Pre-and Postoperative Circulating Tumour DNA in Patients With Gastrointestinal Stromal Tumour - A Methodological Assessment Study.

BACKGROUND/AIM: Gastrointestinal stromal tumours (GISTs) harbour genetic aberrations in receptor tyrosine kinase KIT (KIT) or platelet-derived growth factor receptor A (PDGFRA) in 85-90% of the patients. Circulating tumour DNA (ctDNA) is a potential biomarker in patients with GIST. Previous studies investigating ctDNA around surgery in patients with GIST presented divergent results regarding the proportion of patients with detectable ctDNA. This study aimed to 1) investigate the feasibility of detecting and monitoring ctDNA pre-and postoperative, 2) compare two different circulating free DNA (cfDNA) extraction methods, and validate results obtained by next-generation sequencing (NGS) using Real-Time PCR technology. PATIENTS AND METHODS: Eight patients planned for immediate surgery or surgery after neoadjuvant oncological treatment were included in the study, from whom blood collection was performed pre- and postoperatively for ctDNA analysis. Furthermore, blood samples from six patients with GIST harbouring a point mutation in KIT or PDGFRA in tissues from primary tumours were used for comparison and validation sub-study. RESULTS: In this explorative study, none of the patients with very low to intermediate risk GIST harboured KIT, or PDGFRA mutated ctDNA in pre-or postoperative blood samples. The methods used for cfDNA extraction gave similar output, and the two methods for ctDNA analysis gave identical results. CONCLUSION: There is no benefit in analysing ctDNA around surgery in very low to intermediate-risk GIST patients. Larger studies investigating ctDNA in patients with high-risk GIST around surgery are warranted.

Assessment of recurrence rate and risk factors of relapse in stage in IA vulvar carcinoma.

OBJECTIVE: To evaluate recurrence rates and risk factors of relapse in stage IA vulvar squamous cell carcinoma (VSCC) patients. MATERIAL AND METHODS: Population-based prospectively collected data on stage IA VSCC was retrieved through the Danish Gynecological Cancer Database (DGCD) during 2011-2017. A central pathology review was performed on tumors from women with recurrent disease. RESULTS: 62 women diagnosed and treated for stage IA VSCC were identified. Nine (14.5%) of the included cases relapsed within the observation period. The recurrences were in the vulva, groins or both in 5 (8.1%), 3 (4.8%) and 1 (1.6%) of the women, respectively. At central pathology review, including all recurrent cases (n = 9), 5 out of 21 reviewed patients were upstaged to stage IB due to depth of invasion >1 mm and two were downstaged to Carcinoma in situ. Two of the upstaged women developed an isolated groin recurrence and one an isolated vulvar relapse. After exclusion of the seven cases the overall recurrence rate decreased to 10.9% (n = 6). Among these cases (n = 55) resection margin <8 mm and tumor size were associated with cancer recurrence. CONCLUSION: Pathological assessment of stage IA VSCC (depth of invasion ≤1 mm) may be difficult. This may result in under-staging, which impact the choice of treatment and possibly the prognosis. This suggests a need for further clarification of the FIGO measurement and may require a more radical approach when it comes to treatment and groin exploration in stage IA VSCC. Resection margins <8 mm and tumor size were associated with relapse of the disease.

Assessment of Multifactor Gene-Environment Interactions and Ovarian Cancer Risk: Candidate Genes, Obesity, and Hormone-Related Risk Factors.

