Clinicopathological factors and nomograms predicting nonsentinel lymph node metastases after neoadjuvant chemotherapy in breast cancer patients.

BACKGROUND: Studies have demonstrated the feasibility and accuracy of sentinel lymph node (SLN) biopsy after neoadjuvant chemotherapy (NAC) in breast cancer. Some SLN-positive patients have low risk of nonsentinel lymph node (non-SLN) involvement. Our goal was to determine clinicopathological factors correlating with the presence of non-SLN metastases in patients after NAC and to assess the validity of nomograms predicting additional axillary metastases. METHODS: Patients with infiltrating breast carcinoma (n = 132) were studied prospectively. All patients received NAC. At surgery, SLN biopsy followed by axillary lymph node dissection was performed. Lymphatic mapping was done using the isotope method. Fifty-one patients were SLN positive. RESULTS: In univariate analysis, tumor size (P = 0.016) and the size of SLN metastases (P = 0.0055) were significantly correlated with the presence of non-SLN metastases. In multivariate analysis, SLN macrometastases (P = 0.047) conferred significantly increased risk of non-SLN metastases. The Memorial Sloan-Kettering Cancer Center nomogram was not reliably predictive for non-SLN metastases (area under the receiver operating characteristic curve, AUC, of 0.542), whereas the MD Anderson (AUC 0.716) and Tenon scoring systems (AUC 0.778) were validated. CONCLUSION: Our results suggest that clinicopathological factors predicting non-SLN involvement in SLN-positive patients with and without NAC are essentially the same. The risk of involvement may be assessed using existing nomograms, but additional large prospective studies are needed to determine their accuracy in patients after NAC.

Sentinel lymph node biopsy after neoadjuvant chemotherapy is accurate in breast cancer patients with a clinically negative axillary nodal status at presentation.

BACKGROUND: In breast cancer, neoadjuvant chemotherapy (NAC) is widely used in order to enable a conservative surgery. In patients treated with NAC, the use of sentinel lymph node (SLN) biopsy, which is a good predictor of the axillary nodal status in previously untreated patients, is still discussed. The aim of our study was to determine clinicopathological factors that may influence the accuracy of SLN biopsy after NAC. METHODS: Between March 2001 and December 2006, 129 patients with infiltrating breast carcinoma were studied prospectively. Preoperatively, all of them underwent NAC. At surgery, SLN biopsy followed by axillary lymph node (ALN) dissection was performed. Lymphatic mapping was done using the isotope method. RESULTS: The SLN identification rate was 93.8% (121/129). Fifty-six out of the 121 successfully mapped patients had positive ALN. Eight out of these 56 patients had tumor-free SLN (false-negative rate of 14.3%). The false-negative rate was correlated with larger tumor size (T1-T2 versus T3; P = 0.045) and positive clinical nodal status (N0 versus N1-N2; P = 0.003) before NAC. In particular, the false-negative rate was 0% (0/29) in N0 patients and 29.6% (8/27) in N1-N2 patients. Clinical and pathological responses to NAC did not influence the accuracy of SLN biopsy. CONCLUSION: Our results show that clinical nodal status is the main clinicopathological factor influencing the false-negative rate of SLN biopsy after NAC for breast cancer. SLN biopsy after NAC can predict the ALN status with a high accuracy in patients who are clinically lymph node negative at presentation.

Effects of MDR reversing agent combinations on the 3H-daunomycin accumulation in drug-sensitive and drug-resistant human cancer cells.

