Citations

Abstract Introduction Infection following inflatable penile prosthesis (IPP) placement is an uncommon yet serious complication, and its management poses significant clinical challenges. IPP infection management strategies continue to evolve, however, multicenter and robust studies evaluating and describing current practice patterns are lacking. Objective Using a large cohort from tertiary IPP referral centers in the United States to evaluate current infection management practice patterns and to identify factors that could predict the approach to managing IPP infections. Methods We queried a retrospective 14-center multi-institutional database for patients with IPP infections between April 2017 and January 1/2025. Patients were categorized by infection management strategy, which included device explant, malleable salvage, and 3-piece IPP salvage. Patient characteristics were compared using chi-square and independent t-tests. Multinomial analysis was performed to investigate patient and perioperative factors associated with management strategy at the time of infection. Results Among 2,934 cases, 85 (2.9%) patients developed IPP infection at a median of 40 (22-78) days after IPP implantation. Infections occurred after primary IPP surgery in 59 (69%), revision in 25 (29%), and after infection salvaged with IPP in 1 (1%). Infections were managed with device explant in 32 (38%), malleable salvage in 43 (51%), and IPP salvage in 10 (12%). A significantly higher proportion of non-White patients underwent salvage (either with malleable or IPP) compared to White patients (p=0.01). Multinomial regression showed no association between patient and perioperative characteristics and infection management (p>0.05). Conclusions In this multi-institutional cohort of experienced implanters, infections were most commonly managed with malleable salvage. Patient and perioperative factors did not predict management approach, suggesting that the decision between explanation and salvage is primarily driven by individual surgeon preference. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston scientific

Abstract Introduction With the growing use of 0.05% Chlorhexidine Gluconate (CHG) as irrigation and dip for inflatable penile prosthesis (IPP) surgery, understanding the possible relationship between CHG use and non-infectious complications is imperative. Such information may guide provider decision-making during implant surgery. Objective We therefore sought to determine whether the use of 0.05% Chlorhexidine Gluconate (CHG) during inflatable penile prosthesis (IPP) surgery was associated with non-infectious wound complications. Methods We performed a multi-institutional retrospective cohort study of patients undergoing IPP surgery from January 2017 to March 2024. The primary outcome was wound complications (ex. rash, wound dehiscence, edema). Secondary outcomes included other non-infectious complications (Table 1). The primary exposure was whether patients received intraoperative CHG either as irrigation or dip. Descriptive comparisons were used to compare CHG and non-CHG cohorts. Univariable logistic regression was utilized to assess if CHG use was associated with any non-infectious complication. Multivariable logistic regression was subsequently performed to assess factors associated with certain non-infectious complications after IPP surgery – controlling for age, body mass index, race, diabetes, and hypertension as covariables. Results Across 2,933 patients, there were 1,573 non-CHG and 1,359 CHG patients. Non-infectious complications occurred in 83 (5%) non-CHG patients and in 65 (5%) CHG patients. Median follow-up was 22 months (IQR 7-59) for non-CHG patients and 8 months (IQR 3-16) for CHG patients. The incidence of wound complications was greater among CHG patients than non-CHG patients (1.0% vs. 0.1%, p<0.01). On univariable logistic regression, CHG use was associated with increased odds of wound complications (OR 7.34, 95% CI 1.65-32.71) but was not associated with any other non-infectious complication (Table 2). On multivariable logistic regression, CHG use remained associated with an increased odds of wound complications (OR 13.86, 95% CI 1.80-106.44). Conclusions Among patients experiencing non-infectious complications after IPP, CHG use during IPP surgery appears to be associated with an increased odds of wound complications. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast Corporation and Boston Scientific

