Citations

Objectives: Esophageal cancer (EC) often presents with dysphagia due to tumor obstruction. Esophageal stenting has the potential of palliating dysphagia, improving nutrition, preventing aspiration, and improving quality of life (QoL) but may be associated with risks. The present systematic review and guidelines are intended to assist treatment decision-making when considering stent placement in patients with EC based on the available evidence. Methods: Using the population, intervention, comparator, outcome, timing and study design framework, the evidence was assessed using Cochrane and PRISMA 2020 methodology. Eligible studies included prospective phase II-III trials and retrospective analyses published between January 1, 2010 and December 3, 2024 in the Ovid Medline database. These references were assessed by American Radium Society (ARS) Appropriate Use Criteria (AUC) methodology. RAND-UCLA consensus methodology was used to rate the appropriateness of the use of stents. Results: ARS AUC recommendations include (1) esophageal stenting is usually not appropriate in patients with early-stage EC in whom upfront surgery is planned; (2) esophageal stenting is usually not appropriate in patients with locally-advanced EC in whom neoadjuvant/perioperative therapy and esophagectomy or definitive chemoradiation is planned; (3) esophageal stenting may be appropriate in the setting of metastatic EC, especially in patients with short life expectancy with limited treatment options; (4) esophageal stenting is usually not appropriate for benign stricture following curative-intent therapy; (5) esophageal stenting is usually not appropriate for locally recurrent tumor in the setting of prior radiation; and (6) esophageal stenting is usually appropriate for management of tracheoesophageal fistula before curative-intent treatment. Conclusions: This ARS AUC summary provides guidelines for the use of esophageal stents in patients with EC provides based on available evidence.

3520 Background: Recent analyses highlight nonhierarchical outcomes using the 8 th Edition AJCC staging system for CC. For instance, the 5-year survival rate for stages I and IIIa patients (pts) closely align. Additionally, tumor deposits (TDs) have been established as significant prognostic indicators. The AJCCCCEP commissioned this study to develop an updated pathological staging system for CC focused specifically on pts without distant metastasis (M0), while retaining the existing stage IV classification. Methods: Individual patient data (IPD) from pts diagnosed with cc (2010- 2017) in the NCDB were divided into training (70%) and internal validation (30%) datasets. External validation used IPD from clinical trials. The primary endpoint was overall survival (OS). Risk classification development for M0 pts incorporated ungrouped data on pathologic T categories, the number of involved regional lymph nodes (LN+), and TD counts. Recursive partitioning and regression tree analyses were applied to construct hierarchical staging levels. Pre-specified criteria required survival probabilities to be consecutive and show clear separations using Kaplan-Meier (KM) estimates with pairwise log-rank test P of < 0.005 for the training and < 0.05 for validation analyses. Results: Data from 281,997 pts (median age 67 years, 50% male, 81% white, 55% T3, 19% T4, 44% N+, 26% M+, and 11% with ≥1 TD) were analyzed, with a median follow-up of 7.3 years. The updated staging system (Table) met pre-specified criteria, with all observed pairwise P < 0.0001 in the development and internal validation sets. KM OS curves displayed a hierarchical separation across all sub-levels after the 1 st year of diagnosis. Consistent results were seen in pts treated with adjuvant chemotherapy in 4 trials (all pair-wise P < 0.0001). Conclusions: The proposed pathological staging system for M0 pts fulfills pre-specified criteria for hierarchical risk stratification, validated both internally and externally, and provides an evidence-based update. Pending review process, the AJCCCCEP will recommend that these changes be made to the Version 9 staging protocol for colon cancer to improve prognostication for CC pts. Stage T, # of LN+, # of TD M % of pts 1y OS (CI), % 3y OS (CI), % 5y OS (CI), % I T1, 0, 0 0 5 96 (95-97) 91 (90-92) 84 (83-86) IIa T2, 0, 0 0 10 95 (94-95) 88 (88-89) 80 (79-81) IIb T1, 0, 1+T1, 1+, 0T2, 0, 1+T2, 1-4, 0T3, 0, 0 0 27 93 (92-93) 84 (84-85) 75 (75-76) IIIa T1, 1+, 1+T2, 1-4, 1+T2, 5+, 0T3, 0, 1+T3, 1-4, 0 0 14 92 (91-92) 80 (80-81) 71 (70-72) IIIb T2, 5+, 1+T3, 1-4, 1+T3, 5+, 0T4a, 0-4, 0T4b, 0-2, 0 0 13 86 (86-87) 69 (68-70) 58 (57-59) IIIc T3, 5+, 1+T4a, 0-4, 1+T4a, 5+, anyT4b, 0-2, 1+T4b, 3+, any 0 5 78 (77-80) 53 (51-54) 40 (38-41) IVa Any 1a 19 59 (58-60) 28 (28-29) 17 (16-18) IVb Any 1b 7 43 (42-44) 14 (13-14) 6 (6-7) CI: 95% confidence internal; Peritoneum involvement data were not available before 2018 in NCDB. Thus, IVa/b were based on 7 th Edition.

