Invasive Disease Research Articles

Trends in serotype distribution and antimicrobial susceptibility pattern of invasive Haemophilus influenzae isolates from Brazil, 2009-2021.

Invasive Haemophilus influenzae (Hi) disease poses a significant global health challenge. With the relaxation of COVID-19 pandemic measures and declining H. influenzae serotype b (Hib) vaccination coverage, there is concern about a potential increase in Hi cases worldwide. This study analyzed 1437 invasive Hi isolates in Brazil over 13years, determining capsular serotypes, antimicrobial susceptibility, and genetic relatedness through multilocus sequence typing. The primary source of isolation for these invasive H. influenzae isolates was blood (54.4%), followed by cerebrospinal fluid (37.1%) and lung specimens (8.5%), respectively. Consequently, bacteremia (47%) was the most common clinical presentation, followed by meningitis (39.6%) and pneumonia (13.4%). Non-encapsulated Hi (NTHi) predominated among the isolates (51.4%), along with serotype a (22%) and serotype b (21.5%) among the encapsulated isolates. The majority of the encapsulated isolates were isolated from children under 14years of age (76.7%), while NTHi isolates were identified in patients older than 15years, particularly those ≥ 60years old (40%). Ampicillin resistance was observed in 17.1% of cases, displaying β-lactamase production as the principal resistance mechanism. MLST revealed a diverse NTHi population, whereas the encapsulated isolates presented a clonal structure. This study describes the prevalence of NTHi isolates circulating in Brazil after two decades of the Hib vaccine immunization program. Continuous universal surveillance is crucial for implementing prompt public health measures to prevent and control invasive Hi disease and monitor changes in antibiotic resistance profiles.

Meningococcal Surveillance Australia: Reporting period 1 July to 30 September 2023

The reference laboratories of the Australian Meningococcal Surveillance Programme (AMSP) report data on the number of cases of invasive meningococcal disease (IMD) confirmed by laboratory testing using culture and molecular based techniques. Data contained in quarterly reports are restricted to a description of case numbers of IMD by jurisdiction and serogroup, where known. A full analysis of laboratory confirmations of IMD in each calendar year are contained in the AMSP annual reports.

Meningococcal Surveillance Australia: Reporting period 1 April to 30 June 2023

The reference laboratories of the Australian Meningococcal Surveillance Programme (AMSP) report data on the number of cases of invasive meningococcal disease (IMD) confirmed by laboratory testing using culture and molecular based techniques. Data contained in quarterly reports are restricted to a description of case numbers of IMD by jurisdiction and serogroup, where known. A full analysis of laboratory confirmations of IMD in each calendar year are contained in the AMSP annual reports.

Meningococcal Surveillance Australia: Reporting period 1 October to 31 December 2023

The reference laboratories of the Australian Meningococcal Surveillance Programme (AMSP) report data on the number of cases of invasive meningococcal disease (IMD) confirmed by laboratory testing using culture and molecular based techniques. Data contained in quarterly reports are restricted to a description of case numbers of IMD by jurisdiction and serogroup, where known. A full analysis of laboratory confirmations of IMD in each calendar year are contained in the AMSP annual reports.

Cost-effectiveness of PCV20 to Prevent Pneumococcal Disease in the Pediatric Population: A German Societal Perspective Analysis.

Since 2009, a pneumococcal conjugate vaccine (PCV) covering 13 serotypes (PCV13) has been included by Germany's Standing Committee on Vaccinations for infants, resulting in major reductions in pneumococcal disease (PD). Higher-valent vaccines may further reduce PD burden. This cost-effectiveness analysis compared 20-valent PCV (PCV20) under a 3+1 schedule with 15-valent PCV (PCV15) and PCV13, both under 2+1 schedule, in Germany's pediatric population. A Markov model with annual cycles over a 10-year time horizon was adapted to simulate the clinical and economic impact of pediatric vaccination with PCV20 versus lower-valent PCVs in Germany. The model used PCV13 clinical effectiveness and impact studies as well as PCV7 efficacy studies for vaccine direct and indirect effect estimates. Epidemiologic, utility, and medical cost inputs were obtained from published sources. Benefits and costs were discounted at 3% from a German societal perspective. Outcomes included PD cases, deaths, costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs). In the base case, PCV20 provided greater health benefits than PCV13, averting more cases of invasive pneumococcal disease (IPD; 15,301), hospitalized and non-hospitalized pneumonia (460,197 and 472,365, respectively), otitis media (531,634), and 59,265 deaths over 10 years. This resulted in 904,854 additional QALYs and a total cost saving of €2,393,263,611, making PCV20 a dominant strategy compared with PCV13. Compared to PCV15, PCV20 was estimated to avert an additional 11,334 IPD, 704,948 pneumonia, and 441,643 otitis media cases, as well as 41,596 deaths. PCV20 was associated with a higher QALY gain and lower cost (i.e., dominance) compared with PCV15. The robustness of the results was confirmed through scenario analyses as well as deterministic and probabilistic sensitivity analyses. PCV20 3+1 dominated both PCV13 2+1 and PCV15 2+1 over 10 years. Replacing lower-valent PCVs with PCV20 would result in greater clinical and economic benefits, given PCV20's broader serotype coverage.

