101
|
HAMEEDUDDIN A, SINGH NK, COOK GJR, CHUA SC. Assessment of incidental and clinically unsuspected fluorodeoxyglucose-avid foci detected on oncological positron emission tomography/CT. IMAGING 2013. [DOI: 10.1259/imaging.20110088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
102
|
Habibollahi P, van den Berg NS, Kuruppu D, Loda M, Mahmood U. Metformin--an adjunct antineoplastic therapy--divergently modulates tumor metabolism and proliferation, interfering with early response prediction by 18F-FDG PET imaging. J Nucl Med 2013; 54:252-8. [PMID: 23376854 DOI: 10.2967/jnumed.112.107011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Over the last several years, epidemiologic data have suggested that the antidiabetes drug metformin (MET), an adenosine monophosphate-activated protein kinase (AMPK) activator, improves progression-free survival of patients with multiple cancers; more than 30 clinical trials are under way to confirm this finding. We postulated that the role of AMPK as a central cellular energy sensor would result in opposite effects on glucose uptake and proliferation, suggesting different roles for (18)F-FDG and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) in assessing its effectiveness as an antineoplastic agent. METHODS Colon cancer cell lines HT29 (human) and MC26 (murine) were treated for 24 or 72 h with a range of MET concentrations (0-10 mM). Western blotting was used to study the activation of AMPK after MET treatment. Glucose uptake and cell proliferation were measured by cell retention studies with either (18)F-FDG or (18)F-FLT. EdU (ethynyl deoxyuridine, a thymidine analog) and annexin-propidium iodide flow cytometry was performed to determine cell cycle S-phase and apoptotic changes. In vivo (18)F-FDG and (18)F-FLT PET images were acquired before and 24 h after MET treatment of HT29 tumor-bearing mice. RESULTS After 24 h of MET incubation, phosphorylated AMPK levels increased severalfold in both cell lines, whereas total AMPK levels remained unchanged. In cell retention studies, (18)F-FDG uptake increased but (18)F-FLT retention decreased significantly in both cell lines. The numbers of HT29 and MC26 cells in the S phase decreased 36% and 33%, respectively, after MET therapy. Apoptosis increased 10.5-fold and 5.8-fold in HT29 and MC26 cells, respectively, after 72 h of incubation with MET. PET imaging revealed increased (18)F-FDG uptake (mean ± SEM standardized uptake values were 0.71 ± 0.03 before and 1.29 ± 0.11 after MET therapy) (P < 0.05) and decreased (18)F-FLT uptake (mean ± SEM standardized uptake values were 1.18 ± 0.05 before and 0.89 ± 0.01 after MET therapy) (P < 0.05) in HT29 tumor-bearing mice. CONCLUSION MET, through activation of the AMPK pathway, produces a dose-dependent increase in tumor glucose uptake while decreasing cell proliferation in human and murine colon cancer cells. Thus, changes in (18)F-FDG uptake after MET treatment may be misleading. (18)F-FLT imaging is a promising alternative that correlates with the tumor response.
Collapse
Affiliation(s)
- Peiman Habibollahi
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | | | | | | | | |
Collapse
|
103
|
Honka H, Mäkinen J, Hannukainen JC, Tarkia M, Oikonen V, Teräs M, Fagerholm V, Ishizu T, Saraste A, Stark C, Vähäsilta T, Salminen P, Kirjavainen A, Soinio M, Gastaldelli A, Knuuti J, Iozzo P, Nuutila P. Validation of [18F]fluorodeoxyglucose and positron emission tomography (PET) for the measurement of intestinal metabolism in pigs, and evidence of intestinal insulin resistance in patients with morbid obesity. Diabetologia 2013; 56:893-900. [PMID: 23334481 DOI: 10.1007/s00125-012-2825-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 12/17/2012] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS The role of the intestine in the pathogenesis of metabolic diseases is gaining much attention. We therefore sought to validate, using an animal model, the use of positron emission tomography (PET) in the estimation of intestinal glucose uptake (GU), and thereafter to test whether intestinal insulin-stimulated GU is altered in morbidly obese compared with healthy human participants. METHODS In the validation study, pigs were imaged using [(18)F]fluorodeoxyglucose ([(18)F]FDG) and the image-derived data were compared with corresponding ex vivo measurements in tissue samples and with arterial-venous differences in glucose and [(18)F]FDG levels. In the clinical study, GU was measured in different regions of the intestine in lean (n = 8) and morbidly obese (n = 8) humans at baseline and during euglycaemic hyperinsulinaemia. RESULTS PET- and ex vivo-derived intestinal values were strongly correlated and most of the fluorine-18-derived radioactivity was accumulated in the mucosal layer of the gut wall. In the gut wall of pigs, insulin promoted GU as determined by PET, the arterial-venous balance or autoradiography. In lean human participants, insulin increased GU from the circulation in the duodenum (from 1.3 ± 0.6 to 3.1 ± 1.1 μmol [100 g](-1) min(-1), p < 0.05) and in the jejunum (from 1.1 ± 0.7 to 3.0 ± 1.5 μmol [100 g](-1) min(-1), p < 0.05). Obese participants failed to show any increase in insulin-stimulated GU compared with fasting values (NS). CONCLUSIONS/INTERPRETATION Intestinal GU can be quantified in vivo by [(18)F]FDG PET. Intestinal insulin resistance occurs in obesity before the deterioration of systemic glucose tolerance.
