Case report: reinitiating pembrolizumab treatment after small bowel perforation

J. Goyette E, West LA, Bentz JL. Recurrent pembrolizumab-induced mechanical small bowel obstruction in a patient with metastatic cervical cancer

•Adverse events of pembrolizumab have been documented, but more severe gastrointestinal effects are not as well described.•We report a case of a patient with cervical cancer treated with pembrolizumab who developed small bowel obstruction (SBO)•Histological analysis and gastrointestinal workup points to pembrolizumab as likely cause of SBO.

[Emergencies in cancer therapy: surgical indications under systemic therapy]

Emergency surgery due to side-effects of cancer therapy in patients with metastatic disease of the genitourinary tract is rare. Nevertheless, there are a number of emergencies that require rapid intervention and should be recognized by every uro-oncologist. The following review will work out important side-effects requiring surgical treatment, highlighting the main symptoms and the initial management.

Characteristics, treatment, and outcome of patients with bowel perforation after immune checkpoint inhibitor exposure

PURPOSE

Exposure to immune checkpoint inhibitors (ICIs) can predispose to immune-related adverse events (irAEs) involving the gastrointestinal tract. The association between ICIs and bowel perforation has not been well studied. We aimed to describe the clinical course, complications, treatment, and outcomes of patients experiencing bowel perforation during or after ICI treatment.

METHODS

This retrospective, single-center study included adult cancer patients with bowel perforation that occurred between the first dose of ICI treatment and up to 1 year thereafter between 1/1/2010 and 4/30/2021. Patients' clinical course, imaging, treatment, and outcomes related to bowel perforation were collected and analyzed.

RESULTS

Of the 13,991 patients who received ICIs during the study period, 90 (0.6%) met the inclusion criteria. A majority were male (54.4%), the most common cancer type was melanoma (23.3%), and most patients had received PD-1/L1 inhibitor treatment (58.8%). Onset of perforation occurred after a median of four ICI treatment cycles. The most common symptom was abdominal pain (95.5%). The colon was the most common location for the perforation (37.7%). Evidence of diverticulitis, enterocolitis, or appendicitis was seen in 32 (35.6%) patients, and 6 (6.6%) patients had luminal cancer involvement at the time of perforation. The overall hospitalization rate related to perforation was 95.5%, with mortality of 15.5% during the same admission. Antibiotics were given in 95% of our sample; 37.8% of patients also required surgical/interventional radiology intervention. Forty-six patients (51.1%) had perforation-related complications (e.g., sepsis, fistula, abscess), which were associated with a higher mortality rate (30%).

CONCLUSION

Our findings suggest a low incidence of bowel perforation after ICI treatment (0.6%), with 40% of patients having coexisting bowel inflammation as a potential contributing factor. Patients with bowel perforation had an aggressive disease course and high rates of hospitalization, complications, and mortality. Early recognition and prompt intervention is critical to improve patient outcomes. Future studies are warranted to further investigate the cause, predictive markers, and optimal treatment for this patient population.

An updated review of gastrointestinal toxicity induced by PD-1 inhibitors: from mechanisms to management

PD-1 inhibitors, as one of commonly used immune checkpoint inhibitors, enable T-cell activation and prevent immune escape by blocking the PD-1/PD-L1 signaling pathway. They have transformed the treatment landscape for cancer in recent years, due to the advantages of significantly prolonging patients' survival and improving their life quality. However, the ensuing unpredictable immune-related adverse effects (irAEs) plague clinicians, such as colitis and even potentially fatal events like intestinal perforation and obstruction. Therefore, understanding the clinical manifestations and grading criteria, underlying mechanisms, available diverse therapies, accessible biomarkers, and basis for risk stratification is of great importance for the management. Current evidence suggests that irAEs may be a marker of clinical benefit to immunotherapy in patients, so whether to discontinue PD-1 inhibitors after the onset of irAEs and rechallenge after remission of irAEs requires further evaluation of potential risk-reward ratios as well as more data from large-scale prospective studies to fully validate. At the end, the rare gastrointestinal toxicity events caused by PD-1 inhibitors are also sorted out. This review provides a summary of available data on the gastrointestinal toxicity profile caused by PD-1 inhibitors, with the aim of raising clinicians' awareness in daily practice, so that patients can safely benefit from therapy.