Abstract Introduction 0.05% Chlorhexidine Gluconate (CHG) has increasingly been used as an irrigant for inflatable penile prosthesis (IPP) surgery. Recent in vitro data shows mixed results regarding efficacy, but clinical data is lacking. Objective To explore the cultured organisms and infection characteristics of IPP infections with and without intraoperative CHG use from a large multi-institutional cohort. Methods We queried a retrospective multi-institutional database of patients who underwent IPP placement for cases resulting in IPP Infection. We stratified cases by intraoperative use of CHG as an irrigant or dip. We compared patient and infection characteristics using chi squared tests and independent t-tests. Culture data from IPP explant was reviewed for descriptive analysis. Results We identified 70 IPP infections, 43 with intraoperative CHG use. Patient demographics were similar between infection cohorts. (Table 1). Median time to infection was similar, 46.5 days in the CHG cohort and 34 days in the non-CHG cohort (p=0.518). Culture data were available for 57 (81.4%) patients. For CHG IPP infections, 8 had Escherichia coli cultured at time of explant and 6 grew methicillin sensitive Staphylococcus aureus. For non-CHG IPP infections, Staphylococcus epidermidis (4) and Pseudomonas aeruginosa (3) were the most common cultured organisms. A total of nine unique organisms were cultured for both CHG and non-CHG infections. Negative growth cultures were recorded for 2 patients in both the CHG and non-CHG infection groups. (Figure 1) Conclusions In a large, multi-institutional cohort, IPP infections after intraoperative CHG use were associated with a variety of cultured organisms, most commonly Escherichia coli and Methicillin sensitive Staphylococcus aureus. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast: Advisory board, speaker; Endo: Advisory board; Haleon: Advisory board; Halozyme: Advisory board, speaker; Masimo: Intellectual property; Softwave: Advisory board; Sprout: Consultant; Vertica: Research investigator; Xialla: Advisory board.

Abstract Introduction 0.05% Chlorhexidine Gluconate (CHG) has gained popularity as an irrigant and dip for inflatable penile prosthesis (IPP) surgery. Prior in vitro data is conflicting on the impact of CHG use with hydrophilic coated devices. Objective We sought to identify possible associations between CHG use and hydrophilic IPP infection rate. Methods We conducted a retrospective cohort study of 2,933 patients undergoing IPP implantation across 14 referral centers. Data collection spanned from January 1, 2017 to March 1, 2024. Each surgeon contributed patients who underwent IPP implantation with CHG used as an irrigant and/or dip as well as an equal number of consecutive control patients without CHG use. The primary outcome was IPP explant for postoperative infection. Univariable analysis was used to compare patient demographics, and logistic regression analysis was performed to assess factors associated with infection. Results Hydrophilic devices were implanted in 2,150 patients. Median follow-up for non-CHG patients was 13 months (IQR 18) and four months (IQR 9) for CHG patients. The incidence of infection with intraoperative CHG use was significantly higher compared to those without CHG use (4.6%, 46/1,001 vs. 2.1%, 24/1,148, p<0.001). On multivariable logistic regression analysis, intraoperative CHG use was associated with infection (OR 2.07, 95% CI 1.24-3.47, p=0.01). Additional variables associated with infection included immunosuppression, prior IPP infection, prior priapism, and revision surgery (p<0.01, Table). On subgroup analyses, the increased infection risk of CHG was most clear when CHG was used as both irrigation and dip (OR 2.03, 95% CI 1.19-3.46, p=0.01) and when CHG was used during revision surgery (OR 3.36, 95% CI 1.15-9.82, p=0.03). Conclusions In a large multi-institutional cohort, intraoperative CHG use was associated with an elevated incidence of hydrophilic IPP infection. Providers may take these findings into consideration when performing IPP surgery with hydrophilic devices, especially during revision surgery. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast Corporation and Boston Scientific

Abstract Introduction Benign prostatic hyperplasia (BPH) is an age-related condition affecting many men. Emerging evidence highlights a strong relationship between BPH, lower urinary tract symptoms (LUTS) and sexual dysfunction, including erectile dysfunction (ED), reduced sexual desire, hormonal imbalances, and ejaculatory dysfunction, warranting a comprehensive approach to diagnosis and management. Objectives This report aims to provide recommendations for identifying and managing sexual dysfunction associated with BPH and LUTS. Methods Based on guidelines from the International Consultation on Sexual Medicine, a literature review was conducted. Recommendations were graded using the Grading of Recommendations Assessment, Development and Evaluation system. Results The association between BPH, LUTS, and sexual dysfunction is significant, with ED, ejaculatory dysfunction, and hypogonadism being common complications. Lifestyle modifications, medical therapies, minimally invasive surgical therapies, prostate artery embolization, and surgeries (eg, Transurethral resection of the prostate, HoLEP, Aquablation) are among the recommended treatments. Each intervention carries varying risks of sexual dysfunction, requiring specific tailored treatment plans. Conclusions BPH/LUTS significantly affect sexual health, emphasizing the need for a multidisciplinary approach to management. Future research should refine diagnostic criteria and develop treatments that minimize sexual side effects. Enhanced education for patients and their partners could improve quality of life and coping mechanisms.