BACKGROUND: As multidrug resistant (MDR) tumour cells generally exhibit a drug accumulation deficit, the effects of three prototype modulators and their combinations were investigated by studying the modulation of 3H-dounomycin cellular accumulation. MATERIALS AND METHODS: Two cell lines derived from a rhino-pharingeal human carcinoma, either sensitive (KB-3-1) or selected as MDR (KB-A1) were used. Verapamil (10mumol.L-1), PSC 833 (lmumol.L-1) and S9788 (5mumol.L-1) were tested alone or in association two by two. The cells were characterized by reverse transcriptase polymerase chain reaction (RT-PCR) in terms of pleiotropic resistance gene expression. RESULTS: A strong mdr1 and a light LRP gene expression were found in KB-A1 resistant cells compared to KB-3-1, whereas MRP expression was found to a similar extent. Relative to the KB-3-1, cells, accumulation of 3H-daunomycin was reduced to 31 +/- 5% in the KB-A1 cells. In these KB-A1 cells, the three agents tested significantly increased the 3H-daunomycin intracellular concentration, S9788 being the most active (311 +/- 37%) and inducing a near complete reversion to the basal level of the sensitive cells. Verapamil and PSC 833 demonstrated an additive effect (252 +/- 69% compared to 188 +/- 33% and 126 +/- 27%, respectively). On KB-3-1 sensitive cells, S9788 had no effect, while verapamil or PSC 833 moderately increased the 3H-daunomycin accumulation, without additive effect. CONCLUSION: These results show a strong MDR reversing effect of S9788, which appears specific to P-glycoprotein (Pgp) and an additive effect between verapamil and PSC 833, suggesting a better therapeutic efficiency if used in well defined combinations.

Comparative 99mTc-sestamibi and 3H-daunomycin uptake in human carcinoma cells: relation to the MDR phenotype and effects of reversing agents.

UNLABELLED: Because 99mTc-sestamibi (MIBI) appears to be a potent candidate for multidrug resistance (MDR) evaluation in tumors, its cellular uptake should be similar to that of 3H-daunomycin in a variety of conditions of expression and inhibition of MDR activity. METHODS: We used a human rhinopharyngeal carcinoma cell line (KB-3-1) and its MDR variant (KB-A1). Cells were incubated 2 h with 99mTc-MIBI and 3H-daunomycin under control conditions or in the presence of a reversing agent such as verapamil (10 pmol/L), PSC833 (1 micromol/L) or S9788 (5 micromol/L). RESULTS: Relative to the KB-3-1-sensitive cells, accumulations of 99mTc-MIBI and 3H-daunomycin were reduced to 31% +/- 5% and 36% +/- 11% (P < 0.001 for both) in KB-A1-resistant cells. In sensitive cells, accumulation of both agents was increased by verapamil and PSC833 (range 115%-140%; P < 0.05) but not by S9788. In KB-A1 cells, only S9788 significantly increased the cellular uptake of 99mTc-MIBI (138% +/- 25%; P < 0.01), whereas the intracellular uptake of 3H-daunomycin was markedly increased with the three reversing agents (up to 311% +/- 37% with S9788; P < 0.001). With this last treatment, uptake of 3H-daunomycin in KB-A1 cells nearly returned to its basal level in sensitive cells. CONCLUSION: 99mTc-MIBI monitors the MDR phenotype of tumor cells effectively but responds to reversing agents differently than 3H-daunomycin.

Scintimammography with technetium-99m methoxyisobutylisonitrile: results of a prospective European multicentre trial.

The aim of the trial was to determine the diagnostic accuracy of scintimmammography with technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) in the detection of primary breast cancer and to verify its clinical usefulness. A total of 246 patients with a suspicious breast mass or positive mammogram were included in this prospective European multicentre trial. At 5 min and 60 min (optional) p.i. two lateral prone images were acquired for 10 min each; 30 min p.i. one anterior image was acquired for 10 min. There were 253 lesions (195 palpable and 58 non-palpable), in respect of which histology revealed 165 cancers and 88 benign lesions. Institutional and blinded read results were correlated to core laboratory histopathology results obtained during excisional biopsy. Diagnostic accuracy for the detection of breast cancer was calculated per lesion. The overall sensitivity and specificity of blinded read scintimammography were 71% and 69%, respectively. For palpable lesions, the sensitivity of blinded read and institutional read scintimammography was 83% and 91%, respectively. Sensitivity was not dependent on the density of the breast tissue. Invasive ductal and invasive lobular cancers showed similar sensitivity. The sensitivity and specificity of mammography were 91% and 42%, respectively, and did not depend on the tumour size. In 60% of false-negative mammograms, 99mTc-MIBI was able to diagnose malignancy (true-positive). High-quality imaging with 99mTc-MIBI has a high diagnostic accuracy for the detection of primary breast cancer. Used as a complementary method, scintimammography with 99mTc-MIBI can help to diagnose breast cancer at an earlier stage in patients with dense breasts.