Targets in the Tumour Matrisome to Promote Cancer Therapy Response

The extracellular matrix (ECM) is composed of complex fibrillar proteins, proteoglycans, and macromolecules, generated by stromal, immune, and cancer cells. The components and organisation of the matrix evolves as tumours progress to invasive disease and metastasis. In many solid tumours, dense fibrotic ECM has been hypothesised to impede therapy response by limiting drug and immune cell access. Interventions to target individual components of the ECM, collectively termed the matrisome, have, however, revealed complex tumour-suppressor, tumour-promoter, and immune-modulatory functions, which have complicated clinical translation. The degree to which distinct components of the matrisome can dictate tumour phenotypes and response to therapy is the subject of intense study. A primary aim is to identify therapeutic opportunities within the matrisome, which might support a better response to existing therapies. Many matrix signatures have been developed which can predict prognosis, immune cell content, and immunotherapy responses. In this review, we will examine key components of the matrisome which have been associated with advanced tumours and therapy resistance. We have primarily focussed here on targeting matrisome components, rather than specific cell types, although several examples are described where cells of origin can dramatically affect tumour roles for matrix components. As we unravel the complex biochemical, biophysical, and intracellular transduction mechanisms associated with the ECM, numerous therapeutic opportunities will be identified to modify tumour progression and therapy response.

Cytomegalovirus surveillance after antiviral prophylaxis in CMV mismatched transplant patients: Does recurrent cytomegalovirus DNAemia impact patient survival?

Cytomegalovirus (CMV) mismatched, donor IgG-positive/recipient IgG-negative, solid organ transplant recipients (SOTRs) are at high risk of CMV invasive disease. Post-prophylaxis disease is an issue in this population. Some programs employ surveillance after prophylaxis (SAP) to limit the incidence of post-prophylaxis disease. This was a single-center retrospective cohort study that included all CMV mismatched SOTRs from 2003 to 2017. Patients underwent SAP with weekly CMV plasma viral load for 12 weeks. The subjects were classified into three post-prophylaxis DNAemia patterns: no DNAemia, one episode of DNAemia, and multiple episodes of DNAemia. We calculated the cumulative incidence of each DNAemia pattern. We also determined 5-year mortality based on DNAemia pattern stratified by organ transplant type. Post-prophylaxis recurrent DNAemia occurred in 63% of lung recipients and 32% of non-lung recipients (p = .003). Tissue invasive CMV disease was diagnosed in 3% of the population and CMV syndrome was diagnosed in 33%. Recurrent DNAemia was not associated with 5-year mortality. In this cohort, undergoing SAP tissue invasive disease was uncommon and CMV DNAemia recurrence did not have an impact on long-term mortality.

Accumulation of resistance genes in Salmonella Typhimurium transmitted between poultry and dairy farms increases the risk to public health.

Salmonella Typhimurium is a zoonotic pathogen that poses a major threat to public health. This generalist serotype can be found in many hosts and the environment where varying selection pressures may result in the accumulation of antimicrobial resistance determinants. However, the transmission of this serotype between food-producing hosts, specifically between poultry layer flocks and nearby dairy herds, was never demonstrated. We investigated an outbreak at a dairy in Israel to determine the role of nearby poultry houses to be sources of infection. The 2-month outbreak resulted in a 47% mortality rate among 15 calves born in that period. Routine treatment of fluid therapy, a nonsteroidal anti-inflammatory, and cefquinome was ineffective, and control was achieved by the introduction of vaccination of dry cows against Salmonella (Bovivac S, MSD Animal Health) and a strict colostrum regime. Whole genome sequencing and antimicrobial sensitivity tests were performed on S. Typhimurium strains isolated from the dairy (n = 4) and strains recovered from poultry layer farms (n = 10). We identified acquired antimicrobial-resistant genes, including the blaCTX-M-55 gene, conferring resistance to extended-spectrum cephalosporins, which was exclusive to dairy isolates. Genetic similarity with less than five single nucleotide polymorphism differences between dairy and poultry strains suggested a transmission link. This investigation highlights the severe impact of S. Typhimurium on dairy farms and the transmission risk from nearby poultry farms. The accumulation of potentially transferable genes conferring resistance to critically important antimicrobials underscores the increased public health risk associated with S. Typhimurium circulation between animal hosts.IMPORTANCESalmonella Typhimurium is one of the major causes of food-borne illness globally. Infections may result in severe invasive disease, in which antimicrobial treatment is warranted. Therefore, the emergence of multi-drug-resistant strains poses a significant challenge to successful treatment and is considered one of the major threats to global health. S. Typhimurium can be found in a variety of animal hosts and environments; however, its transmission between food-producing animals, specifically poultry layers flocks and dairy herds, was never studied. Here, we demonstrate the transmission of the pathogen from poultry to a nearby dairy farm. Alarmingly, the multi-drug-resistant strains collected during the outbreak in the dairy had acquired resistance to extended-spectrum cephalosporins, antibiotics critically important in treating Salmonellosis in humans. The findings of the study emphasize the increased risk to public health posed by zoonotic pathogens' circulation between animal hosts.

