Sosuke Adachi

Serum leptin-adiponectin ratio and endometrial cancer risk in postmenopausal female subjects

OBJECTIVE Obesity is a well-known risk factor for the development of endometrial cancer. Elevated endogenous estrogen and insulin resistance are recognized to be major factors that link obesity and cancer development. However, there is increasing evidence that the adipokines adiponectin and leptin, which are directly produced in adipose tissue, impact several obesity-related cancers. The purpose of the current study was to investigate the relationships of the concentration of leptin, adiponectin, and the leptin-to-adiponectin ratio (L/A ratio) with the endometrial cancer risk in postmenopausal female subjects. METHODS A case-control study was performed in 146 postmenopausal female subjects with endometrial cancer and 150 control subjects with no history of cancer. The serum levels of the adipokines leptin and adiponectin were measured, and the associations of these adipokines and the L/A ratios with the endometrial cancer risk were analyzed. RESULTS The leptin levels and the L/A ratios were significantly higher in the incident cases of endometrial cancer (8.2 ± 0.5, 2.05 ± 1.08 ng/ml) than in the controls subjects (4.5 ± 0.5, 0.98 ± 0.18, P<0.0001), whereas the adiponectin levels were significantly lower in the incident cases (6.2 ± 0.4 μg/ml) than in the control subjects (9.0 ± 0.4 μg/ml, P<0.0001). For the incident cases, the serum levels of the adipokines were significantly correlated with the patient body mass index (BMI) (P<0.001 for leptin, P<0.05 for adiponectin), and the leptin levels and the L/A ratios were significantly correlated with the homeostasis model assessment ratio (HOMA-R) and the fasting insulin levels (P<.001). Higher L/A ratios were found to be significantly associated with an increased risk of endometrial cancer [OR (95% CI) for the top vs. the bottom tertile of the L/A ratio was 6.0 (3.2-11.9), P-value<0.0001]. Moreover, the ORs of the L/A ratios were higher than those of leptin or adiponectin alone. The association of the L/A ratios with endometrial cancer risk remained after adjusting for the obesity indices, hypertension, and presence of diabetes mellitus. CONCLUSION The present results suggested that the L/A ratio was independently associated with an increased risk for endometrial cancer development. Additional research will elucidate the molecular mechanisms by which these adipokines are associated with the development of endometrial cancer.

Meta-analysis of genome-wide association scans for genetic susceptibility to endometriosis in Japanese population

To identify susceptibility genes for endometriosis in Japanese women, genome-wide association (GWA) analysis was performed using two case–control cohorts genotyped with the Affymetrix Mapping 500K Array or Genome-Wide Human SNP Array 6.0. In each of the two array cohorts, stringent quality control (QC) filters were applied to newly obtained genotype data, together with previously analyzed data from the Japanese Integrated Database Project. After QC-based filtering of samples and single nucleotide polymorphisms (SNPs) in each cohort, 282 838 SNPs in both genotyping platforms were tested for association with endometriosis using a meta-analysis of the two GWA studies with 696 patients with endometriosis and 825 controls. The meta-analysis revealed that a common susceptibility locus conferring a large effect on the disease risk was unlikely. On the other hand, an excess of SNPs with P-values <10−4 (36 vs 28 SNPs expected by chance) was observed in the meta-analysis. Of note, four of the top five SNPs with P-values <10−5 were located in and around IL1A (interleukin 1α), which might be a functional candidate gene for endometriosis. Further studies with larger case–control cohorts will be necessary to elucidate the genetic risk factors.

Germline Copy Number Variations in BRCA1- Associated Ovarian Cancer Patients

We investigated characteristics of germline copy number variations (CNV) in BRCA1‐associated ovarian cancer patients by comparing them to CNVs present in sporadic ovarian cancer patients. Germline CNVs in 51 BRCA1‐associated, 33 sporadic ovarian cancer patients, and 47 healthy women were analyzed by both signal intensity and genotyping data using the Affymetrix Genome‐Wide Human SNP Array 6.0. The total number of CNVs per genome was greater in the sporadic group (median 26, range 12–34) than in the BRCA1 group (median 21, range 11–35; post hoc P < 0.05) or normal group (median 20, range 7–32; post hoc P < 0.05). While the number of amplifications per genome was higher in the sporadic group (median 13, range 7–26) than in the BRCA1 group (median 8, range 3–23; post hoc P < 0.001), the number of deletions per genome was higher in the BRCA1 group (median 12, range 6–24) than in the sporadic group (median 9, range 3–17; post hoc P < 0.01). In addition, 31 previously unknown CNV regions were present specifically in the BRCA1 group. When we performed pathway analysis on the 241 overlapping genes mapped to these novel CNV regions, the ‘purine metabolism’ and ‘14‐3‐3‐mediated signaling’ pathways were over‐represented (Fishers exact test, P < 0.01). Our study shows that there are qualitative differences in genomic CNV profiles between BRCA1‐associated and sporadic ovarian cancer patients. Further studies are necessary to clarify the significance of the genomic CNV profile unique to BRCA1‐associated ovarian cancer patients.