Background: Myxofibrosarcomas are notoriously highly infiltrative soft-tissue sarcomas, making negative surgical margins difficult to obtain. Recently, vacuum-assisted closure (VAC) is used to delay wound closure until a negative margin has been achieved; however, this can delay care and increase costs. Our institution has historically performed single-stage resections with intraoperative frozen margin analysis and reconstruction in these patients. The purpose of this study is to report the outcomes of this technique. Methods: We reviewed 112 patients (62 males, mean age 70 ± 14 years) with superficial myxofibrosarcoma. Eighty-eight patients received preoperative radiation. All patients underwent surgical resection with intraoperative frozen margin analysis, and the planned reconstruction was performed in a single anesthetic. Results: The 10-year local recurrence-free survival was 90%; positive intraoperative frozen section (HR 7.44, p = 0.004) and final permanent margins (HR 8.53, p = 0.007) were associated with local recurrence. Intraoperative margins were negative in 103 (92%) of patients, 1 of which was positive on final permanent section. There were nine cases of microscopically positive margins, of which seven underwent immediate re-excision to a negative margin. The accuracy of frozen margin assessment for myxofibrosarcoma was between 92.92 and 98.23%. All patients underwent reconstruction at the time of resection, with 19% needing an additional procedure, most commonly due to a wound complication (12%). Conclusions: Multidisciplinary single-stage excision with intraoperative frozen margin assessment and soft-tissue reconstruction yields low rates of local recurrence in patients with superficial myxofibrosarcoma.

e15003 Background: Antibody-drug conjugates (ADCs) have shown substantial promise as therapies for metastatic breast cancer (mBC). However, direct comparisons of different ADC-based regimens are limited. We assessed survival outcomes in mBC patients treated with ADCs. Methods: Randomized controlled trials (RCTs) published before October 2024 were searched in Medline, Embase, ClinicalTrials.gov, and Cochrane Library. Progression-free survival (PFS) and overall surcvival (OS) outcomes were extracted from the most updated publications. Participants were stratified based on molecular subtypes, hormone receptor (HR) status, duration of cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) treatment, and sensitivity to endocrine therapy (ET). Bayesian frameworks were deployed, presenting the synthesized outcomes of indirect comparisons using the surface under the cumulative ranking curve (SUCRA), hazard ratio (HR), and 95% credible interval (Crl). This study was prospectively registered on the International Platform of Registered Systemic Reviews and Meta-analysis Protocols (INPLASY) (INPLASY2024110021). Results: A total of 6449 patients from 12 RCTs of ADCs ado-trastuzumab emtansine (T-DM1), sacituzumab govitecan (SG), trastuzumab deruxtecan (T-DXd), and datopotamab deruxtecan (Dato-DXd) were included in the analysis. Compared to chemotherapy, T-DXd significantly improved PFS (HR 0.35, 95% Crl 0.15-0.84) and OS (HR 0.56, 95% Crl 0.32-1.0). SG also significantly extended OS (HR 0.65, 95% Crl 0.43-0.97) but not PFS. In HER2+ mBC, pooled analyses revealed T-DXd was the most effective treatment in terms of PFS, with a SUCRA of 94.2%, followed by T-DM1 (58.9%), and chemotherapy with HER2-directed therapy (34.2%). Synthesized outcomes of OS mirrored the PFS outcomes. In HR+/HER2- mBC (some of which was HER2-low), Dato-DXd (76.1%) showed slightly superior efficacy over SG (67.4%) for PFS, while SG (85.1%) was advantageous over Dato-DXd (49.1%) in terms of OS. Among patients with HR+/HER2+ mBC, T-DXd (80.0%), SG (55.5%), and chemotherapy with HER2-directed therapy (53.1%) were the most effective therapies for prolonging PFS. Regarding OS, SG (70.3%) and T-DM1 (60.3%) were the most effective, with comparable efficacy observed between chemotherapy with HER2-directed therapy (52.1%) and T-DXd (52.0%). In HR-/HER2+ mBC, T-DXd (78.1%), SG (56.1%), and T-DM1 (51.5%) significantly prolonged PFS, while SG (69.4%) had the most substantial benefit for OS, followed by T-DXd (62.8%) and chemotherapy with HER2-directed therapy (57.6%). Dato-DXd showed an advantage over SG in mBC patients received CDK4/6i for > 12 months. Conclusions: This network meta-analysis showed prominent survival benefits with ADC-containing regimens for mBC. Our results provide valuable insights into personalized treatment strategies for mBC patients.

