Pneumatosis intestinalis in cancer patients who received immune checkpoint inhibitors

PURPOSE

Immune checkpoint inhibitor (ICI) therapy may give rise to immune-related adverse events (irAEs). Pneumatosis intestinalis (PI), or gas within the bowel wall, has very rarely been observed following ICI therapy, and its clinical significance is unclear. We described the clinical characteristics and outcomes of PI as a possible irAE in cancer patients.

METHODS

We retrospectively identified 12 adult cancer patients with radiologic evidence of PI within 1 year after ICI exposure during January 2010-January 2023. Clinical characteristics, treatment, and outcomes were evaluated.

RESULTS

The median age of our sample was 64 years. The most common cancer types were thoracic/head & neck and gastrointestinal. Eleven patients (92%) received anti-PD-1/L1 monotherapy, while 1 patient (8%) received a combination of anti-PD-1/L1 and anti-CTLA-4. PI occurred a median of 7 months after the first ICI dose. Half the patients (50%) were asymptomatic on diagnosis, and the most common presenting symptom was abdominal pain (42%). Six patients experienced complications, namely pneumoperitoneum (n = 6, 50%) and microperforation (n = 1, 8%), identified on imaging. Nine patients were treated with antibiotics and 3 patients were monitored conservatively. Nine patients (75%) resumed cancer treatment after PI.

CONCLUSION

PI may develop as an irAE. While half of cases were incidental radiologic findings, management with antibiotics as well as hospitalization for observation may still be appropriate. The decision to restart cancer therapy and possibly resume ICI therapy remains to be elucidated. Further large-scale studies may be warranted to clarify the association between PI and ICI therapy.

Colon Adenoma After Diagnosis of Immune Checkpoint Inhibitor-mediated Colitis

Purpose: While the occurrence of colitis during immune checkpoint inhibitor (ICI) treatment is recognized as a sign of robust immune activation and correlates with better oncological outcomes, the long-term impact of ICI-mediated colitis on the colonic mucosa has not been studied. We thus aim to describe the colonoscopy and histology findings in patients at a follow-up time of ≥ 6 months post initial colitis event. Methods: This retrospective analysis included adult cancer patients diagnosed with ICI colitis at a tertiary cancer center between October 2013 and June 2020. The study group included patients diagnosed with immune mediated colitis who had also undergone a follow up colonoscopy or flex sigmoidoscopy. The control group was patients exposed to ICI without immune mediated colitis. We reported patients' colitis clinical course, treatment, outcomes, and endoscopic and histologic features at diagnosis and at follow-up time of ≥ 6 months. Results: Total 39 patients met the study criteria, with 82% being male, and 35.8% having melanoma. Most patients received a combination of CTLA-4 and PD-1/L1 inhibitors (82%). On initial endoscopic evaluation, inflammation without ulceration was reported in 76.9% of patients and active inflammation on histologic examination in 79.3% of patients. Most patients (79.4%) received corticosteroids, and 56.4% received add-on selective immunosuppressive therapy. Four patients received fecal microbiota transplantation. On follow-up, new incidence of colonic polyps was reported in 51.2% of patients, including adenomas in 33.3% among the colitis patients with median follow up duration of 12 months. The incidence of adenoma polyps 12 months after the colitis event was significantly higher compared to the control group without colitis based on the time-to-event analysis (p=0.041). Conclusion: At a median follow up of 12 months after their initial colitis diagnosis, 51.2% of the patients had new incidence of colonic polyps, including a third with adenoma, at a significantly higher incidence than the control group without colitis. Studies with larger sample sizes are needed to further define the long-term impact of colitis and its treatments on colon health and to refine recommendations for surveillance of colonic adenomas and colorectal cancer.

Performance and attitudes toward real-time computer-aided polyp detection during colonoscopy in a large tertiary referral center in the United States

BACKGROUND AND AIMS

Computer-aided detection (CADe) has been shown to improve polyp detection in clinical trials. Limited data exist on the impact, utilization, and attitudes toward artificial intelligence (AI)-assisted colonoscopy in daily clinical practice. We aimed to evaluate the effectiveness of the first U.S. Food and Drug Administration-approved CADe device for polyp detection in the United States and the attitudes toward its implementation.