Surgical management of spontaneous bowel perforation and fascial dehiscence in a patient on bevacizumab and pembrolizumab in the setting of active Clostridium difficile infection

Immunotherapy such as bevacizumab and pembrolizumab is used to treat an increasing number of malignancies. These medications have been associated with poor wound healing and several gastrointestinal complications, including intestinal perforations in rare cases. We present a unique case of a patient with metastatic cervical cancer on pembrolizumab and recent bevacizumab therapy, presenting with a colonic perforation requiring urgent exploratory laparotomy, in the setting of active Clostridium difficile infection. She required a second laparotomy shortly after due to fascial dehiscence, where a synthetic absorbable mesh was used for fascial approximation. We review the factors that led to these events and describe the surgical technique used for safe abdominal closure.

Differential diagnosis and management of immune checkpoint inhibitor-induced colitis: A comprehensive review

Immune checkpoint inhibitors (ICIs) are a new class of cancer pharmacotherapy consisting of antibodies that block inhibitory immune regulators such as cytotoxic T lymphocyte antigen 4, programmed cell death 1 and programmed death-ligand 1. Checkpoint blockade by ICIs reactivates a tumor-specific T cell response. Immune-related adverse events can occur in various organs including skin, liver, and gastrointestinal tract. Mild to severe colitis is the most common side effect with some experiencing rapid progression to more serious complications including bowel perforation and even death. Prompt diagnosis and management of ICI-induced colitis is crucial for optimal outcome. Unfortunately, its clinical, endoscopic and histopathologic presentations are non-specific and overlap with those of colitis caused by other etiologies, such as infection, medication, graft-versus-host disease and inflammatory bowel disease. Thus, a definitive diagnosis can only be rendered after these other possible etiologies are excluded. Sometimes an extensive clinical, laboratory and radiologic workup is required, making it challenging to arrive at a prompt diagnosis. Most patients experience full resolution of symptoms with corticosteroids and/or infliximab. For ICI-induced colitis that is treatment-refractory, small scale studies offer alternative strategies, such as vedolizumab and fecal microbiota transplantation. In this review, we focus on the clinical features, differential diagnosis, and management of ICI-induced colitis with special attention to emerging treatment options for treatment-refractory ICI-induced colitis.

Immune Checkpoint Inhibitor-Associated Colitis: From Mechanism to Management

Immune checkpoint inhibitors (ICIs), as one of the innovative types of immunotherapies, including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors, have obtained unprecedented benefit in multiple malignancies. However, the immune response activation in the body organs could arise immune-related adverse events (irAEs). Checkpoint inhibitor colitis (CIC) is the most widely reported irAEs. However, some obscure problems, such as the mechanism concerning gut microbiota, the confusing differential diagnosis with inflammatory bowel disease (IBD), the optimal steroid schedule, the reintroduction of ICIs, and the controversial prognosis features, influence the deep understanding and precise diagnosis and management of CIC. Herein, we based on these problems and comprehensively summarized the relevant studies of CIC in patients with NSCLC, further discussing the future research direction of this specific pattern of irAEs.

NSCLC Immunotherapy and Related Rare Toxicities: A Monocentric Real-Life Experience

BACKGROUND

In the last years immunotherapy has revolutionized the treatment of non-small cell lung cancer (NSCLC) not supported by a driver mutation. Immunotherapy related adverse events (irAEs) have a unique toxicity profiles distinct from the toxicities of classical chemotherapy treatment relating to their mechanism of action. We analyzed some serious and uncommon life-threatening irAEs, needing a change in the therapeutic strategy.

METHOD

Between October 2018 and October 2020, 63 NSCLC patients underwent immunotherapy. Thirty-eight patients underwent first-line Pembrolizumab, 200 mg every 21 days (Group A). Twenty patients were treated in second line with Pembrolizumab 200 mg every 21 days or Nivolumab 240 mg every 14 days or Atezolizumab 800 mg every 14 days (Group B). Five stage III patients treated after radio chemotherapy with Durvalumab 1500 mg every 14 days (Group C).