Impaired upper respiratory tract barrier function during postnatal development predisposes to invasive pneumococcal disease.

Infants are highly susceptible to invasive respiratory and gastrointestinal infections. To elucidate the age-dependent mechanism(s) that drive bacterial spread from the mucosa, we developed an infant mouse model using the prevalent pediatric respiratory pathogen, Streptococcus pneumoniae (Spn). Despite similar upper respiratory tract (URT) colonization levels, the survival rate of Spn-infected infant mice was significantly decreased compared to adults and corresponded with Spn dissemination to the bloodstream. An increased rate of pneumococcal bacteremia in early life beyond the newborn period was attributed to increased bacterial translocation across the URT barrier. Bacterial dissemination in infant mice was independent of URT monocyte or neutrophil infiltration, phagocyte-derived ROS or RNS, inflammation mediated by toll-like receptor 2 or interleukin 1 receptor signaling, or the pore-forming toxin pneumolysin. Using molecular barcoding of Spn, we found that only a minority of bacterial clones in the nasopharynx disseminated to the blood in infant mice, indicating the absence of robust URT barrier breakdown. Rather, transcriptional profiling of the URT epithelium revealed a failure of infant mice to upregulate genes involved in the tight junction pathway. Expression of many such genes was also decreased in early life in humans. Infant mice also showed increased URT barrier permeability and delayed mucociliary clearance during the first two weeks of life, which corresponded with tighter attachment of bacteria to the respiratory epithelium. Together, these results demonstrate a window of vulnerability during postnatal development when altered mucosal barrier function facilitates bacterial dissemination.

Residual cancer burden in two-stage nipple sparing mastectomy after first stage lumpectomy and devascularization of the nipple areolar complex.

Ischemic complications after nipple-sparing mastectomy (NSM) can be ameliorated by 2-stage procedures wherein devascularization of the nipple-areolar complex (NAC) and lumpectomy with or without nodal staging surgery is performed first (1S), weeks prior to a completion NSM (2S). We report the time interval between procedures in relation to the presence of residual carcinoma at 2S NSM. Women with breast cancer who received 2S NSM from 2015 to 2022 were identified. Both patient level and breast level analyses were conducted. Clinical staging at presentation, pathologic staging at 1S and residual disease at 2S pathology are noted. Residual disease was classified as microscopic (1-2mm), minimal (3-10mm), and moderate (> 10mm). 59 patients (108 breasts) underwent 2S NSM. The median time interval between 1 and 2S for all patients was 34days: 31days for upfront surgery invasive cancer, 41days for upfront DCIS surgery and 31days for those receiving neoadjuvant therapy. Completion NSM was performed within 6weeks for 72% of the breasts analyzed. Of the 53 breasts with invasive cancer on 1S pathology, 35% (19/53) had no residual invasive disease and 24.5% (13/53) had neither residual invasive nor in situ carcinoma on final 2S. Among the 50 women who had upfront surgery, 16 (32%) had residual invasive cancer found at 2S NSM, 9 of which had less than or equal to 1cm disease. Invasive cancers were completely resected during 1S procedure in 65% of breasts. Residual disease was minimal and there was only one case of upstaging at 2S. Added time of two-stage surgery is offset by a reduction in ischemic mastectomy flap complications.

Invasive meningococcal disease in older adults: current perspectives and call for action.

Invasive meningococcal disease (IMD) is a devastating condition. While most attention is directed towards disease in children and adolescents, IMD poses an important cause of morbidity and mortality in adults ≥60years. While immunization is a critical component of healthy ageing strategies, meningococcal immunization is not routinely offered to older adults. The aim of this review was to summarize clinical and epidemiological aspects of IMD and available immunization strategies, with a particular focus on disease in older individuals, to emphasize the importance of this rather neglected area. An expert working group was established to evaluate clinical and epidemiological data toraise awareness of IMD in older individuals, and develop suggestions to improve the existing burden. Routine child and adolescent meningococcal immunization has substantially reduced IMD in these targeted populations. Consequently, prevalence and proportion of IMD among those ≥60years, mostly unvaccinated, is increasing in developed countries (accounting for up to 25% of cases). IMD-related mortality is highest in this age-group, with substantial sequelae in survivors. IMD due to serogroups W and Y is more prevalent among older adults, often with atypical clinical features (pneumonia, gastrointestinal presentations) which may delay timely treatment. IMD in older adults remains overlooked and greater awareness is required at clinical and societal levels. We encourage clinicians and immunization policy makers to reconsider IMD, with a call for action to remedy existing inequity in older adult access to protective meningococcal immunization.

Cost-Effectiveness of 20-Valent Pneumococcal Conjugate Vaccine in Argentinean Adults.