METHODS

We performed a retrospective analysis of a prospectively maintained database of patients undergoing colonoscopy at a tertiary center in the United States before and after a real-time CADe system was made available. The decision to activate the CADe system was at the discretion of the endoscopist. An anonymous survey was circulated among endoscopy physicians and staff at the beginning and conclusion of the study period regarding their attitudes toward AI-assisted colonoscopy.

RESULTS

CADe was activated in 52.1% of cases. Compared with historical control subjects, there was no statistically significant difference in adenomas detected per colonoscopy (1.08 vs 1.04, P = .65), even after excluding diagnostic and therapeutic indications and cases where CADe was not activated (1.27 vs 1.17, P = .45). In addition, there was no statistically significant difference in adenoma detection rate (ADR), median procedure, and withdrawal times. Survey results demonstrated mixed attitudes toward AI-assisted colonoscopy, of which main concerns were high number of false-positive signals (82.4%), high level of distraction (58.8%), and impression it prolonged procedure time (47.1%).

CONCLUSIONS

CADe did not improve adenoma detection in daily practice among endoscopists with high baseline ADRs. Despite its availability, AI-assisted colonoscopy was only activated in half of the cases, and multiple concerns were raised by staff and endoscopists. Future studies will help elucidate the patients and endoscopists that would benefit most from AI-assisted colonoscopy.

Is the Management of Rectal Cancer Using a Watch and Wait Approach Feasible, Safe and Effective in a Publicly Funded General Hospital?

AIMS

Although there is emerging evidence to suggest equivalent oncological outcomes using a watch and wait approach compared with primary total mesorectal excision surgery, there is a paucity of evidence about the safety and efficacy of this approach in routine clinical practice. Here we report the long-term outcomes and quality of life from patients managed with watch and wait following a clinical complete response (cCR) to neoadjuvant therapy.

MATERIALS AND METHODS

Patients with adenocarcinoma of the rectum with cCR following neoadjuvant therapy managed using watch and wait were retrospectively identified. Demographic data, performance status, pretreatment staging information, oncological and surgical outcomes were obtained from routinely collected clinical data. Quality of life was measured by trained clinicians during telephone interviews.

RESULTS

Over a 7-year period, 506 patients were treated for rectal cancer, 276 had neoadjuvant therapy and 72 had a cCR (26.1%). Sixty-three were managed with watch and wait. Thirteen patients had mucosal regrowth. There was no significant difference in the incidence of metastatic disease between the surgical and watch and wait cohorts (P = 0.38). The 13 patients with mucosal regrowth underwent salvage surgery. Eleven of the patients who underwent surgical resection had R0 resections. There was also a statistically and clinically significant improvement in the Functional Assessment of Cancer Therapy - Colorectal (FACT-C) trial outcome index (P = 0.022).

CONCLUSION

This study shows that watch and wait is safe and effective outside of tertiary referral centres. It suggests that an opportunistic cCR is durable and when mucosal regrowth occurs it can be salvaged. Finally, we have shown that quality of life is probably improved if a watch and wait approach is adopted.

Patients with non-colorectal cancers may be at elevated risk of colorectal neoplasia

Background: Screening for colonic neoplasia has decreased the incidence of colorectal cancer in the United States in the past two decades. Whether personal history of noncolorectal cancer is a risk factor for colonic neoplasia has not been well studied. We assessed the risk of colorectal neoplasia in noncolorectal cancer survivors.

Methods: We conducted a retrospective study of patients who had undergone colonoscopy for any indication between 2009 and 2018. Colonic adenoma detection rate and multivariate logistic regression were conducted to assess for the primary outcomes of the study.