Objectives: To evaluate the clinical heterogeneity of sarcomas by examining associations between histological subtypes, metastatic patterns, treatment modalities, and survival outcomes. Methods: We analyzed data from 97,062 adult patients diagnosed with sarcoma between 2000 and 2020, using the Surveillance, Epidemiology, and End Results (SEER) database. Fourteen histological subtypes were included. Propensity score matching (PSM) was employed to adjust for baseline differences, and Cox proportional hazards models were used to identify prognostic variables. Results: The most prevalent subtypes were sarcoma not otherwise specified (31.9%), leiomyosarcoma (17.1%), and liposarcoma (13.9%). Metastatic patterns differed significantly by subtype; liver metastases were most common in sarcomas with small blue round cell (SBRC) features (8.9%) and stromal sarcoma (6.1%), while lung metastases were frequently observed in Ewing sarcoma (10.0%) and rhabdomyosarcoma (9.7%). Median overall survival (mOS) varied widely, ranging from 234 months in chondrosarcoma to 16–20 months in rhabdomyosarcoma and SBRC sarcoma. Overall, patients with primary sarcoma had significantly better survival than those with treatment-related disease (119.0 vs. 45.0 months, p < 0.0001), with this trend consistent across most subtypes. Treatment responses were subtype- and size-dependent. For instance, surgery plus radiotherapy improved outcomes in giant cell sarcoma regardless of tumor size, whereas chemotherapy provided benefit only in tumors larger than 5 cm. Combined surgery and radiotherapy offered additional survival benefit in select subtypes, including chordoma, leiomyosarcoma (>5 cm), and synovial sarcoma (<5 cm). Conclusions: Sarcomas exhibit substantial clinical and prognostic heterogeneity across histological subtypes. These findings underscore the importance of subtype-specific, individualized treatment strategies in optimizing patient outcomes.

Abstract Poly ADP ribose polymerase inhibitors (PARPi) are being investigated in combination with photon and proton radiotherapy in clinical trials of pediatric and adult malignancies. The precise mechanisms of PARPi radiosensitization, and whether differences in photon and proton-mediated relative efficacy exist, have not been fully elucidated. To study mechanisms of PARPi radiosensitization we investigated the effects of PARPi in combination with photons and two different ionizing densities of protons delivered at the entrance (ENT) or the Bragg peak (BP) of the profile (dose-averaged LET [LETd] 2.2 and 7.0 keV/µm, respectively) of a 76.8 MeV proton beam after observing an extreme tumor and normal tissue response in an 18-year-old female patient with high grade glioma treated veliparib and proton therapy in a Children’s Oncology Group clinical trial. BRCA1/2 wild-type hTERT RPE-1, U2OS, and MDA-MB-231 cells were hypersensitive to the combination of veliparib and proton BP, with enhanced relative biological effectiveness (RBE) at 2 Gy values of 1.7, 1.4, and 1.3, respectively. Similar findings were observed with talazoparib and olaparib, suggesting that PARP trapping efficiency was not a major influence on the proton BP RBE. Further, we did not observe differences in transcription replication conflict between the different proton ionizing densities. Unexpectedly, DNA fiber assays revealed more elongated replication fork tracks in PARPi treated cells 60 minutes after proton BP compared with proton ENT, indicative of accelerated replication fork progression. To assess gap formation in the vicinity of nascent DNA we treated cells with the ssDNA-specific S1 nuclease and found that the lengths of CldU-labeled tracks were significantly reduced in cells treated with the PARPi/proton BP combination, suggestive of greater gap formation at replication forks. We postulated that more ssDNA gaps were being converted to DSBs during replication as we further observed that PARPi/proton BP resulted in increased γH2AX foci at 4- and 24-hours after treatment. Consistent with increased DSB formation, a higher proportion of cells arrested in the G2/M phase of the cell cycle at 24 hours following PARPi/proton BP. Despite being arrested in G2/M when homologous recombination is active, there was a significant increase in 53BP1 and a decrease in RAD51 recruitment, indicative of upregulated repair by more error-prone non-homologous end-joining (NHEJ) repair pathway. The enhanced proton BP RBE in PARPi treated cells was abrogated upon knockdown of XRCC4, a critical component of NHEJ repair pathway, suggesting that toxic NHEJ may be contributing to the enhanced proton BP RBE. In conclusion, PARPi renders cells hypersensitive to high LET BP proton irradiation. Enhancing the LET in combination with PARPi warrants further investigation to overcome therapeutic resistance. Citation Format: Yiqun Han, Qin Zhou, Anna Olson, Cameron M. Callaghan, Bin Chen, Nicholas B. Remmes, Meng Xu Welliver, Zheming Wu, Daniel K. Ebner, Jake A. Kloeber, Zhenkun Lou, Robert W. Mutter. Poly ADP ribose polymerase inhibitors potentiate proton therapy end-of-range relative biological effective dose by increasing replication stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4689.