Citations

801 Background: SBA is a rare, poorly understood gastrointestinal malignancy. Adenocarcinomas are often grouped with other small bowel cancer histologies in epidemiologic and outcomes reports, which limits the ability to detect SBA-specific trends. Recent studies in European populations show increasing SBA incidence, but there are limited published data in American cohorts. Identifying trends in SBA can improve understanding of the population most at risk for developing SBA. This study describes U.S. trends in SBA incidence and outcomes from 2000 to 2019. Methods: Using the 2022 SEER research-limited dataset, we identified SBA cases and measured the incidence change from 2000-2019. We built linear regression models to evaluate changes in annual incidence by groups, including sex, race, and age of diagnosis, separately. We then compared the overall incidence and trends between subgroups. We investigated overall survival (OS) through the SEER research case listings for SBA patients diagnosed during the study period. Results: An average of 0.67 cases/100,000 SBA cases were reported annually from 2000-2019, with a median diagnosis age of 69 years. SBA incidence has increased annually by 0.3% per year from 2000-2019 (p=0.05). From 2000-2019, men were at a higher risk for SBA compared to women (p=0.02). In men, SBA cases increased at a rate of 0.004 cases/100,000/year from 2000-2019 (p=0.01) and a nonsignificant decrease in women of 0.00012 cases/100,000/year. There were no statistically significant differences in incidence or the change in incidence of SBA by race. The age-adjusted incidence was significantly higher each year between 2000 and 2019 in the > 70 cohort compared to the <70 cohort (p=0.02). Cases of SBA increased at a rate of 0.02 cases/100,000/year in adults >70 years (p=0.02). There were no differences in incidence rates in patients <70 years. There was no significant difference in OS for patients diagnosed with SBA in 2000, 2005, 2010, 2015, and 2019 (p=0.21). Conclusions: The overall annual incidence of SBA is increasing in the U.S. population. The most significant rate increases are in men and adults older than 70. In the SEER population, trends in SBA contrast with the recent rise of colorectal cancer in the young adult population, highlighting the unique nature of SBA compared to other gastrointestinal malignancies. Additionally, survival outcomes in patients diagnosed with SBA have remained stable over the past 20 years, while other malignancies have shown improvement in the same period. The small cohort size and the lack of a universal U.S. cancer registry limited this evaluation. Improved reporting of SBA cases and further research to identify risk factors are urgently needed to reduce the growing impact of SBA.

732 Background: Ampullary carcinoma (AC) is a rare malignancy arising from the ampulla of Vater which has a more favorable prognosis compared to other pancreatic malignancies. Current guidelines favor surgical resection followed by adjuvant therapy for average risk patients (pts), however the type of regimen as well as other perioperative treatment modalities are still being explored. The objective of this retrospective study aims to provide insight into the management of locoregional disease. Methods: Pathology records from Mayo Clinic (AZ, FL, MN) denoting AC between 2010 to 2024 were searched using Mayo Data Explorer and selected for retrospective review. Pt demographics, treatment courses, and next generation sequencing (NGS) data were collected. Statistical analysis was conducted using SAS version 9.04. Results: A total of 137 pts (62% male, n = 85) were identified with median age 66 years old. Histologic subtypes were 54% pancreatobiliary (44/81), 40% intestinal (32/81), 6% mixed (5/81), with 56 pts unknown. Stages at diagnosis were 81% resectable (111/137), 11% locally advanced (15/137), and 8% metastatic (11/137). Nearly all (93%, n = 103/111) pts with localized disease had resection with a 97% R0 resection rate (100/103). Majority (68%, n = 75/111) of resectable pts had perioperative chemotherapy with 5-FU or gemcitabine-based regimens (24%, n = 18/75 neoadjuvant vs. 76%, n = 57/75 adjuvant). Perioperative chemoradiation was given in 17% (19/111) of pts. At median follow up of 30.5 months, recurrence rates were 40% (41/103), primarily to the liver (18/41). Median recurrence free survival (RFS) was 29.3 months (95% CI 24.7 – NE). Median overall survival (OS) has not been reached. The 5-year RFS and OS rates were 0.37 (95% CI 0.25 - 0.55) and 0.69 (95% CI 0.58 - 0.82), respectively. Univariate analysis showed no difference in OS with the addition of neoadjuvant or adjuvant chemotherapy or chemoradiation. Somatic NGS testing showed pathogenic mutations in 90% of pts (63/70): 57% KRAS (36/63; 44% G12D, 19% G12V, 8% G12C, 8% G12D, 19% others); 13% homologous recombination (HR) (8/63); 6% ERRB2 /Her2 amplification (4/63), and 5% mismatch repair (MMR) (3/63). Conclusions: AC has a favorable prognosis in resectable pts. However, high recurrence rates indicate the need for better systemic therapies and improved selection of pts who would benefit from these treatments. Future research should focus on refining perioperative strategies to enhance outcomes and reduce recurrence.

