Increased risk of intestinal cancer in Crohn's disease: a meta-analysis of population-based cohort studies

OBJECTIVES

The risk of intestinal malignancy in Crohn's disease (CD) remains uncertain since risk estimates vary worldwide. The global CD population is growing and there is a demand for better knowledge of prognosis of this disease. Hence, the aim of the present study was to conduct a meta-analysis of population-based data on intestinal cancer risk in CD.

METHODS

The MEDLINE search engine and abstracts from international conferences were searched for the relevant literature by use of explicit search criteria. All papers fulfilling the strict inclusion criteria were scrutinized for data on population size, time of follow-up, and observed to expected cancer rates. STATA meta-analysis software was used to perform overall pooled risk estimates (standardized incidence ratio (SIR), observed/expected) and meta-regression analyses of the influence of specific variables on SIR.

RESULTS

Six papers fulfilled the inclusion criteria and reported SIRs of colorectal cancer (CRC) in CD varying from 0.9 to 2.2. The pooled SIR for CRC was significantly increased (SIR, 1.9; 95% CI 1.4-2.5), as was the risk for colon cancer separately (SIR, 2.5; 95% CI 1.7-3.5). Regarding small bowel cancer, five studies reported SIRs ranging from 3.4 to 66.7, and the overall pooled estimate was 27.1 (95% CI 14.9-49.2).

CONCLUSIONS

The present meta-analysis of intestinal cancer risk in CD, based on population-based studies only, revealed an overall increased risk of both CRC and small bowel cancer among patients with CD. However, some of the available data were several decades old, and future studies taking new treatment strategies into account are required.

Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are heterogeneous malignancies arising from the diffuse neuroendocrine system. They frequently originate in the gastroenteropancreatic (GEP) tract and the bronchopulmonary tree, and their incidence has steadily increased in the last 3 decades. Fundamental biologic and genomic differences underlie the clinical heterogeneity of NETs, and distinct molecular features characterize NETs of different grades and different primary sites. Although surgery remains the cornerstone of treatment for localized tumors, systemic treatment options for patients with metastatic NETs have expanded considerably. Somatostatin analogs have demonstrated both antisecretory and antitumor efficacy. Peptide receptor radionuclide therapy with lutetium-177 dotatate (¹⁷⁷ Lu-DOTATATE) has been approved for advanced GEP-NETs. The antitumor activity of everolimus has been demonstrated across a wide spectrum of NETs, and the antiangiogenic agent sunitinib has been approved for pancreatic NETs (pNETs). Chemotherapy with temozolomide and capecitabine has recently demonstrated an unprecedented prolongation of progression-free survival in a randomized trial of pNETs. Multiple retrospective series have reported the efficacy of liver-directed therapies both for palliating symptoms of hormone excess and for controlling tumor growth. Telotristat, an oral inhibitor of tryptophan hydroxylase, has been shown to reduce diarrhea in patients with carcinoid syndrome. Defining the therapeutic algorithm and identifying biomarkers predictive of response to treatments are among the main priorities for the next decade of research in the NET field.

Adenocarcinoma of the small bowel: presentation, prognostic factors, and outcome of 217 patients

BACKGROUND

Primary adenocarcinoma of the small bowel is a rare neoplasm, and to the authors' knowledge, few studies to date have addressed the topic.

METHODS

In the current study, the records of 217 patients with small bowel adenocarcinoma were reviewed retrospectively for the presentation, prognostic factors, treatment modalities, and outcome.

