Well Differentiated Grade 3 Neuroendocrine Tumors of the Digestive Tract: A Narrative Review

Methodology of the SORENTO clinical trial: a prospective, randomised, active-controlled phase 3 trial assessing the efficacy and safety of high exposure octreotide subcutaneous depot (CAM2029) in patients with GEP-NET

BACKGROUND

The current standard of care (SoC) for the initial treatment of unresectable or metastatic well-differentiated gastroenteropancreatic neuroendocrine tumours (GEP-NET) requires initiation of first-generation somatostatin receptor ligand (SRL) therapy, octreotide and lanreotide, which provide safe and efficacious tumour/symptom control in most patients. However, disease progression can occur with SoC SRL treatment and the optimal dose response of SRL remains unknown. Octreotide subcutaneous depot (CAM2029) is a novel, long-acting, high-exposure formulation that has shown greater bioavailability and improved administration than octreotide long-acting release (LAR) with a well-tolerated safety profile. Retrospective data have highlighted a potential benefit of high-exposure SRL for improved disease control in patients who did not adequately respond to the current SoC SRL treatment. This trial will investigate the efficacy and tolerability of CAM2029 compared to the current SoC, including octreotide LAR and lanreotide autogel (ATG).

METHODS

SORENTO is a prospective, multicentre, randomised, active-controlled, open-label phase 3 trial aiming to demonstrate superiority of treatment with 20 mg octreotide subcutaneous depot (CAM2029) every 2 weeks (Q2W) compared to treatment with the Investigator's choice of SRL therapy at standard doses for tumour control (octreotide LAR 30 mg or lanreotide ATG 120 mg every 4 weeks [Q4W]) as assessed by progression-free survival (PFS) in approximately 300 patients with unresectable/metastatic and well-differentiated GEP-NET. Upon confirmation of disease progression (determined by a Blinded Independent Review Committee [BIRC] and defined as per RECIST 1.1), patients may enter an open-label extension treatment period with once weekly dosing, to investigate the effects of higher frequency dosing. Overall survival follow-up will end a maximum of 2 years after primary analysis. The primary endpoint will be analysed after 194 confirmed PFS events.

DISCUSSION

This is the first trial investigating the efficacy of CAM2029 versus SoC SRL therapy using a head-to-head, superiority trial design. It is expected to be the first trial to investigate the efficacy of increased dosing frequency of a high-exposure SRL. A BIRC will limit bias and measurement variability and ensure high-quality efficacy data. Additionally, inclusion of patients with well-differentiated Grade 3 NET may elucidate treatment strategies for this rarely investigated patient population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05050942. Registered on 21st September 2021.

Gastric Neuroendocrine Tumors According to the 2019 World Health Organization Grading System: A Single-Center, Retrospective Study

Background/Aims

Although gastric neuroendocrine tumors (NETs) are uncommon neoplasms, their prevalence is increasing. The clinical importance of the World Health Organization (WHO) classification of gastric NETs, compared with NETs in other organs, has been underestimated. This study aimed to systematically evaluate the clinical and pathologic characteristics of gastric NETs based on the 2019 WHO classification and to assess the survival outcomes of patients from a single-center with a long-term follow-up.

Methods

The medical records of 427 patients with gastric NETs who underwent endoscopic or surgical resection between January 2000 and March 2020 were retrospectively reviewed. All specimens were reclassified according to the 2019 WHO classification. The clinicopathologic characteristics, treatment, and oncologic outcomes of 139 gastric NETs were analyzed.

Results

The patients' median age was 53.0 years (interquartile range [IQR], 46.0 to 63.0 years). The median follow-up period was 36.0 months (IQR, 15.0 to 63.0 months). Of the patients, 92, 44, and 3 had grades 1, 2, and 3 NETs, respectively. The mean tumor size significantly increased as the tumor grade increased (p=0.025). Patients with grades 2 and 3 gastric NETs more frequently had lymphovascular invasion (29.8% vs 10.9%, p=0.005) and deeper tissue invasion (8.5% vs 0%, p=0.012) than those with grade 1 tumors. The overall disease-specific survival rate was 100%. Two patients with grades 2-3 gastric NETs experienced extragastric recurrence.

Conclusions

Although gastric NETs have an excellent prognosis, grade 2 or grade 3 gastric NETs are associated with a larger size, deeper invasion, and extragastric recurrence, which require active treatment.

