The road to tailored adjuvant chemotherapy for all four non-pancreatic periampullary cancers: An international multimethod cohort study.

BACKGROUND: Despite differences in tumour behaviour and characteristics between duodenal adenocarcinoma (DAC), the intestinal (AmpIT) and pancreatobiliary (AmpPB) subtype of ampullary adenocarcinoma and distal cholangiocarcinoma (dCCA), the effect of adjuvant chemotherapy (ACT) on these cancers, as well as the optimal ACT regimen, has not been comprehensively assessed. This study aims to assess the influence of tailored ACT on DAC, dCCA, AmpIT, and AmpPB. PATIENTS AND METHODS: Patients after pancreatoduodenectomy for non-pancreatic periampullary adenocarcinoma were identified and collected from 36 tertiary centres between 2010 - 2021. Per non-pancreatic periampullary tumour type, the effect of adjuvant chemotherapy and the main relevant regimens of adjuvant chemotherapy were compared. The primary outcome was overall survival (OS). RESULTS: The study included a total of 2866 patients with DAC (n = 330), AmpIT (n = 765), AmpPB (n = 819), and dCCA (n = 952). Among them, 1329 received ACT, and 1537 did not. ACT was associated with significant improvement in OS for AmpPB (P = 0.004) and dCCA (P < 0.001). Moreover, for patients with dCCA, capecitabine mono ACT provided the greatest OS benefit compared to gemcitabine (P = 0.004) and gemcitabine - cisplatin (P = 0.001). For patients with AmpPB, no superior ACT regime was found (P > 0.226). ACT was not associated with improved OS for DAC and AmpIT (P = 0.113 and P = 0.445, respectively). DISCUSSION: Patients with resected AmpPB and dCCA appear to benefit from ACT. While the optimal ACT for AmpPB remains undetermined, it appears that dCCA shows the most favourable response to capecitabine monotherapy. Tailored adjuvant treatments are essential for enhancing prognosis across all four non-pancreatic periampullary adenocarcinomas.

PD-L1 Expression in Ampullary Adenocarcinoma.

INTRODUCTION: Ampullary adenocarcinoma is a rare neoplasm often treated by the complex Whipple's procedure. Several histological factors predict poor prognosis including pancreatobiliary morphology, presence of lymphovascular, perineural invasion and local or distant metastasis. Systemic therapy with gemcitabine, 5-fluorouracil regimens are given with variable benefits. Immunotherapy checkpoint inhibitors have shown beneficial anti-tumor effects in several carcinomas, the most remarkable being in non-small cell lung cancer. Administration of these novel drugs is based on immunohistochemical expression (which may or may not be indicative of response to therapy) along with meticulous decision making by the multidisciplinary team. Immunohistochemistry (IHC) is an effective means of immune marker demonstration and has been used in various tumor types for predictive and prognostic purposes. METHODS: PD-L1 IHC (clone E1L3N) was applied in 101 cases of ampullary adenocarcinoma. Tumor infiltrating lymphocytes were also evaluated. The immunoreactivity was assessed and categorized into following staining thresholds: <1%, <5%, <10% and ≥10% for tumor cells (membranous and/or cytoplasmic staining pattern), and 5% and 10% cut-offs for immune cells. RESULTS: We found that at a 10% cut-off, 73.3% (74/101) patients were men (P = .006) older than 50 years of age (P < .001) presenting with a tumor measuring <3 cm (P = .001). It was significantly associated with intestinal differentiation (P = .004) and grade 1 tumors (P = .001). Twelve patients presented with recurrence as well (P = .03). CONCLUSION: In the context of ampullary adenocarcinoma, this study highlights the positivity observed with the PD-L1 IHC clone E1L3N at different thresholds, with the particularly stronger associations being evident at a 10% cut-off.

[A Case of Duodenal Tumor Accompanied by Liver and Lymph Node Metastases after Ten Years of Observation].