RESULTS

The median age of the patients was 55 years and there were 133 (61%) males. Tumors originated in the duodenum in 113 (52%) patients, the jejunum in 54 (25%) patients, the ileum in 28 (13%) patients, and in nonspecified sites in 22 (10%) patients. Patients with proximal tumors were diagnosed for the most part using endoscopy (i.e., 46 of 108 [43%]), whereas laparotomy enabled diagnosis in 16 of 28 (57%) patients with distal tumors. Based on TNM staging, 9 (4%) patients had Stage I disease, 43 (20%) patients had Stage II disease, 86 (39%) patients had Stage III disease, and 75 (35%) patients had Stage IV disease. The liver was the most common site of metastasis in 44 (59%) patients. Cancer-directed surgery was performed in 146 (67 %) patients, including the Whipple procedure in 36 patients (17%). The median overall survival time was 20 months. The 5-year overall survival rate was 26%. Cancer-directed surgery, early-stage disease, and lymph node involvement ratio were significantly associated with overall survival by univariate analysis. However, only cancer-directed surgery and lymph node involvement ratio were independent predictors of overall survival in a multivariate analysis (adjusted rate ratio = 0.14; 95% confidence interval [95% CI], 0.04-0.46; P = 0.001 and adjusted rate ratio = 0.25; 95% CI, 0.12-0.53; P < 0.001, respectively).

CONCLUSIONS

Performing an oncologic surgery resulted in the best outcome in patients with nonmetastatic disease. Because cancer-directed surgery is associated with high morbidity and mortality in primary centers, these patients should be referred to a tertiary center for adequate treatment.

Malignant gastrointestinal stromal tumors of the small intestine: a review of 50 cases from a prospective database

BACKGROUND

Malignant gastrointestinal stromal tumors (M-GIST) are rare mesenchymal tumors originating in the wall of the gastrointestinal (GI) tract. Previous studies have included limited numbers of patients, and most included malignant and benign cases from throughout the GI tract. We reviewed the experience of a single tertiary cancer care center with M-GIST of the small intestine only.

METHODS

A prospective database identified all patients seen from 1989 to 1998. Clinical and pathological data, treatment, and outcome were analyzed. Overall median follow-up time was 24 months (range, 1-176 months).

RESULTS

Fifty patients (31 male, 19 female) were identified. Mean age at diagnosis was 55 years. Disease was localized in 11 patients, locally advanced (invasion into adjacent organs/peritoneum) in 24 patients, perforated in 4 patients, multiple primary lesions in 2 patients, and distant metastases in 9 patients. All patients underwent resection, which was complete in 70%. Locoregional recurrence (LR) developed in 43% (median, 25 months), and distant metastases in 59% (median, 21 months) of patients at risk. At last follow-up, 14 patients were alive (6 disease-free), 2 had died disease-free, and 34 died with recurrent disease. Overall survival (OS) was similar for localized and locally advanced disease; OS also was similar for patients with multiple primaries and distant metastases at diagnosis. Patients were grouped into three stages: (I) patients with localized and locally advanced disease; (II) patients with perforated; and (III) patients with multiple primaries and distant metastases. Actuarial OS at 5 years was 41% (n = 50)--42% for those with complete resection and 8% for incomplete resection. Univariable analysis showed that earlier stage at diagnosis (P = .001) and completeness of resection (P = .004) predicted for longer OS.

CONCLUSIONS

Most patients with M-GIST of the small intestine relapse following resection, but survival may be prolonged. In univariable analysis, stage at presentation and complete resection were significant prognostic variables for OS; grade was not significant. Localized and locally advanced M-GIST of the small intestine have a mean OS > 5 years. Complete resection should be the goal of initial surgical treatment.

Supportive-expressive group therapy for women with metastatic breast cancer: survival and psychosocial outcome from a randomized controlled trial

BACKGROUND

Mixed reports exist about the impact of supportive-expressive group therapy (SEGT) on survival.

METHODS

From 485 women with advanced breast cancer recruited between 1996-2002, 227 (47%) consented and were randomized within an average 10 months of cancer recurrence in a 2:1 ratio to intervention with 1 year or more of weekly SEGT plus three classes of relaxation therapy (147 women) or to control receiving three classes of relaxation therapy (80 women). The primary outcome was survival; psychosocial well-being was appraised secondarily. Analysis was by intention-to-treat.