e15682 Background: Small cell carcinoma (SCC) of gastrointestinal tract is a highly aggressive rare malignancy with an estimated prevalence of 0.1% to 1% of all GI neoplasms. Treatment and survival outcomes data are very limited. Here we present an analysis of outcomes of patients with intestinal SCC using data from the Survival, Epidemiology, and End Result (SEER) database. Methods: SEER (2000-2020) was used to identify patients with SCC involving of the small intestine, colon and rectum. Variables included age, race, site, stage, chemotherapy (chemo), radiation therapy (RT) and surgery. Cox regression was used to model survival outcomes based on site, stage, and treatment received in the overall group and stage subgroups. Results: 1,169 patients with SCC of the small intestine, colon, and rectum were identified. Median age was 65 (24-90). 631 (54%) were male; majority of patients were white (989; 85%), followed by black (128; 11%) and other races (50; 4.3%). Colon (569; 49%) and rectum (514; 44%) were the predominant sites while small intestine only comprised 7.4% of the patients. Distant, regional and local diseases were reported in 55%, 17% and 7.5% of the patients. Median overall survival (mOS) of the entire group was 8 months (m). Primary tumor sites of small intestine and rectum were significantly associated with lower mortality rate in comparison to colon (11 m and 9 m vs 5 m, p < 0.001 for both). Patients with localized disease had the lowest mortality rate when compared with those with regional or distant metastatic diseases (38 m vs. 16 m and 5 m, p < 0.001 for both). Receiving surgery (HR: 0.458, p < 0.001), chemo (HR: 0.473, p < 0.001), and RT (HR: 0.733, p = 0.003) were all significantly associated with lower mortality rate (Table). These differences remained significant in each stage-based subgroup except for chemotherapy in localized disease subgroup, which encompassed only 87 patients. Conclusions: Intestinal SCC has poor prognosis, with SCC of the colon being most prevalent and with the highest mortality. Majority of patients presented with distant metastatic disease which led to high mortality. Multimodality treatment may improve survival for these patients. Number of cases (%) HR (CI) p-value mOS (months) vs reference Site (ref: colon) Rectum 514 (44%) 0.750 (0.648-0.867) <0.001 9 (ref: 5) Small intestine 86 (7.4%) 0.574 (0.44-0.749) <0.001 11 (ref: 5) Stage (ref: localized) Regional 201 (17%) 2.087 (1.507-2.891) <0.001 16 (ref: 38) Distant 639 (55%) 4.222 (3.110-5.733) <0.001 5 (ref: 38) Unknown/unstaged 242 (21%) 1.639 (1.160-2.315) 0.005 8 (ref: 38) Chemo (ref: none/unknown) Yes 590 (50%) 0.473 (0.404-0.553) <0.001 10 (ref:3) RT (ref: none/unknown) Yes 175 (15%) 0.733 (0.598-0.897) 0.003 12 (ref: 7) Surgery (ref: no surgery) Yes 363 (31%) 0.458 (0.385-0.546) <0.001 12 (ref: 6) Unknown 138 (12%) 0.717 (0.549-0.936) 0.01 7.5 (ref: 6)