BACKGROUND: Many epithelial ovarian cancer (EOC) risk factors relate to hormone exposure and elevated estrogen levels are associated with obesity in postmenopausal women. Therefore, we hypothesized that gene-environment interactions related to hormone-related risk factors could differ between obese and non-obese women. METHODS: We considered interactions between 11,441 SNPs within 80 candidate genes related to hormone biosynthesis and metabolism and insulin-like growth factors with six hormone-related factors (oral contraceptive use, parity, endometriosis, tubal ligation, hormone replacement therapy, and estrogen use) and assessed whether these interactions differed between obese and non-obese women. Interactions were assessed using logistic regression models and data from 14 case-control studies (6,247 cases; 10,379 controls). Histotype-specific analyses were also completed. RESULTS: SNPs in the following candidate genes showed notable interaction: IGF1R (rs41497346, estrogen plus progesterone hormone therapy, histology = all, P = 4.9 × 10(-6)) and ESR1 (rs12661437, endometriosis, histology = all, P = 1.5 × 10(-5)). The most notable obesity-gene-hormone risk factor interaction was within INSR (rs113759408, parity, histology = endometrioid, P = 8.8 × 10(-6)). CONCLUSIONS: We have demonstrated the feasibility of assessing multifactor interactions in large genetic epidemiology studies. Follow-up studies are necessary to assess the robustness of our findings for ESR1, CYP11A1, IGF1R, CYP11B1, INSR, and IGFBP2 Future work is needed to develop powerful statistical methods able to detect these complex interactions. IMPACT: Assessment of multifactor interaction is feasible, and, here, suggests that the relationship between genetic variants within candidate genes and hormone-related risk factors may vary EOC susceptibility. Cancer Epidemiol Biomarkers Prev; 25(5); 780-90. ©2016 AACR.

The association between socioeconomic status and tumour stage at diagnosis of ovarian cancer: A pooled analysis of 18 case-control studies.

PURPOSE: Socioeconomic status (SES) is a known predictor of survival for several cancers and it has been suggested that SES differences affecting tumour stage at diagnosis may be the most important explanatory factor for this. However, only a limited number of studies have investigated SES differences in tumour stage at diagnosis of ovarian cancer. In a pooled analysis, we investigated whether SES as represented by level of education is predictive for advanced tumour stage at diagnosis of ovarian cancer, overall and by histotype. The effect of cigarette smoking and body mass index (BMI) on the association was also evaluated. METHODS: From 18 case-control studies, we obtained information on 10,601 women diagnosed with epithelial ovarian cancer. Study specific odds ratios (ORs) with corresponding 95% confidence intervals (CI) were obtained from logistic regression models and combined into a pooled odds ratio (pOR) using a random effects model. RESULTS: Overall, women who completed ≤high school had an increased risk of advanced tumour stage at diagnosis compared with women who completed >high school (pOR 1.15; 95% CI 1.03-1.28). The risk estimates for the different histotypes of ovarian cancer resembled that observed for ovarian cancers combined but did not reach statistical significance. Our results were unchanged when we included BMI and cigarette smoking. CONCLUSION: Lower level of education was associated with an increased risk of advanced tumour stage at diagnosis of ovarian cancer. The observed socioeconomic difference in stage at diagnosis of ovarian cancer calls for further studies on how to reduce this diagnostic delay.

HE4 and CA125 levels in the preoperative assessment of endometrial cancer patients: a prospective multicenter study (ENDOMET).

OBJECTIVE: To evaluate whether human epididymis protein 4 (HE4) and CA125 correlate with known high-risk prognostic factors for endometrial cancer. DESIGN: Prospective multicenter study. SETTING: Three Danish tertiary gynecological oncology centers. POPULATION: A total of 352 patients with endometrial cancer and atypical endometrial hyperplasia consecutively referred between 1 September 2009 and 1 January 2012. METHODS: Preoperative blood samples were obtained from all patients. Biomarker levels were correlated with pathological characteristics of hysterectomy specimens. MAIN OUTCOME MEASURES: FIGO stage, depth of myometrial invasion, cervical involvement, lymph node metastases, and histological type and grade of tumor. RESULTS: We found that both HE4 and CA125 were significantly positively correlated with histological grade (HE4: p = 0.002 and CA125: p = 0.027), lymph node metastases (HE4: p = 0.013 and CA125: p < 0.0001), myometrial invasion (p < 0.0001) and cervical involvement (p < 0.0001). Furthermore, a significant increase was found with increasing FIGO stage for both markers (p < 0.0001). In a combined index including age, the diagnostic value increases. Area under the receiver operating characteristics curves were higher for the index compared with the markers individually for all our endpoints. The calculated plots for the combined index may assist gynecologists in predicting the risk of deep myometrial invasion, cervical involvement and lymph node metastases. The analyses emphasize that the combined markers should be used in the prediction of prognostic factors. CONCLUSION: This study confirmed that the markers are significantly elevated in patients with prognostic high-risk factors and may, therefore, be used as an additional tool in combination with imaging and clinical information when planning the treatment of endometrial cancer patients.

