Sokbom Kang

Major clinical research advances in gynecologic cancer in 2013.

In 2013, 10 topics were selected for major clinical research advances in gynecologic oncology; these included three topics regarding cervical cancer, three regarding ovarian cancer, two regarding endometrial cancer, and one each regarding breast cancer and radiation oncology. For cervical cancer, bevacizumab was first demonstrated to exhibit outstanding clinical efficacy in a recurrent, metastatic setting. Regarding cervical cancer screening, visual inspections with acetic acid in low-resource settings, p16/Ki-67 double staining, and the follow-up results of four randomized controlled trials of human papillomavirus-based screening methods were reviewed. Laparoscopic para-aortic lymphadenectomy before chemoradiation for locally advanced cervical cancer was the final topic for cervical cancer. Regarding front-line ovarian cancer therapies, dose-dense paclitaxel and carboplatin, intraperitoneal chemotherapy, and other targeted agents administered according to combination or maintenance schedules were discussed. Regarding recurrent ovarian cancer treatment, cediranib, olaparib, and farletuzumab were discussed for platinum-sensitive disease. The final overall survival data associated with a combination of bevacizumab and chemotherapy for platinum-resistant disease were briefly summarized. For endometrial cancer, the potential clinical efficacy of metformin, an antidiabetic drug, in obese patients was followed by integrated genomic analyses from the Cancer Genome Atlas Research Network. For breast cancer, three remarkable advances were reviewed: the long-term effects of continued adjuvant tamoxifen for 10 years, the effects of 2-year versus 1-year adjuvant trastuzumab for human epidermal growth factor receptor 2-positive disease, and the approval of pertuzumab in a neoadjuvant setting with a pathologic complete response as the surrogate endpoint. Finally, the recent large studies of intensity-modulated radiotherapy for gynecologic cancer were briefly summarized.

Sentinel lymph node biopsy in endometrial cancer: Meta-analysis of 26 studies

OBJECTIVE The validity of the sentinel lymph node (SLN) procedure for the assessment of nodal status in patients with endometrial cancer is unclear. We aimed to assess the diagnostic performance of this procedure. METHODS We searched the PubMed and Embase databases for studies published before June 1, 2011. Eligible studies had a sample size of at least 10 patients, and reported the detection rate and/or sensitivity of the SLN biopsy. RESULTS We identified 26 eligible studies, which included 1101 SLN procedures. The overall weighted-mean number of harvested SLNs was 2.6. The detection rate and the sensitivity were 78% (95% confidence interval [CI]=73%-84%) and 93% (95% CI=87%-100%), respectively. Significant between-study heterogeneity was observed in the analysis of the detection rate (I-squared statistic, 80%). The use of pericervical injection was correlated with the increase of the detection rate (P=0.031). The hysteroscopic injection technique was associated with the decrease of the detection rate (P=0.045) and the subserosal injection technique was associated with the decrease of the sensitivity (P=0.049), if they were not combined with other injection techniques. For the detection rate, significant small-study effects were noted (P<0.001). CONCLUSIONS Although SLN biopsy has shown good diagnostic performance in endometrial cancer, such performance should be interpreted with caution because of significant small study effects. Current evidence is not yet sufficient to establish the true performance of SLN biopsy in endometrial cancer.

Anti-apoptotic protein TCTP controls the stability of the tumor suppressor p53

MINT‐8057126: p53 (uniprotkb:P04637) physically interacts (MI:0915) with TCTP (uniprotkb:P13693) by anti tag coimmunoprecipitation (MI:0007) MINT‐8057160: TCTP (uniprotkb:P13693) physically interacts (MI:0915) with p53 (uniprotkb:P04637) by two hybrid (MI:0018)

Additional value of MR/PET fusion compared with PET/CT in the detection of lymph node metastases in cervical cancer patients