[Positron emission tomography (PET) and (F-18)-fluorodeoxyglucose in (FDG) in cancerology]. / Tomographie par émission de positons (TEP) et [F-18]-fluorodésoxyglucose (FDG) en cancérologie.

Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a scintigraphic imaging technique undergoing a rapid growth in the field of oncology. The constant progress of the detectors, either CDET or PET dedicated cameras, allows to obtain in routine conditions images with a 5 mm spatial resolution. Absolute tracer uptake quantification is also possible, which allows to evaluate objectively therapy efficacy. The mechanisms of FDG tissular accumulation are now better understood. Increase of glycolysis and of transmembrane transport of glucose seems to be at the origin of the high tumorous accumulation of FDG. The main current oncologic application of FDG PET is the diagnosis of malignancy of the isolated pulmonary nodules, with a sensitivity of more than 95%, and in the staging of lung cancer where PET shows higher performances than conventional imaging. The same stands in cutaneous melanoma and for malignancies of the digestive tract, either in colorectal, pancreatic or esophageal localizations. In colorectal cancers, the role of PET has for long being recognized in the differential diagnosis between recurrence and postoperative fibrosis. In the head and neck tumors, FDG also allows to differentiate between recurrence and postradiation necrosis. In lymphoma, the most suitable site for biopsy can be identified on a PET scan and therapy efficacy can also be assessed. In breast cancer, the detection of metastases seems to be possible with FDG. In brain and thyroid cancers, the role of FDG PET remains to be further determined. The low uptake of FDG in prostate cancer metastasis is not in favor of its use in this indication. In conclusion, the indications of FDG PET in oncology are now becoming more precise and it can be expected that clinical PET centers will soon appear in France.

Cultured neonatal rat cardiomyocytes and 99mTc-sestamibi to assess the direct effects of cardioplegia.

The efficacy of cardioplegia in neonatal myocardial protection is still a matter of debate. 99mTc-sestamibi cellular accumulation reflects sarcolemmal and mitochondrial electrical gradients. It was used to monitor the direct effects of two cardioplegic solutions, modified St Thomas' Hospital and Bretschneider, on normoxic and metabolically-inhibited cultured cells. Cellular accumulation of 99mTc-sestamibi, expressed by the ratio between intra and extra cellular concentrations, was assessed in three different sets of neonatal rat cardiomyocytes. Cells were either treated with different concentrations of modified St Thomas' solution (50, 75, 100%), they were treated or recovering from a treatment with modified St Thomas and Bretschneider solutions at 50% concentrations, or were recovering from treatment with modified St Thomas' and Bretschneider solution at 50% concentrations mixed with metabolic inhibitors. Cardioplegia depressed the tracer accumulation in a concentration-dependent manner. This effect was independent of the type of cardioplegia (120-min uptake, as a percentage of control values, modified St Thomas' 68+/-12 and Bretschneider 59+/-7) and was rapidly reversible. Cardioplegia was unable to prevent the depression of tracer accumulation induced by metabolic inhibitors and even induced a deleterious effect (120-min uptake, as a percentage of control values, metabolic inhibitors 69+/-12, metabolic inhibitors + modified St Thomas 38+/-14, metabolic inhibitors + Bretschneider 43+/-6) during recovery after 30 min of metabolic inhibition. It was concluded that cardioplegia has an apparent detrimental effect on neonatal cardiomyocytes accumulation of 99mTc-sestamibi during recovery from an ischaemic-like insult.

Comparison between technetium-99m-sestamibi and hydrogen-3-daunomycin myocardial cellular retention in vitro.

UNLABELLED: This study was undertaken to verify whether 99mTc-sestamibi uptake parallels that of 3H-daunomycin in cells treated with multidrug resistance (MDR) reversing agents. Since we have detected in a previous work a moderate typical MDR phenotype in rat cardiac cells, a model of cultured myocardial cells was used. METHODS: Newborn-rat cultured myocardial cells were incubated 120 min with the MDR-reversing agent verapamil 50 microM, PSC833 1 microM or S9788 10 microM alone or in combination, and the cellular retention of 3H-daunomycin and 99mTc-sestamibi was counted. RESULTS: Hydrogen-3-daunomycin cellular accumulation was never modified by more than 15% when compared to control values, while 99mTc-sestamibi decreased to 75% +/- 32% (m +/- s.d.) of controls in the presence of S9788 and to 44% +/- 19% when S9788 was associated with verapamil. CONCLUSION: The variations of 99mTc-sestamibi and 3H-daunomycin cellular accumulation induced by MDR-reversing agents in cultured myocardial cells can be dramatically different. While some MDR-reversing agents can significantly increase the 3H-daunomycin retention in cardiac cells, they have unexpected effects on that of 99mTc-sestamibi.