In Argentina, vaccination with 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23; PCV13 → PPSV23) has been recommended for all adults aged ≥ 65 years and younger adults with chronic medical ("moderate-risk") or immunocompromising ("high-risk") conditions since 2017. With the approval of a 20-valent PCV (PCV20), we evaluated the cost-effectiveness of PCV20 versus current recommendations for moderate-/high-risk adults aged 18-64 years and all adults 65-99 years. A probabilistic cohort model was used to project lifetime outcomes and costs associated with invasive pneumococcal disease (IPD) and all-cause non-bacteremic pneumonia (NBP), and the expected impact of vaccination. Clinical outcomes were projected annually based on Argentinean data. Economic costs were estimated based on cases and corresponding medical costs (adjusted to 2023 USD) and costs of vaccine and administration. Cost-effectiveness of PCV20 was evaluated versus the current strategy, PCV13 → PPSV23, and alternatively, versus sequentially administered 15-valent PCV and PPSV23 (PCV15 →  PPSV23), and presented as cost per quality-adjusted life year gained; a healthcare system perspective was used. Costs and benefits were discounted at 3%/year. PCV20 in lieu of PCV13 → PPSV23 among moderate-/high-risk adults aged 18-64 years and all adults 65-99 years (N = 13.4M) prevented 3838 IPD, 4377 inpatient NBP, and 6003 outpatient NBP cases, and 1865 disease-related deaths; relative to PCV15 → PPSV23 the corresponding reductions were 2775, 3285, 4518, and 1348. PCV20 was projected to be the dominant strategy versus PCV13 → PPSV23 and PCV15 → PPSV23 as overall costs were lower by $87.6M and $80.8M, respectively. In probabilistic sensitivity analyses, PCV20 was dominant (i.e., more effective, less costly) in 100% of 1000 simulations. Analyses suggest implementing a PCV20 vaccination program in moderate-/high-risk adults aged 18-64 years and all adults ≥ 65 years-in lieu of PCV13 → PPSV23-would yield substantial reductions in pneumococcal disease and would be cost saving to the Argentinean healthcare system.

Diagnostic value of microbial cell-free DNA sequencing for suspected invasive fungal infections: a retrospective multicenter cohort study

Abstract Background An early diagnosis and treatment of invasive fungal disease(IFD) is associated with improved outcome, but the moderate sensitivity of non-invasive diagnostic tests makes this challenging. Invasive diagnostic procedures like bronchoalveolar lavage(BAL) have a higher yield but are not without risk. The detection and sequencing of microbial cell-free DNA(mcfDNA) may facilitate a non-invasive diagnosis. Materials In a prospective observational study, we collected plasma in the 120 hours preceding or following a BAL in patients with hematological malignancies suspected for a pulmonary IFD. The EORTC/MSGERC2020 criteria were used for IFD classification. Sequencing was performed by Karius(Redwood City, California) using their Karius Test® (KT) on plasma and a ‘research use only test'(RUO-KT) on BAL fluid if available. Cases with a probable/proven IFD were identified based on standard diagnostic tests on serum and BAL (microscopy, PCR, GM, culture) and used to calculate the sensitivity, specificity and additional diagnostic value of the KT. Results Of 106 patients enrolled, 39 (37%) had a proven/probable invasive aspergillosis (IA), 7 (7%) a non-Aspergillus IFD and 4 (4%) a mixed IFD. The KT detected fungal mcfDNA in 29 (28%) patients. Compared with usual diagnostic tests, the sensitivity and specificity were 44.0%(95%CI:31.2–57.7%) and 96.6%(95%CI:88.5–99.1%). Sensitivity of the KT was higher in non-Aspergillus IFD (Mucorales:2/3, Pneumocystis jirovecii:3/5). On BAL, the sensitivity was 72.2% (95%CI:62.1–96.3%) and specificity 83.3%(95%CI:49.1–87.5%). Conclusions Sequencing of mcfDNA may facilitate a non-invasive diagnosis of IFD in particular non-Aspergillus IFD. However, on plasma and similar to currently available diagnostics, it cannot be used as a “rule-out” test.

Preclinical validation of an Escherichia coli O-antigen glycoconjugate for the prevention of serotype O1 invasive disease.

The Escherichia coli serotype O1 O-antigen serogroup is a common cause of invasive bloodstream infections (BSI) in populations at risk such as newborns and the elderly. Sequencing of US BSI isolates and structural analysis of O polysaccharide antigens purified from strains that are representative of genotypic sub-groups confirmed the relevance of the O1a subtype as a vaccine antigen. O polysaccharide was purified from a strain engineered to produce long-chain O1a O-antigen and was chemically conjugated to CRM197 carrier protein. The resulting glycoconjugate elicited functional antibodies and was protective in mice against lethal challenges with virulent K1-encapsulated O1a isolates.