Collapse
Affiliation(s)
- H Honka
- Turku PET Centre, University of Turku, PL 52, FIN-20520 Turku, Finland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
104
|
Jamar F, Buscombe J, Chiti A, Christian PE, Delbeke D, Donohoe KJ, Israel O, Martin-Comin J, Signore A. EANM/SNMMI guideline for 18F-FDG use in inflammation and infection. J Nucl Med 2013; 54:647-58. [PMID: 23359660 DOI: 10.2967/jnumed.112.112524] [Citation(s) in RCA: 383] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Francois Jamar
- Department of Nuclear Medicine, Université Catholique de Louvain, Brussels, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
105
|
Massollo M, Marini C, Brignone M, Emionite L, Salani B, Riondato M, Capitanio S, Fiz F, Democrito A, Amaro A, Morbelli S, Piana M, Maggi D, Cilli M, Pfeffer U, Sambuceti G. Metformin temporal and localized effects on gut glucose metabolism assessed using 18F-FDG PET in mice. J Nucl Med 2013; 54:259-66. [PMID: 23287574 DOI: 10.2967/jnumed.112.106666] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED In the course of metformin treatment, staging abdominal cancer lesions with (18)F-FDG PET images is often hindered by the presence of a high bowel radioactivity. The present study aimed to verify the mechanism underlying this phenomenon. METHODS Fifty-three mice were submitted to dynamic acquisitions of (18)F-FDG kinetics under fasting conditions. Three small-animal PET scans were obtained over a 4-mo study period. The animals were subdivided into 4 groups according to the following metformin administration protocol: group 1, untreated mice (n = 15); group 2, mice exposed to metformin treatment (750 mg/kg/d) for the 48 h before each PET study (pulsed, n = 10); group 3, mice treated for the whole study period (prolonged, n = 10); and group 4, mice in which prolonged treatment was interrupted 48 h before PET (interrupted, n = 8). The rate constant of (18)F-FDG uptake was estimated by Patlak analysis. At the end of the study, the ileum and colon were harvested, washed, and counted ex vivo. Two further groups, of 5 animals each, were included to evaluate the effect of prolonged metformin treatment on phosphorylated adenosine monophosphate (AMP)-activated protein kinase (pAMPK) form and gene expression for thioredoxin-interacting protein (TXNIP). RESULTS Pulsed treatment did not modify gut tracer retention with respect to the untreated group. Conversely, prolonged treatment induced a progressive increase in (18)F-FDG uptake that selectively involved the colonic wall, without any significant contamination of bowel content. This effect persisted after a complete drug washout in the interrupted group. These responses were paralleled by increased pAMPK availability and by reduced expression of TXNIP messenger RNA in colonic enterocytes exposed to prolonged metformin treatment. CONCLUSION Metformin causes a selective increase in colonic (18)F-FDG uptake. This effect appears after a relatively long period of treatment and persists soon after drug washout. Accordingly, the increased bowel glucose metabolism reflects a biologic response to chronic metformin treatment characterized by increased levels of pAMPK and reduced levels of TXNIP.