RESULTS

SEGT did not prolong survival (median survival 24.0 months in SEGT and 18.3 in controls; univariate hazard ratio for death 0.92 [95% CI, 0.69-1.26]; multivariate hazard ratio, 1.06 [95% CI, 0.74-1.51]). Significant predictors of survival were treatment with chemotherapy and hormone therapy (p<0.001), visceral metastases (p<0.001) and advanced disease at first diagnosis (p<0.05). SEGT ameliorated and prevented new DSM-IV depressive disorders (p = 0.002), reduced hopeless-helplessness (p = 0.004), trauma symptoms (p = 0.04) and improved social functioning (p = 0.03).

CONCLUSIONS

SEGT did not prolong survival. It improved quality of life, including treatment of and protection against depression.

Midgut neuroendocrine tumours with liver metastases: results of the UKINETS study

We intended to identify the prognostic factors and the results of interventions on patients with liver metastatic midgut carcinoids. Five institutions that are part of United Kingdom and Ireland neuroendocrine tumour (NET) group took part in this study. Patients were included if they had histology proven NET of midgut origin and liver metastases at the time of the study. Clinical and biochemical data were collected retrospectively from hospital charts, pathology reports, radiology reports and biochemistry records for each patient. Three hundred and sixty patients were included in the study. The median survival from date of diagnosis was 7.69 years (confidence interval (CI) 6.40-8.99) and 5.95 years (CI 5.02-6.88) from date of diagnosis of liver metastases. On univariate analysis, increasing age at diagnosis, increasing urinary hydroxyindole acetic acid levels, increasing plasma chromogranin A levels, high Ki67, high tumour volume and treatment with chemotherapy were identified as factors associated with a significantly poorer outcome. Resection of liver metastases, resection of small bowel primary, treatment with somatostatin analogue therapy and treatment with peptide receptor therapy were associated with improved prognosis. Multivariate analysis revealed that age at diagnosis (P=0.014), Ki67 level (P=0.039) and resection of primary (P=0.015) were independent predictors of survival. This is the largest study to our knowledge looking specifically at the prognosis and clinical course of patients with liver metastatic midgut NETs. For the first time, we have shown that Ki67 and resection of primary are independent predictors of survival for this group of patients.

The American College of Surgeons Commission on Cancer and the American Cancer Society. Adenocarcinoma of the small bowel: review of the National Cancer Data Base, 1985-1995

BACKGROUND

Small bowel adenocarcinoma (SBA) accounts for 2% of gastrointestinal (GI) tumors and 1% of GI cancer deaths. The objective of this study was to review the National Cancer Data Base (NCDB) to identify case-mix characteristics, patterns of treatment, and factors influencing survival of patients with SBA.

METHODS

NCDB data from patients diagnosed with primary SBA between 1985-1995 were analyzed. Chi-square statistics were used to compare differences between groups. Disease specific survival (DSS) was calculated using the life table method for patients diagnosed between 1985-1990; univariate differences in survival were compared using the Wilcoxon statistic, and multivariate analyses were performed using a Cox regression model.

RESULTS

There were 4995 SBA cases reported to the NCDB between 1985-1995, 55% of which occurred in the duodenum, 18% in the jejunum, 13% in the ileum, and 14% in nonspecified sites. The overall 5-year DSS was 30.5%, with a median survival of 19.7 months. By multivariate analysis, factors significantly correlated with DSS included patient age, tumor site, disease stage, and whether cancer-directed surgery was performed.

CONCLUSIONS

SBA is found most commonly in the duodenum, and patient DSS is reduced at this site compared with those patients with jejunal or ileal tumors. This reduction in survival was associated with a lower percentage of cancer-directed surgery. Patients age > 75 years had a reduced DSS and more duodenal tumors, and were less frequently treated by cancer-directed surgery than their younger counterparts. This study reflects the experience with SBA from a large cross-section of U.S. hospitals, allowing for the identification of prognostic factors and providing a reference with which results from single institutions may be compared.