Integrating Functional Imaging and Molecular Profiling for Optimal Treatment Selection in Neuroendocrine Neoplasms (NEN)

PURPOSE OF REVIEW

Gastroenteropancreatic NEN (GEP-NEN) are group of malignancies with significant clinical, anatomical and molecular heterogeneity. High-grade GEP-NEN in particular present unique management challenges.

RECENT FINDINGS

In the current era, multidisciplinary management with access to a combination of functional imaging and targeted molecular profiling can provide important disease characterisation, guide individualised management and improve patient outcome. Multiple treatment options are now available, and combination and novel therapies are being explored in clinical trials. Precision medicine is highly relevant for a heterogenous disease like NEN. The integration of dual-tracer functional PET/CT imaging, molecular histopathology and genomic data has the potential to be used to gain a more comprehensive understanding of an individual patient's disease biology for precision diagnosis, prognostication and optimal treatment allocation.

The Complex Histopathological and Immunohistochemical Spectrum of Neuroendocrine Tumors-An Overview of the Latest Classifications

Neuroendocrine neoplasms (NENs) originate from the neuroendocrine cell system, which may either take the shape of organoid cell aggregations or be composed of dispersed cells across various organs. Therefore, these tumors are heterogenous regarding the site of origin, functional status, degree of aggressiveness, and prognosis. When treating patients with neuroendocrine tumors, one of the most significant challenges for physicians is determining the correct tumor grade and thus classifying patients into risk categories. Over the years, the classification of these tumors has changed significantly, often causing confusion due to clinical, molecular, and immunohistochemical variability. This review aims to outline the latest NENs classifications regardless of their site of origin. Thus, an overview of the key histopathological and immunohistochemical characteristics of NENs could pave the way to validate possible predictive and prognostic markers and also guide the therapeutic conduct.

Risk Stratification of Pancreatic Neuroendocrine Neoplasms Based on Clinical, Pathological, and Molecular Characteristics

Pancreatic neuroendocrine neoplasms consist of heterogeneous diseases. Depending on the novel features detected by various modern technologies, their classification and related prognosis predictions continue to change and develop. The role of traditional clinicopathological prognostic factors, including classification systems, is also being refined, and several attempts have been made to predict a more accurate prognosis through novel serum biomarkers, genetic factors, and epigenetic factors that have been identified through various state-of-the-art molecular techniques with multiomics sequencing. In this review article, the latest research results including the traditional approach to prognostic factors and recent advanced strategies for risk stratification of pancreatic neuroendocrine neoplasms based on clinical, pathological, and molecular characteristics are summarized. Predicting prognosis through multi-factorial assessments seems to be more efficacious, and prognostic factors through noninvasive methods are expected to develop further advances in liquid biopsy in the future.

Well-Differentiated Grade 3 Neuroendocrine Tumors: Characteristics, Treatments, and Outcomes From a Population-Based Study

OBJECTIVES

We evaluated a population-based cohort of metastatic well-differentiated grade 3 gastroenteropancreatic neuroendocrine tumors (G3 NETs) to describe their characteristics, prognosis, and treatment outcomes.

METHODS

The British Columbia provincial database was queried for G3 NETs diagnosed 2004 to 2021, and charts were reviewed to describe clinical features and outcomes.

RESULTS

Forty-one patients were identified, most were diagnosed with pancreatic (58.5%) or midgut (26.8%) primary tumor and Ki-67 was less than 55% in 68.3%. The primary was resected in 19 (46.3%) with median disease-free survival of 25.2 months. Once metastatic, patients received a median of one line of systemic therapy. Median overall survival with metastatic disease was 33.8 months. Median progression-free survival was longest in patients treated with capecitabine-temozolomide (20.6 months) or somatostatin analogs (7.9 months), while etoposide-platinum provided little benefit (2.4 months). Limited data of efficacy for targeted therapies and radionuclide therapy was available. Seven patients (17.1%) were also treated with local therapies, which were associated with improved overall survival (median not reached, hazard ratio, 0.23; P = 0.012).

CONCLUSIONS

Capecitabine-temozolomide and somatostatin analogs were associated with clinically meaningful benefit, and use of local therapies provided benefits in selected patients. Multidisciplinary discussion is essential to optimize individual outcomes in this heterogeneous population.