33 Background: Since the late 1990s, both the incidence and mortality of invasive colorectal cancer (CRC) have decreased across the United States, including in Kentucky. Despite this, CRC incidence and mortality are above national average in Kentucky. Over the last two decades, a disparity in CRC incidence and mortality has emerged between Appalachian Kentucky (AK), a distinct eastern region, and Non-Appalachian Kentucky (NAK). This disparity is attributed to differences in social and structural determinants of health (SSDH) between these populations. Methods: Age-adjusted CRC incidence and mortality rates (2016-2020) for both Kentucky and the U.S. were obtained from the National Cancer Institute’s public database. Data from the Kentucky Cancer Registry were used to compare CRC incidence and mortality rates in AK and NAK counties from 1994-2021. Incidence rate ratio analyses across discrete time periods demonstrated statistical differences between these regions. Results: Compared to national data (2016-2020), Kentucky's CRC age-adjusted incidence and mortality rates were significantly higher: 45.9 vs. 36.5/100,000, 25.8%, for incidence, and 16.2 vs. 13.1/100,000, 23.7%, for mortality (both p<0.0001). From 1995-2003 incidence and 1994-2003 mortality of CRC, were higher in NAK, these rates eventually decreased and equalized between NAK and AK. By 2010-2015 both incidence and mortality rates were higher in AK, 55.8 vs 48/100,000, 16.3%, (p=<0.0001) and 20.1 vs 15.8/100,000, 27.2%, (p=<0.0001) respectively. The most recent data (2016-2021) shows that these significant disparities persist, with AK’s incidence and mortality 51.8 vs 44.1/100,000, 17.5% (p=<0.0001) and mortality 19.0 vs 15.1/100,000, 25.8% (p=<0.0001) higher, respectively. Conclusions: While CRC rates have decreased nationwide and in Kentucky, a pronounced gap in both incidence and mortality has developed between Appalachian and Non-Appalachian Kentucky. Appalachian counties—which are more rural and impoverished—face greater barriers to accessing preventive healthcare, contributing to this disparity. Additionally, AK has higher rates of obesity, poverty, smoking, and lower educational attainment and screening rates . Recent public health efforts, such as promoting stool-based screening and increasing preventive care discussions, aim to reduce these disparities. However, delays in CRC screenings during the COVID-19 pandemic— resulting in approximately 1.7 million missed colonoscopies nationally— may have skewed the most recent data, necessitating further analysis in the coming years.