Results: The study included 9408 cancer patients and 3295 control patients. Colonic adenomas were detected in 4503 cancer patients (48%) and 950 cancer-free patients (29%). Histologic examination of these adenomas revealed tubulovillous features in 620 patients (5%) and villous in 153 (1%). High-grade dysplasia was detected in 1611 patients (13%). Invasive colorectal adenocarcinoma was detected in 455 patients (12%); this rate was highest in patients with multiple myeloma (14%). Multivariate analysis revealed that a personal history of noncolorectal cancer was associated with increased risk of adenoma (Odd ratio, 2.04; 95% CI, 1.84-2.26; P<0.001). The adenoma detection rate was 30% in patients younger than 40 years (n=1211), 32% in patients between 41 and 50 years (n=812), 47% in patients between 51 and 60 years (n=2892), and 55% in patients older than 60 years (n=4493).

Conclusions: The adenoma detection rate in patients with a personal history of noncolorectal cancer is higher than the reported rate of the general population and our control group.

Gastrointestinal Motility Issues in Cancer Patients

PURPOSE OF REVIEW

This paper seeks to highlight GI motility disorders that are frequently present in patients with a malignancy. GI dysmotility can occur due to the cancer itself or as a consequence of medical and surgical treatments. Often, symptoms are nonspecific and the diagnosis requires a high index of suspicion. The goal of the paper is to review the common motility problems seen in patients with cancer, their clinical manifestations, and options for management.

RECENT FINDINGS

Studies show that newer endoscopy techniques such as endoscopic mucosal dissection can cause esophageal dysmotility. Opioid-induced constipation is frequently encountered in patients with cancer. Motility disorders in cancer patient can lead to clinical morbidity, poor quality of life, and malnutrition. Newer diagnostic tests and medical and surgical treatments may be helpful in improving the diagnosis and management of these disorders.

288. Hepatitis B Virus Reactivation in Patients with Hematologic Malignancies after Anticancer Therapy Which Included Ibrutinib

Background

Several cases of severe bacterial, fungal, and viral infections have been reported following ibrutinib therapy. Here, we report a case of a patient with non-Hodgkin lymphoma who developed hepatitis B virus (HBV)–associated liver failure after anti-cancer treatment most recently with ibrutinib. We also review reported cases of HBV reactivation (HBVr) after ibrutinib.

Methods

We searched the Medline and Embase databases and identified 5 patients with HBVr related to ibrutinib for a total of 6 study patients, including our case (figure). HBV-related outcomes were defined according to the 2018 AASLD HBV guidance document.

Results

All 6 patients were men and most (5 or 83%) had chronic lymphocytic leukemia and past HBV infection (table). Three patients (50%) developed HBV-related hepatitis and 2 of them progressed to liver failure. Four patients (67%) had a remote history (≥24 months) of other potential risk factors besides ibrutinib that could contribute to HBVr, including the use of direct-acting antivirals for hepatitis C co-infection (1 pt), hematopoietic cell transplant (HCT) (1 pt) and rituximab use (4 patients). HBVr occurred at least 6 months after initiation of ibrutinib in most patients (4 or 67%), with a median of 9.7 months (range, 1.5–42). In all 4 patients pretreated with rituximab, that treatment was completed at least 24 months before HBVr. Two of these patients received anti-HBV prophylaxis that was stopped 12 months after the completion of rituximab; the other 2 patients were only monitored without antivirals. The HCT recipient received anti-HBV prophylaxis per guidelines. None of the 6 patients treated with ibrutinib were receiving anti-HBV prophylaxis at the time of HBVr, but 5 patients were started on anti-HBV drugs at the first sign of HBVr. Four received entecavir and 1, tenofovir. All treated patients recovered from HBVr. No pt died of HBVr.

Conclusion

Life-threatening HBVr can occur following ibrutinib therapy in patients with past or chronic HBV infection. The temporal association between ibrutinib therapy and reactivation indicates that ibrutinib is the likely cause of the HBVr, and clinicians should be aware of the risk of HBVr in these patients. A provisional approach could be HBV monitoring at regular intervals with initiation of antiviral therapy at the earliest sign of HBV reactivation.

Disclosures

All authors: No reported disclosures.