Abstract Background Optimal treatment for resectable gastric and gastroesophageal junction (GEJ) adenocarcinoma remains unclear due to limited head-to-head comparisons among chemotherapy and chemoradiation regimens. This network meta-analysis aimed to determine the relative efficacy of available multimodality treatment regimens in these patients. Methods MEDLINE, EMBASE, Scopus, Web of Science, and CENTRAL were searched till September 20, 2024. Phase 3 randomized trials evaluating perioperative/neoadjuvant systemic therapy ± radiation in resectable gastric/GEJ adenocarcinoma were included. Primary outcomes were disease-free survival (DFS) and overall survival (OS). Frequentist network meta-analysis was conducted to compare hazard ratios (HRs) and 95% confidence intervals (CIs). Results Fifteen trials (8072 patients) were analyzed. pFLOT (perioperative fluorouracil, leucovorin, oxaliplatin, and docetaxel) ranked highest for DFS in the overall population (P-score 91%), achieving significant improvements compared to surgery alone (HR 0.48, 95% CI, 0.38-0.60) and nCROSS (neoadjuvant paclitaxel, carboplatin, and radiotherapy) (0.67, 0.56-0.81). For OS, nPLF + nCRT(EP) (neoadjuvant cisplatin, leucovorin, and fluorouracil for induction, followed by etoposide, cisplatin, and radiotherapy) (P-score 90%) and pFLOT (P-score 87%) were the top regimens. pFLOT significantly outperformed surgery alone (0.57, 0.45-0.72) and nCROSS (0.73, 0.60-0.89). Based on the limited data available, adding neoadjuvant chemoradiation to pFLOT provided no additional OS (1.14, 0.76-1.72) or DFS (1.22, 0.83-1.82) benefit. Similarly, adding pembrolizumab to perioperative chemotherapy (cisplatin and fluorouracil/capecitabine) was not superior to pFLOT (DFS: 1.10, 0.71-1.69; OS: 1.09, 0.69-1.72). Conclusions pFLOT demonstrated superior efficacy in resectable gastric/GEJ adenocarcinoma, outperforming surgery alone, nCROSS, and alternative perioperative regimens. The additive role of immunotherapy requires further investigation to optimize patient selection and outcomes.

PURPOSE Limited treatment options exist for patients with locally advanced or metastatic biliary tract cancers (BTCs). Recently, several clinical trials provided preliminary evidence for human epidermal growth factor receptor 2 (HER2) as a new target for patients with HER2-expressing BTC. We conducted a systematic review and pooled analysis of the safety and efficacy of anti-HER2 agents in patients with advanced BTCs. METHODS A comprehensive search of PubMed/MEDLINE and EMBASE was performed to identify phase I, II, or III clinical trials published between January 2019 and March 2024 that evaluated anti-HER2 therapy in locally advanced or metastatic BTC. Participant data included in the analysis were from trials evaluating the efficacy and safety of various anti-HER2 agents. The primary end points included objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). The secondary end points included incidence of treatment-related adverse events (TRAEs), rate of treatment discontinuation, and death. RESULTS The analysis included 368 patients from eight publications diagnosed with advanced BTC. Patients were treated with several anti-HER2 agents including zanidatamab, pertuzumab plus trastuzumab, tucatinib plus trastuzumab, trastuzumab deruxtecan, trastuzumab plus chemotherapy, trastuzumab-pkrb plus chemotherapy, and neratinib. The pooled ORR and DCR were 34% (95% CI, 24 to 44) and 64% (95% CI, 51 to 77), respectively. The pooled weighted PFS and median overall survival were 4.8 and 9.4 months, respectively. The pooled duration of response for the reporting trials was 5.0 months. In the study cohort, 82.6% of patients experienced any adverse event and 32.1% experienced a grade 3-4 adverse event. Only 5.7% of the patients discontinued treatment secondary to TRAEs. CONCLUSION In patients with HER2-expressing BTCs, anti-HER2 therapies are viable options, particularly in the second-line setting.