A 67-year-old woman presented with a history of upper abdominal pain and weight loss. Physical examination revealed a lump in the right lower quadrant. She had undergone esophagogastroduodenoscopy at another hospital ten years ago, which showed a 15-mm elevated lesion in the duodenal bulb. The patient had not undergone further examinations or received treatment during the 10 years. Esophagogastroduodenoscopy conducted in our hospital revealed an enlarged tumor that was difficult to assess on the whole image. The tumor was diagnosed as a well-differentiated adenocarcinoma based on a biopsy specimen. Enhanced computed tomography revealed a hypervascular duodenal tumor with liver and lymph node metastases. The patient was treated with capecitabine plus oxaliplatin for the duodenal cancer. Lymph node metastases increased markedly after 2 courses of chemotherapy. The patient died 3 months after the initiation of chemotherapy. The natural history of sporadic non-ampullary duodenal epithelial tumors remains to be fully elucidated due to the low incidence rate. This case suggests that sporadic non-ampullary duodenal epithelial tumors have a biological potential for invasive malignancy.

[A Case of Primary Duodenal Adenocarcinoma in the Third Portion Treated with Partial Duodenectomy and Adjuvant Chemotherapy].

A 69-year-old man was referred for vomiting. CT and upper gastrointestinal endoscopy revealed a circumferential stenotic lesion in the third portion of the duodenum, and partial duodenectomy and lymph node dissection were performed for the diagnosis of duodenal adenocarcinoma. The histopathological diagnosis was pT3, pN0, pStage ⅡA(UICC 8th)well differentiated tubular adenocarcinoma. The patient was treated with FOLFOX as adjuvant chemotherapy and is alive 2 years and 4 months postoperatively without recurrence. Primary duodenal adenocarcinoma in the third portion is rare, and further case experience is required for selection of the operation and adjuvant therapy.

Neuroendocrine tumor chromogranin A response following synthetic somatostatin analog (lanreotide): Early observations from an isolated duodenal neoplasm .

Neuroendocrine tumors (NETs) of duodenal origin are an unusual subset among all NETs, comprising only about 3% of this neoplasm class. In general, NETs are characterized by overexpression of somatostatin receptors and carry an excellent prognosis with early diagnosis and intervention. Chromogranin A (CgA), a protein originating in secretory vesicles of neurons and endocrine cells, has gained wide usage in NET diagnosis and surveillance. Lanreotide is a synthetic octapeptide somatostatin analog with potent anti-proliferative action which has been approved by the FDA (U.S.) and EMA (E.U.) for NET treatment. It is known for its inhibitory effects on growth hormone, serotonin, CgA, and other markers. Here we describe a 56yr-old female with functional NET of duodenal origin, where serum CgA was successfully reduced from 3636 to <100 ng/mL after multidose lanreotide within five months. Of note, no metastatic spread was identified on positron emission tomography/computed tomography with 64Cu-labeled somatostatin analog tracer. Surgical resection of distal antrum, pylorus, and proximal duodenum was completed without complication. Histology revealed well-differentiated tumor cells with characteristic neuroendocrine features and clear surgical margins; low proliferation index (2%) was noted on Ki-67 staining. While select laboratory and imaging modalities are available for diagnosis and monitoring of duodenal NET, this is the first reported therapeutic use of lanreotide in this NET setting. The observed serum chromogranin A attenuation, even before surgery, supports its effectiveness in management of primary nonmetastatic duodenal NET after resection.

Antitumor Effect of Galectin-9 on Cell Proliferation and Tumor Growth of Human Duodenal Adenocarcinoma Cells.

BACKGROUND/AIM: Galectin-9 (Gal-9) induces tumor cell apoptosis in lymphoma and other malignant cell types. Duodenal adenocarcinoma is a rare malignancy, and there are insufficient data to determine a standard therapeutic approach. Here, we investigated the antitumor effect of Gal-9 in HuTu-80 duodenal adenocarcinoma cells. MATERIALS AND METHODS: Cell proliferation was examined in HuTu-80 cells using a Cell Counting Kit-8 assay. Cell cycle analysis, apoptosis array, and microRNA expression analysis were performed to identify the effect of Gal-9 on HuTu-80 cells. The antitumor effect of Gal-9 was also examined using xenograft mouse models. RESULTS: Gal-9 suppressed the proliferation of HuTu-80 via blockade of the G0 to G1 cell cycle transition. This blockade was accompanied by a strong decrease in cyclin D1 and phosphorylated Rb, suggesting a G1 arrest. Additionally, Gal-9 induced apoptosis, and the expression of cleaved caspase-3 was increased in Gal-9-treated HuTu-80 cells according to the apoptosis array. MiRNA microarrays revealed that Gal-9 altered the expression of miRNAs in HuTu-80 cells. CONCLUSION: These data demonstrate the therapeutic potential of Gal-9 and provide molecular mechanistic insights into its antitumor effect in HuTu-80 cells.