Genomic surveillance of invasive meningococcal disease during a national MenW outbreak in Australia, 2017–2018

Abstract Background In Australia, invasive meningococcal disease (IMD) incidence rapidly increased between 2014 and 2017 due to rising serogroup W (MenW) and MenY infections. We aimed to better understand the genetic diversity of IMD during 2017-18 using whole-genome sequencing (WGS) data. Methods Whole-genome sequencing data from 440 Australian IMD isolates collected during 2017-18 and 1737 international MenW:CC11 isolates collected in Europe, Africa, Asia, North America, and South America between 1974 and 2020 were used in phylogenetic analyses; genetic relatedness was determined from single nucleotide polymorphisms. Results Australian isolates comprised 181 MenW (41%), 144 MenB (33%), 88 MenY (20%), 16 MenC (4%), 1 MenW/Y (0.2%), and 10 non-genogroupable (2%) isolates. Eighteen clonal complexes (CC) were identified; three (CC11, CC23, CC41/44) accounted for 78% of isolates (343/440). These CCs were associated with specific serogroups; CC11 (199) predominated among MenW (181) & MenC (15), CC23 (80) among MenY (78), and CC41/44 (64) among MenB (64). MenB isolates were highly diverse, MenY intermediately diverse, and MenW & MenC isolates demonstrated the least genetic diversity. Thirty serogroup and CC-specific genomic clusters were identified. International CC11 comparison revealed diversification of MenW in Australia. Conclusions WGS comprehensively characterised Australian IMD isolates, indexed their genetic variability, provided increased within-CC resolution, and further elucidated the evolution of CC11 in Australia.

Abstract PO3-09-05: Potential novel treatments for high-risk subsets of breast cancer in postpartum and African American women

Abstract Semaphorin 7a (SEMA7A) is a neuroimmune molecule first recognized for its roles in axonal guidance and inflammation. More recently, SEMA7A has emerged as a driver of tumor progression in multiple types of cancer including lung, glioblastoma and breast. Our studies have focused on the roles of SEMA7A in promoting tumor cell growth and survival as well as invasion and metastasis in mouse models including xenograft and syngeneic. Using patient samples and datamining we have shown that SEMA7A can predict for recurrence in women with postpartum breast cancer (PPBC), or breast cancers diagnosed within 10 years of recent childbirth, and SEMA7A mRNA expression in TCGA is highest in young and African American (AA) women with BC, who typically have poor prognosis. Additionally, our analysis of the Cancer Genome Atlas (TCGA) breast cancer (n=593) and METABRIC cohorts (n=2,136) revealed that SEMA7A is increased in invasive disease and in the top 9% and 27% of upregulated genes (p=1.09E-19&p=0.009), respectively. Additionally, ~1.2 (TCGA) and ~1.1 (METABRIC) fold increases in SEMA7A mRNA conferred significantly decreased 5-year survival rates (p=0.009&p=0.002) and SEMA7A was in the top 4% of mRNAs upregulated in patients who died within 5 years of diagnosis 20,24-26. Cumulatively, these results suggest that identifying therapeutic vulnerabilities of SEMA7A+BC, or direct targeting of SEMA7A, could improve prognosis for these high-risk populations. We have identified several targets in pre-clinical models of SEMA7A+BC that include clinically available, FDA approved drugs, as well as novel inhibitors that exhibit efficacy. In published studies, we have shown that venetoclax, a Bcl-2 inhibitor, reverses ER+SEMA7A+BC resistance to endocrine therapy in mouse models. In unpublished studies, we have extended our observations in ER+SEMA7A+BC to show that alpelisib and a novel PI3K kinase inhibitor, GCT-007, both inhibit growth of human and mouse mammary tumor cells. Furthermore, in models of ER-SEMA7A+BC where we have shown cells to be resistant to chemotherapy, we have utilized age matched cell lines from AA and CA women to dissect the downstream pro-survival signaling that is mediated by SEMA7A and we have shown that anti-PD-1 and anti-PD-L1 therapies are efficacious in reducing tumor growth in vivo. Finally, we have developed a novel monoclonal antibody-based therapy that directly targets SEMA7A signaling via pro-survival pathways and inhibits tumor growth in vivo and in vitro. Collectively our results suggest that SEMA7A+BC should be identified clinically, and alternative treatments advised for this high-risk subset of breast cancer. Citation Format: Traci Lyons, Lyndsey Crump, Rachel Steinmetz, Kelsey Kines, Heather Fairchild, Alan Elder. Potential novel treatments for high-risk subsets of breast cancer in postpartum and African American women [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-09-05.

Abstract PO4-23-05: Magnetic lymphatic tracing for omission of sentinel lymph node biopsies in mastectomy patients: a community cancer center experience