Enteropathy-type intestinal T-cell lymphoma: clinical features and treatment of 31 patients in a single center

PURPOSE

We report the clinical features and treatment of 31 patients with a diagnosis of enteropathy-type intestinal T-cell lymphoma treated at the Wessex Regional Medical Oncology Unit in Southampton between 1979 and 1996 (23 men, eight women).

PATIENTS AND METHODS

Patients were identified from our lymphoma database. Details of history, physical examination, staging investigations, treatment, and outcome were taken from patient records.

RESULTS

Twelve patients (35%) had a documented clinical history of adult-onset celiac disease, and a further three had histologic features consistent with celiac disease in resected areas of the small bowel not infiltrated with lymphoma. After diagnosis, 24 (77%) of the 31 patients were treated with chemotherapy; the remaining seven had surgical treatment alone. More than half were unable to complete their planned chemotherapy courses, often because of poor nutritional status; 12 patients required enteral or parenteral feeding. A response to initial chemotherapy was observed in 14 patients (complete response, n = 10; partial response, n = 4). Observed complications of treatment were gastrointestinal bleeding, small-bowel perforation, and the development of enterocolic fistulae. Relapses occurred 1 to 60 months from diagnosis in 79% of those who responded to initial therapy. Of the total 31 patients, 26 (84%) have died, all from progressive disease or from complications of the disease and/or its treatment. The actuarial 1- and 5-year survival rates are 38.7% and 19.7%, respectively, with 1- and 5-year failure-free survival rates of 19.4% and 3.2%, respectively.

CONCLUSION

The prognosis for these patients is poor. This, in part, reflects late diagnosis and poor performance status at the time of presentation. The role of salvage treatments and high-dose chemotherapy at relapse is not clear. However, it is encouraging that there are five long-term survivors in our patient population.

Immune system stimulation by probiotics

The immune system consists of organs and several cell types. Antigen interaction with these cells induces a cellular immune response mediated by activated cells and a humoral immune response mediated by antibodies. The cellular interactions are enhanced by adhesion molecules, and the activated cells release different cytokines. These complex cellular interactions induce a systemic immune response. If the antigen penetrates by the oral route, a secretory immune response is obtained, which is mediated by secretory IgA. The determination of the number of T or B cells, the quantitative or qualitative measure of the cytokines, antibody levels, or the study of cellular function such as phagocytic activity is used to evaluate the state of the immune system. The effects of lactic acid bacteria on the systemic immune response and on the secretory immune system are described. Potential health benefits of lactic acid bacteria include protection against enteric infections, use as an oral adjuvant, the immunopotentiator in malnutrition, and the prevention of chemically induced tumors. The results showed that Lactobacillus casei could prevent enteric infections and stimulate secretory IgA in malnourished animals, but could produce bacteria translocation. Yogurt could inhibit the growth of intestinal carcinoma through increased activity of IgA, T cells, and macrophages.

Carcinoid tumors

Carcinoid tumors are rare, slow-growing neuroendocrine tumors arising from the enterochromaffin cells disseminated throughout the gastrointestinal and bronchopulmonary systems. Though they have been traditionally classified based on embryologic site of origin, morphologic pattern, and silver affinity, newer classification systems have been developed to emphasize the considerable clinical and histopathologic variability of carcinoid tumors found within each embryologic site of origin. These neoplasms pose a diagnostic challenge because they are often innocuous at the time of presentation, emphasizing the need for a multidisciplinary diagnostic approach using biochemical analysis, standard cross-sectional imaging, and newer advances in nuclear medicine. Similarly, treatment of both primary and disseminated carcinoid disease reflects the need for a multidisciplinary approach, with surgery remaining the only curative modality. The prognosis for patients with these tumors is generally favorable; however, it can be quite variable and is related to the location of the primary tumor, extent of metastatic disease at initial presentation, and time of diagnosis.