[Clinical Research Advances of Duodenal-Type Follicular Lymphoma--Review].

Duodenal-type follicular lymphoma (DFL) is a unique subtype of follicular lymphoma (FL), which often involves the second portion of duodenum (descending part of duodenum). Due to its specific pathological features, such as lack of follicular dendritic cells meshwork and disappearance of activation-induced cytidine deaminase expression, DFL presents an inert clinical course and is often confined to the intestinal tract. Inflammation-related biomarkers suggest that the microenvironment may play a likely role in the pathogenesis and favorable prognosis of DFL. Since patients generally have no obvious clinical symptoms and low progression rate, the treatment regimen for DFL is mainly observation and waiting (W&W) strategy. This study will review the latest research progress of epidemiology, diagnosis, treatment and prognosis of DFL in recent years.

Phase II trial of weekly erlotinib dosing to reduce duodenal polyp burden associated with familial adenomatous polyposis.

IMPORTANCE: Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal adenomas and cancer. Combination sulindac and erlotinib was previously shown to reduce duodenal polyp burden but was associated with a relatively high adverse event (AE) rate. OBJECTIVE: To evaluate if a once weekly dosing schedule for erlotinib intervention improves the AE profile, while still providing efficacy with respect to reduced polyp burden, in participants with FAP. DESIGN, SETTING AND PARTICIPANTS: Single-arm trial, enrolling 46 participants with FAP, conducted from October 2017 to September 2019 in eight academic cancer centres. EXPOSURES: Participants self-administered 350 mg of erlotinib by mouth, one time per week for 6 months. MAIN OUTCOMES AND MEASURES: Duodenal polyp burden (sum of polyp diameters) was assessed in the proximal duodenum by esophagogastroduodenoscopy performed at baseline and 6 months, with mean per cent change defined as the primary efficacy outcome of interest. Rate of grade 2-3 AEs was evaluated as a co-primary outcome. Secondary outcomes included changes in total duodenal polyp count, along with changes in lower gastrointestinal (GI) polyp burden and count (for participants examined by optional lower endoscopy). RESULTS: Forty-six participants (mean age, 44.1 years (range, 18-68); women, 22 (48%)) were enrolled; 42 participants completed 6 months of intervention and were included in the per-protocol analysis. Duodenal polyp burden was significantly reduced after 6 months of weekly erlotinib intervention, with a mean per cent change of -29.6% (95% CI, -39.6% to -19.7%; p<0.0001). Similar results were observed in subgroup analyses defined by participants with advanced duodenal polyposis (Spigelman 3) at baseline (mean, -27%; 95% CI, -38.7% to -15.2%; p<0.0001). Post-intervention Spigelman stage was downstaged in 12% of the participants. Lower GI polyp number was also decreased after 6 months of intervention (median, -30.8%; IQR, -47.4% to 0.0%; p=0.0256). Grade 2 or 3 AEs were reported in 71.7% of subjects, with only two experiencing grade 3 toxicity at least possibly related to intervention. CONCLUSION: In this single-arm, multi-centre trial of participants with FAP, erlotinib one time per week resulted in markedly lower duodenal polyp burden, and modestly reduced lower GI polyp burden, after 6 months of intervention. While AEs were still reported by nearly three-quarters of all participants, these events were generally lower grade and well-tolerated. These findings support further investigation of erlotinib as an effective, acceptable cancer preventive agent for FAP-associated GI polyposis. TRIAL REGISTRATION NUMBER: NCT02961374.

Adjuvant chemotherapy for resected duodenal adenocarcinoma: a case-matched analysis in nation wide cohort.