2854 High Resolution Esophageal Manometry Findings in Patients With Esophageal Symptoms After Head and Neck Radiation Therapy

INTRODUCTION:

Head and neck radiation therapy is known to cause esophagitis and esophageal strictures as early and late effects after radiation exposure, respectively. The negative effects of radiation on esophageal motor function have been speculated in case reports but have not been studied in a larger population with high resolution manometry (HRM). The aim of this study was to evaluate HRM findings in patients who received head and neck or mediastinal radiation and presented with esophageal symptoms.

METHODS:

There were a total of 718 patients who received HRM from 2010 to 2018 at the Michael E. DeBakey VA Medical Center. Patients were excluded if they had undergone esophageal surgery, found to have oro-pharyngeal dysphagia, or if they had a mechanical cause on esophagogastroduodenoscopy of esophageal symptoms. Among the cohort, 14 patients met our inclusion criteria of receiving head and neck or mediastinal radiation prior to HRM. Chicago Classification v3.0 was used for HRM diagnoses.

RESULTS:

The most common symptom for which HRM was performed was esophageal dysphagia in 8 patients. Regurgitation and chest pain were each reported in 3 patients. Heartburn (n = 2), odynophagia (n = 1), and hoarseness (n = 1) were also reported symptoms. Seven of 14 patients (50.0%) were found to have abnormal findings on HRM (Table 1). Findings included hypotensive lower esophageal sphincter (LES) (n = 2), hypertensive LES (n = 1), hypotensive upper esophageal sphincter (UES) (n = 1), UES stricture (n = 1), spastic achalasia (n = 1), and ineffective esophageal motility (n = 1). There was no difference in HRM findings based on radiation dose received (Figure 1). There was an association towards increased HRM abnormalities with time since last radiation (Figure 2).

CONCLUSION:

This is one of the largest studies to show the effects of head and neck radiation on esophageal motility using HRM. Fifty percent of patients in this cohort exposed to head and neck radiation had abnormalities on HRM. We have also shown an association towards increased abnormal HRM findings with time, especially greater than five years after radiation exposure. Similar to our study, achalasia and ineffective peristalsis have been reported both early and late after head and neck radiation. Despite reports of esophageal motility complications with increasing doses of radiation, we were unable to demonstrate this. Our findings suggest that patients with esophageal symptoms after radiation exposure should be investigated for esophageal motor dysfunction.

Quality of endoscopy reporting at index colonoscopy significantly impacts outcome of subsequent EMR in patients with > 20 mm colon polyps

Background and study aims  Endoscopic mucosal resection (EMR) is safe and cost-effective in management of patients with colon polyps. However, very little is known about the actions of the referring endoscopist following identification of these lesions at index colonoscopy, and the impact of those actions on the outcome of subsequent referral for EMR. The aim of this study was to identify practices at index colonoscopy that lead to failure of subsequent EMR. Patients and methods  Two hundred and eighty-nine consecutive patients with biopsy-proven non-malignant colon polyps (> 20 mm) referred for EMR were analyzed to identify practices that could be improved from the time of identifying the lesion at index colonoscopy until completion of therapy. Results  EMR was abandoned at colonoscopy at the EMR center in 71 of 289 patients (24.6 %). Reasons for abandoning EMR included diagnosis of invasive carcinoma (n = 9; 12.7 %), tethered lesions (n = 21; 29.6 %) from prior endoscopic interventions, and overly large (n = 22; 31 %) and inaccessible lesions (n = 17; 24 %) for complete and safe resection whose details were not recorded in the referring endoscopy report, or polyposis syndromes (n = 2; 2.8 %) that were not recognized. Conclusions  In our practice, one in four EMR attempts were abandoned as a result of inadequate diagnosis or management by the referring endoscopist, which could be improved by education on optical diagnosis of polyps, comprehensive documentation of the procedure and avoidance of interventions that preclude resection.

Dysphagia: An Unusual Presentation of Metastatic Uterine Cervical Carcinoma

Worldwide, cervical cancer is the third most common cancer among women and the fourth leading cause of death from cancer. The most common sites of metastasis are the pelvic lymph nodes, vagina, and the pelvic sidewalls. Distant metastases are uncommon but can involve the bone, lung, and liver. Characteristics associated with increased rate of distant metastasis include bulky tumor, endometrial extension, lymph node involvement, and advanced disease. We report the case of a woman with stage II cervical carcinoma, who presented with dysphagia due to cervical cancer metastases to the mediastinum.