163 Background: CRC with PM has a poor prognosis and limited treatment options. Immunotherapy has shown promise in improving outcomes for patients with microsatellite instability-high (MSI-H), mismatch repair-deficient (dMMR), and high tumor mutational burden (TMB-H) tumors. However the peritoneal niche has a unique microenvironment, which can influence the effectiveness of immune check point inhibitors (ICIs). We assessed the impact of ICI on progression-free survival (PFS) and overall survival (OS) in CRC patients (pts) and PM, considering key clinical and molecular characteristics. Methods: A retrospective review aiming to identify CRC pts with MSI-H/dMMR and PM treated with immunotherapy between 2015 and 2023 was performed. Data collected included pt demographics, tumor characteristics, and treatment details. Responses were evaluated using RECIST v1.1 criteria. Results: 37 pts were included, 9 (24%) had Lynch syndrome. The median age of diagnosis was 61 years and most pts were females (65%). Most pts had MSI-H/dMMR tumors, while one pt was treated based on ultra-hypermutated phenotype (TMB 202) and POLE mutation. Among those with available TMB data, the median TMB was 52 mutations/Mb (0-202). Common mutations were PMS2 (51%), MLH1 (38%), MSH6 (16.2%), and MSH2 (16.2%). Right-sided tumors were in 54%, mucinous histology in 62%, and ascites in 54%. Pts received a median of 11 cycles of ICI (2-52). Pembrolizumab was the most frequently used ICI (78%), while Nivolumab was used either alone (11%) or in combination with Ipilimumab (11%). Median PFS in our cohort was 7.8 months and median OS was 29.9 months. The disease control rate (DCR) was 81%, with an objective response rate (ORR) of 51.3% (9 complete responses, 12 partial responses). At the time of data collection, 30% of pts were off systemic therapy and 5-FU-based chemotherapy combined with a biologic agent was the most common subsequent treatment in 32% who had PD. Univariate analysis showed no significant differences in PFS or OS based on tumor sidedness, isolated PM, liver metastases, mucinous vs. non mucinous histology or BRAF / RAS status (WT vs mutant). Malignant ascites was associated with worse OS(HR 0.3; p= 0.03). Conclusions: Treatment with ICIs in pts with MSI-H/dMMR and/or TMB-H CRC and PM improved disease control in CRC pts with PM, however, as compared to historical controls for patients with MSI-H/d-MMR disease treated with ICI, this group showed less favorable outcomes. Malignant ascites was associated with poorer overall survival. Further research of the immune response and tumor microenvironment in the peritoneal cavity is warranted.

142 Background: Fruquintinib (F) is a highly selective, oral tyrosine kinase inhibitor of all 3 vascular endothelial growth factor receptors (VEGFRs -1, -2, -3) that is approved by the US FDA and in the EU, UK, and Japan for previously treated metastatic colorectal cancer (mCRC), regardless of biomarker status. FRESCO-2 (NCT04322539) met its primary endpoint demonstrating significantly improved overall survival (OS) with F + best supportive care (BSC) vs placebo (P) + BSC. This subgroup analysis assessed landmark survival of all FRESCO-2 patients (pts), and baseline (BL) characteristics and safety data of pts treated with F who had OS ≥10 months (mos) compared with the intent-to-treat (ITT) population (pop). Methods: Pts were randomized 2:1 to receive F 5 mg or matching P, by mouth, once daily, 3 weeks on, 1 week off, + BSC. Pts had received prior chemotherapy, anti-VEGF therapy and, if RAS wild type, anti-EGFR therapy; and had prior exposure to trifluridine/tipiracil (TAS-102) and/or regorafenib. The hazard ratio (HR) between the two treatment arms was calculated from a stratified Cox proportional hazard model with treatment group as the only covariate in the model. Results: In the ITT pop, OS was improved with F vs P (HR 0.66); OS rates (95% confidence intervals [CIs]) at 6 and 9 mos were 60.4% (55.9–64.9) vs 41.5% (35.0–48.0) and 41.1% (36.4–45.8) vs 28.2% (22.1–34.3), respectively. Progression-free survival (PFS) rates (95% CIs) at 6 and 9 mos were 23.8% (19.7–28.0) vs 