Abstract Background Patients with ductal carcinoma in situ (DCIS) and patients undergoing risk reduction mastectomy traditionally undergo sentinel lymph node biopsy (SLNB) at the time of mastectomy to complete axillary staging were invasive malignancy to be identified on final pathology. About 10% of patients with DCIS undergoing mastectomy will have invasive disease on final pathology; thus, about 90% would be able to avoid SLNB. Standard lymphatic mapping for SLNB includes a combination of radioisotope and blue dye, which have a short half-life. Superparamagnetic tracers, such as Magtrace®, are non-inferior to this standard and remain active for several weeks, allowing many patients to avoid SLNB in the setting of mastectomy. Reducing SLNB may also reduce associated risks with SLNB such as hematoma, seroma, and subsequent lymphedema. Objective We hypothesized using Magtrace® would reduce the number of SLNB in patients undergoing mastectomy for DCIS or risk reduction. Consequently, this would reduce the number of SLNB-associated complications. We report a community cancer center experience with Magtrace® for omission of SLNB in select mastectomy patients. Methods This was a retrospective review of 52 female patients with DCIS or known genetic predisposition undergoing mastectomy. Magtrace® was injected ipsilateral to DCIS or bilateral for prophylactic mastectomy patients. Our primary outcome was rate of return to the OR for delayed SLNB. Secondary outcomes included post operative complications within 30 days of surgery and OR time. We compared outcomes to a control group of 28 women undergoing mastectomy for DCIS or risk reduction who underwent SLNB at their index operation. Continuous variables were reported using median and interquartile range (IQR) and were compared using the Mann-Whitney U-test. Categorical data were reported using frequency and percent; they were compared using Pearson’s Chi-Square or Fisher’s Exact test, as appropriate. Alpha was set to 0.05 to determine statistical significance. Results There were a total of 80 patients (52 Magtrace®, 28 control). Median age of Magtrace patients was 49.5 (IQR 40-60.75) vs. 54.5 (IQR 48-65) years for the controls. 57.7% of Magtrace® patients underwent mastectomy for DCIS vs. 89.3% in the control group. 8 Magtrace® patients (15.4%) had invasive ductal carcinoma on final pathology and 7 of those patients underwent SLNB and none were positive for metastatic disease. Of these, 6 patients underwent mastectomy for DCIS. Average number of sentinel lymph nodes was 1.57 in Magtrace® patients and 1.60 in the control patients. Rates of post operative complications were similar between the groups, including hematoma, seroma, surgical site infection, skin necrosis. OR times were also similar with median OR time 202 minutes (min) for the Magtrace® group vs. 195 min for the control group. Conclusion Use of Magtrace® avoided SLNB in 84.6% of our patients. We found no difference in rates of postoperative complications or operative times in patients using Magtrace® for omission of SLNB at time of mastectomy compared to the control group. Our findings suggest SLNB can be avoided in a majority of patients undergoing mastectomy for DCIS or risk reduction in the setting of genetic predisposition. Table. Citation Format: Mia Samaha, Barbara Wexelman, Anne Kurtizky, Kathleen Raque, Angie Fellner. Magnetic lymphatic tracing for omission of sentinel lymph node biopsies in mastectomy patients: a community cancer center experience [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-23-05.

Abstract PO5-11-07: Short- and long-term treatment-related effects on physical health in breast cancer survivors

Abstract Background. Breast cancer (BC) survivors experience greater physical health declines compared to cancer-free women of the same age, which is thought to be caused by their cancer and its treatment. However, the short- and long-term effects of different types of treatment on physical health are not well understood, especially for hormone therapy. Moreover, whether specific aspects of physical health, such as activities of daily living (ADL), are affected by treatment is unknown. Methods. This analysis was conducted in the Cancer Prevention Study 3 (CPS-3), a prospective cohort study with approximately 300,000 participants enrolled between 2006-2013. Participants returned a baseline survey and triennial follow-up surveys beginning in 2015. Incident, non-metastatic, female BC patients were included in this analysis if they returned a survey at least 90 days after their diagnosis through June 30, 2020, the end of follow-up for this analysis. All 2,551 BC patients included in this study had pre- and post-diagnostic surveys and underwent breast surgery if they were diagnosed with invasive disease. They were matched to up to five cancer-free women on age and year of survey returns (N=12,704). Self-reported physical health and ADL were assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Scale instrument. Treatment information was obtained from cancer registries and self-report and included surgery, chemotherapy, radiation and hormonal therapy. Odds Ratios (OR) and 95% confidence intervals (CI) between treatment received and self-reported physical function were estimated using multivariable ordinal logistic regression models at three time points relative to the case’s diagnosis date: before diagnosis, within 90 days to 5 years after diagnosis, and more than 5 years after diagnosis. Results. Median age at diagnosis was 56 years (interquartile range (IQR): 50-62). Approximately 82% of the tumors were hormone-receptor positive. The median times from the three physical health measurements to diagnoses were 1.7 years before diagnosis (IQR: 0.9 – 2.7), 1.7 years (IQR: 0.9 – 2.5) from 90 days to 5 years post-diagnosis and 6.6 years (IQR: 5.5-7.0) for more than 5 years post-diagnosis. There was a significant risk of physical decline within 5 years of diagnosis for women who received chemotherapy or hormonal therapy compared to cancer-free women (Table 1). However, more than 5 years after diagnosis, the risk of physical decline was only observed among those who received chemotherapy. Treatment combinations that included chemotherapy were also associated with a decline in the ability to carry out ADL during the first 5 years. Patients who received hormonal therapy without chemotherapy were comparable to cancer-free women in their ability to carry out ADL during the post-diagnosis period. BC patients who received surgery only or surgery and radiation reported physical health and ADLs similar to cancer-free women within 5 and >5 years after diagnosis. Conclusions. Post-diagnosis physical health decline is time and treatment dependent. Patients receiving chemotherapy have the greatest overall physical health decline and it is long-lasting. Beyond five years from diagnosis, physical health of breast cancer patients who did not receive chemotherapy were similar to cancer-free women. Strategies are needed to help BC patients receiving chemotherapy overcome the long-term physical function limitations of their cancer treatment. Table. Associations between treatment received and physical health and ability to carry out activities of daily living. OR: Odds Ratio; CI: confidence interval; chemo: chemotherapy; radio: radiation therapy; horm: hormonal therapy. *Associations were adjusted for matching factors, which included age and time from diagnosis to measurement of physical health. Citation Format: Clara Bodelon, Matthew Masters, Lauren McCullough, Alpa Patel, Lauren Teras. Short- and long-term treatment-related effects on physical health in breast cancer survivors [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-11-07.

