Citations

Abstract Solitary bone plasmacytoma (SBP) and SBP with minimal marrow involvement (SBPmm) are treated similarly with definitive radiation therapy (RT) followed by observation. However, differences in the natural disease course after RT between the two, are not well described. We performed a multicenter study assessing outcomes after RT in 141 patients with SBP and 102 with SBPmm diagnosed between January 2010 and December 2024. About 92% of patients with SBPmm progressed to multiple myeloma (MM) vs 76% of those with SBP (P = .01). Among patients with SBP, 21% progressed with a second solitary bone lesion vs 4% with SBPmm (P< .01). Patients with longer time to progression (TTP) after initial RT could achieve durable responses with RT to a second solitary plasmacytoma in the absence of other myeloma-defining events (MDE). Multifocal lytic bone lesions were the most common MDE, occurring in 89% and 81% of patients with SBPmm and SBP, respectively. Patients with SBPmm had a median TTP of 15 months (95% confidence interval [CI], 14-21) compared to 43 months (95% CI, 34-55) for those with SBP (P< .0001); 67% with SBPmm progressed within 2 years of diagnosis. Del(17p) and 1q+ (gain or amplification) were associated with shorter TTP to MM in SBPmm, with 2-year progression rates of 100% and 82%, respectively. We report significant differences in risk and modes of progression between SBP and SBPmm. Patients with SBPmm are at particularly high risk for early progression to MM, with most developing bone disease as the MDE. These findings support prospective studies incorporating frontline systemic therapy for SBPmm.

Enteroblastic, hepatoid, and clear cell carcinomas are rare subtypes of colorectal carcinoma (CRC) with histologic and immunohistochemical (IHC) overlap. We assessed 37 CRCs that possibly represent these subtypes. Provisional criteria for each subtype, along with case photomicrographs and IHC data, were circulated among the authors to provide diagnostic interpretations. Based on plurality consensus, the carcinomas were classified as enteroblastic (n=13), hepatoid (n=6), and clear cell (n=18). Unanimous agreement was reached in 18% (3 clear cell, 3 hepatoid). Interobserver analysis revealed a mean pairwise Cohen κ of 0.63 (range: 0.32 to 0.91), with the hepatoid subtype eliciting the greatest consensus. Clear cell areas were the most likely to intermix with areas of conventional CRC ( P <0.001). Seven patients (20%) had inflammatory bowel disease (mostly linked to enteroblastic CRC). Twenty-three of 34 patients (68%) had nodal metastasis, and 12 (32%) had distant metastasis (mostly to the liver) at presentation. Median recurrence-free survival was 17 months, with enteroblastic cases the most likely to recur (54%, P =0.015). Median follow-up length was 27 months, with 14 patients (40%) dying of disease (representing 7 enteroblastic, 4 hepatoid, and 3 clear cell CRC). Mutations were identified in TP53 (n=8) , APC (n=3) , FBXW7 (n=2), and KRAS (n=1). Inflammatory bowel disease significantly worsened recurrence-free survival on multivariate analysis, while distant metastasis significantly worsened both recurrence-free and overall survival on multivariate analysis. Enteroblastic, hepatoid, and clear cell CRC demonstrate morphologic and IHC overlap, leading to interobserver variability in diagnosis. Given potential differences in clinical correlations and outcomes, more refined criteria are likely necessary.