Genomic Profiling of Small-Bowel Adenocarcinoma

IMPORTANCE

Small-bowel adenocarcinomas (SBAs) are rare cancers with a significantly lower incidence, later stage at diagnosis, and worse overall survival than other intestinal-derived cancers. To date, comprehensive genomic analysis of SBA is lacking.

OBJECTIVE

To perform in-depth genomic characterization of a large series of SBAs and other gastrointestinal tumors to draw comparisons and identify potentially clinically actionable alterations.

DESIGN, SETTING, AND PARTICIPANTS

Prospective analysis was performed of clinical samples from patients with SBA (n = 317), colorectal cancer (n = 6353), and gastric carcinoma (n = 889) collected between August 24, 2012, and February 3, 2016, using hybrid-capture-based genomic profiling, at the request of the individual treating physicians in the course of clinical care for the purpose of making therapy decisions.

RESULTS

Of the 7559 patients included in analysis, 4138 (54.7%) were male; the median age was 56 (range, 12-101) years. The frequency of genomic alterations seen in SBA demonstrated distinct differences in comparison with either colorectal cancer (APC: 26.8% [85 of 317] vs 75.9% [4823 of 6353], P < .001; and CDKN2A: 14.5% [46 of 317] vs 2.6% [165 of 6353], P < .001) or gastric carcinoma (KRAS: 53.6% [170 of 317] vs 14.2% [126 of 889], P < .001; APC: 26.8% [85 of 317] vs 7.8% [69 of 889], P < .001; and SMAD4: 17.4% [55 of 317] vs 5.2% [46 of 889], P < .001). BRAF was mutated in 7.6% (484 of 6353) of colorectal cancer and 9.1% (29 of 317) of SBA samples, but V600E mutations were much less common in SBA, representing only 10.3% (3 of 29) of BRAF-mutated cases. The ERBB2/HER2 point mutations (8.2% [26 of 317]), microsatellite instability (7.6% [13 of 170]), and high tumor mutational burden (9.5% [30 of 317]) were all enriched in SBA. Significant differences were noted in the molecular profile of unspecified SBA compared with duodenal adenocarcinoma, as well as in inflammatory bowel disease-associated SBAs. Targetable alterations in several additional genes, including PIK3CA and MEK1, and receptor tyrosine kinase fusions, were also identified in all 3 series.

CONCLUSIONS AND RELEVANCE

This study presents to our knowledge the first large-scale genomic comparison of SBA with colorectal cancer and gastric carcinoma. The distinct genomic differences establish SBA as a molecularly unique intestinal cancer. In addition, genomic profiling can identify potentially targetable genomic alterations in the majority of SBA cases (91%), and the higher incidence of microsatellite instability and tumor mutational burden in SBA suggests a potential role for immunotherapy.

Intestinal non-Hodgkin's lymphoma: a multicenter prospective clinical study from the German Study Group on Intestinal non-Hodgkin's Lymphoma

PURPOSE

Intestinal non-Hodgkin's lymphomas are not well characterized. We therefore studied prospectively their clinical features and response to standardized therapy.

PATIENTS AND METHODS

Fifty-six patients with primary intestinal lymphoma were included in a prospective, nonrandomized multicenter study. Lymphoma resection was recommended and staging was performed according to the Ann Arbor classification. Patients were scheduled to receive six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) chemotherapy, and at stages EIII to EIV, they received additional involved-field radiotherapy. Corticosteroids were used in patients who could not receive chemotherapy.

RESULTS

Thirty-five patients had intestinal T-cell lymphoma (ITCL), 21 patients had intestinal B-cell lymphoma (IBCL; 18 diffuse large-cell lymphomas, two marginal-cell lymphomas, and one follicle-center lymphoma). Thirty-four patients at stages EI to EII (14 ITCL and 20 IBCL) and nine patients at stages EIII to EIV (all ITCL) received chemotherapy. No patient in stages EIII to EIV received radiotherapy, because death occurred in 12 of 14 patients. Two-year cumulative survival in patients with IBCL was 94% (95% CI, 82% to 100%) and higher than in patients with ITCL (28% [95% CI, 13% to 43%]; P <.0001), even when only stages EI to EII were considered (ITCL, 37.5% [95% CI, 16.5% to 58.5%]; P <.0001). IBCL patients compared with ITCL patients were at lower lymphoma stages (P <.01), had higher Karnofsky status (P <.005), had intestinal perforation less often (P <.05), required emergency operation less often (P <.05), received CHOP (P <.05) more often, and reached complete remission (P <.0005) more frequently.