1.1% (0–2.6) and 11.3% (8.1–14.6) vs 0.5% (0–1.6), respectively. Of 461 pts who received F, 113 (24.5%) had OS ≥10 mos (range 10.0–18.9) with a median duration of F treatment of 6.3 mos (range 0.7–19.1). Among pts receiving F, a higher proportion (≥10% difference) of pts with OS ≥10 mos had no liver metastases (mets) and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 at BL compared with the ITT pop (Table). In pts with OS ≥10 mos, 61.9% experienced a grade ≥3 treatment-emergent adverse event compared with 62.7% in the ITT pop. Conclusions: Longer-term OS and PFS rates at 6 and 9 mos were higher with F vs P in the FRESCO-2 ITT pop. The data show a higher proportion of pts with OS ≥10 mos had an absence of liver mets and ECOG PS 0 at BL than the ITT pop. The safety profile of F in pts with OS ≥10 mos was consistent with the ITT pop. Clinical trial information: NCT04322539 . BL characteristics of pts treated with F with OS ≥10 mos vs ITT pop. BL characteristic Pts with OS ≥10 mos (n=113) ITT pop(n=461) ECOG PS (0 / 1), % 54.0 / 46.0 42.5 / 57.5 Median time since 1 st CRC diagnosis, mos 52.0 47.2 Primary tumor location at 1 st diagnosis (colon / rectum / both), % 51.3 / 35.4 / 13.3 60.5 / 31.0 / 8.5 Primary site at 1 st diagnosis (colon left / colon right), % 42.5 / 15.9 41.6 / 21.0 Liver mets, % 58.4 73.5 Median duration of mCRC, mos 42.7 37.9 Prior lines of therapy for mCRC (≤3 / >3), % 26.5 / 73.5 27.1 / 72.9 Prior TAS-102, % 46.9 52.1 Prior regorafenib, % 12.4 8.7

131 Background: KRAS G12C mutations occur in 3%–4% of CRC cases and are associated with poor prognosis. In the phase 1/2 KRYSTAL-1 study (NCT03785249), at a median follow-up of 11.9 months (mo), Ada (irreversible inhibitor of KRAS G12C ) in combination with Cetux (anti-EGFR antibody) demonstrated promising clinical activity (objective response rate [ORR] of 34% per blinded independent central review [BICR] and 43% per investigator [INV]) and was well tolerated in patients (pts) with previously treated KRAS G12C -mutated mCRC. Based on these findings, Ada + Cetux was granted accelerated approval in the United States for these pts. Here, we present longer-term follow-up analyses from this study. Methods: Adults with previously treated KRAS G12C -mutated mCRC and ECOG performance status of 0 or 1 were treated with Ada (600 mg BID) in combination with Cetux (400 mg/m 2 followed by 250 mg/m 2 QW or 500 mg/m 2 Q2W) until disease progression, unacceptable toxicity, withdrawal of consent, or death, in separate phase 1 and phase 2 cohorts. Primary endpoints were safety (phase 1) and ORR per BICR (phase 2). Secondary endpoints were duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety (phase 2). Results: A total of 94 pts received Ada + Cetux. The median number of prior lines of systemic therapy was 3 (range, 1–9); 23 pts (24%) had received ≥ 4 prior lines of systemic therapy. The most frequent sites of metastases at baseline were the lung (71%) and liver (64%). At a median follow-up of 20.4 mo, ORR per INV was 43% (95% CI 32–53) and all were partial responses; median DOR was 5.9 (95% CI 5.5–7.6) mo. Disease control rate per INV was 86% (95% CI 78–92). Median PFS per INV was 6.9 (95% CI 5.9–7.4) mo; 6- and 12-mo PFS rates were 61% and 19%, respectively. Median OS was 16.0 (95% CI 13.3–18.8) mo; 6- and 12-mo OS rates were 88% and 66%, respectively. Any-grade treatment-related adverse events (TRAEs) were reported in 100% of pts, 28% of which were grade 3/4. TRAEs led to discontinuation in 10% of pts. Efficacy analyses by BICR, subgroup analyses, and additional safety results will be presented. Conclusions: In heavily pretreated pts with KRAS G12C -mutated mCRC, Ada + Cetux continued to demonstrate clinically meaningful activity and tolerable safety with longer follow-up. These updated results are consistent with those from the primary analysis and constitute the longest duration of follow-up for dual KRAS G12C /EGFR blockade in this setting. Efficacy of second-line Ada + Cetux vs chemotherapy in KRAS G12C -mutated mCRC is being investigated in the phase 3 KRYSTAL-10 study (NCT04793958). Clinical trial information: NCT03785249 .

