Seongmin Kim

Concordance of Genomic Alterations in Ovarian Cancer Tissues and Circulating-Tumor DNA: A Pilot Study

High-grade serous ovarian carcinoma (HGSOC) is characterized by profound genomic instability and spatial heterogeneity. Liquid biopsy, utilizing circulating tumor DNA (ctDNA), offers a non-invasive approach to capture the comprehensive mutational landscape of the disease. This pilot study evaluated the concordance of genomic alterations between cell-free DNA (cfDNA) and matched tumor tissue in patients with HGSOC. Twelve patients with HGSOC undergoing primary cytoreductive surgery were enrolled. Using the Macrogen® Axen™ Cancer Panel 2 with unique molecular identifier (UMI) technology for error suppression, we achieved a theoretical limit of detection of ~0.36% VAF. The mean cfDNA concentration was 107.3 ng/mL, showing a significant positive correlation with FIGO stage (p = 0.016). While the sensitivity of cfDNA to detect tissue-confirmed mutations was 57.6%, the overall gene-level concordance was 95.3%, largely driven by negative agreement in wild-type genes. Liquid biopsy revealed a significantly broader mutational spectrum (mean 9.67 alterations/patient) compared to tissue (5.50/patient). Crucially, concordant mutations exhibited high variant allele frequencies (VAFs) (mean 41.4%), whereas plasma-unique discordant mutations showed significantly lower VAFs (mean 7.31%, p < 0.001). These preliminary findings suggest that while tissue biopsy likely reflects the dominant clonal population, liquid biopsy may serve as a potential molecular mirror, capturing subclonal variants from spatially distinct metastatic sites and hypoxic niches.

Fertility-sparing treatments for patients with endometrial cancer: A comprehensive review

Endometrial cancer (EC) in young women is relatively likely to be early-stage, low-grade, and without risk factors. Fertility-sparing treatment with progestin is a potential primary approach for certain patients. However, several factors should be considered according to available guidelines. The potential indication for fertility-sparing treatment in patients with EC, as recommended by various societies of gynecologic oncology, includes young women with grade 1 endometrioid adenocarcinoma confined to the endometrium. Magnetic resonance imaging should be performed to rule out myometrial invasion and extrauterine disease before initiating fertility-sparing treatment. Other imaging modalities may also be used to exclude extrauterine disease. Various fertility-sparing therapies exist, the most common of which is high-dose oral progestin. After initiating fertility-sparing treatment, pathological re-evaluation of the endometrium at 3 to 6 months is recommended. The optimal duration of fertility-sparing treatment is up to 15 months, but guidelines recommend continuing progestin therapy until attempting conception. Ovarian stimulation drugs used for pregnancy are considered safe after a complete response is achieved. Hysterectomy is recommended after childbearing, while oophorectomy is not mandatory for young women. Close surveillance should continue for women who do not wish to undergo surgery after childbirth. Based on existing evidence, fertility-preserving treatments have demonstrated effectiveness and do not appear to negatively impact prognosis. If a qualified patient expresses a strong desire for fertility preservation despite the potential for recurrence, the physician should consider fertility-sparing treatment while maintaining vigilant monitoring.

Learning curve for sentinel lymph node mapping in gynecologic malignancies

AbstractBackground and ObjectivesOnly a few studies have reported the learning curve for sentinel lymph node (SLN) detection in gynecologic malignancies. We investigated the learning curve for SLN detection during robot‐assisted laparoscopic surgery for endometrial and cervical carcinomas.MethodsThis retrospective analysis included patients with stage IA to IIA1 cervical cancer or stage I to III endometrial cancer who underwent SLN mapping using indocyanine green during robot‐assisted laparoscopic surgery performed by a single surgeon. Learning curves were analyzed in consecutive cases using SLN detection rates and the cumulative sum (CUSUM) method.ResultsSLN mapping was achieved in 81.25% (65/80), 77.50% (62/80), and 66.25% (53/80) of the cases involving the right, left, and simultaneous bilateral pelvic areas, respectively. Learning curve analysis based on the cumulative detection rate showed initial fluctuations followed by stabilization; the time required for proficiency was discordant among the LN regions. However, the CUSUM method showed proficient mapping of the right, left, and bilateral SLNs after 27 to 28 cases.ConclusionAt least 27 cases were required for SLN mapping proficiency in gynecologic cancer; the learning period could influence the surgical quality. Further studies are warranted to confirm the impact of this learning curve on disease outcomes.

Learning curve could affect oncologic outcome of minimally invasive radical hysterectomy for cervical cancer

Recent prospective studies have shown poorer oncologic outcomes following minimally invasive surgery, which has led many surgeons to deeply inspect their practices. We reviewed our experience and evaluated the results of radical hysterectomy in patients with early stage cervical cancer. This retrospective study included patients with early stage cervical cancer (Ia1 - IIa1) who were treated with radical hysterectomy from May 2006 to Dec 2016. Patients were divided into three groups according to the surgical approach: radical abdominal hysterectomy (RAH), laparoscopic radical hysterectomy (LRH), and robot-assisted radical hysterectomy (RRH). Learning curves of each type of surgery were obtained using the cumulative sum method. Survival rates were compared using Kaplan-Meier curves. To analyze the learning curve of a single surgeon, 89 patients were selected from the whole population. Learning curves of each group showed two distinct phases. The minimum number of cases required to achieve surgical improvement were 16 in RAH, 13 in LRH, and 21 in RRH. Progression-free survival (PFS) and overall survival did not vary between RAH and minimally invasive surgery (MIS) (p = .828 and p = .757, respectively). However, when stratified by the phases of the learning curves, patients included in the early phase of MIS showed a poorer PFS (p = .014). Surgical proficiency could significantly affect the oncologic outcome in MIS. A prospective study regarding sufficient surgical competence is necessary for elaborate analysis of the feasibility of minimally invasive radical hysterectomy.

Comparing efficacy of high-dose rate brachytherapy versus helical tomotherapy in the treatment of cervical cancer

Boost radiation using brachytherapy (BT) is a standard treatment for local disease control in concomitant chemoradiation therapy (CCRT) for advanced cervical cancer. However, it is associated with gastrointestinal and genitourinary complications. Hence, this study investigates the feasibility of helical tomotherapy (HT) as an alternative to BT. Medical records of patients who underwent CCRT between 2000 and 2017 at a single institution were retrospectively reviewed. Patients with stage IIB-IVA cancers were selected based on the 2009 criteria of The International Federation of Gynaecology and Obstetrics. External beam radiation combined with chemotherapy was followed by either BT or HT. The propensity score matching of both groups was calculated using logistic regression analysis. Disease outcomes and treatment-related adverse events were compared between the 2 groups. The matched population included 70 BT patients and 35 HT patients. The 5-year progression-free survival rates for BT and HT were 72.6% and 72.5%, respectively (p=0.721). There was no difference in the overall survival rate between the two groups (p=0.203). The presence of acute and chronic gastrointestinal complications was also similar between the groups (p=0.460 and p=0.563, respectively). The chronic genitourinary toxicities were also comparable (p=0.105). HT boost treatment showed comparable disease outcomes with those observed with conventional BT in patients with advanced cervical cancer. HT could be a complementary boost protocol as a single modality or hybrid with BT in selected patients. Further studies with longer follow-up periods are warranted to confirm long-term outcomes.