BACKGROUND: Duodenal adenocarcinoma (DA) is a rare tumor for which survival data on adjuvant chemotherapy in patients after surgical treatment are unclear. This case-matched study in a nationwide cohort aims to investigate the benefit of adjuvant chemotherapy for patients with resectable DA on overall survival. METHODS: All patients diagnosed with DA and intestinal type periampullary adenocarcinoma (PVA) in the Netherlands between 2000 and 2015 were included (n = 1316). Patients with disease stages II and III who underwent resection and adjuvant chemotherapy were matched (1:2), based on identified covariates associated with OS, with patients who underwent surgery alone. Overall survival was compared using Kaplan-Meier estimates. RESULTS: The median OS was 49.9 months in patients who underwent curative resection (n = 649). Univariate and multivariate analysis showed a significant influence of age, lymph node involvement, and T- stage on survival. The group of patients receiving adjuvant treatment consisted of 43 patients and the non-adjuvant group of 83 case-matched patients. The median OS of the complete matched cohort (n = 126) was 26.9 months. No statistically significant survival benefit was found for the adjuvant group as compared to the group treated with surgery alone (median OS = 34.4 months and 23.0 months, p = 0.20). CONCLUSION: This population-based, case-matched analysis demonstrates no statistically significant survival benefit for adjuvant chemotherapy after curative resection in stages II and III patients. Future studies with specified treatment regimens as well as thorough stratification for prognostic factors will be required in order to more definitively determine the role of adjuvant therapy.

[A Case Report of SOX Therapy for an Elderly Patient with Hemorrhagic Primary Duodenal Carcinoma].

BACKGROUND: Although pancreatoduodenectomy is recommended as a radical surgery for duodenal carcinoma, it has been reported that pancreatoduodenectomy in elderly patients has a high risk of surgical complications. CASE PRESENTATION: A man in his 80's was diagnosed with advanced duodenal carcinoma, presenting with anemia(Hb 5.4 g/dL). Computed tomography scanning showed wall thickening in the descending leg of the duodenum, pancreatic invasion was suspected, and clinical diagnosis was Stage ⅡB(cT4N0M0). Although radical surgery was possible, the patient refused surgery considering the risks of surgical complications. The gastroduodenal bypass surgery was performed to control bleeding, and the patient was treated with S-1 plus oxaliplatin(SOX; S-1 100 mg/body, days 1-14; oxaliplatin 100 mg/m2, day 1 q21 days). After 6 courses of the SOX regimen, the wall thickening of duodenum disappeared, and SOX was switched to S-1 monotherapy (S-1 100 mg/body, days 1-28, q42 days)according to Grade 2 thrombocytopenia and decreased performance status. After 11 courses of S-1, upper gastrointestinal endoscopy showed that the tumor had disappeared, the biopsy of duodenum showed no evidence of malignancy, and chemotherapy was terminated. The patient has been followed up for 7 months without recurrence. CONCLUSIONS: SOX for elderly patient showed efficacy against hemorrhagic duodenal carcinoma.

[A Case of Primary Somatostatin-Producing Tumor of the Duodenum with Liver Metastases with Long-Term Survival of More than 20 Years].

A 52-year-old woman underwent esophagogastroduodenoscopy after an abnormal medical examination, which revealed a mass lesion over half the circumference of the superior duodenal angulus. Immunostaining was diffusely positive for somatostatin, synaptophysin, and chromogranin A. A 3 cm-sized mass in the pancreaticoduodenal region and multiple nodular lesions of a few mm in both lobes of the liver were revealed by CT. The diagnosis is primary somatostatin-producing tumor of the duodenum with multiple liver metastases. She underwent gastric jejunal bypass for impaired transit. Afterwards hepatic infusion and systemic chemotherapy were continued, and 5 years passed without progression. When she stopped chemotherapy for 6 months, she started somatostatin analogue therapy because of the increase of the tumors. The tumors did not increase, and 20 years have passed since the start of treatment. We report a case of primary somatostatin-producing tumor of the duodenum with liver metastases that is still alive for a long period of time, with a review of the literature.

Surgical results of non-ampullary duodenal cancer: a nationwide survey in Japan.