Collapse
Affiliation(s)
- Michela Massollo
- Nuclear Medicine, Department of Internal Medicine, University of Genoa and IRCCS San Martino-IST, 16132 Genoa, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
106
|
Pollak MN. Investigating metformin for cancer prevention and treatment: the end of the beginning. Cancer Discov 2012; 2:778-90. [PMID: 22926251 DOI: 10.1158/2159-8290.cd-12-0263] [Citation(s) in RCA: 379] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED Laboratory research and pharmacoepidemiology are providing converging evidence that the widely used antidiabetic drug metformin has antineoplastic activity, but there are caveats. Although population studies suggest that metformin exposure is associated with reduced cancer risk and/or improved prognosis, these data are mostly retrospective and nonrandomized. Laboratory models show antineoplastic activity, but metformin concentrations used in many experiments exceed those achieved with conventional doses used for diabetes treatment. Ongoing translational research should be useful in guiding design of clinical trials, not only to evaluate metformin at conventional antidiabetic doses, where reduction of elevated insulin levels may contribute to antineoplastic activity for certain subsets of patients, but also to explore more aggressive dosing of biguanides, which may lead to reprogramming of energy metabolism in a manner that could provide important opportunities for synthetic lethality through rational drug combinations or in the context of genetic lesions associated with hypersensitivity to energetic stress. SIGNIFICANCE There are tantalizing clues that justify the investigation of antineoplastic activities of biguanides. The complexity of their biologic effects requires further translational research to guide clinical trial design.
Collapse
Affiliation(s)
- Michael N Pollak
- Department of Oncology, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
107
|
Ciappuccini R, Trzepla G, Heutte N, Sevin E, Galais MP, Bardet S. Sorafenib increases 18-FDG colic uptake: demonstration in patients with differentiated thyroid cancer. EJNMMI Res 2012; 2:18. [PMID: 22564710 PMCID: PMC3426461 DOI: 10.1186/2191-219x-2-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/07/2012] [Indexed: 11/23/2022] Open
Abstract
Background To assess 18-fluorodeoxyglucose (FDG) bowel uptake in patients with differentiated thyroid cancer (DTC) treated with sorafenib. Findings Visual (5-point scale) and high maximum standard uptake value (SUVmax) semi-quantitative analyses were conducted in 63 positron emission tomography (PET) studies performed in patients on sorafenib (group 1, n = 20), in a control group (group 2, n = 28) and in patients on sunitinib or vandetanib (group 3, n = 15). Moderate or high and diffuse bowel uptake (grade 4 or 5) was observed in 90% of the PET scans of group 1 versus none in group 2. Only 20% of PET scans in group 3 were scored grade 4. SUVmax values were significantly higher for all colic segments in group 1 than in group 2 (P < 0.0001) or 3 (P < 0.0004). This uptake pattern appeared rapidly (one month) and disappeared after sorafenib withdrawal. Conclusions FDG uptake is increased in the colon of DTC patients treated by sorafenib.
Collapse
Affiliation(s)
- Renaud Ciappuccini
- Departments of Nuclear Medicine and Thyroid Unit, Centre François Baclesse, 3 Avenue Général Harris - BP 5026, Cedex 05, Caen, 14076, France.
| | | | | | | | | | | |
Collapse
|
108
|
Higurashi T, Takahashi H, Endo H, Hosono K, Yamada E, Ohkubo H, Sakai E, Uchiyama T, Hata Y, Fujisawa N, Uchiyama S, Ezuka A, Nagase H, Kessoku T, Matsuhashi N, Yamanaka S, Inayama Y, Morita S, Nakajima A. Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial. BMC Cancer 2012; 12:118. [PMID: 22443173 PMCID: PMC3353167 DOI: 10.1186/1471-2407-12-118] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 03/26/2012] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF). ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients. METHODS/DESIGN This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation. DISCUSSION This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with type 2 diabetes taking under treatment with metformin have been reported to be at a lower risk of cancer development than those not taking under treatment with metformin. We showed in a previous study that metformin suppressed the formation of human colorectal ACF. We therefore decided to conduct a study to determine whether metformin might suppress the formation of human colorectal polyps. TRIAL REGISTRATION This trial has been registered in the University hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000006254.
Collapse
Affiliation(s)
- Takuma Higurashi
- Division of Gastroenterology, Yokohama City University School of Medicine, Yokohama, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
109
|
Maurer AH, Burshteyn M, Adler LP, Steiner RM. How to differentiate benign versus malignant cardiac and paracardiac 18F FDG uptake at oncologic PET/CT. Radiographics 2012; 31:1287-305. [PMID: 21918045 DOI: 10.1148/rg.315115003] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Patients undergoing 2-[fluorine 18]fluoro-2-deoxy-d-glucose (FDG) whole-body oncologic positron emission tomography (PET)/computed tomography (CT) are studied while fasting. Cardiac FDG uptake in fasted patients has been widely reported as variable. It is important to understand the normal patterns of cardiac FDG activity that can be seen in oncologic FDG PET/CT studies. These include focal and regional patterns of increased FDG myocardial activity. Focal activity can be observed in papillary muscles, the atria, the base, and the distal anteroapical region of the left ventricle. Regional increased cardiac FDG activity may be diffuse or localized in the posterolateral wall or the base of the left ventricle. Abnormal patterns of cardiac FDG activity not related to malignancy include those associated with lipomatous hypertrophy of the interatrial septum, epicardial and pericardial fat, increased atrial activity associated with atrial fibrillation or a prominent crista terminalis, cardiac sarcoidosis, endocarditis, myocarditis, and pericarditis. Knowledge of these patterns of cardiac FDG activity is important to be able to recognize malignant disease involving the paracardiac spaces, myocardium, and pericardium. With a better understanding of the range of normal and abnormal patterns of cardiac FDG activity, important benign and malignant diseases involving the heart and pericardium can be recognized and diagnosed.
