Prospective Evaluation of MGMT-Promoter Methylation Status and Correlations with Outcomes to Temozolomide-Based Chemotherapy in Well-Differentiated Neuroendocrine Tumors

Temozolomide (TEM) as a single agent or in combination with capecitabine (CAPTEM) is active in well-differentiated advanced neuroendocrine tumors (NETs) of gastro-entero-pancreatic and thoracic origin. The predictive role of MGMT-promoter methylation in this setting is controversial. We sought to prospectively evaluate the MGMT-promoter methylation status ability to predict outcomes to TEM-based chemotherapy in patients with NET. A single-center, prospective, observational study has been conducted at the ENETS Center-of-Excellence Outpatient Clinic of the IRCCS Policlinico Sant'Orsola-Malpighi in Bologna, Italy. Patients with advanced, gastro-entero-pancreatic or lung well-differentiated NETs candidate to TEM-based chemotherapy and with available tumor samples for MGMT-promoter methylation assessment were included. The MGMT-promoter methylation status was analyzed by using pyrosequencing. The primary endpoint was progression-free survival (PFS) by the MGMT-promoter methylation status. Secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety. Survival outcomes were compared by restricted mean survival time (RMST) difference. Of 26 screened patients, 22 were finally enrolled in the study. The most frequent NET primary sites were the pancreas (64%) and the lung (23%). MGMT promoter was methylated in five tumors (23%). At a median follow-up time of 47.2 months (95%CI 29.3-89.7), the median PFS was 32.8 months (95%CI 17.2-NA), while the median OS was not reached. Patients in the methylated MGMT group, when compared to those in the unmethylated MGMT group, had longer PFS (median not reached [95%CI NA-NA] vs. 30.2 months [95%CI 15.2-NA], respectively; RMST p = 0.005) and OS (median not reached [95%CI NA-NA] vs. not reached [40.1-NA], respectively; RMST p = 0.019). After adjusting for confounding factors, the MGMT-promoter methylation status was independently associated to the PFS. Numerically higher ORR (60% vs. 24%; p = 0.274) and DCR (100% vs. 88%; p = 1.00) were observed in the methylated vs. unmethylated MGMT group. TEM-based chemotherapy was well-tolerated (adverse events grade ≥3 < 10%). In this prospective study, MGMT-promoter methylation predicted better outcomes to TEM-based chemotherapy in patients with NET.

An Overview on Molecular Characterization of Thymic Tumors: Old and New Targets for Clinical Advances

Thymic tumors are a group of rare mediastinal malignancies that include three different histological subtypes with completely different clinical behavior: the thymic carcinomas, the thymomas, and the rarest thymic neuroendocrine tumors. Nowadays, few therapeutic options are available for relapsed and refractory thymic tumors after a first-line platinum-based chemotherapy. In the last years, the deepening of knowledge on thymus' biological characterization has opened possibilities for new treatment options. Several clinical trials have been conducted, the majority with disappointing results mainly due to inaccurate patient selection, but recently some encouraging results have been presented. In this review, we summarize the molecular alterations observed in thymic tumors, underlying the great biological differences among the different histology, and the promising targeted therapies for the future.

Immunobiology of Thymic Epithelial Tumors: Implications for Immunotherapy with Immune Checkpoint Inhibitors

Thymic epithelial tumors (TETs) are a group of rare thoracic malignancies, including thymic carcinomas (TC) and thymomas (Tm). Autoimmune paraneoplastic diseases are often observed in TETs, especially Tms. To date, chemotherapy is still the standard treatment for advanced disease. Unfortunately, few therapeutic options are available for relapsed/refractory TETs. In the last few years, the deepening of knowledge on thymus' immunobiology and involved altered genetic pathways have laid the foundation for new treatment options in these rare neoplasms. Recently, the immunotherapy revolution has landed in TETs, showing both a dark and light side. Indeed, despite the survival benefit, the occurrence of severe autoimmune treatment-related adverse events has risen crescent uncertainty about the feasibility of immunotherapy in these patients, prone to autoimmunity for their cancer biology. In this review, after summarizing immunobiology and immunopathology of TETs, we discuss available data on immune-checkpoint inhibitors and future perspectives of this therapeutic strategy.