BACKGROUND: As non-ampullary duodenal cancer is relatively rare, the optimal treatment strategy, including the appropriate surgical procedure and efficacy of adjuvant chemotherapy, remains unclear. This nationwide survey aimed to clarify the actual lymph node spread pattern and determine the optimal treatment strategy for this disease, using a large-scale database. METHODS: We used a questionnaire and a retrospective registry of 1083 patients with non-ampullary duodenal cancer who had undergone surgery during 2008-2017 in 114 high-volume Japanese Society of Hepatobiliary and Pancreatic Surgery-certified training institutions. Propensity score-matched analyses were conducted to minimise background bias. Cox regression was performed to identify covariates associated with recurrence-free survival. There were distinct disparities in the nodal dissection rate according to the predominant tumor location and tumor invasion depth. Metastases were frequently observed in the peripancreatic nodes and those along the superior mesenteric artery, irrespective of tumor location. Their dissection seemed to be beneficial for improved survival. In the overall cohort, no survival benefit was observed in patients who received adjuvant chemotherapy when compared with that in patients who underwent surgery alone. Nevertheless, in the matched cohort, adjuvant chemotherapy for > 6 months was associated with a significant improvement in recurrence-free survival (median: 43.5 vs. 22.5 months, p = 0.016), particularly in patients with tumor invasion of the subserosa or deeper tumor invasion, lymph node metastasis, or elevated serum carbohydrate antigen 19-9 levels. CONCLUSION: Pancreatoduodenectomy should be the standard procedure for advanced non-ampullary duodenal cancer. Adjuvant chemotherapy for > 6 months, especially for advanced tumors, significantly improves survival.

[A Case of Long-Term Survival with Multidisciplinary Treatment after Surgery for Duodenal Cancer with Left Supraclavicular Lymph Node Metastasis].

The patient was a 71-year-old man with a diagnosis of duodenal carcinoma. Abdominal computed tomography(CT) showed no distant metastasis, and he underwent subtotal stomach-preserving pancreaticoduodenectomy. Postoperative adjuvant chemotherapy was not administered. A left supraclavicular lymph node recurrence was detected on CT 15 months after surgery. Capecitabine and oxaliplatin(CAPOX)therapy was administered and the metastatic lesion shrank. Positron emission tomography(PET)-CT showed no lesions at other sites and left cervical lymph node dissection was performed 5 months after the recurrence. Postoperative adjuvant therapy with S-1 was administered for 6 months. However, 2 years and 10 months after the first recurrence, CT showed recurrence in the left supraclavicular lymph node. CAPOX therapy was resumed, but due to an allergic reaction to oxaliplatin, the patient was treated with capecitabine alone. The recurrent lesion was gradually increased in size, and FOLFIRI therapy was introduced. One year and 5 months after secondary recurrence, PET-CT showed that the second recurrent lesion had grown but was confined to the left supraclavicular lymph node, so radiation therapy(60 Gy)to the left neck was performed. The disease was stable for about 10 months and chemotherapy could be discontinued. The lesion increased in size thereafter, and the patient died 7 years after initial surgery.

Vascular endothelial growth factor-A is an Immunohistochemical biomarker for the efficacy of bevacizumab-containing chemotherapy for duodenal and jejunal adenocarcinoma.

BACKGROUND: The efficacy and safety of bevacizumab-containing chemotherapy for patients with metastatic duodenal and jejunal adenocarcinoma (mDJA) are unclear. The present study aimed to evaluate the efficacy of bevacizumab and to explore immunohistochemical markers that can predict the efficacy of bevacizumab for patients with mDJA. METHODS: This multicentre study included patients with histologically confirmed small bowel adenocarcinoma who received palliative chemotherapy from 2008 to 2017 at 15 hospitals. Immunostaining was performed for vascular endothelial growth factor-A (VEGF-A), TP53, Ki67, ß-catenin, CD10, MUC2, MUC5AC, MUC6, and mismatch repair proteins. RESULTS: A total of 74 patients were enrolled, including 65 patients with mDJA and 9 with metastatic ileal adenocarcinoma. Patients with mDJA who received platinum-based chemotherapy with bevacizumab as first-line treatment tended to have a longer progression-free survival and overall survival than those treated without bevacizumab (P = 0.075 and 0.077, respectively). Multivariate analysis extracted high VEGF-A expression as a factor prolonging progression-free survival (hazard ratio: 0.52, 95% confidence interval: 0.30-0.91). In mDJA patients with high VEGF-A expression, those who received platinum-based chemotherapy with bevacizumab as a first-line treatment had significantly longer progression-free survival and tended to have longer overall survival than those treated without bevacizumab (P = 0.025 and P = 0.056, respectively), whereas no differences were observed in mDJA patients with low VEGF-A expression. CONCLUSION: Immunohistochemical expression of VEGF-A is a potentially useful biomarker for predicting the efficacy of bevacizumab-containing chemotherapy for patients with mDJA.