Collapse
Affiliation(s)
- Alan H Maurer
- Department of Radiology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
| | | | | | | |
Collapse
|
110
|
Yılmaz S, Ozhan M, Sager S, Yörük Atik D, Halac M, Sönmezoğlu K. Metformin-Induced Intense Bowel Uptake Observed on Restaging FDG PET/CT Study in a Patient with Gastric Lymphoma. Mol Imaging Radionucl Ther 2011; 20:114-6. [PMID: 23486704 PMCID: PMC3590950 DOI: 10.4274/mirt.020573] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 07/13/2010] [Indexed: 12/26/2022] Open
Abstract
A 53-year-old man with a diagnosis of gastric non-Hodgkin lymphoma (NHL) underwent PET/CT scans both prior to starting chemotherapy and immediately following completion of chemotherapy to evaluate the response to therapy. Pre-therapy PET/CT images showed intense FDG uptake in the antral region of the stomach. Biodistribution of FDG was otherwise unremarkable. The patient was started on metformin in the middle of his therapy period to provide glycemic control. Post-therapy PET/CT study performed after 6 courses of chemotherapy showed complete resolution of the disease with no evidence of residual FDG uptake. However, intense and diffuse FDG accumulation is observed in the bowel, which was interpreted as physiological and most probably due to metformin administration. It should be borne in mind that there are a number of physiological variants of FDG biodistribution seen on PET/CT imaging. Recognizing physiologic bowel activity is crucial for the accuracy of PET image interpretation. Conflict of interest:None declared.
Collapse
Affiliation(s)
- Sabire Yılmaz
- Department of Nuclear Medicine, Cerrahpasa Medical Faculty, University of Istanbul, Istanbul, Turkey
| | | | | | | | | | | |
Collapse
|
111
|
Lin M, Koo JH, Abi-Hanna D. Management of patients following detection of unsuspected colon lesions by PET imaging. Clin Gastroenterol Hepatol 2011; 9:1025-32. [PMID: 21723237 DOI: 10.1016/j.cgh.2011.06.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 04/29/2011] [Accepted: 06/14/2011] [Indexed: 12/11/2022]
Abstract
Positron emission tomography (PET) is a well-established and integral component of multimodality imaging in oncology. However, the expanded use of PET in oncological and also non-oncological imaging (such as in assessing inflammatory conditions) has identified more lesions or tumors at unsuspected locations, such as in the large bowel during examination of patients not known to have colorectal disease. We review the clinical significance of colon lesions that were discovered incidentally by PET imaging and management strategies for gastroenterologists.
Collapse
Affiliation(s)
- Michael Lin
- Department of Nuclear Medicine and PET, Liverpool Hospital, University of New South Wales, Liverpool, New SouthWales, Austrailia.
| | | | | |
Collapse
|
112
|
Colonic FDG uptake pattern in subjects receiving oral contrast with no known or suspected colonic disease. Clin Nucl Med 2011; 36:754-6. [PMID: 21825842 DOI: 10.1097/rlu.0b013e31821c9921] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM We assessed the pattern of metabolic activity in the colon of subjects who received oral contrast and had no known or suspected colonic disease. METHODS Positron emission tomography/computed tomography (PET/CT) with [F-18]-fluorodeoxyglucose was performed in 50 patients with cancer and no known or suspected colonic pathology. Studies with intense focal or segmental colonic activity (in comparison to liver reference activity), which are known to be predictive of colonic pathology were excluded. Retrospectively, colon was divided into cecum, ascending, transverse, descending, and rectosigmoid partitions, and the corresponding volumetric regions of interest were drawn on all relevant CT images. Partitioned colonic maximum standardized uptake values (SUVmax) were compared using Wilcoxon rank-sum test. Frequency of occurrence for the various colonic uptake rank orders was also tabulated. RESULTS For colonic partitions, range and median SUVmax, respectively, were in decreasing order: rectosigmoid (1.5-9.9, 2.9), cecum (1.2-6.3, 2.6), ascending (0.7-4.0, 1.8), transverse (0.4-4.1, 1.2), and descending (0.6-3.1, 1.2). The SUVmax at different colonic partitions were significantly different from each other (P<0.001), except for the SUVmax between descending and transverse colonic segments (P=0.77). Combining the latter segments, the uptake rank order of "rectosigmoid>cecum>ascending" was demonstrated in 50% and "cecum>rectosigmoid>ascending" in 30% of subjects. CONCLUSIONS Rectosigmoid and cecum tend to demonstrate higher metabolism than other colonic segments in the majority subjects who receive oral contrast during [F-18]-fluorodeoxyglucose positron emission tomography/CT and have no known or suspected colonic pathology.