Scintigraphic imaging of breast tumors.

Technetium-99m-sestamibi scintigraphy has recently emerged as a new procedure for the imaging of malignant breast tumors. A large clinical experience has now been collected and this article reviews the main published results. The major drawback of the procedure appears to be its low sensitivity in detecting lesions smaller than 1 cm. The biological background underlying the tracer accumulation is also described. The stimulating potent applications of this functional imaging technique to non-invasively explore the development, and possibly the reversal, of a multidrug resistance under chemotherapy are discussed. The data related to the use of the positron emitter fluor-18-labeled fluorodeoxyglucose (FDG), a very promising agent for imaging breast as well as other solid tumors, are also reviewed. This situation of specific agents, still under development and such as labeled receptor ligands, is examined.

In vitro detection of the MDR phenotype in rat myocardium: use of PCR, [3H]daunomycin and MDR reversing agents.

A decrease in the intracellular drug concentration in resistant cells as compared to sensitive cells is one of the characteristics of the MDR phenotype. P-glycoprotein (Pgp) is thought to be responsible for an active efflux of some lipophilic drugs such as anthracyclines. Anthracyclines such as daunomycin are highly effective anticancer agents but induce a well-described, while incompletely explained, cardiac toxicity. In this study, we investigated the MDR phenotype in rat myocardium in terms of gene expression, detection of Pgp and indirect evaluation of Pgp function. A clear mdr1a gene specific expression in rat cultured myocardial cells and cardiac tissue was detected by RT-PCR. The incorporation of [3H]daunomycin in myocardial cell cultures was studied with and without reversing agents. Daunomycin was found to have a high accumulation in cardiac cells illustrated by a Ci/Ce ratio of 2890. This high accumulation was moderately but significantly (p < 0.05) increased in the presence of a MDR reversing agent such as verapamil, PSC 833 or S9788. These results suggest that blockade of the Pgp in humans may result in an increased toxicity of several Pgp substrates in normal tissues like the myocardium.

Technetium-99m-sestamibi uptake in breast tumor and associated lymph nodes.

UNLABELLED: The aim of this study was to measure the accumulation of 99mTc-sestamibi in breast tumors and their axillary lymph nodes in patients undergoing scintimammography. METHODS: Eighteen patients who were scheduled for breast surgery underwent scintimammography with 740 MBq of 99mTc-sestamibi on the day before the operation. The next morning, reinjection with 370 MBq was performed. Immediately after the surgical procedure, the 99mTc activity of the tumor samples and, when available, the related lymph nodes was measured in a gamma counter. The samples were weighed and prepared for histological analysis. The activity of each sample was normalized to the mean activity of normal tissue samples obtained from the same patient. RESULTS: Among the 198 samples analyzed, the relative uptake of sestamibi was increased in 111 containing normal lymph nodes (1.80+/-0.79 vs 1.00+/-0.22, p<0.05), as well as in the seven containing invaded lymph nodes (2.01+/-0.83, p<0.01) and more dramatically, in the 22 with a carcinoma (5.64+/-3.06, p<0.001). In two patients with a benign lesion, both scintigraphy and counting demonstrated increased activity in the tumor. Four patients had negative scan results despite the presence of malignant tumor and a more than fourfold increase of sestamibi concentration in two of them. CONCLUSION: Technetium-99m-sestamibi concentrates strongly in breast carcinoma, sometimes even when the scan results appear normal, and mildly in lymph nodes, especially when invaded; it also concentrates in some benign tumors, possibly in relation to the presence of epithelial hyperplasia.

[Positron-emission tomography: role of 18F-fluorodeoxyglucose (18FDG) imaging in oncology]. / Tomographie par émission de positons: place de l'exploration par 18F-fluorodéoxyglucose (18FDG) en oncologie.