CONCLUSION

IBCL patients at stages EI and EII respond well to chemotherapy, but the prognosis and treatment of ITCL patients is unsatisfactory.

Four years of North American registry home parenteral nutrition outcome data and their implications for patient management

The OASIS Registry started annual collection of longitudinal data on patients on home parenteral nutrition (HPN) in 1984. This report describes outcome profiles on 1594 HPN patients in seven disease categories. Analysis showed clinical outcome was principally a reflection of the underlying diagnosis. Patients with Crohn's disease, ischemic bowel disease, motility disorders, radiation enteritis, and congenital bowel dysfunction all had a fairly long-term clinical outcome, whereas those with active cancer and acquired immunodeficiency syndrome (AIDS) had a short-term outcome. The long-term group had a 3-year survival rate of 65 to 80%, they averaged 2.6 complications requiring hospitalization per year, and 49% experienced complete rehabilitation. The short-term group had a mean survival of 6 months; they averaged 4.6 complications per year and about 15% experienced complete rehabilitation. The registry data also indicated HPN was used for 19,700 patients in 1987 with therapy growth averaging about 8% per year. This growth was chiefly from new cancer patients. The number of new patients with long-term disorders in whom HPN was initiated appeared rather constant. We conclude that these clinical outcome assessments justify HPN for long-term patients, but the utility and appropriateness of HPN for the cancer and AIDS patients remains uncertain and requires further study. Medical, social, and fiscal aspects of HPN management in long-term and short-term patients appear to involve quite separate considerations.

Diagnosis and outcome of small bowel tumors found by capsule endoscopy: a three-center Australian experience

OBJECTIVE

The objective of the study was to examine diagnosis and outcome in a series of patients with small bowel tumors detected by capsule endoscopy (CE) in three Australian centers.

METHODS

Review of prospectively collected data from 416 CEs identified 27 tumors in 26 patients. Clinical parameters, tumor histology, and follow-up are reported.

RESULTS

Twenty-seven tumors were identified in 26 patients (mean age 61 +/- 13.7 yr). Indications for CE were obscure gastrointestinal (GI) bleeding (21), suspected tumor (3), abdominal pain (1), diarrhea (1). Prior radiology found a possible lesion in 8 of 23 (35%). Nine tumors were proven benign: hamartoma (4), cystic lymphangioma (1), primary amyloid (1), lipoma (1). Two lesions were non-neoplastic: heterotopic gastric mucosa and inflammatory fibroid polyp. Seventeen tumors were malignant: five adenocarcinomas, six carcinoids, two melanoma metastases, two gastrointestinal stromal tumors (GIST), one colon carcinoma metastasis, one non-Hodgkin's lymphoma. Tumors were surgically resected in 23 patients. Resection was considered curative in 12 (52%). Mean duration of follow-up was 26 +/- 13.7 months. Of the five patients with primary adenocarcinoma only one remains disease free. Three of the six with carcinoid tumors have had no recurrence up to 51 months postresection. Both patients with GIST are disease free. Anemia resolved after surgery in the patients with melanoma.

CONCLUSIONS

Small bowel tumors are a significant finding at CE and are often missed by other methods of investigation. In many patients, detection of a tumor alters management and improves outcome. Even in malignant lesions, treatment is potentially curative in the absence of metastatic disease.