Collapse
|
113
|
Abstract
Because each cancer is a heterogeneous mix of cancer cells at different stages of development, we are faced with trying to treat many different diseased cells all at once. An authentic approach is to build a genomic and proteomic profile of a patient, identify the target oncogenes, and prescribe the combination of targeted drugs tailored for that patient. However, there are many practical problems with this personalized medicine approach: (i) cancers often generate treatment-resistant phenotypes, (ii) the treatment could be enormously expensive, and (iii) most of the targeted drugs have not been developed yet. We propose a different approach: therapies that combine 2-deoxyglucose (2DG) with Bcl-2 antagonist such as ABT-263/737 (ABT). Proapoptotic protein Bak is normally sequestered by Mcl-1 and Bcl-xL. Only when Bak is released from both Mcl-1 and Bcl-xL can it induce apoptosis. 2DG can prime highly glycolytic cells by dissociating Bak-Mcl-1 complex. Some brain cells and most cancer cells are primed by 2DG. ABT can bind to Bcl-xL, dissociating Bak-Bcl-xL complex, freeing Bak and inducing apoptosis. Because ABT cannot cross blood-brain barrier, the only cells exposed to both agents are highly glycolytic cancer cells located outside the brain. Because ABT directly triggers apoptosis at the step very near the terminal point of apoptosis, 2DG-ABT combination therapies are applicable to many types of cancer at all stages of development, with little side effect.
Collapse
|
114
|
|
115
|
Increased F-18 FDG intestinal uptake in diabetic patients on metformin: a matched case-control analysis. Clin Nucl Med 2011; 36:452-6. [PMID: 21552023 DOI: 10.1097/rlu.0b013e318217399e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE A matched case-control study was performed to assess the relationship between metformin use and the degree of F-18 fluorodeoxyglucose (FDG) bowel activity in diabetic patients. MATERIALS AND METHODS Seventy-seven diabetic patients referred to our department for a positron emission tomography/computed tomography study, including 45 on metformin, were compared with nondiabetic controls matched for sex, age, and body mass index. Positron emission tomography studies were obtained in a standard manner and reviewed in a blinded fashion. F-18 FDG uptake in the GI tract was evaluated quantitatively using maximal standardized uptake values and visually using a previously published semiquantitative scale. RESULTS F-18 FDG uptake in small and large bowel was significantly increased in metformin patients compared with nondiabetic controls both visually and quantitatively (all P < 0.0001), as well as compared with nonmetformin patients with diabetes. Control sites (liver, fat, muscle) showed similar uptake. Multiple regression analysis confirmed that metformin was the variable most strongly associated with bowel uptake. CONCLUSION Physiologic accumulation of F-18 FDG in bowel is increased in diabetic patients maintained on metformin.
Collapse
|
116
|
|
117
|
Bouchoucha M, Uzzan B, Cohen R. Metformin and digestive disorders. DIABETES & METABOLISM 2011; 37:90-6. [DOI: 10.1016/j.diabet.2010.11.002] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 10/22/2010] [Accepted: 11/03/2010] [Indexed: 12/22/2022]
|
118
|
Culverwell AD, Scarsbrook AF, Chowdhury FU. False-positive uptake on 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) in oncological imaging. Clin Radiol 2011; 66:366-82. [PMID: 21356398 DOI: 10.1016/j.crad.2010.12.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 12/14/2010] [Accepted: 12/21/2010] [Indexed: 01/29/2023]
Abstract
With the increasing utilization of integrated positron-emission tomography/computed tomography (PET/CT) using the glucose analogue 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) in oncological imaging, it is important for radiologists and nuclear medicine physicians to be aware that FDG uptake is not specific for malignancy, as many different physiological variants and benign pathological conditions can also exhibit increased glucose metabolism. Such false-positive FDG uptake often arises outside the area of primary interest and may mimic malignant disease, thereby confounding accurate interpretation of PET/CT studies. With the use of illustrative clinical cases, this article will provide a systematic overview of potential interpretative pitfalls and illustrate how such unexpected findings can be appropriately evaluated.