Identification of Receptor Tyrosine Kinase, Discoidin Domain Receptor 1 (DDR1), as a Potential Biomarker for Serous Ovarian Cancer

Ovarian cancer, one of the most common gynecological malignancies, has an aggressive phenotype. It is necessary to develop novel and more effective treatment strategies against advanced disease. Protein tyrosine kinases (PTKs) play an important role in the signal transduction pathways involved in tumorigenesis, and represent potential targets for anticancer therapies. In this study, we performed cDNA subtraction following polymerase chain reaction (PCR) using degenerate oligonucleotide primers to identify specifically overexpressed PTKs in ovarian cancer. Three PTKs, janus kinase 1, insulin-like growth factor 1 receptor, and discoidin domain receptor 1 (DDR1), were identified and only DDR1 was overexpressed in all ovarian cancer tissues examined for the validation by quantitative real-time PCR. The DDR1 protein was expressed in 63% (42/67) of serous ovarian cancer tissue, whereas it was undetectable in normal ovarian surface epithelium. DDR1 was expressed significantly more frequently in high-grade (79%) and advanced stage (77%) tumors compared to low-grade (50%) and early stage (43%) tumors. The expression of the DDR1 protein significantly correlated with poor disease-free survival. Although its functional role and clinical utility remain to be examined in future studies, our results suggest that the expression of DDR1 may serve as both a potential biomarker and a molecular target for advanced ovarian cancer.

Significance of histologic pattern of carcinoma and sarcoma components on survival outcomes of uterine carcinosarcoma

BACKGROUND To examine the effect of the histology of carcinoma and sarcoma components on survival outcome of uterine carcinosarcoma. PATIENTS AND METHODS A multicenter retrospective study was conducted to examine uterine carcinosarcoma cases that underwent primary surgical staging. Archived slides were examined and histologic patterns were grouped based on carcinoma (low-grade versus high-grade) and sarcoma (homologous versus heterologous) components, correlating to clinico-pathological demographics and outcomes. RESULTS Among 1192 cases identified, 906 cases were evaluated for histologic patterns (carcinoma/sarcoma) with high-grade/homologous (40.8%) being the most common type followed by high-grade/heterologous (30.9%), low-grade/homologous (18.0%), and low-grade/heterologous (10.3%). On multivariate analysis, high-grade/heterologous (5-year rate, 34.0%, P = 0.024) and high-grade/homologous (45.8%, P = 0.017) but not low-grade/heterologous (50.6%, P = 0.089) were independently associated with decreased progression-free survival (PFS) compared with low-grade/homologous (60.3%). In addition, older age, residual disease at surgery, large tumor, sarcoma dominance, deep myometrial invasion, lymphovascular space invasion, and advanced-stage disease were independently associated with decreased PFS (all, P < 0.01). Both postoperative chemotherapy (5-year rates, 48.6% versus 39.0%, P < 0.001) and radiotherapy (50.1% versus 44.1%, P = 0.007) were significantly associated with improved PFS in univariate analysis. However, on multivariate analysis, only postoperative chemotherapy remained an independent predictor for improved PFS [hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.27-0.43, P < 0.001]. On univariate analysis, significant treatment benefits for PFS were seen with ifosfamide for low-grade carcinoma (82.0% versus 49.8%, P = 0.001), platinum for high-grade carcinoma (46.9% versus 32.4%, P = 0.034) and homologous sarcoma (53.1% versus 38.2%, P = 0.017), and anthracycline for heterologous sarcoma (66.2% versus 39.3%, P = 0.005). Conversely, platinum, taxane, and anthracycline for low-grade carcinoma, and anthracycline for homologous sarcoma had no effect on PFS compared with non-chemotherapy group (all, P > 0.05). On multivariate analysis, ifosfamide for low-grade/homologous (HR 0.21, 95% CI 0.07-0.63, P = 0.005), platinum for high-grade/homologous (HR 0.36, 95% CI 0.22-0.60, P < 0.001), and anthracycline for high-grade/heterologous (HR 0.30, 95% CI 0.14-0.62, P = 0.001) remained independent predictors for improved PFS. Analyses of 1096 metastatic sites showed that carcinoma components tended to spread lymphatically, while sarcoma components tended to spread loco-regionally (P < 0.001). CONCLUSION Characterization of histologic pattern provides valuable information in the management of uterine carcinosarcoma.