ABSTRACTBackground and AimsAcute liver failure (ALF) is a serious condition, typically in individuals without prior liver disease. Drug‐induced ALF (DIALF) constitutes a major portion of ALF cases. Our research aimed to identify potential genetic predispositions to DIALF.MethodsWe analysed the potential genetic variants associated with DIALF using the whole exome sequencing data from 75 cases, including 40 non‐Finnish European cases in the pilot study. Chi‐square tests were performed for case–control analysis against the 1000 genomes project as the control. A replication study of 44 DIALF cases that included 24 non‐Finnish Europeans was conducted to validate candidate variants. The association between clinical phenotype and genotypes was analysed using one‐way analysis of variance.ResultsEight variants (rs561037, rs561042, rs608339, rs655260, rs1142886, rs1142888, rs1142889 and rs1142890) in the guanylate binding protein 4 (GBP4) were significantly associated with DIALF in non‐Finnish Europeans in the pilot study and confirmed in the replication study. Rs561037 and rs561042 were highly significant with the lowest allele frequencies in both pilot and replication studies. An association was also found between these variants and milder clinical outcomes, indicated by lower peak levels of ALT, AST and higher Karnofsky performance scores.ConclusionOur study identified eight GBP4 missense variants linked to a lower risk of DIALF in the non‐Finnish European population. The GBP4 protein, activated by interferon‐gamma, plays a critical role in innate immunity. These findings suggest that GBP4 variants might influence immune and inflammatory responses in DIALF, though further studies are needed to elucidate the underlying mechanisms.

Emerging evidence supports the beneficial effects of dietary fiber supplementation in alleviating gut dysbiosis, which leads to a reduction in uremic toxins and inflammatory markers in chronic kidney disease (CKD) patients. However, current evidence-based renal nutrition guidelines do not provide recommendations regarding dietary fiber intake. We performed a systematic review and meta-analysis to investigate and highlight the effects of dietary fiber supplementation on modulating uremic toxins and inflammatory markers in individuals with CKD, with or without dialysis. The eligible randomized controlled trials (RCTs) were identified from PubMed, Scopus, and Cochrane Central Register of Controlled trials until 27 November 2024. The results were synthesized using a random-effects model and presented as standardized mean differences (SMDs) with a 95% confidence interval (CI). A total of 21 studies with 700 patients were included. When compared with the control group, dietary fiber supplementation ranging from 6 to 50 g/day, for typically more than 4 weeks, could significantly reduce the levels of serum uremic toxins, including p-cresyl sulfate, indoxyl sulfate, and blood urea nitrogen (SMD −0.22, −0.34, −0.25, respectively, with p-values < 0.05), as well as biomarkers of inflammation, including interleukin-6 and tumor necrosis factor alpha (SMD −0.44, −0.34, respectively, with p-values < 0.05). These beneficial effects were consistent across different types of fibers and CKD status (with or without dialysis). However, no significant reduction in serum trimethylamine N-oxide, uric acid, and high-sensitivity C-reactive protein levels was observed with dietary fiber intervention. This study would pave the way for prioritizing dietary quality, particularly a fiber-rich diet, beyond the traditional focus on the quantities of protein, energy, and electrolyte restrictions among individuals with CKD.