Immune Checkpoint Inhibitor Therapy in Patients With Preexisting Inflammatory Bowel Disease

PURPOSE

The risk of immune checkpoint inhibitor therapy-related GI adverse events in patients with cancer and inflammatory bowel disease (IBD) has not been well described. We characterized GI adverse events in patients with underlying IBD who received immune checkpoint inhibitors.

PATIENTS AND METHODS

We performed a multicenter, retrospective study of patients with documented IBD who received immune checkpoint inhibitor therapy between January 2010 and February 2019. Backward selection and multivariate logistic regression were conducted to assess risk of GI adverse events.

RESULTS

Of the 102 included patients, 17 received therapy targeting cytotoxic T-lymphocyte antigen-4, and 85 received monotherapy targeting programmed cell death 1 or its ligand. Half of the patients had Crohn's disease, and half had ulcerative colitis. The median time from last active IBD episode to immunotherapy initiation was 5 years (interquartile range, 3-12 years). Forty-three patients were not receiving treatment of IBD. GI adverse events occurred in 42 patients (41%) after a median of 62 days (interquartile range, 33-123 days), a rate higher than that among similar patients without underlying IBD who were treated at centers participating in the study (11%; P < .001). GI events among patients with IBD included grade 3 or 4 diarrhea in 21 patients (21%). Four patients experienced colonic perforation, 2 of whom required surgery. No GI adverse event-related deaths were recorded. Anti-cytotoxic T-lymphocyte antigen-4 therapy was associated with increased risk of GI adverse events on univariable but not multivariable analysis (odds ratio, 3.19; 95% CI, 1.8 to 9.48; P = .037; and odds ratio, 4.72; 95% CI, 0.95 to 23.53; P = .058, respectively).

CONCLUSION

Preexisting IBD increases the risk of severe GI adverse events in patients treated with immune checkpoint inhibitors.

The functioning side of the pancreas: a review on insulinomas

PURPOSE

Insulinomas are a rare type of neuroendocrine tumors, originating in the pancreas, difficult to diagnose and to treat. Due to its rarity, insulinomas are a not well-known pathological entity; thus, the diagnostic process is frequently a medical challenge with many possible differential diagnoses. The diagnostic process varies between non-invasive procedures, such as the fasting test or imaging techniques, and invasive ones. Insulinomas are rarely malignant, but the glycemic imbalance correlated with this tumor can frequently alter the quality of life of the patients and the consequent hypoglycemia can be extremely dangerous. Moreover, insulinomas can be associated with different genetic syndromes, such as Multiple Endocrine Neoplasia 1, accompanied by other specific symptoms. There are many different treatment strategies, depending on the need to control symptoms or control diseases progression, the only curative one being surgery.

METHODS AND RESULTS

We reviewed the evidences present in the literature on insulinomas and reported its main clinical characteristics and management strategies.

CONCLUSION

The aim of this review of the literature is to present the current knowledge on insulinomas, exploring the main clinical characteristics, the diagnostic tools, and the therapeutic strategies.

Prognostic impact of tumour burden in stage IV neuroendocrine neoplasia: A comparison between pancreatic and gastrointestinal localizations

BACKGROUND

Although prognosis of NENs is affected by several features including tumour burden, the specific role of this factor in pancreatic NENs (PanNENs) and gastrointestinal NENs (GI NENs) is not well established.

AIM

To compare the prognostic role of tumour burden in PanNENs and GI NENs.

PATIENTS AND METHODS

This study was a retrospective analysis of stage IV PanNENs and GI NENs. Tumours were classified based on liver tumour volume (<25% or >25%). Overall survival as assessed by Kaplan-Meier curves, and Cox proportional hazards method was used to perform risk factor analysis.