Abstract Background: Pyrimidine synthesis is a therapeutic vulnerability in cancer but inhibition results in toxicity to normal cells. Differential targeting of CTP synthase 1 (CTPS1), sparing the CTPS2 isoenzyme, is a therapeutic strategy in lymphoid cancers, supported by human genetic studies, that can potentially avoid toxicity; however, CTPS2 activity may compensate in epithelial tumours. Loss of CTPS2 protein expression characterises 25% of solid tumours and is predicted to expose a synthetic lethal vulnerability to CTPS1 inhibition. Dencatistat (STP938) is a first in class oral CTPS1 inhibitor showing &gt;1,300-fold selectivity over CTPS2. In preclinical studies, CTPS2 expression was confirmed as a key modulator of response to CTPS1 inhibition, and dencatistat induced tumour regression in an in vivo model of CTPS2 negative ovarian cancer. Study design: The study comprises a standard 3+3 phase 1a dose escalation design, in which intra-patient dose escalation is encouraged, followed by a phase 1b safety expansion. The dose escalation study is recruiting participants with high grade advanced tumours who have exhausted standard of care therapy (excluding haematological cancers, salivary gland tumours and low grade tumours of any tissue). In addition, participants with high grade serous ovarian cancer whose tumours lack expression of CTPS2 (per central laboratory testing by immunohistochemistry) are eligible for backfill into cleared cohorts during dose escalation. The recommended phase 2 dose (RP2D) will be nominated based on safety, tolerability, target engagement and early signs of clinical efficacy. The phase 1b safety expansion study will recruit participants with CTPS2 negative ovarian, lung or endometrial cancer who will receive treatment at the RP2D. Standard inclusion criteria apply; patients with ECOG performance score &gt;2 (&gt;1 for phase 1a in France) or active/symptomatic CNS metastases are not eligible. The primary objectives of the study are to evaluate the safety and tolerability of single agent dencatistat and to determine the RP2D for further development. Secondary objectives comprise evaluation of pharmacokinetic properties and preliminary clinical activity. Exploratory endpoints include evaluation of target engagement, molecular features associated with response, and determination of drug metabolites. The study opened to enrolment in the UK, France and USA in September 2024 and is currently in dose escalation (NCT06297525). The phase 1b study is expected to commence mid-2026 and will include additional centres in Spain. Citation Format: Donna M. Graham, David Sommerhalder, Douglas Orr, Rowan Miller, Neeharika Makani, David O'Malley, Ira Winer, Philip A. Beer, Karen Smith, Maureen Higgins, John R. Hawse, Xiyin Wang, Saravut J. Weroha, Christophe Massard, Patricia Roxburgh. Lack of CTPS2 expression exposes synthetic lethal vulnerability to selective CTPS1 inhibition: A phase 1 dose escalation study of dencatistat (STP938) with safety expansion in biomarker selected cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr CT075.

Abstract Despite long-standing interest in combining topoisomerase I (TOP1) poisons with PARP inhibitors (PARPis), the mechanistic basis for the variable and often unpredictable response to this strategy remains unclear. Early preclinical studies suggested that PARP inhibition amplifies TOP1 poison-induced DNA damage, implying broad therapeutic potential; however, emerging translational and clinical data—particularly in ovarian cancer—indicate that synergy is context-dependent and governed by tumor-intrinsic features that have not been fully defined.Here we assessed determinants of response in five HR proficient ovarian cancer (OC) patient-derived xenografts (PDXs) previously treated with the SN-38 prodrug etirinotecan pegol (NKTR-102) in combination with the PARPi rucaparib (C. Nitschmann, Clin. Cancer Res. 22(2) Suppl. B50, 2016). Although all models were refractory to single-agent rucaparib, 50% exhibited enhancement of NKTR-102-induced tumor regression with the addition of rucaparib. Neither PARP1 abundance nor extent of rucaparib-mediated poly(ADP-ribose) suppression correlated with therapeutic benefit. Instead, sensitization was restricted to PDXs intrinsically responsive to NKTR-102 and was strongly associated with high levels of NKTR-102-induced TOP1-DNA covalent complexes. In further analysis, 2 of 3 resistant PDXs exhibited high levels of the ABC transporter ABCG2 despite lack of previous therapy, revealing a previously underappreciated mechanism of de novo resistance that limits effective TOP1 inhibitor activity independent of homologous recombination status. Notably, NKTR-102 response did not track with platinum/taxane sensitivity, highlighting the distinct molecular circuitry governing TOP1 poison susceptibility.Collectively, these findings demonstrate that rucaparib can potentiate NKTR-102-induced regression in tumors capable of forming abundant TOP1-DNA covalent complexes. This work identifies TOP1-DNA complex trapping and lack of ABCG2 expression as mechanistic predictors of benefit, providing an updated framework for selecting patients most likely to respond to TOP1 poison/PARPi combinations and challenging the long-standing assumption that PARP inhibition can universally resensitize tumors to TOP1 poisons. Citation Format: Annapoorna Venkatachalam, Caroline C. Nitschmann, Karen S. Flatten, Rachel Hurley, Xiaonan Hou, Cristina Correia, Paula A. Schenider, Krista Goergen, Matthew Maurer, Ethan P. Heinzen, Ann L. Oberg, S John Weroha, Paul Haluska, Scott H. Kaufmann, Elizabeth M. Swisher. TOP1-DNA protein complex as a predictive biomarker for NKTR-102/Rucaparib combination therapy in PARP-inhibitor resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(8_Suppl):Abstract nr LB364.