We evaluated the additional diagnostic value of magnetic resonance/positron emission tomography (MR/PET) fusion in the detection of metastatic lymph nodes in cervical cancer patients. Seventy nine patients with FIGO stage IB-IVA cervical cancer who had undergone both magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) before lymphadenectomy were included in this study. Image analysis was first performed with PET/CT images only. A second analysis was then performed with MR/PET fused images that focused on the additional information obtained from the MR images. Lymphadenectomy involved removing all visible lymph nodes in the surgical field. To enable nodal group-specific comparisons, para-aortic and pelvic lymph nodes were divided into seven nodal groups: para-aortic, both common iliac, both external iliac and both internal iliac/obturator areas. Histopathological evaluation of lymph nodes has been the diagnostic standard. The value of the additional information from the MR images was evaluated by means of receiver operating characteristic (ROC) analysis. Fused MR/PET rendered readers to detect six more metastatic lymph node groups. The sensitivity and specificity of PET/CT and fused MR/PET were 44.1%, 93.9% and 54.2%, 92.7% respectively. The ROC analysis demonstrated a higher diagnostic performance of fused MR/PET compared to PET/CT alone for detecting lymph node metastases (p=0.0259). The findings of this study demonstrate the additional diagnostic value of fused MR/PET images compared with PET/CT in the detection of metastatic lymph nodes in patients with uterine cervical cancer.

Comparison of DNA hypermethylation patterns in different types of uterine cancer: Cervical squamous cell carcinoma, cervical adenocarcinoma and endometrial adenocarcinoma

The incidence of cervical adenocarcinoma (CA) is rising, whereas the incidence of cervical squamous cell carcinoma (CSCC) continues to decrease. However, it is still unclear whether different molecular characteristics underlie these 2 types of cervical carcinoma. To better understand the epigenetic characteristics of cervical carcinoma, we investigated the DNA promoter hypermethylation profiles in CA and CSCC. In addition, we investigated whether DNA hypermethylation patterns might be used for the molecular diagnosis of CA and endometrial adenocarcinoma (EA). Using the bisulfite‐modification technique and methylation‐specific PCR, we examined the aberrant promoter hypermethylation patterns of 9 tumor suppressor genes (APC, DAPK, CDH1, HLTF, hMLH1, p16, RASSF1A, THBS1 and TIMP3) in 62 CSCCs, 30 CAs and 21 EAs. After Bonferroni correction adjustment (statistically significant at p < 0.0055), we found that the aberrant hypermethylations of CDH1 and DAPK were more frequent in CSCCs than in CAs (80.6% vs. 43.3%, p = 0.001; 77.4% vs. 46.7%, p = 0.005), whereas HLTF and TIMP3 were more frequently methylated in CAs (3.2% vs. 43.3%, p < 0.001; 8.1% vs. 53.3%, p = 0.001). The hypermethylations of RASSF1A and APC were more frequent in CAs than in CSCCs, but this was not significant (9.7% vs. 33.3%, p = 0.008; and 14.5% vs. 40.0%, respectively, p = 0.009). In addition, RASSF1A hypermethylation was significantly more frequent in EAs than in CAs (81.0% vs. 33.3%, p = 0.001). In conclusion, the existence of these unique methylation patterns in these cancers suggests that their tumorigenesis may involve different epigenetic mechanisms.

Incidence of cervical, endometrial, and ovarian cancer in Korea, 1999-2010

Objective To investigate the recent incidence of and trends in cervical, endometrial, and ovarian cancer in Korean females. Methods Data from the Korea Central Cancer Registry between 1999 and 2010 were analyzed. Age-standardized rates (ASRs) and annual percent changes (APCs) were calculated. Results The absolute incidence rates of the three major gynecologic cancers increased: 6,394 in 1999 to 7,454 in 2010. The ASR for gynecologic cancer was 23.7 per 100,000 in 1999 and decreased to 21.0 in 2010 (APC, -1.1%; 95% confidence interval [CI], -1.53 to -0.70) due to a definitive decrease in the incidence of cervical cancer (APC, -4.3%). Endometrial cancer has been definitively increasing (APC, 6.9% during 1999-2010), especially in females <30 years old (APC, 11.2%) and in females ≥80 years old (APC, 9.5%). The incidence of ovarian cancer is increasing gradually (APC, 1.5%). Conclusion ASRs and APC for gynecologic cancers overall are decreasing due to the decrease in the incidence of cervical cancer. However, the incidence of endometrial and ovarian cancer has been increasing.