RESULTS

The analysis included 300 patients, including 166 panNENs (55.3%) and 134 GI NENs (44.7%). A total of 158 patients (52.7%) had G2 tumours, 107 had G1 tumours (35.7%), and 35 had G3 tumours (11.6%). Tumour liver involvement >25% was observed in 187 patients (62.3%): 106 PanNENs (56.7%), and 81 GI NENs (43.3%) (p = 0.551). Bone metastases were present in 45 patients (15%): 22 PanNENs (13.2%) and 23 GI NENs (17.1%) (p = 0.416). Characteristics of the PanNENs, including: grading (G2 vs G1, HR = 3.7; G3 vs G1, HR = 16.40), liver involvement > 25% (HR = 3.09), and bone metastases (HR = 2.27) were independent predictors for poor survival, whereas the only significant risk factor in GI NENs was grading (G2 vs G1, HR = 4.36; G3 vs G1, HR = 8.60).

CONCLUSIONS

PanNENs and GI NENs have different risk profiles. Liver tumour volume and the presence of bone metastases significantly affect survival in patients with PanNENs but has no impact on the clinical outcomes of GI NENs.

Tumour type and size are prognostic factors in gastric neuroendocrine neoplasia: A multicentre retrospective study

BACKGROUND

Gastric neuroendocrine neoplasias (gNEN) are defined as type I if associated with atrophic body gastritis and type III when tumour is sporadic. This classification, together with grading and size, plays a crucial prognostic role. Nevertheless, the impact of these features on clinical outcome is not clear.

AIM

To identify factors predicting poor outcome.

PATIENTS AND METHODS

Analysis of type I and type III gNEN. A composite endpoint was defined if tumour-related death or metastases or angioinvasion were observed.

RESULTS

156 gNENs were evaluated: 137 (87.8%) type I and 19 (12.2%) type III. Among type I, 103 were G1 (75.2%) and 34 (24.8%) were G2. In type III group, 8 were G1 (42.1%), 10 were G2 (52.6%), and 1 was G3 (5.3%). Negative endpoint occurred in 18 patients including 10 type III and 8 type I. Male gender (p = 0.032), tumour type (p = 0.003) and size >10 mm (p = 0.024) were predictors for poor outcome, whereas Ki67 was not confirmed on multivariate analysis (p = 0.192). 5-yr survival rates in type I and type III were 100% and 76.2%, respectively (p = 0.0002).

CONCLUSIONS

Tumour size, tumour type and gender affect clinical outcome in gNENs. In contrast to NENs rising from other sites, Ki67 plays a less important role.

Biliary stone disease in patients receiving somatostatin analogs for neuroendocrine neoplasms. A retrospective observational study

BACKGROUND

Somatostatin analogs are the backbone of neuroendocrine neoplasms treatment. Biliary stone disease is a potentially severe adverse event of somatostatin analogs: an increased incidence has been reported in somatostatin analogs-treated acromegalic patients, but studies on patients with neuroendocrine neoplasms are lacking.

AIMS

To evaluate biliary stone disease incidence and associated factors in a large series of patients treated with somatostatin analogs for neuroendocrine neoplasms.

METHODS

A prospectively-collected database of patients with a diagnosis of neuroendocrine neoplasms of any grade and site, treated with somatostatin analogs at our Institution between 1995 and 2017, was retrospectively analyzed. Patients' demographics and disease characteristics were analyzed to evaluate the incidence and the factors related to biliary stone disease.

RESULTS

Three-hundred patients were included; 101 (33.7%) patients underwent cholecystectomy before starting somatostatin analogs. Among 164 patients with gallbladder in situ and no history of stone disease, 60 (36.6%) developed gallstones after a mean of 36.7 months (range 1-239) from treatment start with a mean yearly incidence of 8.73%. Previous cholecystectomy was associated with a lower rate of development of gallstones (p < 0.001) or related complications (p = 0.017).

CONCLUSION

We observed a high incidence of biliary stone disease in patients treated with somatostatin analogs-treated for neuroendocrine neoplams. Previous cholecystectomy was the only factor associated with a lower occurrence of biliary stone disease.