An update on the development of concepts, diagnostic criteria, and challenging issues for neuroendocrine neoplasms across different digestive organs

Digestive neuroendocrine neoplasms (NENs) are a group of heterogeneous neoplasms found throughout the digestive tract, with different behaviour and genetic background. In the last few years, nomenclature and WHO/UICC classifications of digestive NENs have changed, and molecular classifications have emerged, especially in pancreatic locations. Increasing patho-molecular details are needed to diagnose the different categories of NEN, including the use of helpful immunohistochemical markers. In this review, we address these topics in three successive chapters. We first briefly review recent updates in classifications, discuss important grading and proliferating issues and advances in the molecular understanding of NEN. Then, we provide an update on diagnosis, including the most important differential diagnoses of NEN, with a focus on high-grade neoplasms and mixed tumours. Finally, we highlight a variety of currently used and next-generation predictive and prognostic biomarkers as well as biomarkers of tumour origin and describe some site specificities of gastrointestinal NEN. We specifically focus on biomarkers available to pathologists with the potential to change the way patients with NEN are diagnosed and treated.

A Well-Differentiated Grade-3 Neuroendocrine Tumor in the Ascending Colon: A Case Report

Patient: Male, 60-year-old

Final Diagnosis: Colon mass • neuroendocrine tumor G3

Symptoms: Altered bowel habit • anemia

Medication: —

Clinical Procedure: Rt HemiColectomy

Specialty: Oncology • Surgery

A Retrospective Analysis of the Correlation between Functional Imaging and Clinical Outcomes in Grade 3 Neuroendocrine Tumors (NETs G3)

Grade 3 (G3) neuroendocrine tumors (NETs) are a novel category among digestive neuroendocrine neoplasms, characterized by Ki-67 >20% and a well-differentiated morphology, presenting high intra-tumor heterogeneity. We aimed to explore the role of dual-tracer PET imaging (68Gallium (Ga)-DOTATOC and 18Fluorodeoxyglucose (FDG)) as overall survival (OS) predictor in NET G3 patients. We performed a retrospective analysis in NET G3 patients treated at our institution between 2003 and 2021. Accordingly, 30 NET G3 patients were analyzed. 68Ga-DOTA-TOC and 18F-FDG uptake were assessed by tumor/non-tumor (T-nonT) ratio. We reported a slightly better OS for patients with ≥75% concordance between 68Ga-DOTA-TOC and 18F-FDG PET/CT (p = 0.42). Among patients with discordant functional imaging, we reported a better 5-y OS rate for patients with a prevalent 68Ga-DOTATOC vs. 18F-FDG PET/CT (p = 0.016). In positive 18F-FDG PET/CT cases, we reported a better OS for <4 vs. ≥4 T/non-T ratio (p = 0.021). Among upfront-NET G3 patients with concordant exams, 5-y OS rate was 83.3% (95% CI: 27.3-97.5). Among patients with discordant exams, 5-y OS rate was 81.3% (52.5-93.5), 100% for those with prevalent receptor expression, and 50% (11.1-80.4) for those with prevalent 18F-FDG uptake. Our findings suggest that dual-tracer PET/CT can be considered as a predictor of patient outcome, able to stratify NET G3 patients with poorer prognosis.

A Subset of Large Cell Neuroendocrine Carcinomas in the Gastroenteropancreatic Tract May Evolve from Pre-existing Well-Differentiated Neuroendocrine Tumors

In the gastro-entero-pancreatic (GEP) tract, neuroendocrine neoplasms (NENs) include well differentiated neuroendocrine tumors (NETs) and high-grade NE carcinomas (NECs), which are thought to make up separate and mutually exclusive tumor entities. Little is known, however, as to whether there may be any pathogenetic link between them. Clustering analysis of a 10-gene panel generated from a previously reported next-generation sequencing analysis on 48 GEP-NENs with clinical annotations was used in the study. Unsupervised cluster analysis showed three histology-independent clusters, namely, C1, C2, and C3, which accounted for 44% of patients but the entire array of mutations. All but two NECs fell into the clusters, yet with different prevalence rates (p < 0.0001). A model was devised according to which NETs were likely to evolve into NECs upon progression of C3 into C1 and C2, despite different morphology. The median Ki-67 labeling index was 5% in C3 showing better prognosis and 50% in C1 and C2 experiencing worse prognosis, with an impressive intra-tumor heterogeneity of diversely proliferating tumor areas. This study suggests that a subset of large cell NECs in the gastroenteropancreatic tract may evolve from pre-existing well-differentiated NETs.