RESULTS

We experienced: a) 2 bowel perforations (3.2%), necessitating Hartmann's resection. Only one of the two patients restored immunotherapy; b) 1 chronic renal insufficiency (1.6%, creatinine up to 8 mg/dL) and 2 severe hypertransaminasemias (3.2%, up to 65 U/L), requiring the immediate and definitive interruption of ICIs; c) 2 pericardial effusions (3.2%), of which one needed subxiphoid pericardiocentesis for cardiac tamponade. Patient restored immunotherapy after resolution of the acute event.

CONCLUSIONS

Immunotherapy include monoclonal antibodies reducing the suppression of effector T cells and improving the tumor-specific immune responses. Most common irAEs are evident in mild and reversible form, but sometimes life-threatening irEAs show up. Therefore, further clinical trials needed to increase knowledge of drugs and prevent unexpected irAEs.

Perforated appendicitis induced by pembrolizumab: a case report and review of the literature

Monoclonal antibodies against programmed cell death protein 1 (PD-1) and PD-1 ligand 1 (PD-L1) are the main representatives in the field of immunotherapy and their indications are constantly increasing in medical oncology and hematology during the last decade. They are associated with long-lasting responses and an acceptable toxicity profile, although they may infrequently cause life-threatening complications requiring prolonged hospitalization or urgent interventions. With the current report, we present the case of a 75-year-old woman diagnosed with stage IV lung adenocarcinoma, who developed acute abdominal pain without preceding symptomatology while on pembrolizumab-pemetrexed maintenance treatment. A contained rupture of the appendix was found, for which she was managed conservatively. Subsequent endoscopic as well as histopathological findings from biopsies obtained via colonoscopy associated the clinical and imaging findings with grade 4 immune-mediated colitis. Interestingly, high-grade colitis is more frequent with anti-CTLA-4 agents in comparison to anti-PD-1 agents; moreover, most cases of anti-PD-1-mediated colitis present with preceding symptomatology (like diarrhea or vomiting), while cases or colonic perforation are extremely rare if ever described.

Colonic Perforation After Treatment With Nivolumab in Esophageal Cancer: A Case Report

With the advent of checkpoint inhibitors, it has opened up opportunities for numerous cancer patients. However, as is the case with every treatment, complications need to be weighed. Gastrointestinal adverse effects, such as diarrhea and colitis are well-known complications for checkpoint inhibitors. In severe cases, colitis-induced colonic perforation may occur with an estimation of 1.0% to 1.5% in anti-CTLA-4 antibodies. However, only a handful of cases of such devastating complications have been reported in anti-PD-1 antibodies such as pembrolizumab and nivolumab. We here report a case of intestinal perforation in a patient treated with nivolumab.

Chemoimmunotherapy-related enteritis resulting in a mechanical small bowel obstruction - A case report

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The causes of a mechanical small bowel obstruction are diverse, several of which can be managed non-operatively.

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One such example is when an obstruction occurs due to an enteritis in the setting of chemo- and immunotherapy.

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Treatment is initially supportive in the form fluid resuscitation, gut rest, antiemetics and nasogastric decompression.

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Corticosteroids and biological agents may be considered under some circumstances.

Introduction and importance

Mechanical small bowel obstruction (SBO) is amongst the commonest diagnoses encountered in surgical departments. Although the aetiology is frequently post-surgical adhesions, the condition can arise in a virgin abdomen and we now know several of these cases do not require acute operative management. Here we report one such case where a small bowel obstruction transpired due to enteritis in the setting of chemoimmunotherapy with no prior abdominal surgery.

Case presentation

A 62 year old male presented to our department with 2 days of vomiting and obstipation. This is on a background of metastatic non-small cell lung cancer for which he was due for his 4^th cycle of carboplatin, pemetrexed and pembrolizumab. Computed Tomography (CT) of the abdomen demonstrated a segment of thickened distal small bowel without any mass lesion, along with upstream dilatation. The findings were consistent with a mechanical SBO due to enteritis. Infective causes were excluded. The patient successfully recovered with non-operative intervention in the coming days.

Clinical discussion

Enteritis is an established adverse effect of various chemoimmunotherapy agents, though a case severe enough to produce a mechanical bowel obstruction is exceptionally rare. We demonstrate through this case that the condition may resolve through conservative measures.

Conclusion

The diagnosis of chemoimmunotherapy-related enteritis producing an SBO although uncommon, should be considered in the relevant population. A non-operative approach may be appropriate under some circumstances.