Collapse
Affiliation(s)
- A D Culverwell
- Department of Clinical Radiology, Leeds Teaching Hospitals NHS Trust, UK
| | | | | |
Collapse
|
119
|
Impact of medication discontinuation on increased intestinal FDG accumulation in diabetic patients treated with metformin. AJR Am J Roentgenol 2011; 195:1404-10. [PMID: 21098202 DOI: 10.2214/ajr.10.4663] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE We evaluated the impact of stopping medication for 2 days on reductions in the high intestinal FDG uptake induced by metformin. SUBJECTS AND METHODS One hundred thirty-eight diabetic patients were divided into two groups: one in which the antihyperglycemic drug regimen included metformin (group A; n = 107) and one in which the regimen did not include metformin (group B; n = 31). Fifty-two patients without diabetes mellitus served as the control group (group C). Group A was divided into two subgroups: 77 patients (group A1) were taking metformin at the time of FDG PET/CT scans, whereas the remaining 30 patients (group A2) were asked to stop taking metformin for 2 days before PET/CT scans. In addition, 10 diabetic patients underwent two consecutive PET/CT scans before and after the discontinuation of metformin. The intestinal FDG uptake and blood glucose levels were compared among the four groups, as well as before and after the discontinuation of metformin. RESULTS The high intestinal FDG uptake in group A1 was significantly reduced after the discontinuation of metformin (p < 0.001 vs group A2); thus, there were no significant differences among group A2, group B, and group C (p = 0.581-0.872). There were also no statistically significant differences in the blood glucose levels among the three groups of diabetic patients (p > 0.9). In 10 patients who underwent serial PET/CT scans, mean intestinal FDG uptake decreased by 64% without significant changes in the blood glucose level. Hidden colorectal malignancies were revealed in two patients after the discontinuation of medication. CONCLUSION The discontinuation of metformin for 2 days is feasible for reducing the high intestinal FDG uptake induced by metformin.
Collapse
|
120
|
Normal variants of bowel FDG uptake in dual-time-point PET/CT imaging. Ann Nucl Med 2010; 25:173-8. [PMID: 21088936 DOI: 10.1007/s12149-010-0439-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 10/08/2010] [Indexed: 10/18/2022]
|
121
|
|
122
|
Abstract
(18)F-fluorodeoxyglucose (FDG) is the radiotracer used in the vast majority of positron emission tomography (PET) cancer studies. FDG is a powerful radiotracer that provides valuable data in many cancer types. Normal FDG biodistribution is easily identified. In the PET-only era, physiological uptake provided important anatomical landmarks. However, the normal biodistribution of FDG is often variable and can be altered by intrinsic or iatrogenic factors. Recognizing these patterns of altered biodistribution is important for optimal FDG-PET interpretation. Altered FDG uptake in muscles, brown adipose tissue, bone marrow, the urinary tract, and the bowel is demonstrated in a significant proportion of patients, which can hide underlying malignant foci or mimic malignant lesions. The introduction of PET/computed tomography revolutionized PET imaging, bringing much-needed anatomical information. This modality allowed better characterization of some types of uptake, particularly brown adipose tissue FDG uptake. Different approaches to minimize interference from altered FDG biodistribution should be considered when performing PET scans. Otherwise, careful review and correlation of metabolic (FDG-PET) and anatomical (computed tomography) data should be performed to accurately characterize the foci of increased FDG uptake.
Collapse
Affiliation(s)
- Christian Cohade
- Department of Nuclear Medicine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
| |
Collapse
|
123
|
Abstract
Retrospective studies that may be impractical to confirm prospectively suggest that diabetics treated with metformin have a substantially reduced cancer burden compared with other diabetics. It is unclear if this reflects a chemopreventive effect, an effect on transformed cells, or both. It also remains to be established if these data have relevance to people without diabetes. Laboratory models, however, provide independent impressive evidence for the activity of metformin and other biguanides in both cancer treatment and chemoprevention. Investigations of mechanisms of action of biguanides have revealed considerable complexity and have identified important gaps in knowledge that should be addressed to ensure the optimal design of clinical trials of these agents. Such trials may define important new indications for biguanides in the prevention and/or treatment of many common cancers.
