Purpose: Considering the current lack of consensus on post–poly(adenosine diphosphate-ribose) polymerase inhibitor (PARPi) treatment strategies, this study aimed to evaluate the efficacy of subsequent therapy and compare the outcomes of regimes in patients with recurrent ovarian cancer after PARPi treatment. Materials and Methods: This multi-center retrospective cohort study analyzed data on patients diagnosed with ovarian cancer between January 2012 and June 2023 who had previously used PARPi after first- to fourth-line platinum-based chemotherapy. The primary endpoint was progression-free survival (PFS), which was the interval between recurrence after using PARPi and subsequent recurrence in the case of recurrence. Results: Of 318 patients, 147/318 (46.2%) recurred after the PARPi maintenance. Patients were categorized into groups based on subsequent therapy except non-treated (11/147, 7.5%): platinum-based chemotherapy (89/147, 60.5%), non-platinum-based chemotherapy (21/147, 14.3%), other treatments (26/147, 17.7%), and the median PFS (mPFS) for each group were 7.3, 4.8, and 11.4 months, respectively. Among the platinum-based chemotherapy group, the gemcitabine+carboplatin regimen demonstrated a longer mPFS (10.1 months) than the other regimens (6.6 months, p=0.019). In non-platinum-based chemotherapy, no statistically significant differences were observed among the regimens. And, in the other therapy group, where the proportion of patients with oligometastasis was as high as 88.5%, no significant differences were observed among the therapies, including other modalities. Conclusion In the subsequent chemotherapy of recurrent ovarian cancer after platinum-based chemotherapy and PARPi, the gemcitabine+carboplatin regimen demonstrated a potential to delay recurrence more effectively compared to other therapies.

Purpose: This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries. Methods: This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon. Results: Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%). Conclusion The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.

Purpose: This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries. Methods: This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon. Results: Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%). Conclusion The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.

Purpose: The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients. Materials and Methods: We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided. Results: From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient. Conclusion Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.

Purpose: This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries. Methods: This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon. Results: Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%). Conclusion The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.

Purpose: The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients. Materials and Methods: We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided. Results: From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient. Conclusion Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.

Purpose: The Korean Cancer Study Group (KCSG) is a nationwide cancer clinical trial group dedicated to advancing investigator-initiated trials (IITs) by conducting and supporting clinical trials. This study aims to review IITs conducted by KCSG and quantitatively evaluate the survival and financial benefits of IITs for patients. Materials and Methods: We reviewed IITs conducted by KCSG from 1998 to 2023, analyzing progression-free survival (PFS) and overall survival (OS) gains for participants. PFS and OS benefits were calculated as the difference in median survival times between the intervention and control groups, multiplied by the number of patients in the intervention group. Financial benefits were assessed based on the cost of investigational products provided. Results: From 1998 to 2023, KCSG conducted 310 IITs, with 133 completed and published. Of these, 21 were included in the survival analysis. The analysis revealed that 1,951 patients in the intervention groups gained a total of 2,558.4 months (213.2 years) of PFS and 2,501.6 months (208.5 years) of OS, with median gains of 1.31 months in PFS and 1.58 months in OS per patient. When analyzing only statistically significant results, PFS and OS gain per patients was 1.69 months and 3.02 months, respectively. Investigational drug cost analysis from six available IITs indicated that investigational products provided to 252 patients were valued at 10,400,077,294 won (approximately 8,046,481 US dollars), averaging about 41,270,148 won (approximately 31,930 US dollars) per patient. Conclusion Our findings, based on analysis of published research, suggest that IITs conducted by KCSG led to survival benefits for participants and, in some studies, may have provided financial benefits by providing investment drugs.

Purpose: This study aimed to evaluate the impact of declining surgical residency program enrollment on patient care and outcomes in colorectal cancer surgeries. Methods: This retrospective observational study included 676 patients (410 males; median age: 69 years) who underwent colorectal cancer surgery at Pusan National University Hospital between January 2018 and June 2024. Patients were divided into Group A (before December 31, 2023; with residents) and Group B (after January 1, 2024; without residents). All surgeries were performed by a single attending surgeon. Results: Preoperative variables were comparable between groups. Group A had more emergency and open surgeries, and a higher proportion of advanced-stage cancers. Overall complication rates were similar, but Group B had a longer hospital stay (9.72 days vs. 11.95 days). Specific complications such as anastomotic leakage and surgical site infections differed significantly. The overall number of surgical procedures declined markedly in 2024 compared to 2018 (77.1% vs. 49.9%). Conclusion The absence of residents did not increase overall complication rates but was associated with longer hospital stays and shifts in clinical practice. Greater reliance on attending surgeons contributed to more defensive decision-making and conservative patient management. Addressing these issues requires systemic reforms, including multidisciplinary collaboration and legal protections to improve surgical care.

Abdominal actinomycosis is a rare chronic infection caused by Actinomyces species that often mimics advanced intra-abdominal malignancies, making early diagnosis difficult. We report the case of an 82-year-old woman who presented with intermittent left abdominal pain and a palpable mass. Imaging revealed a large pericolic mass with suspected invasion of the stomach and abdominal wall, raising strong suspicion for colon cancer with regional lymph node involvement and possible peritoneal carcinomatosis. Core needle biopsy results suggested an inflammatory myofibroblastic tumor. Because malignancy could not be ruled out, surgical resection—comprising extended left hemicolectomy, gastric wedge resection, and abdominal wall excision—was performed. Histopathological examination demonstrated multiple abscesses containing gram-positive bacilli, consistent with actinomycosis. The patient received high-dose intravenous penicillin followed by prolonged oral therapy and remained symptomfree at the 1-year follow-up. This case underscores the diagnostic challenge of abdominopelvic actinomycosis, particularly when it involves multiple organs and radiologically mimics invasive malignancy. Clinicians should consider this rare entity in the differential diagnosis of tumorlike abdominal lesions, especially when radiologic or endoscopic findings are atypical, to avoid unnecessary aggressive interventions and ensure appropriate management.

Objectives: The main Brucella species causing human infections in the Republic of Korea is Brucella abortus, which uses cattle as its host. However, since 2014, Brucella melitensis, whichuses sheep and goats as hosts, has also been identified. This study investigated whether a shifthas occurred in the predominant species of Brucella pathogens. Methods: Brucellosis is a class 3 infectious disease requiring mandatory reporting and registration in the Korea Disease Control and Prevention Agency’s infectious disease surveillance system (http://is.kdca.go.kr). Cases from 2014 to 2023 were studied, and whole-genome sequencing analysis was conducted using BruMLSA21. Results: Out of 51 patients, males (45 patients, 88.2%) were predominantly affected. Twentyfive patients (49%) came from the livestock industry, and within the livestock sector group, the route of infection occurred exclusively through contact (25/25, 100%), whereas in other occupations, it was split between contact (9/26 patients, 34.6%) and ingestion (8/26 patients, 30.8%). Among the 31 patients who underwent Brucella culture tests, B. melitensis was found to be more prevalent than B. abortus (14 patients, 45.2% vs. 11 patients, 35.5%). In all cases where B. melitensis was isolated, the infections were of foreign origin, consistent with the results ofBruMLSA21. Conclusion Regular monitoring of the causative agent of brucellosis is necessary due to its varying host preferences and antibiotic resistance. Furthermore, given the increasing prevalence of B. melitensis worldwide, changes in dietary habits (e.g., increased lamb consumption), and the increase in foreign workers and Chinese immigrants, a multi-ministerial One Health response will be required.