Current status of medical treatment for gastroenteropancreatic neuroendocrine neoplasms and future perspectives

Neuroendocrine neoplasms (NENs) constitute a heterogeneous group of tumors. In this review, we summarize the results of various clinical trials that have been conducted to investigate the efficacy and safety of various therapeutic options for NENs. Based on the encouraging results obtained from these trials, various therapeutic options have been established for the treatment of NENs, including somatostatin analogs (SSAs), molecularly targeted drugs and cytotoxic agents. In addition, peptide receptor radionucleotide therapy has recently been evaluated for the treatment of various NENs. We also discuss the approach for selecting the appropriate drugs and sequence of treatment with the various drug classes, as recommended by different treatment guidelines. Finally, we discuss the scope for future research in this field, especially into the merits of combination therapy with molecularly targeted drugs plus SSAs, along with ongoing studies.

Neuroendocrine Carcinomas of the Digestive Tract: What Is New?

Neuroendocrine carcinomas (NEC) are rare tumors with a rising incidence. They show poorly differentiated morphology with a high proliferation rate (Ki-67 index). They frequently arise in the lung (small and large-cell lung cancer) but rarely from the gastrointestinal tract. Due to their rarity, very little is known about digestive NEC and few studies have been conducted. Therefore, most of therapeutic recommendations are issued from work on small-cell lung cancers (SCLC). Recent improvement in pathology and imaging has allowed for better detection and classification of high-grade NEN. The 2019 World Health Organization (WHO) classification has described a new entity of well-differentiated grade 3 neuroendocrine tumors (NET G-3), with better prognosis, that should be managed separately from NEC. NEC are aggressive neoplasms often diagnosed at a metastatic state. In the localized setting, surgery can be performed in selected patients followed by adjuvant platinum-based chemotherapy. Concurrent chemoradiotherapy is also an option for NEC of the lung, rectum, and esophagus. In metastatic NEC, chemotherapy is administered with a classic combination of platinum salts and etoposide in the first-line setting. Peptide receptor radionuclide therapy (PRRT) has shown positive results in high-grade NEN populations and immunotherapy trials are still ongoing. Available therapies have improved the overall survival of NEC but there is still an urgent need for improvement. This narrative review sums up the current data on digestive NEC while exploring future directions for their management.

Digestive Well-Differentiated Grade 3 Neuroendocrine Tumors: Current Management and Future Directions

Digestive well-differentiated grade 3 neuroendocrine tumors (NET G-3) have been clearly defined since the 2017 World Health Organization classification. They are still a rare category lacking specific data and standardized management. Their distinction from other types of neuroendocrine neoplasms (NEN) not only lies in morphology but also in genotype, aggressiveness, functional imaging uptake, and treatment response. Most of the available data comes from pancreatic series, which is the most frequent tumor site for this entity. In the non-metastatic setting, surgical resection is recommended, irrespective of grade and tumor site. For metastatic NET G-3, chemotherapy is the main first-line treatment with temozolomide-based regimen showing more efficacy than platinum-based regimen, especially when Ki-67 index <55%. Targeted therapies, such as sunitinib and everolimus, have also shown some positive therapeutic efficacy in small samples of patients. Functional imaging plays a key role for detection but also treatment selection. In the second or further-line setting, peptide receptor radionuclide therapy has shown promising response rates in high-grade NEN. Finally, immunotherapy is currently investigated as a new therapeutic approach with trials still ongoing. More data will come with future work now focusing on this specific subgroup. The aim of this review is to summarize the current data on digestive NET G-3 and explore future directions for their management.

Spontaneous intra-abdominal hemorrhage of a well-differentiated, grade 3 gastric neuroendocrine tumor during drug-based treatment

Grade 3, well-differentiated, gastric neuroendocrine tumors (NET G3) are extremely rare. Herein, we report the case of a 64-year-old man with a grade 3 neuroendocrine tumor of the stomach who experienced intra-abdominal bleeding during the course of drug treatment. The patient was referred to our hospital for examination of a gastric tumor that was initially diagnosed by a local medical doctor. Esophagogastroduodenoscopy revealed an elevated lesion with a central ulcer in the upper body of the stomach, and biopsy specimens confirmed the pathological diagnosis of NET G3. Abdominal contrast-enhanced computed tomography (CT) showed a 25-cm, well-defined mass lesion showing heterogeneous enhancement in the liver. A clinical diagnosis of NET G3 with multiple liver metastases was given, after which everolimus was administered in combination with a somatostatin analogue. However, the patient developed sudden-onset epigastric abdominal pain and general fatigue 2 months later, and emergency abdominal contrast-enhanced CT confirmed the presence of intra-abdominal hemorrhage. Following blood transfusion, the patient's symptoms and general condition improved. Although the patient was treated with streptozocin, abdominal CT indicated progression of the liver metastases. Unfortunately, despite receiving best supportive care, the patient died 8 months after the initial of the treatment. To the best of our knowledge, this is the first case of a patient who developed spontaneous hemoperitoneum during drug treatment for a NET G3 to be reported in the English literature. It is essential that additional data be obtained to determine the optimal treatment for this disease.