Collapse
Affiliation(s)
- Michael Pollak
- 3755 Cote-Ste.-Catherine, Montreal, Quebec, Canada H3T 1E2.
| |
Collapse
|
124
|
Jalving M, Gietema JA, Lefrandt JD, de Jong S, Reyners AKL, Gans ROB, de Vries EGE. Metformin: taking away the candy for cancer? Eur J Cancer 2010; 46:2369-80. [PMID: 20656475 DOI: 10.1016/j.ejca.2010.06.012] [Citation(s) in RCA: 300] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 06/07/2010] [Indexed: 12/16/2022]
Abstract
Metformin is widely used in the treatment of diabetes mellitus type 2 where it reduces insulin resistance and diabetes-related morbidity and mortality. Population-based studies show that metformin treatment is associated with a dose-dependent reduction in cancer risk. The metformin treatment also increases complete pathological tumour response rates following neoadjuvant chemotherapy for breast cancer, suggesting a potential role as an anti-cancer drug. Diabetes mellitus type 2 is associated with insulin resistance, elevated insulin levels and an increased risk of cancer and cancer-related mortality. This increased risk may be explained by activation of the insulin- and insulin-like growth factor (IGF) signalling pathways and increased signalling through the oestrogen receptor. Reversal of these processes through reduction of insulin resistance by the oral anti-diabetic drug metformin is an attractive anti-cancer strategy. Metformin is an activator of AMP-activated protein kinase (AMPK) which inhibits protein synthesis and gluconeogenesis during cellular stress. The main downstream effect of AMPK activation is the inhibition of mammalian target of rapamycin (mTOR), a downstream effector of growth factor signalling. mTOR is frequently activated in malignant cells and is associated with resistance to anticancer drugs. Furthermore, metformin can induce cell cycle arrest and apoptosis and can reduce growth factor signalling. This review discusses the role of diabetes mellitus type 2 and insulin resistance in carcinogenesis, the preclinical rationale and potential mechanisms of metformin's anti-cancer effect and the current and future clinical developments of metformin as a novel anti-cancer drug.
Collapse
Affiliation(s)
- Mathilde Jalving
- Department of Medical Oncology, University Medical Centre Groningen, Groningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
125
|
Salpeter SR, Greyber E, Pasternak GA, Salpeter EE. Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus. Cochrane Database Syst Rev 2010; 2010:CD002967. [PMID: 20393934 PMCID: PMC7138050 DOI: 10.1002/14651858.cd002967.pub4] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age. OBJECTIVES To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies. SEARCH STRATEGY A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators. SELECTION CRITERIA Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy. DATA COLLECTION AND ANALYSIS The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data. MAIN RESULTS Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies. AUTHORS' CONCLUSIONS There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.
Collapse
Affiliation(s)
- Shelley R Salpeter
- Stanford University, and Santa Clara Valley Medical CenterMedicine2400 Moorpark Ave, Suite 118San JoseCAUSA95128
| | - Elizabeth Greyber
- Santa Clara Valley Medical CenterMedicine2400 Moorpark Ave, Suite 118San JoseCAUSA95128
| | - Gary A Pasternak
- Santa Clara Valley Medical CenterMedicine2400 Moorpark Ave, Suite 118San JoseCAUSA95128
| | - Edwin E Salpeter
- Cornell UniversityCenter for Radiophysics and Space Research612 Space Sciences BuildingIthacaNYUSA14853
| | | |
Collapse
|
126
|
Ozülker T, Ozülker F, Mert M, Ozpaçaci T. Clearance of the high intestinal (18)F-FDG uptake associated with metformin after stopping the drug. Eur J Nucl Med Mol Imaging 2010; 37:1011-7. [PMID: 20107796 DOI: 10.1007/s00259-009-1330-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2009] [Accepted: 11/06/2009] [Indexed: 12/26/2022]
Abstract
PURPOSE This study was done to determine whether interruption of metformin before (18)F-FDG PET/CT imaging could prevent the increased (18)F-FDG uptake in the intestine caused by this drug. METHODS Included in the study were 41 patients with known type 2 diabetes mellitus who were referred to our department for evaluation of various neoplastic diseases. Patients underwent two (18)F-FDG PET/CT scans, the first while they were on metformin and the second after they had stopped metformin. They stopped metformin and did not take any other oral antidiabetic medication starting 3 days before the second study and their blood glucose level was regulated with insulin when necessary to keep it within the range 5.55-8.33 mmol/l. FDG uptake was graded visually according to a four-point scale and semiquantitatively by recording the maximum standardized uptake value (SUVmax) in different bowel segments. A paired-samples t-test method was used to determine whether there was a significant difference between SUVmax measurements and visual analysis scores of the metabolic activity of the bowel in the PET/CT scans before and after stopping metformin. RESULTS Diffuse and intense (18)F-FDG uptake was observed in bowel segments of patients, and the activity in the colon was significantly decreased both visually and semiquantitatively in PET/CT scans performed after patients stopped metformin (p<0.05). There was a statistically significant decrease in activity in the small intestine on visual analysis (p<0.05), but semiquantitative measurements did not show a significant decrease in the SUVmax values in the duodenum or jejunum (p>0.05). CONCLUSION Metformin causes an increase in (18)F-FDG uptake in the bowel and stopping metformin before PET/CT study significantly decreased this unwanted uptake, especially in the colon, facilitating the interpretation of images obtained from the abdomen and preventing the obliteration of lesions.