Association between excision repair cross-complementation group 1 polymorphism and clinical outcome of platinum-based chemotherapy in patients with epithelial ovarian cancer

ERCC1 is a DNA repair gene and has been associated with resistance to DNA damaging agents. In this study we hypothesized that a polymorphism of ERCC1 Asn118Asn (C→T) might affect the platinum-resistance of epithelial ovarian cancer patients to platinum-taxane chemotherapy administered postoperatively. Using the SNapShot assay, we assessed this polymorphism in ERCC1 in 60 ovarian cancer patients. Platinum-resistance was defined as progression on platinum-based chemotherapy or recurrence within 6 months of completing therapy. Although not significant, platinum-resistance was less frequently observed in patients with the C/T+T/T genotype (P=0.064). Multivariate analysis showed that the C/T+T/T genotypes constituted an independent predictive factor of reduced risk of platinum-resistance in ovarian cancer (odds ratio 0.17, 95% confidence interval 0.04-0.74, P=0.018, Fishers exact test). No significant correlation was observed between overall survival and the ERCC1 polymorphism. Our results suggest that genotyping of the ERCC1 polymorphism Asn118Asn may be useful for predicting the platinum-resistance of epithelial ovarian cancer patients. However, these findings require prospective confirmation.

MRI for Pretreatment Lymph Node Staging in Uterine Cervical Cancer

OBJECTIVE The purpose of this article is to assess the accuracy of MRI in detecting pelvic and paraaortic lymph node metastasis from uterine cervical cancer using various imaging criteria. CONCLUSION Although MRI analysis resulted in relatively low sensitivity, size and margin (spiculated or lobulated) were useful criteria for predicting lymph node metastasis from cervical cancer.

Preoperative Identification of a Low-Risk Group for Lymph Node Metastasis in Endometrial Cancer: A Korean Gynecologic Oncology Group Study

PURPOSE The aim of this study was to develop a preoperative risk prediction model for lymph node metastasis in patients with endometrial cancer and to identify a low-risk group before surgery. PATIENTS AND METHODS The medical records of 360 patients with endometrial cancer who underwent surgical staging were collected from four institutions and were retrospectively reviewed. By using serum CA-125 levels, preoperative biopsy data, and magnetic resonance imaging (MRI) data, a multivariate logistic model was created. Patients whose predicted probability was less than 4% were defined as low risk. The developed model was externally validated in 180 patients from two independent institutions. RESULTS Serum CA-125 levels and three MRI parameters (deep myometrial invasion, lymph node enlargement, and extension beyond uterine corpus) were found to be independent risk factors for nodal metastasis. The model classified 53% of patients as part of a low-risk group, and the false negative rate was 1.7%. In the validation cohort, the model classified 43% of patients as low-risk, and the false negative rate was 1.4%. The model showed good discrimination (area under the receiver operator characteristic curve = 0.85) and was calibrated well. The negative likelihood ratio of our low-risk criteria was 0.11 (95% CI, 0.04 to 0.29), which was equivalent to the false-negative rate of 1.3% (95% CI, 0.5% to 3.3%) at the assumed prevalence of nodal metastasis of 10%. CONCLUSION Using serum CA-125 and MRI as criteria resulted in the accurate identification of a low-risk group for lymph node metastasis among patients with endometrial cancer.

Thioridazine induces apoptosis by targeting the PI3K/Akt/mTOR pathway in cervical and endometrial cancer cells

Recently, thioridazine (10-[2-(1-methyl-2-piperidyl) ethyl]-2-methylthiophenothiazine), a well-known anti-psychotic agent was found to have anti-cancer activity in cancer cells. However, the molecular mechanism of the agent in cellular signal pathways has not been well defined. Thioridazine significantly increased early- and late-stage apoptotic fraction in cervical and endometrial cancer cells, suggesting that suppression of cell growth by thioridazine was due to the induction of apoptosis. Cell cycle analysis indicated thioridazine induced the down-regulation of cyclin D1, cyclin A and CDK4, and the induction of p21 and p27, a cyclin-dependent kinase inhibitor. Additionally, we compared the influence of thioridazine with cisplatin used as a control, and similar patterns between the two drugs were observed in cervical and endometrial cancer cell lines. Furthermore, as expected, thioridazine successfully inhibited phosphorylation of Akt, phosphorylation of 4E-BP1 and phosphorylation of p70S6K, which is one of the best characterized targets of the mTOR complex cascade. These results suggest that thioridazine effectively suppresses tumor growth activity by targeting the PI3K/Akt/mTOR/p70S6K signaling pathway.