Background: Rates of early-onset colorectal cancer (eoCRC), defined as disease diagnosed at <50 years of age, are increasing. The incidence and spectrum of somatic and pathogenic germline variants (PGV) in this population are not well understood. Methods: This cross-sectional study leveraged Tempus’ clinicogenomic database, including de-identified records of patients diagnosed with CRC between 2000–2022, to analyze and compare eoCRC and average-onset colorectal cancer (aoCRC, disease diagnosed ≥50 years of age) patients. The frequency and spectrum of somatic mutations and PGVs in patients with eoCRC and aoCRC were evaluated and compared. Results: Among 11,006 participants in this study, 57% were male, 76% were white, and 80% had stage 4 disease. Within the total cohort, 2379 had eoCRC and 8627 had aoCRC. Among patients with eoCRC, 4.2% had a tumor with high microsatellite instability and/or deficient mismatch repair (MSI-H/dMMR) and 6.8% with aoCRC had an MSI-H/dMMR tumor (p < 0.001). The most frequent somatic mutations involved TP53, APC, and KRAS, with the most significant difference in BRAF, which was more frequently mutated in aoCRC (9.8% vs. 4.7%, p < 0.0001). In total, 1413 (59.4%) eoCRC and 4898 (56.8%) aoCRC patients had matched normal specimen (blood or saliva) sequencing and a PGV was identified in 6.9% of eoCRC and 5.0% of aoCRC patients. Conclusions: Somatic and germline mutation profiles were similar for eoCRC and aoCRC patients and may not adequately explain differences in tumor behavior and age of disease onset.

Intrahepatic cholangiocarcinoma is an aggressive malignancy with rising incidence and poor outcomes. This review examines recent advancements in locoregional therapies for unresectable intrahepatic cholangiocarcinoma, focusing on external beam radiotherapy, transarterial radioembolization (TARE), hepatic artery infusion pump (HAIP) chemotherapy, and liver transplantation. Stereotactic body radiation therapy and proton beam therapy have shown promise in achieving local control and improving survival. TARE, with personalized dosimetry, has demonstrated encouraging results in select patient populations. HAIP chemotherapy, primarily studied using floxuridine, has yielded impressive survival outcomes in phase II trials. Liver transplantation, once contraindicated, is now being reconsidered for carefully selected patients with localized disease. While these locoregional approaches show potential, randomized controlled trials comparing them to standard systemic therapy are lacking. Patient selection remains crucial, with factors such as liver function, tumor burden, and molecular profile influencing treatment decisions. Ongoing research aims to optimize treatment sequencing, explore combination strategies with systemic therapies, and refine phenotype identification and patient selection criteria. As the landscape of intrahepatic cholangiocarcinoma management evolves, a multidisciplinary approach is essential to tailor treatment strategies and improve outcomes for patients with this challenging disease.