The Role of mTOR in Neuroendocrine Tumors: Future Cornerstone of a Winning Strategy?

The mechanistic target of rapamycin (mTOR) is part of the phosphoinositide-3-kinase (PI3K)/protein kinase B (AkT)/mTOR pathway and owes its name to the inhibitory effect of rapamycin. The mTOR has a central converging role for many cell functions, serving as a sensor for extracellular signals from energy status and nutrients availability, growth factors, oxygen and stress. Thus, it also modulates switch to anabolic processes (protein and lipid synthesis) and autophagy, in order to regulate cell growth and proliferation. Given its functions in the cell, its deregulation is implicated in many human diseases, including cancer. Its predominant role in tumorigenesis and progression of neuroendocrine tumors (NETs), in particular, has been demonstrated in preclinical studies and late clinical trials. mTOR inhibition by everolimus is an established therapeutic target in NETs, but there are no identified predictive or prognostic factors. This review is focused on the role of mTOR and everolimus in NETs, from preclinical studies to major clinical trials, and future perspectives involving mTOR in the treatment of NETs.

Atrial fibrillation in amyloidotic cardiomyopathy: prevalence, incidence, risk factors and prognostic role

BACKGROUND

Although atrial fibrillation (AF) is a known complication of amyloidotic cardiomyopathy (AC), a precise pathophysiological and prognostic characterization is not available. We therefore aimed to assess prevalence, incidence, risk factors and prognostic significance of AF in light-chain (AL), hereditary transthyretin-related (m-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC.

METHODS

Retrospective study of 262 patients with AC (123 AL, 94 m-ATTR, 45 wt-ATTR) from a single center.

RESULTS

AF prevalence was 15% (AL 9%, m-ATTR 11%, wt-ATTR 40%). During a median follow-up of 1.2 years 11 patients developed AF (2.1% person-years). Age, heart failure (HF), left ventricular (LV) ejection fraction, renal involvement, left atrial size and right atrial pressure were independently associated with AF. AF was associated with incident HF but not with increased mortality. All AF patients were prescribed warfarin and none suffered thromboembolic events.

CONCLUSIONS

In AC the prevalence of AF varies widely according to etiology with a mean value of 15% that reaches 40% in wt-ATTR amyloidosis. Age, HF, LV ejection fraction, left atrial size and right atrial pressure were the main independent risk factors, while wall thickness and etiology were not the main independent risk factors. AF does not seem to impact all-cause mortality but was strongly associated with prevalent and incident HF.

[Transthyretin-related amyloidotic cardiomyopathy: looking for the etiological treatment]

Transthyretin (TTR)-related amyloidosis is a disease caused by the deposition of insoluble fibrils deriving from the misfolding of TTR, a protein mainly produced by the liver. In the hereditary form of the disease (ATTRm), protein misfolding is secondary to a mutation in the TTR gene. ATTRm can manifest with different phenotypes: mainly neurological, mainly cardiac, or mixed. In the senile form of the disease (wild-type TTR or SSA), the deposition of non-mutated TTR occurs and, clinically, cardiomyopathy is predominant. Cardiac amyloidosis is still an underdiagnosed disease and clinical heterogeneity makes the diagnosis challenging. Until recently, no specific pharmacological treatment was available, liver transplantation being the only therapeutic option aimed at slowing disease progression in ATTRm and treatment was based on symptom relief. This review focuses on the emerging pharmacological treatments for TTR-related amyloidosis targeting different steps of the amyloidogenic process (blocking hepatic TTR synthesis, TTR tetramer stabilization and promotion of TTR amyloid fibril clearance).

Endometriosis of the abdominal wall: ultrasonographic and Doppler characteristics

OBJECTIVES

To describe the sonographic and clinical features of abdominal wall endometriosis (AWE), a frequently misdiagnosed condition.

