by postoperative imaging. Methods: All women with stage IIIC/IV EOC subjected to surgery at our institution from January 2014 to October 2016 were retrospectively identified from a database. Among these, women subjected to CPLN resection during surgery were identified. Pre- and postoperative computed tomography (CT) scans, pathology reports, surgical approach and outcomes were reviewed. Results: One hundred and eighty women with stage IIIC/IV EOC subjected to surgery with curative intent were identified. Twenty-four (13%) of these women underwent CPLN resection. All had CT imaging suggestive of CPLN metastases. 20/24 (83%) had confirmed metastases upon final pathology. CPLN resection was associated with longer operation time, more often advanced upper abdominal surgery and more postoperative complications but there was no difference in days from surgery to initiation of chemotherapy. Postoperative CT was still indicative of CPLN metastases in 13/22 (59%) women despite resection with confirmative pathology. Conclusions: Resection of CPLN metastases is highly feasible without considerable added morbidity. Concern regarding surgical clearance is raised since postoperative imaging was indicative of metastases in the majority of women. The prognostic significance of stage IV disease based exclusively on CPLN metastases is unclear and any survival benefit from the procedure is yet to be determined.