["Sentinel" lymph node biopsy in breast carcinoma. Current experiences]. / "Sentinel"-Lymphknotenbiopsie beim Mammakarzinom. Aktuelle Erfahrungen.

Recent studies show the sentinel lymph node biopsy (SNB) as a reliable method for the determination of the nodal status in patients with breast cancer. We present our experience with this method during 3 years and discuss its potential and limitations. From 11/95 to 3/99 we performed a sentinel node detection in 146 patients with breast cancer stage I to III. We used the raionuclide method including preoperative lymphscintigraphy and intraoperative gamma.probe detection. The detection rate varied with the tumor size between 94% for tumors with a diameter < 1 cm, 85% (1-3 cm), 70% (3-5 cm) and 63% (> 5 cm). The accuracy of the SNB in the prediction of the nodal status varied also with the tumor diameter between 100% for very small tumors (< 1 cm), 97% (1-3 cm), 88% (3-5 cm) and 67% (> 5 cm). In the subgroup of patients restricted to T1-2-tumors (n = 106), 57 patients (53%) showed true negative, 4 (4%) false negative SNB. 38 (36%) revealed tumor cells in the HE-staining and an additional 7 patients (7%) solely in the immunohistochemical staining. The presented results show, that SNB is a reliable method for the evaluation of the nodal status in early breast cancer patients with a tumor size up to ca. 3 cm. While in about 50% of these patients a surgical intervention could be avoided after a negative SNB, an additional 5-10% of conventionally nodal negative patients can be found by the immunohistochemical examination of the sentinel node. The sn-concept can also identify parasternal metastasis and can be applied in patients after neoadjuvant therapy and patients with recurrent tumor. Indications and contraindications of this method, however, still remain to be determined.

Differences in immunoreactivity of estrogen receptor (ER) in tamoxifen-sensitive and -resistant breast carcinomas: preclinical and first clinical investigations.

Inherited or acquired tamoxifen resistance is a major constraint in the endocrinological treatment of breast carcinomas. We developed an enzyme-immunoassay that discriminates between tamoxifen-sensitive and -resistant tumors. The procedure was established and standardized using two xenografted breast carcinomas--3366 (highly sensitive to tamoxifen) and 3366/TAM (acquired tamoxifen resistance). The latter model was developed by treatment of 3366 tumor-bearing nude mice during serial passaging over 3 years with tamoxifen. Both lines were estrogen receptor (ER) positive (101 or 82 fmol/mg protein), and revealed no differences in the nucleotide sequences of the hormone binding domain of the ER protein. However, while in the sensitive tumors an upregulation of ER levels was registered after estradiol treatment of tumor bearing nude mice, the ER expression in the resistant line remained unchanged. The tamoxifen sensitive and -resistant breast carcinoma 3366 differed, additionally, in their immunoreactivity of ER to mAB H222. While an incubation with estradiol or tamoxifen of immobilized ER prepared from cytosols of the sensitive tumors 3366 led to a significant increase in immunoreactivity, samples of resistant tumors failed in the exposition of additional immunologically reactive epitopes. These results were the basis for the development of an assay for determination of the tamoxifen response in patients. Our retrospective results with 38 breast tumors from a tumor bank indicated that patients with an increase of immunoreactivity of ER more rarely had a recurrence while under going tamoxifen therapy compared with patients expecting no increase. However, the data indicate interesting changes occurring with the ER of tam-resistant tumors that are to be explained by further mutational or protein-chemical analysis.

Sentinel lymph node dissection in breast cancer.

During the last years, the efficacy and reliability of the sentinel lymph node biopsy (snb) as a minimal invasive diagnostic procedure for the nodal status has been intensively evaluated. After the widespread clinical use in the staging of melanoma patients the snb is currently introduced in the clinical management of breast cancer patients. We present our experience with this method during 3, 5 years and discuss its potential and pitfalls. From 11/95 to 3/99 we performed sentinel node detection in 146 patients with breast cancer stage I to III, consisting of 127 patients with pT1/2-tumors and 19 patients with pT3/4-tumors. We used the radionuclid method including preoperative lymphoscintigraphy and intraoperative gamma-probe detection. The detection rate varied with the tumor size between 94% for tumors with a diameter < 1 cm, 85% (1-3 cm), 70% (3-5 cm) and 63% (> 5 cm). The accuracy of the snb in the prediction of the nodal status changed also with the tumor diameter between 100% for very small tumors (< 1 cm), 97% (1-3 cm), 88% (3-5 cm) and 67% (> 5 cm). In the subgroup of patients restricted to T1-2-tumors (n = 106). 57 patients (53%) showed true negative snb. 38 patients (36%) revealed tumor cells in the H&E-staining and an additional 7 patients (7%) solely in the immunohistochemical staining. 4 (4%) of these patients, all of them from the first half of the study period, underwent false-negative snb, 3 of them showing lymphangiosis carcinomatosa. The presented results show, that snb using the radionuclid method is a reliable method for the evaluation of the nodal status in early breast cancer patients with a tumor size up to ca. 3 cm. Therefore the sn procedure should be restricted to small tumors with clinically uninvolved axillary nodes or patients with a ductal carcinoma in situ (DCIS) to rule out invasiveness.