METHODS

This was a retrospective study of 21 consecutive women with pathologically proven endometriosis of the abdominal wall. Ultrasonographic and Doppler examinations were performed, before surgery, with a high-frequency linear transducer. The clinical data and the results of the sonographic examinations were reviewed and described.

RESULTS

At ultrasound, all the nodules appeared as discrete solid masses that were less echogenic than the surrounding hyperechoic fat. The nodules had a median diameter of 20 (range, 5-50) mm and in 18/21 (86%) cases the nodules had a round/oval shape. In eight of 21 (38%) women the AWE was located at the umbilicus, in six of 21 (29%) it was between the transverse suprapubic line and the umbilicus, in five of 21 (24%) it was found along the scar of a previous Cesarean section and in two of 21 (9%) it was in the right inguinal canal. The content was homogeneously hypoechoic in 12/21 (57%) women and inhomogeneous in the other nine (43%). The outer borders were invariably ill defined. Scarce blood vessels were found by power Doppler. Cyclic or continuous spontaneous pain at the level of the AWE was present in 19/21 (91%) cases, and two (9%) patients were asymptomatic.

CONCLUSIONS

Hypoechoic round/oval nodules with ill-defined borders and a hyperechoic rim should raise the suspicion of abdominal wall endometriosis, even in patients with no history of endometriosis or previous laparotomic surgery. Pressing the ultrasound probe against the nodule should reinforce a suspected diagnosis because of the pain it induces.

Comparison of transvaginal sonography and double-contrast barium enema for diagnosing deep infiltrating endometriosis of the posterior compartment

OBJECTIVES

To compare the diagnostic accuracy of transvaginal sonography (TVS) and double-contrast barium enema (DCBE) in the preoperative detection of deep infiltrating endometriosis (DIE) of the posterior compartment.

METHODS

This was a prospective study of 69 consecutive patients with results of pelvic examination or symptoms suggestive of DIE of the posterior compartment. TVS and DCBE were performed before surgery by two groups of physicians specialized in endometriosis, each blinded to the results of the other technique. Imaging data were compared with histopathologic analysis of the resected specimen (gold standard). Sensitivity, specificity, positive and negative predictive values and test accuracies were calculated for both imaging modalities.

RESULTS

Sixty seven of the 69 women had a nodule of DIE confirmed at laparoscopy and histopathologic examination. TVS diagnosed DIE in 57 (85%) of these patients, while DCBE revealed the presence of the lesion in 24 (36%) women. For the diagnosis of posterior DIE, TVS and DCBE had, respectively, a sensitivity of 85% and 36%, specificity of 100% and 100%, positive predictive value of 100% and 100%, negative predictive value of 17% and 4% and accuracy of 85.5% and 38%. In patients with pure bowel DIE the sensitivity was 91% and 43%, specificity was 100% and 100%, positive predictive value was 100% and 100%, negative predictive value was 29% and 6% and accuracy was 91% and 45%, respectively.

CONCLUSIONS

TVS has a much higher sensitivity than does DCBE in detecting the presence of posterior DIE and should thus be regarded as the imaging modality of choice when there is clinical suspicion of the disease.

Diagnostic accuracy and potential limitations of transvaginal sonography for bladder endometriosis

OBJECTIVES

To evaluate the accuracy and the potential limitations of transvaginal sonography (TVS) in the preoperative evaluation of women with clinically suspected bladder endometriosis and to describe the sonographic features of the pathological condition in cases in which it was confirmed.

METHODS

In the period between 2001 and 2006, we operated on 490 patients with clinically/sonographically suspected endometriosis. In 41 cases, bladder endometriosis was diagnosed at surgery and confirmed at histopathological examination. All patients underwent TVS in a standardized manner not more than 1 month before surgery. Findings at preoperative TVS were described and compared with those at laparoscopy in order to evaluate the sensitivity, specificity, and positive and negative predictive values of TVS.