Patient-derived tumor xenograft and organoid models established from resected pancreatic, duodenal and biliary cancers.

Patient-derived xenograft (PDX) and their xenograft-derived organoid (XDO) models that recapitulate the genotypic and phenotypic landscape of patient cancers could help to advance research and lead to improved clinical management. PDX models were established from 276 pancreato-duodenal and biliary cancer resections. Initial, passage 0 (P0) engraftment rates were 59% (118/199) for pancreatic, 86% (25/29) for duodenal, and 35% (17/48) for biliary ductal tumors. Pancreatic ductal adenocarcinoma (PDAC), had a P0 engraftment rate of 62% (105/169). KRAS mutant and wild-type PDAC models were molecularly profiled, and XDO models were generated to perform initial drug response evaluations. Subsets of PDAC PDX models showed global copy number variants and gene expression profiles that were retained with serial passaging, and they showed a spectrum of somatic mutations represented in patient tumors. PDAC XDO models were established, with a success rate of 71% (10/14). Pathway activation of KRAS-MAPK in PDXs was independent of KRAS mutational status. Four wild-type KRAS models were characterized by one with EGFR (L747-P753 del), two with BRAF alterations (N486_P490del or V600E), and one with triple negative KRAS/EGFR/BRAF. Model OCIP256, characterized by BRAF (N486-P490 del), had activated phospho-ERK. A combination treatment of a pan-RAF inhibitor (LY3009120) and a MEK inhibitor (trametinib) effectively suppressed phospho-ERK and inhibited growth of OCIP256 XDO and PDX models. PDAC/duodenal adenocarcinoma have high success rates forming PDX/organoid and retaining their phenotypic and genotypic features. These models may be effective tools to evaluate novel drug combination therapies.

Capillary-leak syndrome: an unrecognized early immune adverse effect of checkpoint-inhibitors treatment.

Capillary-leak syndrome is strongly associated with cytokine activity states. It is an ill-recognized adverse effect of checkpoint inhibitors treatment, which are typically associated with cellular immune response. We describe two patients with capillary leak syndrome following immune checkpoint inhibitors treatment. We present linking mechanisms between checkpoint inhibitors, cellular immunity, cytokine action and endothelial damage. We suggest that capillary-leak syndrome is a unique adverse effect of immunotherapy, resulting from complex interactions between cellular and cytokine activation and that its expression is probably depending on inherent host immune variabilities.

Lay abstract Modern cancer treatment increasingly relies on means that encourage the patient's immune system to attack and destroy existing cancer cells. These means are very effective compared with standard treatments. However, the activation of the immune system is sometimes associated with untoward effects as a result of an attack of bystanding healthy tissues by the overactivated immune system and excessive inflammatory processes that accompany the immune response. We describe here two patients treated with immune checkpoint inhibiting drugs that developed transient extensive edema attributed to leakage of serum proteins and water from small blood vessels into the surrounding tissues (so-called 'capillary-leak syndrome'), after the drug-induced activation of the immune system. In both patients, the edema subsided following specific interventions.

ZEBRA: A Multicenter Phase II Study of Pembrolizumab in Patients with Advanced Small-Bowel Adenocarcinoma.

PURPOSE: Small-bowel adenocarcinoma (SBA) is rare, and no standard of care exists for metastatic disease beyond first-line FOLFOX/CAPOX. SBA has higher rates of microsatellite instability (MSI-H) and T-lymphocyte infiltration than other gastrointestinal cancers. We hypothesize that pembrolizumab, a PD-1 inhibitor, will induce antitumor response. PATIENTS AND METHODS: Patients with previously treated advanced SBA received pembrolizumab 200 mg i.v. every 3 weeks until disease progression (PD), toxicity, or 35 doses maximum. Primary endpoint was confirmed overall response rate (ORR) with secondary progression-free survival (PFS), overall survival (OS), and toxicity assessment endpoints. Outcomes were stratified by tumor location, microsatellite stability (MSS) or instability (MSI-H), and PD-L1 level. RESULTS: Forty patients were treated for a median duration of four cycles (range, 1-35). All patients are off study treatment due to PD (75%), death (10%), 35 cycles completed (8%), refusal (3%), and adverse effects (AEs, 5%). Three confirmed partial responses [PRs; 8%; 95% confidence interval (CI), 2-20] did not meet predefined success criteria of ORR 30%. Median OS (7.1 months; 95% CI, 5.1-17.1) and median PFS (2.8 months; 95% CI, 2.7-4.2) were similar across primary tumor sites. One confirmed PR (3%) was seen in patients with low MSS/MSI tumors and correlated with high tumor mutation burden (TMB). Fifty percent of patients with MSI-H tumors achieved PR and remain alive without progression. Twenty-five patients (63%) had grade ≥3 AEs and 11 patients (28%) had grade 4/5 AEs. CONCLUSIONS: In the largest study of SBA to date, pembrolizumab did not induce the hypothesized response rate; however, we did identify responses in key biomarker-selected cohorts.