Morel-Lavallee lesions (MLLs) are traumatic closed degloving injuries with operative intervention (OI), especially excisional debridement, remaining the mainstay of treatment. However, high-quality evidence describing operative techniques and outcomes remains limited. This study aimed to characterize current OI practices and associated outcomes, especially among patients undergoing excisional debridement, hypothesizing an increased risk of wound complications with this approach for MLLs. Methods This prospective (2021-2024), multicenter, observational study was conducted across 15 trauma centers and included patients diagnosed with MLL who underwent OI. The association between operative technique (eg, excisional debridement) and the primary outcome of wound complications was evaluated. Wound complications were defined as cellulitis, deep wound infection, skin necrosis, necrotizing soft tissue infection (NSTI), and/or organized hematoma. Results Of 88 MLL patients undergoing OI, 36 (40.9%) had excisional debridement, with 4 (11.1%) limited excision to skin, 20 (55.6%) extended to subcutaneous tissue, and 12 (33.3%) down to muscle. Excisional debridement had higher rates of skin necrosis (22.2% vs. 1.9%, P = .002). Although overall rates of wound complications were statistically similar between cohorts (33.3% vs. 17.3%, P = .098), univariate analysis demonstrated excisional debridement had increased risk of wound complications (OR 2.52, CI 1.07-5.97, P = .035). Conclusion This prospective multicenter study over three years demonstrated that a fifth of MLLs undergoing excisional debridement developed postoperative skin necrosis. Excisional debridement also had a more than two-fold increased risk of wound complications compared to other OIs. These findings underscore the importance of investigating alternative operative techniques, such as incision and drainage or minimally invasive debridement methods.

Abstract Background Approximately 12 000 adolescents and young adults (ages 15-39, AYAs) are diagnosed with a primary central nervous system (CNS) tumor each year. DNA methylation profiling has transformed CNS tumor classification by refining diagnostic accuracy and identifying biologically distinct subtypes, but its application has not been systematically evaluated in the AYA population. In this study, we examined the spectrum of CNS tumor types across age groups, with a focus on the AYA population. Methods We assembled a large dataset of CNS tumor samples with age annotations and methylation profiles matching with high confidence to a CNS tumor type using the NCI/Bethesda classifier. Prevalence of tumor type, methylation class and DNA copy number aberrations were compared across age strata (pediatric, AYA, and adult). Results The cohort of 21 712 CNS tumors included 5351 tumors from AYAs (25%), which showed a mixed pattern, with tumors typical of childhood (eg, medulloblastoma) as well as those common in older adults (eg, glioblastoma). Several tumor types were specifically enriched in the AYA, including IDH-mutant astrocytoma, pleomorphic xanthoastrocytoma, posterior fossa group B ependymoma, and diffuse hemispheric glioma, H3 G34-mutant, among others. Distinct methylation subclasses of multiple tumor types were observed in the AYA, and patterns of genomic aberrations showed age-specific distributions. Conclusion Large-scale methylation profiling revealed unique classification patterns of CNS tumors in AYAs, with specific tumor types, subclasses, and genomic alterations enriched in this population. These data may serve as a valuable reference resource for better understanding the spectrum of CNS tumors affecting AYA patients.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non-Small Cell Lung Cancer (NSCLC) provide recommendations for the treatment of patients with NSCLC, including diagnosis, primary disease management, surveillance, and subsequent treatment. The panel has updated the list of recommended targeted therapies based on recent FDA approvals and clinical data. This selection from the NCCN Guidelines for NSCLC focuses on treatment recommendations for advanced or metastatic NSCLC with actionable biomarkers.