RESULTS

Bladder endometriosis was correctly identified at TVS in 18/41 cases (43.9%) while 23/41 (56.1%) patients had a negative preoperative sonogram. The sensitivity, specificity and positive and negative predictive values of TVS for bladder endometriosis were 44% (18/41), 100% (449/449), 100% (18/18) and 95% (449/472), respectively, and the total accuracy was 95% (467/490). The detection rate was strongly related to mean lesion diameter as measured by the pathologist (mean +/- SD, 42.5 +/- 22.1 mm in the nodules detected vs. 28.9 +/- 14.8 mm in the nodules missed; P = 0.029) and to a history of previous surgery for endometriosis (70.6% vs. 25.0%; P = 0.005). At TVS, the nodule was hypoechogenic, its morphology was either elongated ('comma-shaped': 12/18, 66.7%) or spherical (6/18, 33.3%), and the site involved was the dome (11/18, 61.1%) or the base (7/18, 38.9%) of the bladder. Small anechogenic cystic areas within the nodule were seen in five of the 18 patients (27.8%) and a bright hyperechogenic rim was seen in 10 (55.6%).

CONCLUSIONS

The detection rate of bladder endometriosis by TVS depends on the size of the endometriotic nodules, with detected nodules being larger than those that were missed. A history of previous surgery for endometriosis increases the likelihood of bladder endometriosis being detected on ultrasound examination.

Post-operative use of oral contraceptive pills for prevention of anatomical relapse or symptom-recurrence after conservative surgery for endometriosis

BACKGROUND

Endometriosis recurrence after conservative surgery is not infrequent. Variable regimens of hormonal therapy have been proposed as adjuvant post-operative measures for prophylaxis against recurrence. Among these, the combined oral contraceptive pills (OCP), represents a valuable option in terms of safety and tolerability for long-term use. The objective of this review is to evaluate the effect of post-operative use of OCP in preventing symptom recurrence, and/or anatomical relapse of endometriosis.

METHODS

A systematic search of Medline identified seven studies evaluating post-operative OCP treatment on prevention of endometriosis recurrence.

RESULTS

A reduction in anatomical relapse rate was observed when oral contraceptive therapy was administered for more than 1 year after conservative surgery. Post-operative use of OCP was associated with a reduction in frequency and intensity of dysmenorrhoea recurrence. No association was found between OCP therapy and dyspareunia prevention, although the effect of OCP on chronic pelvic pain was conflicting.

CONCLUSION

Long-term OCP therapy can be a reliable adjuvant post-operative measure to prevent or reduce frequency/severity of recurrent dysmenorrhoea and anatomical relapse of endometriosis. Since both continuous and cyclic OCP administration regimens seem to have comparable effects, the choice of regimen can be modulated according to patient preferences. The protective effect seems to be related to the duration of treatment.

Surgical outcome and long-term follow up after laparoscopic rectosigmoid resection in women with deep infiltrating endometriosis

The aim of this study was to assess the long-term outcome of treating severely symptomatic women with deep infiltrating intestinal endometriosis by laparoscopic segmental rectosigmoid resection. Detailed intraoperative and postoperative records and questionnaires (preoperatively, 1 month postoperatively and every 6 months for 3 years) were collected from 22 women. The estimated blood loss during surgery was 290 +/- 162 ml (range 180-600), and average hospital stay was 8 days (range 6-19). One woman required blood transfusion after surgery. Two cases were converted to laparotomy. One woman had early dehiscence of the anastomosis. Six months after surgery, there was a significant reduction of symptom scores (greater than 50% for most types of pain) related to intestinal localisation of endometriosis (P < 0.05). Score improvements were maintained during the whole period of follow up. Noncyclic pelvic pain scores showed significant reductions (P < 0.05) after 6 and 12 months, but there was a high recurrence rate later. Dysmenorrhoea and dyspareunia improved in 18/21 and 14/18 women with preoperative symptoms, respectively. Constipation, diarrhoea and rectal bleeding improved in all affected women for the whole period of follow up. Laparoscopic segmental rectosigmoid resection seems safe and effective in women with deep infiltrating colorectal endometriosis resulting in significant reductions in painful and dysfunctional symptoms associated with deep bowel involvement.