Abstract PO3-28-10: MRI Radiomic phenotypes derived from the ECOG-ACRIN E4112 Trial to assess high-risk ductal carcinoma in situ

Abstract INTRODUCTION Ductal carcinoma in situ (DCIS) is a non-lethal pre-invasive breast cancer that can co-exist with invasive disease. Dynamic contrast-enhanced (DCE) MRI is sensitive for the detection of high-grade DCIS and invasive cancer while Oncotype DCIS Score is a 12-gene assay that can assess recurrence risk. In practice, it is difficult to distinguish low- from high-risk DCIS, which leads to overtreatment for up to half of women diagnosed with DCIS. We hypothesize that radiomic phenotypes of DCIS derived from DCE-MRI data may serve as prognostic markers to improve risk stratification by capturing disease heterogeneity. Here we evaluate the ability of these phenotypes to predict DCIS Score and upstaging of DCIS to invasive disease on wide local excision in a multicenter trial. METHODS Data: DCE-MRI data from the ECOG-ACRIN E4112 trial were retrospectively analyzed. Primary analysis focused on participants with data on disease upstaging (N=295), with secondary analysis in a subset (N=174) of participants with DCIS Scores (dichotomized as >55 and 55) and pure DCIS. Clinical information included patient demographics, lesion morphology on MRI, background parenchymal enhancement, DCIS grade, central necrosis, and hormone receptor status. Data analysis: Radiologist-drawn lesion segmentations and publicly available software, CaPTk, were used to compute 64 radiomic features from first post-contrast images for each participant. Radiomic phenotypes were identified using hierarchical clustering on the extracted features. A Chi-square test was used to evaluate the association between radiomic phenotypes and each outcome. The likelihood ratio test was used to compare two logistic regression models: 1)clinical model using only clinical information as predictors and 2) clinical+phenotypes model using clinical information and phenotype assignment as predictors. Each model was used for the prediction of upstaging to invasive disease and DCIS score. Model performance was evaluated as the 10-fold cross-validated area under the receiver operator characteristic curve (AUC). A p< 0.05 was considered significant. RESULTS A total of 45 (15%) cases upstaged to invasive disease. Two radiomic phenotypes were identified: Phenotype 1 indicated greater lesion signal heterogeneity, while Phenotype 2 indicated lower heterogeneity. Radiomic phenotype was strongly associated with disease upstaging (p=0.0034) – with a higher rate of upstaging for Phenotype 1 – but not with DCIS score (p=0.1174, Table 1). For predicting disease upstaging, the clinical+phenotypes model yielded a higher AUC=0.72 and a significantly better fit to the data (p=0.0022) compared to the clinical model parameterized by clinical information alone (AUC=0.69). For predicting DCIS Score, the clinical+phenotypes model (AUC=0.77) showed similar performance compared to the clinical model (AUC=0.76) and no significant improvement in fit to the data (p=0.2920). CONCLUSION Radiomic phenotypes capturing disease heterogeneity show promise as prognostic predictors for predicting disease upstaging in DCIS compared to clinical information alone and may enable more efficient disease management. We observed that phenotypes did not have independent predictive outcome for DCIS score, suggesting that MRI and DCIS Score offer independent information and could be combined in future models to better predict disease recurrence or progression. Clinical applications of radiomic phenotypes may improve risk stratification and potentially result in decreased overtreatment of women diagnosed with DCIS. Table 1: Association between radiomic phenotypes and DCIS outcomes using a Chi square test. Citation Format: Kalina Slavkova, Ruya Kang, Vivian Belenky, Anum Kazerouni, Debosmita Biswas, Hannah Horng, Rhea Chitalia, Michael Hirano, Jennifer Xiao, Ralph Corsetti, Sarah Javid, Derrick Spell, Antonio Wolff, Joseph Sparano, Seema Khan, Christopher Comstock, Justin Romanoff, Jon Steingrimsson, Constantine Gatsonis, Constance Lehman, Savannah Partridge, Despina Kontos, Habib Rahbar. MRI Radiomic phenotypes derived from the ECOG-ACRIN E4112 Trial to assess high-risk ductal carcinoma in situ [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-28-10.