[Sentinel node detection in breast carcinoma]. / "Sentinel node detection" beim Mammacarcinom.

The aim of sentinel node biopsy (SN) in breast cancer patients is to detect the tumor-draining lymph node by means of isosulfan blue or 99mTc-labelled colloids. SN can be detected in 80 to 85% of the patients, depending on the size of the tumor. Preoperative lymphoscintigraphy permits the draining nodes along the internal mammary artery also to be visualized. The predictive value of the histological findings of SN for lymph nodes obtained from axillary dissection is about 95%. Because of different diagnostic procedures using various radiotracers each center has to follow its own learning curve. To be sure that the nodal status derived from a SN procedure is of identical value to axillary dissection about 100 patients have to undergo sentinel node detection, followed by axillary dissection, and concordant results should be obtained in 95% of them at least. The SN, however, offers a chance of assessing the lymph node at risk for metastasis by more detailed histological procedures. Morbidity as a result of treatment for primary breast cancer can be decreased if only patients suffering from metastatic disease are subjected to axillary dissection. Currently, the indication criteria for a SN procedure should be restricted to small tumors (T1) with clinically uninvolved axillary status and patients with ductal carcinoma in situ (DCIS).

[Axillary node removal in clinical node-negative breast carcinoma. Can its indication be individualized by "sentinel node" detection?]. / Axillaausräumung bei klinisch nodal-negativem Mammakarzinom. Kann die Indikation durch "sentinel node"-Nachweis individualisiert werden?

BACKGROUND AND OBJECTIVE: The status of the axillary lymph node(s) is an important prognostic factor in breast cancer and thus decisive in the indication for adjuvant treatment. This study investigated the extent to which examination of the sentinel node (SN) can individualize the need for axillary resection and the diagnosis of lymph nodes be optimized. PATIENTS AND METHODS: 96 consecutive patients with breast cancer were studied (94 women, 2 men; mean age 59 [36-84] years) in whom no lymph node enlargement had been diagnosed clinically. After preoperative lymph-drainage scintigraphy with 99mTc Nanocoll combined with intraoperative scintillation probe detection the SN node was identified in 77 of the 96 patients and was removed. Subsequently the axillary lymph nodes in level I and II were removed by a standard technique and all removed lymph nodes and material then compared histologically. RESULTS: In nine of 77 patients with identifiable SN it was the only lymph node with metastasis. In 18 patients both the SN and other axillary lymph nodes were infiltrated. The SN and other axillary lymph nodes were free of metastases in 44 patients. In six patients the SN was not representative, since it was free of tumour, but other axillary nodes were not. Identification of a SN and prognostication of lymphogenic axillary metastases depended on tumour size. Among T3 and T4 tumours, ten of 16 had a verifiable SN, but in six of them it was not representative for axillary metastasization. But in 62 of 73 patients with tumours up to 5 cm in diameter without involvement of skin or chest wall (T1 and T2, respectively) a SN could be identified that was not representative for axillary metastases in only two cases. CONCLUSIONS: SN resection in breast cancer makes it possible to individualize axillary node resection as part of primary treatment. Specific histological examination of serial sections and immunohistological testing may possibly increase the accuracy of histological diagnosis.

[Sentinel lymph node detection in patients with breast carcinoma]. / Die Sentinel Lymphknoten-Detektion bei Patienten mit Mammakarzinom.

Sentinel node detection enables the definition of the most relevant draining lymph node of a tumor. We analysed 123 patients with breast cancer according to this method. A preoperative lymphoscintigraphy was performed 17 hours after a peritumoral application of 0.5 ml 99mTC-Nanokoll. The sentinel node was identified by means of a gammaprobe in 75 of 89 patients with pT1- and pT2-tumors and in 11 of 17 patients with pT3-4 tumors respectively. The results of histological investigation of the sentinel node in comparison to all other axillary nodes following dissection were correlated. In the pT1-2 group the accuracy of correlative findings was rather high (96%). In patients with pT3- and pT4-tumors the lymph node status was predictable only in 7 patients. Therefore sentinel node biopsy may serve as a tool for individualization of axillary dissection especially in pT1-2 breast cancer patients.

[Sentinel node detection in breast carcinoma]. / Die Sentinel Node Detektion beim Mammakarzinom.

Sentinel node (SN) detection is a reliable method to detect lymph node metastases in breast cancer patients. While blue dye allows to follow the lympatic stream towards the sentinel node the use of radioactive marked protein allows a preoperative identification of the SN (e.g. internal mammary artery). Detection rate and predictive value depend on the tumor size, tumors of a diameter greater than 30 mm show a poor detection rate and a lower predictive value. With regard of the increased rate of detected micrometastases the SN principle has a higher predictive value for the nodal status then the axillary clearance. Since no long term results are available yet the advantage for the patients remain unclear.