Outcome of EMR as an alternative to surgery in patients with complex colon polyps

BACKGROUND AND AIMS

Patients with complex colon polyps were traditionally referred for surgery to avoid adverse events associated with endoscopic resection. Recent advances in endoscopic imaging as well as endoscopic hemostasis and clip closure allow for the use of EMR as an alternative to surgery for such lesions. To determine the outcome of treatment of complex colon polyps with EMR as an alternative to surgery, we conducted a retrospective observational study.

METHODS

Two hundred three patients with complex colon polyps were referred to an EMR center as an alternative to surgery. Patients underwent a protocol-driven EMR. The primary endpoint was the complete resection rate. Secondary endpoints were safety, residual adenoma rate, and incidence of missed synchronous polyps.

RESULTS

EMR was performed in 155 patients and was deferred in 48 patients who were referred to surgery. EMR specimens revealed benign polyps in 149 and cancer in 6 patients. EMR adverse events occurred in 7 patients, requiring hospitalization in 5 of them. None of the patients died as a result of their adverse events. Surveillance colonoscopy at 4 to 6 months after resection of a benign lesion in 137 patients revealed residual adenoma at the scar site in 6 patients and additional synchronous precancerous lesions in 117 patients that were not removed by the referring endoscopist. None underwent surgery for failure of EMR. The overall precancerous lesion burden was 2.83 per patient, the adenoma burden was 2.13 per patient, and the serrated polyp burden was .69 per patient.

CONCLUSIONS

EMR can be used instead of surgery for complex colon polyps in 75% of patients with few adverse events and few residual adenomas at resection sites. In addition, careful repeat examination of the entire colon for synchronous lesions overlooked by the referring endoscopist is required for most patients. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01827241.).

Mutational Profiles Reveal an Aberrant TGF-β-CEA Regulated Pathway in Colon Adenomas

Mutational processes and signatures that drive early tumorigenesis are centrally important for early cancer prevention. Yet, to date, biomarkers and risk factors for polyps (adenomas) that inordinately and rapidly develop into colon cancer remain poorly defined. Here, we describe surprisingly high mutational profiles through whole-genome sequence (WGS) analysis in 2 of 4 pairs of benign colorectal adenoma tissue samples. Unsupervised hierarchical clustered transcriptomic analysis of a further 7 pairs of adenomas reveals distinct mutational signatures regardless of adenoma size. Transitional single nucleotide substitutions of C:G>T:A predominate in the adenoma mutational spectrum. Strikingly, we observe mutations in the TGF-β pathway and CEA-associated genes in 4 out of 11 adenomas, overlapping with the Wnt pathway. Immunohistochemical labeling reveals a nearly 5-fold increase in CEA levels in 23% of adenoma samples with a concomitant loss of TGF-β signaling. We also define a functional role by which the CEA B3 domain interacts with TGFBR1, potentially inactivating the tumor suppressor function of TGF-β signaling. Our study uncovers diverse mutational processes underlying the transition from early adenoma to cancer. This has broad implications for biomarker-driven targeting of CEA/TGF-β in high-risk adenomas and may lead to early detection of aggressive adenoma to CRC progression.

Abstract 67: Genomic and mutational profiling of human colon adenomas reveals early driver mutations and a TGF-β-CEA regulated profile

Introduction: Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world with 143,700 newly diagnosed cases in 2012. The rapid development of cancers in small, sessile adenomas could be a contributing factor that may have been overlooked. Identifying high risk patients through genomic analysis of adenomas could potentially lead to an early intervention therapy.

Methods: Whole Genome Sequence (WGS) and Whole Exome Sequence (WES) analyses were performed for 4 pairs of normal controls (two from proximal colon and two from the distal colon) and colorectal adenomas (2 sessile serrated (SSA) and 2 tubulovillous adenomas (TVA) less than 1 cm in size). Transcriptome sequence analysis was performed in seven pairs of control-test matched adenomas (6 TVA and 1 SSA). Expression level of CEA and TGF-β pathway members were carried out on 30 non dysplastic adenomas and normal colon tissues by immunohistochemistry.