Assessment of hepatocyte growth factor in ovarian cancer mortality.

BACKGROUND: Invasive ovarian cancer is a significant cause of gynecologic cancer mortality. METHODS: We examined whether this mortality was associated with inherited variation in approximately 170 candidate genes/regions [993 single-nucleotide polymorphisms (SNPs)] in a multistage analysis based initially on 312 Mayo Clinic cases (172 deaths). Additional analyses used The Cancer Genome Atlas (TCGA; 127 cases, 62 deaths). For the most compelling gene, we immunostained Mayo Clinic tissue microarrays (TMA, 326 cases) and conducted consortium-based SNP replication analysis (2,560 cases, 1,046 deaths). RESULTS: The strongest initial mortality association was in HGF (hepatocyte growth factor) at rs1800793 (HR = 1.7, 95% CI = 1.3-2.2, P = 2.0 × 10(-5)) and with overall variation in HGF (gene-level test, P = 3.7 × 10(-4)). Analysis of TCGA data revealed consistent associations [e.g., rs5745709 (r(2) = 0.96 with rs1800793): TCGA HR = 2.4, CI = 1.4-4.1, P = 2.2 × 10(-3); Mayo Clinic + TCGA HR = 1.6, CI = 1.3-1.9, P = 7.0 × 10(-5)] and suggested genotype correlation with reduced HGF mRNA levels (P = 0.01). In Mayo Clinic TMAs, protein levels of HGF, its receptor MET (C-MET), and phospho-MET were not associated with genotype and did not serve as an intermediate phenotype; however, phospho-MET was associated with reduced mortality (P = 0.01) likely due to higher expression in early-stage disease. In eight additional ovarian cancer case series, HGF rs5745709 was not associated with mortality (HR = 1.0, CI = 0.9-1.1, P = 0.87). CONCLUSIONS: We conclude that although HGF signaling is critical to migration, invasion, and apoptosis, it is unlikely that HGF genetic variation plays a major role in ovarian cancer mortality. Furthermore, any minor role is not related to genetically-determined expression. IMPACT: Our study shows the utility of multiple data types and multiple data sets in observational studies.

Candidate gene analysis using imputed genotypes: cell cycle single-nucleotide polymorphisms and ovarian cancer risk.

Polymorphisms in genes critical to cell cycle control are outstanding candidates for association with ovarian cancer risk; numerous genes have been interrogated by multiple research groups using differing tagging single-nucleotide polymorphism (SNP) sets. To maximize information gleaned from existing genotype data, we conducted a combined analysis of five independent studies of invasive epithelial ovarian cancer. Up to 2,120 cases and 3,382 controls were genotyped in the course of two collaborations at a variety of SNPs in 11 cell cycle genes (CDKN2C, CDKN1A, CCND3, CCND1, CCND2, CDKN1B, CDK2, CDK4, RB1, CDKN2D, and CCNE1) and one gene region (CDKN2A-CDKN2B). Because of the semi-overlapping nature of the 123 assayed tagging SNPs, we performed multiple imputation based on fastPHASE using data from White non-Hispanic study participants and participants in the international HapMap Consortium and National Institute of Environmental Health Sciences SNPs Program. Logistic regression assuming a log-additive model was done on combined and imputed data. We observed strengthened signals in imputation-based analyses at several SNPs, particularly CDKN2A-CDKN2B rs3731239; CCND1 rs602652, rs3212879, rs649392, and rs3212891; CDK2 rs2069391, rs2069414, and rs17528736; and CCNE1 rs3218036. These results exemplify the utility of imputation in candidate gene studies and lend evidence to a role of cell cycle genes in ovarian cancer etiology, suggest a reduced set of SNPs to target in additional cases and controls.