Importance Essential thrombocythemia, a clonal myeloproliferative neoplasm with excessive platelet production, is associated with an increased risk of thrombosis and bleeding. The annual incidence rate of essential thrombocythemia in the US is 1.5/100 000 persons. Observations Patients with essential thrombocythemia have a persistent platelet count of 450 × 10 9 /L or greater. The differential diagnosis includes myeloproliferative neoplasms (polycythemia vera, primary myelofibrosis, chronic myeloid leukemia); inflammatory conditions such as rheumatoid arthritis and systemic lupus erythematosus; infections; splenectomy; iron deficiency anemia; and solid tumors such as lung cancer. Approximately 90% of individuals with essential thrombocythemia have genetic variants that upregulate the JAK-STAT (signal transducer and activator of transcription 5) signaling pathway, including Janus kinase 2 (JAK2, 64%), calreticulin (CALR , 23%), and myeloproliferative leukemia virus oncogene (MPL , 4%). The median age at diagnosis of essential thrombocythemia is 59 years. The median overall survival exceeds 35 years in those diagnosed at 40 years or younger. Patients with essential thrombocythemia are at increased risk of arterial thrombosis (11%), venous thrombosis (7%), and hemorrhagic complications (8%). Thrombosis risk is increased among those with a history of thrombosis, age older than 60 years, a JAK2 gene variant, and cardiovascular risk factors (eg, hypertension, diabetes mellitus, hyperlipidemias, tobacco use). Use of aspirin (81-100 mg/d) is suggested for most patients with essential thrombocythemia to lower thrombosis risk. In a retrospective study of 300 affected patients with a low thrombosis risk (younger than 60 years with no prior thrombosis), those not taking aspirin (100 mg/d) had a risk of arterial thrombosis of 9.4/1000 patient-years and a venous thrombosis risk of 8.2/1000 patient years; cardiovascular risk factors were associated with a higher risk of arterial thrombi (incidence rate ratio, 2.5 [95% CI, 1.02-6.1]), and a JAK2 gene variant was associated with increased risk of venous thrombosis (incidence rate ratio, 4.0 [95% CI, 1.2-12.9]). In a randomized trial of 114 patients at higher risk for thrombosis (age older than 60 years or a prior thrombotic event), cytoreduction with hydroxyurea significantly lowered the risk of arterial or venous thrombotic events compared with no cytoreductive therapy (3.6% vs 24%; P &amp;lt; .01). At a median of 8.5 years from diagnosis, approximately 10% of patients with essential thrombocythemia develop myelofibrosis and about 3% develop acute myeloid leukemia. Conclusions Essential thrombocythemia is a rare clonal myeloproliferative neoplasm associated with an increased risk of venous and arterial thrombosis, hemorrhage, myelofibrosis, and acute myeloid leukemia. Based on individual risk factors for thrombosis, persons with essential thrombocythemia may be treated with low-dose aspirin, either alone or in combination with a cytoreductive drug such as hydroxyurea.

Adult males and females have markedly different body composition, and energy expenditure and have different degrees of risk for metabolic diseases. A major aspect of metabolic regulation involves the appropriate storage and disposal of glucose and fatty acids. The use of sophisticated calorimetry, tracer, and imaging techniques has provided insight into the complex metabolism of these substrates showing that the regulation of these processes varies tremendously throughout the day, from the overnight fasting condition to meal ingestion, to the effects of physical activity. The sexual dimorphism in substrate metabolism is most readily observed in how fatty acids are stored and mobilized. The objective of this review is to provide a comprehensive and critical summary of the reported sex differences in the mobilization, oxidation, and storage of fat and carbohydrate in adipose tissue and skeletal muscle. We will describe how adipose tissue lipolysis differs between sexes and how this varies between fed, fasted, and exercise conditions. We will also review what is known about endogenous and exogenous fatty acid storage in adipose tissue and muscle, as well as how oxidation compares between men and women in response to exercise. What has been learned about the cellular level regulation of these processes will be described. Although glucose metabolism exhibits fewer differences between men and women, we will also review the existing knowledge on this topic.