639 Background: Limited treatment options exist for patients with locally advanced or metastatic biliary tract cancers (BTCs). Recently, several clinical trials provided preliminary evidence for human epidermal growth factor receptor-2 (HER2) as a new target for patients with HER2 expressing BTC. We conducted a systematic review and pooled analysis of the safety and efficacy of anti-HER2 agents in patients with advanced BTC. Methods: A comprehensive search of PubMed/MEDLINE and EMBASE was performed to identify phase 1, 2, or 3 clinical trials published between January 2019 and March 2024 that evaluated anti-HER2 therapy in locally advanced or metastatic BTC. Primary endpoints included objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). Secondary endpoints included the incidence of treatment-related adverse events (TRAEs), rate of treatment discontinuation, and death. Forest plots were generated to summarize the results and demonstrate the effect size estimates for each study, along with their confidence intervals and the pooled estimate from the random-effects model. The random-effects models were configured to use the Restricted Maximum Likelihood method for estimating between-study variance for all analyses. Results: After excluding duplicate and irrelevant articles, data extraction and analysis were performed on eight selected clinical trials. The analysis included 368 patients with a median age of 64 (range 49-68), with 55% being female. Patients were treated with several anti-HER2 agents, including zanidatamab, pertuzumab plus trastuzumab, tucatinib plus trastuzumab, trastuzumab deruxtecan, trastuzumab plus chemotherapy, trastuzumab-pkrb plus chemotherapy and neratinib. The pooled ORR and DCR were 34% (95% CI 24-44) and 64% (95% CI 51-77) respectively. The pooled weighted PFS and median OS survival were 4.8 and 9.4 months, respectively. The pooled duration of response was 5.0 months. In our subset analysis, which included only patients who had received ≥1 prior therapy, the pooled ORR was 30% (95% CI 22-39), the pooled DCR was 62% (95% CI 48-75), and the pooled median PFS was 4.4 months. In the study cohort, 82.6% of patients experienced any adverse event, and 32.1% experienced a grade 3-4 adverse event. Only 5.7% of the patients discontinued treatment secondary to TRAEs. Conclusions: In patients with HER2 expressing BTCs, anti-HER2 therapies demonstrated preliminary signals of efficacy with manageable toxicities, particularly in the second-line setting.

5 Background: Metastatic anal squamous cell carcinoma is rare and associated with a poor prognosis. There is limited evidence on the impact of local interventions on survival outcomes in patients with metastatic disease. We aimed to evaluate the survival of patients with liver-only metastatic anal cancer following definitive local management of liver lesions. Methods: This is a single-institution retrospective cohort study of patients with liver-limited metastatic anal cancer who underwent curative-intent local therapy. Clinical characteristics were collected and analyzed. The Kaplan-Meier method was used to calculate disease-free survival (DFS) and overall survival (OS). Prognostic factors associated with DFS and OS were assessed using Cox-proportional hazards models. Results: Twenty-five patients were included, median age was 59 years, and 92% were female. None of the patients had known HIV infection, 92% had HPV-positive disease and 76% had metachronous liver metastases following locoregional disease. All patients received chemoradiation for the primary lesion Unilobar hepatic involvement was present in 76% of the patients, with 56% having a single metastatic lesion. Pre-intervention systemic therapy was provided to 52% of the patients, including 8 who received carboplatin and paclitaxel, with a median duration of 3 months and ORR of 69%. Definitive treatment of metastatic disease included surgical resection (60%), non-surgical interventions (20%), and multimodal therapy (20%). All patients had viable tumor in the pathological specimen. With a median follow-up of 22 months, median DFS was 7.3 months, and median OS was 51.3 months. An ECOG performance status of 2, poorly differentiated histology, and extrahepatic recurrence were identified as significant prognostic factors in the univariate analysis, but not in the multivariate analysis. Conclusions: Our results demonstrate potential for long-term survival in liver-limited metastatic anal squamous cell carcinoma amenable to local therapeutic intervention combined with systemic therapy. These findings warrant further prospective study of local therapy in oligometastatic anal cancer. Characteristics N=25 (%) Median number of liver metastases (range), lesions- 1- 2-3- >3 1 (1-20)14 (56)8 (32)3 (12) Median maximal diameter of liver metastases (range), cm 3 (0.9-11.9) Best response of liver metastases to chemotherapy (N=13)- Complete response- Partial response- Stable disease- Progressive disease 2 (15)7 (54)3 (23)1 (8) Surgical procedure (N=20)- Right/left hemi-hepatectomy- Segmentectomy- Wedge resection 4 (20)14 (70)2 (10) Non-surgical procedure (N=10)- Local ablation- Radiotherapy- Other 5 (50)3 (30)2 (20) Hepatic surgical margins (N=20)- Positive margins- Close margins (<1mm)- Negative margins 02 (10)18 (90) Recurrent disease- Yeso Intrahepatico Extrahepatic- No 20 (80)14 (70)6 (30)5 (20)