Small bowel adenocarcinomas--existing evidence and evolving paradigms

Small bowel cancers account for 3% of all gastrointestinal malignancies and small bowel adenocarcinomas represent a third of all small bowel cancers. Rarity of small bowel adenocarcinomas restricts molecular understanding and presents unique diagnostic and therapeutic challenges. Better cross-sectional imaging techniques and development of enteroscopy and capsule endoscopy have facilitated earlier and more-accurate diagnosis. Surgical resection remains the mainstay of therapy for locoregional disease. In the metastatic setting, fluoropyrimidine and oxaliplatin-based chemotherapy has shown clinical benefit in prospective non-randomized trials. Although frequently grouped under the same therapeutic umbrella as large bowel adenocarcinomas, small bowel adenocarcinomas are distinct clinical and molecular entities. Recent progress in molecular characterization has aided our understanding of the pathogenesis of these tumours and holds potential for prospective development of novel targeted therapies. Multi-institutional collaborative efforts directed towards cogent understanding of tumour biology and designing sensible clinical trials are essential for developing improved therapeutic strategies. In this Review, we endeavour to outline an evidence-based approach to present-day management of small bowel adenocarcinoma, describe contemporary challenges and uncover evolving paradigms in the management of these rare 'orphan' neoplasias.

Gastroenteropancreatic Well-Differentiated Grade 3 Neuroendocrine Tumors: Review and Position Statement

: In 2010, the World Health Organization (WHO) classification of neuroendocrine neoplasms was reviewed and validated the crucial role of the proliferative rate. According to the WHO classification 2010, gastroenteropancreatic neuroendocrine neoplasms are classified as well-differentiated neuroendocrine tumors (NETs) of grade 1 or 2 in up to 84%, or poorly differentiated neuroendocrine carcinomas in 6%-8%. Neuroendocrine carcinomas are of grade G. Recently, a proportion of neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified, calling for a new category, well-differentiated grade 3 NET (NET G-3). Studies that have reported the characteristics of neuroendocrine neoplasms have identified more well-differentiated NET G-3 than neuroendocrine carcinomas. The main localizations of NET G-3 are the pancreas, stomach, and colon. Treatment for NET G-3 is not standardized and is balanced between G-1/2 neuroendocrine tumor and neuroendocrine carcinoma treatments. In nonmetastatic neuroendocrine tumors, the European and American guidelines recommended a surgical resection for localized neuroendocrine neoplasm, irrespective of the tumor grading. In NET G-3, chemotherapy is the benchmark if the main treatment goal is reduction of the tumor mass, particularly if it would allow a secondary surgery. In the present work, we review the epidemiology and make recommendations for the management of NET G-3.

IMPLICATIONS FOR PRACTICE

Neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified and named well-differentiated grade 3 neuroendocrine tumors (NET G-3). The main localizations of NET G-3 are the pancreas, stomach, and colon. The prognosis is worse than that for NET G-2. In nonmetastatic NET G-3, surgery appeared to be the first option. The chemotherapy regimen in pancreatic NET G-3 should be in line with that implemented in NET G-1/2 when the Ki-67 index is below 55% and should be in line with that implemented for neuroendocrine carcinoma when Ki-67 is above 55%.

Small Bowel Adenocarcinoma, Version 1.2020, NCCN Clinical Practice Guidelines in Oncology

Small bowel adenocarcinoma (SBA) is a rare malignancy of the gastrointestinal tract that has increased in incidence across recent years. Often diagnosed at an advanced stage, outcomes for SBA are worse on average than for other related malignancies, including colorectal cancer. Due to the rarity of this disease, few studies have been done to direct optimal treatment, although recent data have shown that SBA responds to treatment differently than colorectal cancer, necessitating a separate approach to treatment. The NCCN Guidelines for Small Bowel Adenocarcinoma were created to establish an evidence-based standard of care for patients with SBA. These guidelines provide recommendations on the workup of suspected SBA, primary treatment options, adjuvant treatment, surveillance, and systemic therapy for metastatic disease. Additionally, principles of imaging and endoscopy, pathologic review, surgery, radiation therapy, and survivorship are described.