[Sentinel node biopsy, a step toward selective axillary dissection]. / Sentinel-node-Biopsie, ein Schritt zur selektiven Axilladissektion.

We studied sentinel lymph node detection in 69 patients with breast cancer. A sentinel node (SN) was detected in 58 patients (83%), and the pathological result was compared with the results of the axillary contents. We found a positive correlation of the pathological results of the SN in relation to the axillary contents in 96% in pT1 and pT2 tumors.

Nicotinic acetylcholine receptors are directly affected by agents used to study protein phosphorylation.

1. Messenger RNAs for the subunits of the muscle nicotinic acetylcholine receptor (nAChR) were expressed in Xenopus oocytes. A two-electrode voltage clamp was used to measure the acetylcholine (ACh)-induced macroscopic currents. In addition, patch-clamp techniques were used to study nAChR channels in whole cells and in outside-out patches excised from BC3H-1 cells and in patches from oocytes. The single-channel and macroscopic currents were modified by compounds that are usually used to study protein phosphorylation. 2. IBMX (3-isobutyl-1-methylxanthine) is a phosphodiesterase inhibitor. Because it elevates the intracellular concentration of adenosine 3',5'-cyclic monophosphate (cAMP), IBMX is often used to indirectly activate cAMP-dependent protein kinase. H-7 [1-(5-isoquinolinylsulfonyl)-2-methylpiperazine] is mainly used as a rather nonspecific inhibitor of protein kinase activity. Both IBMX and H-7 directly inhibit ACh-induced currents independent of their action on phosphorylation. This direct effect of these compounds is similar to the previously reported inhibition of nAChRs and K+ channels by forskolin, which is commonly used to elevate intracellular cAMP. 3. Macroscopic currents induced in the oocytes by 50 microM ACh had an average peak current of 605 nA, and the currents decayed biexponentially with tau of 15 and 225 s. When 300 microM H-7 was added simultaneously with the ACh, the average peak current was 228 nA and the tau were 1 and 108 s. When 500 microM IBMX was added simultaneously with the ACh, the average peak current was 308 nA and the tau were 9 and 237 s. H-7 and IBMX decreased the peak current induced by ACh, and the compounds increased the decay rate of the current. Under these experimental conditions, the IC50 for reduction of peak amplitude at -30 mV was 160 microM for H-7 and 475 microM for IBMX. 4. H-7 preferentially inhibits the open conformation of the nAChR channel, but there is also some inhibition of the closed channel. The inhibition is voltage dependent: inhibition decreases e-fold per 34 mV depolarization. H-7 does not become trapped within the closed channel and does not significantly alter desensitization under our experimental conditions. 5. H-7 and IBMX interrupt or terminate single-channel openings in membrane patches excised from oocytes or BC3H-1 cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Tissue culture tube contaminant inhibits excitatory synaptic channels.

Nicotinic acetylcholine receptors (nAChRs) were expressed in Xenopus oocytes. Large, slowly desensitizing macroscopic currents were induced by rapidly infusing an electrolyte solution containing 50 microM ACh in the presence of atropine. The N-methyl-D-aspartate (NMDA) subset of glutamate receptors was studied in CA1 hippocampal neurons. Macroscopic currents were induced by rapidly applying 30 microM NMDA and 10 microM glycine in the presence of picrotoxin, strychnine and tetrodotoxin. Exposing the electrolyte solutions to Falcon brand polypropylene tissue culture tubes (Becton Dickinson Labware) decreased the current through the nAChR channels or through the NMDA receptor channels (1). Purified water shaken in the Falcon brand tubes showed a broad absorbance peak near 200 nm. Before exposing the water to the Falcon tubes, the purified water gave no absorbance signal. The results indicate that a substance released from the Falcon tubes inhibits the currents through nAChR and NMDA receptor channels. Our experiments were with 50-ml Falcon 2098 tubes from lot numbers 72180188 and 80290188 and with 15-ml Falcon 2097 tubes from lot number 83560283. These were the only Falcon tubes we tested.

Non-selective cationic channel in primary cultured cells of brown adipose tissue.

Single channel current events were recorded from membranes of cultured brown adipose tissue cells with the patch-clamp technique. In excised inside-out patches the predominant type of events showed a slope conductance of about 30 pS (25 degrees C). The current was carried by both, Na+ ions and K+ ions. Discrimination between them was poor. The frequency of events increased with increasing temperature. Their amplitude was temperature dependent as well (Q10 approximately equal to 1.4). A single exponential was not sufficient for fitting the histograms of "on-time" or "off-time". We conclude that these events belong to a type of non-selective cation channel described previously for other tissues.