A nonsynonymous variant of IL1A is associated with endometriosis in Japanese population.

Our previous genome-wide association study has demonstrated that single-nucleotide polymorphisms (SNPs) located in intronic and downstream regions of IL1A (interleukin 1α) were associated with the risk of endometriosis. These SNPs on the genome-wide association study platform could be only surrogates for the true causal variant. Thus, we resequenced all the exons of IL1A in 377 patients with endometriosis and 457 healthy controls. We detected seven rare variants (minor allele frequency <0.01) and four common variants. All the rare variants were not associated with endometriosis. The four common variants (rs17561, rs1304037, rs2856836 and rs3783553) in IL1A were significantly associated with endometriosis (P=0.0024, 0.0024, 0.0014 and 0.0061, respectively). All the four SNPs were within a linkage disequilibrium block. Among them, only rs17561 was nonsynonymous (p.A114S), which has been reported to be associated with susceptibility to ovarian cancer. Taken together, we examined association between rs17561 and endometriosis in an independent validation data set (524 patients and 533 healthy controls) replicating significant association (P=4.0 × 10−5; odds ratio (OR), 1.91; 95% confidence interval (CI), 1.41–2.61). Meta-analysis by combining results from the two stages strengthened the evidence of association (P=2.5 × 10−7; OR, 1.90; 95% CI, 1.49–2.43). Our findings demonstrated that the nonsynonymous variant of IL1A might confer genetic susceptibility to endometriosis in Japanese population.

Association of Low-Dose Aspirin and Survival of Women With Endometrial Cancer.

OBJECTIVE: To examine the survival outcomes in women with endometrial cancer who were taking low-dose aspirin (81–100 mg/d). METHODS: A multicenter retrospective study was conducted examining patients with stage I–IV endometrial cancer who underwent hysterectomy-based surgical staging between January 2000 and December 2013 (N=1,687). Patient demographics, medical comorbidities, medication types, tumor characteristics, and treatment patterns were correlated to survival outcomes. A Cox proportional hazard regression model was used to estimate adjusted hazard ratio for disease-free and disease-specific overall survival. RESULTS: One hundred fifty-eight patients (9.4%, 95% confidence interval [CI] 8.8–11.9) were taking low-dose aspirin. Median follow-up time for the study cohort was 31.5 months. One hundred twenty-seven patients (7.5%) died of endometrial cancer. Low-dose aspirin use was significantly correlated with concurrent obesity, hypertension, diabetes mellitus, and hypercholesterolemia (all P<.001). Low-dose aspirin users were more likely to take other antihypertensive, antiglycemic, and anticholesterol agents (all P<.05). Low-dose aspirin use was not associated with histologic subtype, tumor grade, nodal metastasis, or cancer stage (all P>.05). On multivariable analysis, low-dose aspirin use remained an independent prognostic factor associated with an improved 5-year disease-free survival rate (90.6% compared with 80.9%, adjusted hazard ratio 0.46, 95% CI 0.25–0.86, P=.014) and disease-specific overall survival rate (96.4% compared with 87.3%, adjusted hazard ratio 0.23, 95% CI 0.08–0.64, P=.005). The increased survival effect noted with low-dose aspirin use was greatest in patients whose age was younger than 60 years (5-year disease-free survival rates, 93.9% compared with 84.0%, P=.013), body mass index was 30 or greater (92.2% compared with 81.4%, P=.027), who had type I cancer (96.5% compared with 88.6%, P=.029), and who received postoperative whole pelvic radiotherapy (88.2% compared with 61.5%, P=.014). These four factors remained significant for disease-specific overall survival (all P<.05). CONCLUSION: Our results suggest that low-dose aspirin use is associated with improved survival outcomes in women with endometrial cancer, especially in those who are young, obese, with low-grade disease, and who receive postoperative radiotherapy.