Extrapulmonary and pulmonary small-cell carcinoma: tumor biology, therapy, and outcome

Extrapulmonary small-cell cancer is a distinct clinicopathological entity from small-cell anaplastic carcinoma of the lung. Approximately 1,000 cases have been projected annually in the United States, which represents an overall incidence of between 0.1% and 0.4% of all cancer. Not surprisingly then, little information is available regarding the treatment of this disease, which presents a challenge to the clinician when it is regionally confined. The majority of patients with extrapulmonary small-cell neoplasms have only been treated with local modalities of therapy, surgery, radiation, or a combination of both. Prolonged survival is not infrequent, which is in contrast to the experience for small-cell lung cancer and surprising given our current systemic approach to patients with this disease. This report will summarize the similarities and differences in biology, natural history, and clinical characteristics of patients with extrapulmonary small-cell cancer and small-cell anaplastic carcinoma of the lung. The histogenesis of small-cell cancer is briefly reviewed. A general therapeutic approach to patients with small-cell lung cancer is reported. Lastly, recommendations for therapy of patients with regionally confined extrapulmonary small-cell cancer by primary site are outlined.

DKK2 imparts tumor immunity evasion through β-catenin-independent suppression of cytotoxic immune-cell activation

Immunotherapy offers new options for cancer treatment, but efficacy varies across cancer types. Colorectal cancers (CRCs) are largely refractory to immune-checkpoint blockade, which suggests the presence of yet uncharacterized immune-suppressive mechanisms. Here we report that the loss of adenomatosis polyposis coli (APC) in intestinal tumor cells or of the tumor suppressor PTEN in melanoma cells upregulates the expression of Dickkopf-related protein 2 (DKK2), which, together with its receptor LRP5, provides an unconventional mechanism for tumor immune evasion. DKK2 secreted by tumor cells acts on cytotoxic lymphocytes, inhibiting STAT5 signaling by impeding STAT5 nuclear localization via LRP5, but independently of LRP6 and the Wnt-β-catenin pathway. Genetic or antibody-mediated ablation of DKK2 activates natural killer (NK) cells and CD8+ T cells in tumors, impedes tumor progression, and enhances the effects of PD-1 blockade. Thus, we have identified a previously unknown tumor immune-suppressive mechanism and immunotherapeutic targets particularly relevant for CRCs and a subset of melanomas.

Incidence and management of primary malignant small bowel cancers: a well-defined French population study

BACKGROUND AND AIM

Few data are available from population-based statistics on small bowel cancers. The aim of this study was to report on their incidence and management.

METHODS

Data were obtained from the population-based Digestive Cancer Registry of Burgundy over a 26-yr period. Incidence rates were calculated by gender, age group, histological type, and 5-yr period. Treatment and stage at diagnosis were investigated. Prognosis was determined using crude and relative survival rates. A multivariate relative survival analysis was performed.

RESULTS

Age-standardized incidence rates were 1.2/100,000 inhabitants for men and 0.8/100,000 inhabitants for women. The mean 5-yr variation in incidence were, respectively, +46.7% (P < 0.01) and + 53.2% (P < 0.05). There were four main histological types: adenocarcinoma (40.4%), malignant endocrine tumors (30.5%), lymphoma (20.1%), and sarcoma (9.0%). Resection for cure was performed in 56.6% of the cases. Cancer was not extending beyond the organ in 33.2% of the cases, was associated with lymph node metastasis in 32.1%, and with distant metastasis or unresectability in 34.7%. The 5-yr relative survival rate was 37.4%. It varied between 56.8% for endocrine tumors and 17.8% for sarcoma. In the multivariate analysis, age, histology, and stage at diagnosis significantly influenced the prognosis.

CONCLUSIONS

Small bowel cancers represent a heterogeneous group of rare tumors. Prognosis at a population level is worse than in hospital series. In the short term, new therapeutic possibilities represent the best way to improve prognosis.