Abstract PO2-17-06: Real world treatment patterns and clinical outcomes by germline BRCA (gBRCA) mutation status in patients with HER2-negative early breast cancer in the US community oncology setting: a retrospective observational chart-review study

Abstract Background: Women with early-stage breast cancer (eBC) who have inherited BRCA1 or BRCA2 mutations (gBRCAm) are typically diagnosed at a younger age and often require more intensive treatment. In the randomized, double-blind OlympiA trial of HER2-negative (HER2–) gBRCAm patients, olaparib, a targeted poly (ADP-ribose) polymerase inhibitor (PARPi), significantly improved invasive disease free survival (IDFS), distant disease free survival (DDFS) and overall survival (OS) and was subsequently approved for adjuvant treatment of gBRCAm HER2– high-risk eBC patients. This study examined the real-world patient characteristics, treatment patterns and clinical outcomes by gBRCA status among patients with HER2– eBC in a US community oncology setting prior to olaparib US approval for treatment of eBC. Methods: This retrospective observational study used chart review data from The US Oncology Network's iKnowMed database to examine adult patients diagnosed with HER2– eBC (stage I-III) initiating systemic neoadjuvant or adjuvant therapy with chemotherapy and/or endocrine therapy between January 1, 2012 and December 31, 2018. Patients with valid gBRCAm test results (all gBRCAm and randomly selected BRCAwt patients) were included and followed through December 31, 2021. Patients were excluded if they had HER2+ tumors and progressed to stage IV within 6 months after initiation of neoadjuvant therapy or were diagnosed with another primary cancer. Descriptive analyses assessed patient characteristics. Kaplan Meier methods and multivariate Cox proportional hazard models (CPHM) were used to evaluate IDFS, DDFS and OS by gBRCA status and by HR+/HER2– or TNBC eBC subsets. Results: Among 298 BC patients meeting initial criteria, 42% had gBRCAm (n=124, 43% hormone receptor positive [HR+], 56% triple-negative BC [TNBC], 1% unknown), and 58% had gBRCAwt (n=174, 74% HR+, 22% TNBC). Median (interquartile) age at surgery was numerically lower in gBRCAm (45 [36,55] years) than gBRCAwt (48 [41,55] years) patients. A numerically higher proportion of gBRCAm patients received neoadjuvant therapy compared with gBRCAwt (Neoadj: gBRCAm 37.1% vs gBRCAwt 12.6%) but the reverse was true for adjuvant (Adj: gBRCAm 42.7% vs gBRCAwt 65.5%) and neoadjuvant + adjuvant use was numerically similar (Neoadj+Adj: gBRCAm 20.1% vs gBRCAwt 21.8%). The majority of TNBC patients received neoadjuvant therapy while the majority of HR+ patients received adjuvant therapy (Neoadj: TNBC 51.4% vs HR+ 6.6%, Adj: TNBC 29.0% vs HR+ 71.4%, Neoadj+Adj: TNBC 19.6% vs HR+ 22.0%). Median IDFS, DDFS, and OS in both study cohorts were not reached. Median follow-up from surgery was < 5 years (overall 59.0 months; gBRCAm 50.6 months; gBRCAwt 61.3 months). At 60 months, in gBRCAm and gBRCAwt respectively, estimated IDFS were 85.5% and 90.9%, estimated DDFS 88.1% and 92.2%, and estimated survival 91.9% and 95.2%. At 60 months, in HR+/HER2– and TNBC respectively, estimated IDFS were 92.4% and 81.2%, estimated DDFS 93.9% and 85.7%, and estimated survival 96.3% and 90.9%. CPHM results showed that risks of invasive disease (HR 1.74; 95% CI 0.83-3.64; p=0.15), distant disease (HR 1.24; 95% CI 0.50-3.07; p=0.65) and death (HR 1.79; 95% CI 0.52-6.13; p=0.353) were similar between gBRCAm and gBRCAwt patients. Between HR+/HER2– and TNBC patients, risks of invasive disease (HR=0.63; 95% CI 0.21-1.89; p=0.41), distant disease (HR=0.42; 95% CI 0.11-1.67; p=0.22) and death (HR 0.48; 95% CI 0.09-2.70; p=0.41) were similar. Conclusions: This real-world chart review study of data through 2021 (before PARPi approval for eBC) with limited follow up of 5 years found that gBRCAm patients had a numerically shorter survival (IDFS, DDFS and OS) than gBRCAwt, but this difference was not statistically significantly different. Given that the follow-up period was too short to draw conclusions, further studies examining clinical outcomes over a longer follow-up period after approval of PARPi may be of interest. Citation Format: Jay Andersen, Jagadeswara Earla, Nicole Fulcher, Juliet Ndukum, Nicholas J Robert, Mark Robson, Weiyan Li, Jaime Mejia. Real world treatment patterns and clinical outcomes by germline BRCA (gBRCA) mutation status in patients with HER2-negative early breast cancer in the US community oncology setting: a retrospective observational chart-review study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-17-06.