Myeloid and T-Cell Microenvironment Immune Features Identify Two Prognostic Sub-Groups in High-Grade Gastroenteropancreatic Neuroendocrine Neoplasms

High-grade Gastroenteropancreatic Neuroendocrine neoplasms (H-NENs) comprehend well-differentiated tumors (NET G3) and poorly differentiated carcinomas (NEC) with proliferative activity indexes as mitotic count (MC) >20 mitoses/10 HPF and Ki-67 >20%. At present, no specific therapy for H-NENs exists and the several evidences of microenvironment involvement in their pathogenesis pave the way for tailored therapies. Forty-five consecutive cases, with available information about T-cell, immune, and non-immune markers, from surgical pathology and clinical databases of 2 Italian institutions were immunostained for Arginase, CD33, CD163 and CD66 myeloid markers. The association between features was assessed by Spearman’s correlation coefficient. A unsupervised K-means algorithm was used to identify clusters of patients according to inputs of microenvironment features and the relationship between clusters and clinicopathological features, including cancer-specific survival (CSS), was analyzed. The H-NEN population was composed of 6 (13.3%) NET G3 and 39 (86.7%) NEC. Overall, significant positive associations were found between myeloid (CD33, CD163 and Arginase) and T/immune markers (CD3, CD4, CD8, PD-1 and HLA-I). Myeloid and T-cell markers CD3 and CD8 identified two clusters of patients from unsupervised K-means analysis. Cases grouped in cluster 1 with more myeloid infiltrates, T cell, HLA and expression of inhibitory receptors and ligands in the stroma (PD-1, PD-L1) had significantly better CSS than patients in cluster 2. Multivariable analysis showed that Ki-67 (>55 vs. <55, HR 8.60, CI 95% 2.61–28.33, p < 0.0001) and cluster (1 vs. 2, HR 0.43, CI 95% 0.20–0.93, p = 0.03) were significantly associated with survival. High grade gastroenteropancreatic neuroendocrine neoplasms can be further classified into two prognostic sub-populations of tumors driven by different tumor microenvironments and immune features able to generate the framework for evaluating new therapeutic strategies.

Genomics of High-Grade Neuroendocrine Neoplasms: Well-Differentiated Neuroendocrine Tumor with High-Grade Features (G3 NET) and Neuroendocrine Carcinomas (NEC) of Various Anatomic Sites

High-grade neuroendocrine neoplasms (HG-NENs) are clinically aggressive diseases, the classification of which has recently been redefined. They now include both poorly differentiated NENs (neuroendocrine carcinoma, NECs) and high proliferating well-differentiated NENs (called grade 3 neuroendocrine tumors, G3 NETs, in the digestive system). In the last decade, the "molecular revolution" that has affected all fields of medical oncology has also shed light in the understanding of HG NENs heterogeneity and has provided new diagnostic and therapeutic tools, useful in the management of these malignancies. Considering the kaleidoscopic aspects of HG NENs in various anatomical sites, this review systematically addresses the genomic landscape of such neoplasm throughout the more common thoracic and digestive locations, as well as it will consider other rare but not exceptional primary sites, including the skin, the head and neck, and the urogenital system. The revision of the available literature will then be oriented to understand the translational relevance of molecular data, by analyzing conceptual issues, clinicopathological correlations, and unmet needs in this field.

Clinicopathological characteristics and prognosis of 77 cases with type 3 gastric neuroendocrine tumours

BACKGROUND

For the rarity of type 3 gastric neuroendocrine tumours (g-NETs), their clinicopathological characteristics and prognosis are not well illustrated.

AIM

To describe the clinicopathological features and outcome of type 3 g-NETs in the Chinese population.

METHODS

Based on the 2019 WHO pathological classification, the clinicopathological characteristics and prognosis of patients with type 3 g-NETs in China were retrospectively analysed.