Impact of adjuvant therapy on recurrence patterns in stage I uterine carcinosarcoma

BACKGROUND To examine recurrence patterns in women with stage I uterine carcinosarcoma (UCS) stratified by adjuvant therapy pattern. METHODS We examined 443 cases of stage I UCS derived from a retrospective cohort of 1192 UCS cases from 26 institutions. Adjuvant therapy patterns after primary hysterectomy-based surgery were correlated to recurrence patterns. RESULTS The most common adjuvant therapy was chemotherapy alone (41.5%) followed by chemotherapy/radiotherapy (15.8%) and radiotherapy alone (8.4%). Distant-recurrence was the most common recurrence pattern (5-year cumulative rate, 28.1%) followed by local-recurrence (13.3%). On multivariate analysis, chemotherapy but not radiotherapy remained an independent prognostic factor for decreased risk of local-recurrence (5-year cumulative rates 8.7% versus 19.8%, adjusted-hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.25-0.83, P=0.01) and distant-recurrence (21.2% versus 38.0%, adjusted-HR 0.41, 95%CI 0.27-0.62, P<0.001). The chemotherapy/radiotherapy group had a lower 5-year cumulative local-recurrence rate compared to the chemotherapy alone group but it did not reach statistical significance (5.1% versus 10.1%, adjusted-HR 0.46, 95%CI 0.13-1.58, P=0.22). Radiotherapy significantly decreased local-recurrence when tumors had high-grade carcinoma, sarcoma component dominance, and deep myometrial tumor invasion (all, P<0.05); and combining radiotherapy with chemotherapy was significantly associated with decreased local-recurrence compared to chemotherapy alone in the presence of multiple risk factors (5-year cumulative rates, 2.5% versus 21.8%, HR 0.12, 95%CI 0.02-0.90; P=0.013) but not in none/single factor (P=0.36). CONCLUSION Adjuvant chemotherapy appears to be effective to control both local- and distant-recurrences in stage I UCS; adding radiotherapy to chemotherapy may be effective to control local-recurrence when the tumor exhibits multiple risk factors.

Possible involvement of the E-cadherin gene in genetic susceptibility to endometriosis

BACKGROUND Endometriotic cells display invasive characteristics, despite their benign histological appearance. Recently, the epithelial-mesenchymal transition, in which epithelial cells acquire mesenchymal and migratory properties, has attracted attention as a mechanism of tumor invasion. We aimed to investigate the association between endometriosis and polymorphisms of the E-cadherin gene, a central player in the epithelial-mesenchymal transition, in Japanese women. METHODS Twelve single-nucleotide polymorphisms (SNPs) in the E-cadherin gene were identified by real-time polymerase chain reaction using a TaqMan assay in 511 women with endometriosis (the majority in Stages III and IV) and 498 healthy controls. RESULTS Allele frequency analysis indicated that there was a marginally higher frequency of the rs4783689 C allele in women with endometriosis compared with controls (corrected P = 0.007; odds ratio = 1.37; 95% confidence interval, 1.14-1.64). No significant associations with endometriosis were found for the other 11 SNPs. CONCLUSIONS Although this study was limited by sample size, the E-cadherin gene polymorphism rs4783689 was marginally associated with endometriosis in the Japanese population, suggesting that E-cadherin might be involved in genetic susceptibility to endometriosis.

Tumor characteristics and survival outcomes of women with tamoxifen-related uterine carcinosarcoma

OBJECTIVE To examine tumor characteristics and survival outcome of women with uterine carcinosarcoma who had a history of tamoxifen use. METHODS This is a multicenter retrospective study examining stage I-IV uterine carcinosarcoma cases based on history of tamoxifen use. Patient demographics, tumor characteristics, treatment pattern, and survival outcomes were compared between tamoxifen users and non-users. RESULTS Sixty-six cases of tamoxifen-related uterine carcinosarcoma were compared to 1009 cases with no history of tamoxifen use. Tamoxifen users were more likely to be older (mean age, 69 versus 64, P<0.001) and had a past history of malignancy (100% versus 12.7%, P<0.001). Tamoxifen-related uterine carcinosarcoma was significantly associated with a higher proportion of stage IA disease (48.4% versus 29.9%) and a lower risk of stage IVB disease (7.8% versus 16.0%) compared to tamoxifen-unrelated carcinosarcoma (P=0.034). Deep myometrial tumor invasion was less common in uterine carcinosarcoma related to tamoxifen use (28.3% versus 48.8%, P=0.002). On univariate analysis, tamoxifen use was not associated with progression-free survival (5-year rates 44.5% versus 46.8%, P=0.48) and disease-specific survival (64.0% versus 59.1%, P=0.39). After adjusting for age, past history of malignancy, stage, residual disease status at surgery, and postoperative treatment patterns, tamoxifen use was not associated with progression-free survival (adjusted-hazard ratio 0.86, 95% confidence interval 0.50 to 1.50, P=0.60) and disease-specific survival (adjusted-hazard ratio 0.68, 95% confidence interval 0.36 to 1.29, P=0.24). CONCLUSION Our study suggests that tamoxifen-related uterine carcinosarcoma may have favorable tumor characteristics but have comparable stage-specific survival outcomes compared to tamoxifen-unrelated uterine carcinosarcoma.