There is a renewed interest in positron emission tomography (PET) using 18F-fluorodeoxyglucose (18FDG) since the development of large field of view cameras and the capability of regional distribution of 18FDG. This method may help solve three types of problems in clinical oncology: tumor diagnosis and extension assessment, prediction of treatment response and follow-up (diagnosis of recurrences and complications). The aim of this paper is to review the literature in this field. This technique is mostly used for brain, lung, rectal and breast tumors as well as for sarcomas. It is possible to diagnose an anaplastic transformation of a low grade glioma since 18FDG uptake correlates with the histological grade. 18FDG plays another important role in the evaluation of the brain tumor response to treatment and of the secondary effects or sequelae of this treatment. This technique is also useful in breast carcinomas: diagnosis in the case of a dense breast, detection of lymph nodes or other metastases which could modify the strategy. One of the most established roles of 18FDG PET is the diagnosis of rectal tumor recurrences. Furthermore, future results will probably confirm its usefulness in lung carcinoma, for the diagnosis and for treatment evaluation. Lastly, it plays an important role in soft tissue sarcomas at all stages of diagnosis and treatment. The results of the literature still have to be completed. However, if the capability of predicting tumor response to treatment is confirmed, this method will play an important role in patient management and will modify treatment strategies.

Mechanism of uptake of technetium-tetrofosmin. II: Uptake into isolated adult rat heart mitochondria.

BACKGROUND: 99mTc-labeled tetrofosmin is a new myocardial imaging agent that gives stable heart uptake. However, little is known about the mechanism of uptake in heart tissue. The aim of this study was to assess the factors responsible for the uptake and retention of 99mTc-labeled tetrofosmin in isolated heart mitochondria. METHODS AND RESULTS: Mitochondria were isolated from adult rat heart tissue with competent metabolic function (i.e., respiratory control ratio of 3 and adenosine diphosphate/oxygen ratio of 2) for succinate oxidation. Intramitochondrial volume measured by the distribution of 3H-water and 14C-sucrose was 1.16 +/- 0.23 microliters/mg protein (mean +/- SD). In the isolated mitochondria, uptake could be demonstrated within 30 seconds of addition of oxidative substrate, but adenosine triphosphate alone did not stimulate marked uptake. Uptake was proportional to the amount of mitochondrial protein over a range of 0.2 to 3 mg protein but independent of Tc-labeled tetrofosmin concentration over a range of 0.4 to 200 pmol/L (0.1 to 50 microCi/ml). The presence of Tc-labeled tetrofosmin had no effect on the oxidative capability of the mitochondria. Use of the mitochondrial uncoupler 2,4-dinitrophenol caused release of 92% of radioactivity. Addition of Ca2+ to the mitochondria to partially depolarize the membrane resulted in partial release of activity. Application of the Nernst equation to the uptake data gave rise to a value of -163 mV for the mitochondrial membrane potential. CONCLUSION: It was concluded that the accumulation of 99mTc-labeled tetrofosmin by the mitochondria is related to their ability to transduce metabolic energy into electronegative membrane potential.

[An in-vitro study of 99mTc sestamibi uptake by normal and neoplastic cell lines]. / Studiul in vitro pe linii celulare normale si neoplazice al captarii 99mTc sestaMIBI.

The hexakis (2-methoxy isobutyl isonitrile) technetium (I) (99mTc MIBI) is a representative molecule for a class of monocationic lipophile 99mTc compounds, knowing to be initially used like myocardial scintigraphic agents, and now also in oncological scintigraphy. This present study aims to compare the in vitro 99mTc MIBI cellular uptake on some normal and neoplastic cells. Three tumoral cell lines were used: M4Beu (pigmented melanoma), M3Dau (pigmented melanoma), MCF7 (breast cancer), in comparison with newborn rat cardiac myocytes and fibroblasts. Monolayers cultures cell were incubated for 1 hour with 37 kBq of 99mTc MIBI. Our results: (a) confirm a preferentially 99mTc MIBI uptake on the myocytes in comparison of the fibroblasts; (b) show that this uptake is very different on the neoplastic studied cultures cells, depending on the cell type (higher on M3Dau in comparison of the other two malignant cell lines, and also higher than the myocytes. The neoplastic cellular mechanisms to accumulate 99mTc MIBI, are only hypothetically understand; there are thought to be also in relation with the Nernst equations, applied at the plasmatic and mitochondrial membranes level, like in normal cells. A correlation with some phenotypic neoplastic cells characteristics, in relation with the malignancy tumoral potential seems possible. If there is the case, this can be a possible explanation of some in vivo imaging results, obtained with 99mTc MIBI, in oncologic scintigraphy.