Collapse
Affiliation(s)
- Tamer Ozülker
- Department of Nuclear Medicine, Okmeydani Training and Research Hospital, Istanbul, Turkey.
| | | | | | | |
Collapse
|
127
|
Salpeter SR, Greyber E, Pasternak GA, Salpeter Posthumous EE. Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus. Cochrane Database Syst Rev 2010:CD002967. [PMID: 20091535 DOI: 10.1002/14651858.cd002967.pub3] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age. OBJECTIVES To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies. SEARCH STRATEGY A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators. SELECTION CRITERIA Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy. DATA COLLECTION AND ANALYSIS The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data. MAIN RESULTS Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies. AUTHORS' CONCLUSIONS There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.
Collapse
Affiliation(s)
- Shelley R Salpeter
- Medicine, Stanford University, and Santa Clara Valley Medical Center, 2400 Moorpark Ave, Suite 118, San Jose, CA, USA, 95128
| | | | | | | |
Collapse
|
128
|
Vriens D, Visser EP, de Geus-Oei LF, Oyen WJG. Methodological considerations in quantification of oncological FDG PET studies. Eur J Nucl Med Mol Imaging 2009; 37:1408-25. [PMID: 19936745 PMCID: PMC2886126 DOI: 10.1007/s00259-009-1306-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 10/15/2009] [Indexed: 11/26/2022]
Abstract
Purpose This review aims to provide insight into the factors that influence quantification of glucose metabolism by FDG PET images in oncology as well as their influence on repeated measures studies (i.e. treatment response assessment), offering improved understanding both for clinical practice and research. Methods Structural PubMed searches have been performed for the many factors affecting quantification of glucose metabolism by FDG PET. Review articles and references lists have been used to supplement the search findings. Results Biological factors such as fasting blood glucose level, FDG uptake period, FDG distribution and clearance, patient motion (breathing) and patient discomfort (stress) all influence quantification. Acquisition parameters should be adjusted to maximize the signal to noise ratio without exposing the patient to a higher than strictly necessary radiation dose. This is especially challenging in pharmacokinetic analysis, where the temporal resolution is of significant importance. The literature is reviewed on the influence of attenuation correction on parameters for glucose metabolism, the effect of motion, metal artefacts and contrast agents on quantification of CT attenuation-corrected images. Reconstruction settings (analytical versus iterative reconstruction, post-reconstruction filtering and image matrix size) all potentially influence quantification due to artefacts, noise levels and lesion size dependency. Many region of interest definitions are available, but increased complexity does not necessarily result in improved performance. Different methods for the quantification of the tissue of interest can introduce systematic and random inaccuracy. Conclusions This review provides an up-to-date overview of the many factors that influence quantification of glucose metabolism by FDG PET.
Collapse
Affiliation(s)
- Dennis Vriens
- Department of Nuclear Medicine (internal postal code 444), Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500, HB, Nijmegen, The Netherlands.
| | | | | | | |
Collapse
|
129
|
The role of 18F-FDG-PET in the detection of early cancers and precancerous polyps in colorectum. Nucl Med Commun 2009; 30:829-30. [DOI: 10.1097/mnm.0b013e32832ed394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
130
|
Brihaye B, Lidove O, Lussato D, Aparicio T, Papo T. Faux positif du 18F-FDG TEP-TDM secondaire à la prise de metformine. Presse Med 2009; 38:686-7. [DOI: 10.1016/j.lpm.2008.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 03/27/2008] [Accepted: 04/04/2008] [Indexed: 11/25/2022] Open
|