Results: 1. Hyper-mutator profiles were observed in two of the samples (1 SSA and 1 TVA) by WGS with 1709 mutations after normalization with normal paired samples. 2. The samples showed an average mutation frequency of 0.55 mutations per 106 bases. 3. Aberrant mutational profiles was detected in seven of the eleven adenomas, with distinct mutational signatures among the samples, two with high, two intermediate and three low mutational rates. 4. Six of the eleven adenomas (1 SSA and 4 TVAs) showed alteration in the Wnt and p53 pathway. 5. Transitional single nucleotide substitutions of C:T&gt;G:A in the mutational spectrum were observed in 37% of the samples. 6. Subtle localized hyper mutation (kataegis) was observed among two of the samples. 7. Five out of eleven adenomas showed mutations in the TGF-β (transforming growth factor-β) and CEA pathways members, overlapping with Wnt/p53 mutations in four adenomas. 8. Analyses of expression level of CEA and TGF-β pathway members in 30 non dysplastic tissues revealed a marked increase (over 8 fold) in CEA expression in 25% of adenoma samples which was linked to concomitant loss of TGF-β signaling. 9. Further functional studies revealed that CEA associated with TGF-β Type I receptor and disruption of TGF-β tumor suppressor signaling with activation of STAT3.

Conclusions: Our studies indicate that small adenomas both TVAs and SSAs can resemble CRCs in genomic profiling and may reflect a high risk population. Genetic and mechanistic analyses reveal that disruption of CEA/TGF-β pathway in early adenomas may reflect a new and early role for these pathways in CRC. This study further supports the biomarker driven targeting of CEA/TGF-β in high risk adenomas and can be used as a prognostic marker for early detection of aggressive adenoma-CRC progression.

Citation Format: Vipin K. Menon, Raju S. Gottumukkala, Jian Chen, Xiaoping Su, Nipun Mistry, Avijit Majumdar, Ji-Hyun Shin, Shulin Li, Kirti Shetty, Xifeng Wu, Brian Weston, Ethan Miller, John R. Stroehlein, Marta L. Davila, Mehnaz A. Shafi, Asif Rashid, Bhaskar V. Kallakury, Selvi Thirumurthi, John S. McMurray, Sue-Hwa Lin, Wilma Jogunoori, Lopa Mishra. Genomic and mutational profiling of human colon adenomas reveals early driver mutations and a TGF-β-CEA regulated profile. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 67. doi:10.1158/1538-7445.AM2015-67

Post-surgical and obstructive gastroparesis

Post-surgical gastroparesis (PSG) is recognized as a consequence of vagal nerve injury following upper abdominal surgery. It has been well documented following vagotomy for peptic ulcer surgery. With the increasing role of surgical treatment in the management of GERD and morbid obesity, PSG is now being diagnosed after fundoplication and bariatric surgery. PSG has also been reported after heart and lung transplantation, possibly due to opportunistic viral infection or motor-inhibitory effects of the immunosuppressive drugs, in addition to vagal nerve injury. Initial postoperative management of PSG should be conservative as many symptoms following abdominal surgery resolve with time. This occurs possibly because the enteric nervous system is able to adapt to the loss of vagal input or vagal reinnervation occurs. Persistent symptoms are difficult to manage and require a multidisciplinary team approach. Gastric electrical stimulation has shown promise in small series.

Risk factors of acute ulcer bleeding

Peptic ulcer disease is the most common cause of upper gastrointestinal bleeding. Most ulcers stop bleeding spontaneously; however, a poorer prognosis is indicated by clinical features such as severe bleeding, inability to clear gastric lavage, advanced age, and serious co-morbid illness. NSAID usage is an important risk factor particularly in the elderly population. Endoscopic stigmata of recent bleeding may provide the most helpful prognostic information which helps identify high risk patients and direct management specifically at preventing rebleeding in this cohort of patients.