The Effect of Metformin in Treatment of Adenomas in Patients with Familial Adenomatous Polyposis.

Familial adenomatous polyposis (FAP) is a hereditary disease characterized by the development of numerous colorectal adenomas in young adults. Metformin, an oral diabetic drug, has been shown to have antineoplastic effects and a favorable safety profile. We performed a randomized, double-blind, controlled trial to evaluate the efficacy of metformin on the regression of colorectal and duodenal adenoma in patients with FAP. Thirty-four FAP patients were randomly assigned in a 1:2:2 ratio to receive placebo, 500 mg metformin, or 1,500 mg metformin per day orally for 7 months. The number and size of polyps and the global polyp burden were evaluated before and after the intervention. This study was terminated early based on the results of the interim analysis. No significant differences were determined in the percentage change of colorectal and duodenal polyp number over the course of treatment among the three treatment arms (P = 0.627 and P = 1.000, respectively). We found no significant differences in the percentage change of colorectal or duodenal polyp size among the three groups (P = 0.214 and P = 0.803, respectively). The overall polyp burdens of the colorectum and duodenum were not significantly changed by metformin treatment at either dosage. Colon polyps removed from the metformin-treated patients showed significantly lower mTOR signal (p-S6) expression than those from patients in the placebo arm. In conclusion, 7 months of treatment with 500 mg or 1,500 mg metformin did not reduce the mean number or size of polyps in the colorectum or duodenum in FAP patients (ClinicalTrials.gov ID: NCT01725490). PREVENTION RELEVANCE: A 7-month metformin treatment (500 mg or 1,500 mg) did not reduce the number or size of polyps in the colorectum or duodenum of FAP patients as compared to placebo. These results do not support the use of metformin to promote regression of intestinal adenomas in FAP patients.

Phase II study of temozolomide monotherapy in patients with extrapulmonary neuroendocrine carcinoma.

Extrapulmonary neuroendocrine carcinoma (EPNEC) is a lethal disease with a poor prognosis. Platinum-based chemotherapy is used as the standard first-line treatment for unresectable EPNEC. Several retrospective studies have reported the results of the utilization of temozolomide (TMZ) as a drug for the second-line treatment for EPNEC. Patients with unresectable EPNEC that were resistant to platinum-based combination chemotherapy were recruited for a prospective phase II study of TMZ monotherapy. A 200 mg/m2 dose of TMZ was given from day 1 to day 5, every 4 weeks. Response rate (RR) was evaluated as the primary end-point. The presence of O6 -methylguanine DNA methyltransferase (MGMT) in EPNEC patients was also evaluated as exploratory research. Thirteen patients were enrolled in this study. Primary lesions were pancreas (n = 3), stomach (n = 3), duodenum (n = 1), colon (n = 1), gallbladder (n = 1), liver (n = 1), uterus (n = 1), bladder (n = 1), and primary unknown (n = 1). Each case was defined as pathological poorly differentiated neuroendocrine carcinoma from surgically resected and/or biopsied specimens. The median Ki-67 labeling index was 60% (range, 22%-90%). The RR was 15.4%, progression-free survival was 1.8 months (95% confidence interval [CI], 1.0-2.7), overall survival (OS) was 7.8 months (95% CI, 6.0-9.5), and OS from first-line treatment was 19.2 months (95% CI, 15.1-23.3). No grade 3 or 4 hematological toxicity had occurred and there was one case of grade 3 nausea. One case presented MGMT deficiency and this case showed partial response. Temozolomide monotherapy is a feasible, modestly effective, and safe treatment for patients with unresectable EPNEC following platinum-based chemotherapy, especially those with MGMT deficiency.