RESULTS

A total of 77 patients (55.8% of females) with type 3 g-NETs were analysed, with a median age of 48 years (range: 28-79 years). The tumours were mainly located in the gastric fundus/body (83.1%) and were mostly solitary (83.1%), with a median size of 1.5 cm (0.8-3.5 cm). Of these, there were 37 G1 tumours (48.1%), 31 G2 (40.3%), and 9 G3 (11.7%). Ten (13.0%) and 24 (31.2%) patients had lymph node and distant metastasis, respectively. In addition, type 3 g-NETs were heterogeneous. Compared with G1 NETs, G2 NETs had a higher lymph node metastasis rate, and G3 NETs had a higher distant metastasis rate. G1 and G2 NETs with stage I/II disease (33/68) received endoscopic treatment, and no tumour recurrence or tumour-related death was observed within a median follow-up time of 36 mo. Grade and distant metastasis were identified to be independent risk factors for prognosis in multivariable analysis.

CONCLUSION

Type 3 g-NETs are obviously heterogeneous, and the updated WHO 2019 pathological classification may be used to effectively evaluate their biological behaviors and prognosis. Also, endoscopic treatment should be considered for small (< 2 cm), low grade, superficial tumours.

Does the proteasome inhibitor bortezomib sensitize to DNA-damaging therapy in gastroenteropancreatic neuroendocrine neoplasms? - A preclinical assessment in vitro and in vivo

BACKGROUND

Well-differentiated gastroenteropancreatic neuroendocrine neoplasms are rare tumors with a slow proliferation. They are virtually resistant to many DNA-damaging therapeutic approaches, such as chemo- and external beam therapy, which might be overcome by DNA damage inhibition induced by proteasome inhibitors such as bortezomib.

METHODS AND RESULTS

In this study, we assessed several combined treatment modalities in vitro and in vivo. By cell-based functional analyses, in a 3D in ovo and an orthotopic mouse model, we demonstrated sensitizing effects of bortezomib combined with cisplatin, radiation and peptide receptor radionuclide therapy (PRRT). By gene expression profiling and western blot, we explored the underlying mechanisms, which resulted in an impaired DNA damage repair. Therapy-induced DNA damage triggered extrinsic proapoptotic signaling as well as the induction of cell cycle arrest, leading to a decreased vital tumor volume and altered tissue composition shown by magnetic resonance imaging and F-18-FDG-PET in vivo, however with no significant additional benefit related to PRRT alone.

CONCLUSIONS

We demonstrated that bortezomib has short-term sensitizing effects when combined with DNA damaging therapy by interfering with DNA repair in vitro and in ovo. Nevertheless, due to high tumor heterogeneity after PRRT in long-term observations, we were not able to prove a therapeutic advantage of bortezomib-combined PRRT in an in vivo mouse model.

SUMOylation of HSP27 regulates PKM2 to promote esophageal squamous cell carcinoma progression

A previous proteomic screening of differentially expressed biomarkers between Kazakh patients with esophageal squamous cell carcinoma (ESCC) and normal adjacent tissues demonstrated that heat shock protein 27 (HSP27) and pyruvate kinase isoenzyme M2 (PKM2) were both highly expressed in ESCC samples compared with normal controls. However, the regulatory association between HSP27 and PKM2 in ESCC remains elusive. In the present study, immunohistochemistry and immunoblotting were adopted to examine the expression of HSP27, PKM2 and other relevant biomarkers involved in epithelial‑to‑mesenchymal transition in clinical tissue samples. The interactions between proteins were detected by co‑immunoprecipitation (Co‑IP) assay and further confirmed by immunofluorescence assay. The growth and motility of ESCC cells were examined by MTT, Transwell and wound healing assays. Overexpression of HSP27 was found to be significantly associated with T‑cell classification, lymph node metastasis and poor prognosis in ESCC. In addition, HSP27 expression was significantly correlated with PKM2 expression in ESCC specimens. Functionally, knockdown of HSP27 inhibited the growth and motility of ESCC cells. Moreover, HSP27 was found to directly interact with small ubiquitin‑related modified protein 2/3 (SUMO2/3) in ESCC cell lines, as evidenced by Co‑IP and laser confocal imaging. In addition, downregulation of HSP27 was shown to decrease PKM2 and E‑cadherin expression. Knockdown of SUMO2/3 was observed to reduce the expression of HSP27, PKM2 and EMT‑related biomarkers. The results of the present study indicated that the SUMOylation of HSP27 enhances the proliferation, invasion and migration of ESCC cells via PKM2.