Abstract STUDY QUESTION What is the fertility preservation (FP) utilization rate among transgender and gender diverse (TGD) patients at the Transgender and Intersex Specialty Care Clinic (TISCC) within the Mayo Clinic? SUMMARY ANSWER The rate of utilization of FP services by TGD patients at Mayo Clinic’s TISCC was determined to be 6.62%. WHAT IS KNOWN ALREADY TGD patients encounter several barriers when pursuing FP, which may contribute to a lower utilization rate of these services. These barriers include financial constraints and lack of insurance coverage, as well as societal and healthcare provider attitudes; TGD individuals face discrimination or lack of understanding, making it uncomfortable or difficult to discuss FP options. Additionally, there continues to be a lack of inclusive policies and support within healthcare systems that can further impede access to FP services for TGD individuals. STUDY DESIGN, SIZE, DURATION The study was executed in two phases. In the first phase, a retrospective cohort study was completed with TGD patients who provided electronic health record (EHR) research authorization from Mayo Clinic’s TISCC in Rochester, MN between 1 January 2015 and 30 July 2021. Search terms related to FP were used to determine the FP utilization rate among this patient population. In the second phase of the study, two sets of patients, (i) patients who were included in the cohort study in Phase 1, and (ii) members of JASMYN, a community organization specializing in care and wellness coordination for Lesbian, Gay, Bisexual, and Transgender (LGBT) teens and young adults in North Florida. Individuals were invited to participate in a qualitative interview exploring their cumulative healthcare experiences accessing gender-affirming care. Interviews were conducted from January 2023 to June 2023. Interviews examined participants’ perceptions of FP options, motivations for pursuing FP, and barriers to accessing both gender and fertility care. When applicable, participants also discussed their experiences pursuing FP and reflected on their satisfaction with their fertility and family planning decisions. PARTICIPANTS/MATERIALS, SETTING, METHODS In phase 1, a total of N = 1189 patients sought care from Mayo Clinic’s TISCC in Rochester, MN. Out of these patients, N = 589 patients provided research authorization and were included in the retrospective cohort study. The study team assessed whether FP terms were mentioned in each patient’s EHR, and whether patients scheduled and attended appointments with either the Department of Reproductive Endocrinology or the Department of Urology. FP search terms included sperm cryopreservation, sperm extraction, sperm aspiration, testicular tissue cryopreservation, oocyte cryopreservation, embryo cryopreservation, and ovarian tissue cryopreservation. In phase 2, N = 36 participants were interviewed, with N = 25 participants recruited from Mayo Clinic’s TISCC in Rochester, MN, and N = 11 participants recruited from JASMYN in Jacksonville, FL. Participants recruited from the Mayo Clinic participated in a video-call-based interview and those enrolled from JASMYN were interviewed in person. MAIN RESULTS AND THE ROLE OF CHANCE The study team observed a 6.62% utilization rate of FP services among N = 589 patients (median age: 28 years; age range: 8–78 years) included in the retrospective cohort study. N = 39 patients completed FP, with N = 14 receiving these services at other institutions before seeking care with the TISCC at Mayo Clinic. N = 25 patients pursued FP services within the Mayo Clinic. Patients with testes were more likely to complete FP via sperm cryopreservation when compared to the utilization of egg cryopreservation among patients with ovaries. Participants who completed an interview in Phase 2 (median age 27 years; age range: 22–80 years) reflected on their decision on whether to preserve their fertility and what factors influenced these decisions, and how their satisfaction with this decision has changed over their lifespan. The major themes reported here include the desire for biological children, planning gender care around fertility desires, conversations about FP options, physical and psychosocial barriers to pursuing FP, reflections on personal FP decisions, and reflections on having to make decisions about FP at a young age. LIMITATIONS, REASONS FOR CAUTION All participants who completed an interview have done so voluntarily; as such, there is a possibility of selection and recall bias. WIDER IMPLICATIONS OF THE FINDINGS Findings suggest that there is a need for more structured conversations around FP when TGD patients seek medical and surgical gender-affirming care. Accessibility, including financial barriers and limited insurance coverage, continues to limit the utilization of FP services among TGD patients. Increased affordability through insurance coverage may additionally improve FP utilization. STUDY FUNDING/COMPETING INTEREST(S) This project was funded by the Mayo Clinic Department of Obstetrics and Gynecology and the Mayo Clinic Center for Clinical and Translational Science (CCaTS), grant number UL1TR002377. This project was also supported by Clinical and Translational Science Award (CTSA) Grant Number TL1TR002380 from the National Center for Advancing Translational Sciences (NCATS). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. Felicity Enders reports grants from the National Institutes of Health and the Agency for Healthcare Research and Quality paid to her institution; speakers’ fees for lectures or presentations from Mount Sinai, University of Washington, University of Minnesota, University of Rochester, Cincinnati University, the National Institutes of Health, Duke University, Wake Forest University, the Patient Centered Outcomes Research Institute, Johns Hopkins University; travel support from the Association for Clinical and Translational Science and Cold Spring Harbor Laboratory; and an unpaid leadership role on the Board of Directors of the Association for Clinical and Translational Science. All other authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.