In vitro uptake of technetium-99m-teboroxime in carcinoma cell lines and normal cells: comparison with technetium-99m-sestamibi and thallium-201.

Since 201Tl, 99mTc-sestamibi and 99mTc-teboroxime concentrate in cardiac cells through different mechanisms, we compared their uptake in cultured normal cells and carcinoma cell lines in order to define their possible use for tumor evaluation in vivo. Four lines of normal cells from animals, including myocytes from newborn rats, and four lines of human carcinoma cell lines were incubated for 1 hr with 37 kBq of either tracer. Results, expressed in percent of the total activity taken up by 1 million cells, showed a 9% difference between the uptake of teboroxime by normal and carcinoma lines (24.6% +/- 2.8% versus 22.5% +/- 2.1%, respectively, p < 0.05). Mean uptake was 80% higher in tumor than in normal cells for 201Tl (5.39% +/- 1.33% versus 3.00% +/- 1.08%, respectively, p < 0.001) and nearly 4 times higher for sestamibi (5.37% +/- 2.34% versus 1.44% +/- 1.88%, p < 0.001). For both agents, uptake by the myocytes and carcinoma cells was comparable (5.14% +/- 0.11% for 201Tl and 5.28% +/- 1.03% for sestamibi). When the myocytes are excluded from the group of normal cells, the uptake is 112% higher in tumor than in normal cells for 201Tl (5.39% +/- 1.33% versus 2.54% +/- 0.44%, p < 0.001) but it becomes nearly nine times higher for sestamibi (5.37% +/- 2.34% versus 0.60% +/- 0.23%, p < 0.001). It is concluded that these experiments show that the uptake of sestamibi was the most discriminant to separate between normal and malignant cells, while teboroxime was the less discriminant. Potential clinical applications for tumor visualization based on differences in sestamibi and teboroxime uptake could be envisioned.

[Myocardial contusions in closed thoracic injuries: a prospective study]. / Contusions myocardiques dans les traumatismes thoraciques fermés: étude prospective.

Various laboratory investigations were assessed with respect to their accuracy in detecting myocardial contusion in patients with blunt chest trauma. All patients, aged between 18 and 50 years, admitted to the intensive care unit for flail chest, sternal fracture, pulmonary contusion, pleural or mediastinal lesion not requiring surgery, were included over a twelve month period. A complete cardiac assessment was carried out, including a physical examination, electrocardiogram, chest X-ray, enzyme assay (ALAT, ASAT, LDH, CPK and MB isoenzyme), two-dimensional echocardiography (2D-EC), thallium-201 scintigraphy. Myocardial contusion was diagnosed when an area of decreased or absent thallium-201 uptake was found in the scintigraphy. These latter results were compared with those obtained with the other investigations. Sixteen patients, mean age 34 years, were included; two who died before the end of the investigations were excluded. 2D-EC provided the most useful data (pericardial effusions in a third of the cases). The physical examination, enzyme assays, and chest films were of low value. The investigations carried out six months after the initial trauma showed that long term follow-up was not required. All patients were asymptomatic ten months after their trauma Although the diagnosis of myocardial contusion was made in half the cases using thallium-201 scintigraphy, 2D-EC provided reliable data and had the advantage to be carried out at the patient's bedside.

Morphological study of the liver using local rate of uptake analysis.

Four types of liver functional images were obtained by calculating for each point on an image matrix the local uptake rate, the local uptake transit time, the point's own maximum and the time necessary to attain the maximum. The study was based on 52 cases: 21 controls and 31 cases of hepatic disease. The controls showed a homogeneous spread of colloidal substance on the images of local uptake rate and local transit time, despite variations in liver tissue thickness. In the cases of parenchymal lesions revealed by deficient uptake on standard images, local variations of uptake rate were almost always shown even in instances where the standard images showed minimal variation. This technique therefore would seem to bring additional diagnostic assistance by permitting a better appreciation of liver morphology and function and the processing time required (approx. 1.5 min.) does not necessitate an increase in overall examination time.