Multicenter clinical trial on sentinel lymph node biopsy using superparamagnetic iron oxide nanoparticles and a novel handheld magnetic probe.

BACKGROUND: Sentinel lymph node biopsy is a standard staging procedure for early axillary lymph node-negative breast cancer. As an alternative to the currently used radioactive tracers for sentinel lymph node (SLN) detection during the surgical procedure, a number of studies have shown promising results using superparamagnetic iron oxide (SPIO) nanoparticles. Here, we developed a new handheld, cordless, and lightweight magnetic probe for SPIO detection. METHODS: Resovist (SPIO nanoparticles) were detected by the newly developed handheld probe, and the SLN detection rate was compared to that of the standard radioisotope (RI) method using radioactive colloids (99m Tc) and a blue dye (indigo carmine). This was a multicenter prospective clinical trial that included 220 patients with breast cancer scheduled for sentinel node biopsy after a clinical diagnosis of negative axillary lymph node from three facilities in Japan. RESULTS: Of the 210 patients analyzed, SLN was detected in 94.8% (199/210 cases, 90% confidence interval [CI]) with our magnetic method and in 98.1% (206/210 cases, 90% CI) with the RI method. The magnetic method exceeded the threshold identification rate of 90%. CONCLUSION: This was the first clinical study to use a novel handheld magnetometer to detect SLN, which we demonstrate to be not inferior to the RI method.

Rapid HER2 cytologic fluorescence in situ hybridization for breast cancer using noncontact alternating current electric field mixing.

BACKGROUND: Human epidermal growth factor receptor 2-in situ hybridization (HER2-ISH) is widely approved for diagnostic, prognostic biomarker testing of formalin-fixed paraffin-embedded tissue blocks. However, cytologic ISH analysis has a potential advantage in tumor samples such as pleural effusion and ascites that are difficult to obtain the histological specimens. Our aim was to evaluate the clinical reliability of a novel rapid cytologic HER2 fluorescence ISH protocol (rapid-CytoFISH). MATERIALS AND METHODS: Using a new device, we applied a high-voltage/frequency, noncontact alternating current electric field to tissue imprints and needle rinses, which mixed the probe within microdroplets as the voltage was switched on and off (AC mixing). Cytologic samples (n = 143) were collected from patients with immunohistochemically identified HER2 breast cancers. The specimens were then tested using standard dual-color ISH using formalin-fixed paraffin-embedded tissue (FFPE-tissue DISH) for HER2-targeted therapies, CytoFISH, and rapid-CytoFISH (completed within 4 h). RESULTS: All 143 collected cytologic specimens (50 imprinted cytology specimens from resected tumors and 93 liquid-based cytology specimens from needle rinses) were suitable for FISH analysis. The HER2/chromosome enumeration probe (CEP) 17 ratios did not significantly differ between FFPE-tissue DISH and either CytoFISH protocol. Based on HER2 scoring criteria, we found 95.1% agreement between FFPE-tissue DISH and CytoFISH (Cohen's kappa coefficient = 0.771 and 95% confidence interval (CI): 0.614-0.927). CONCLUSION: CytoFISH could potentially serve as a clinical tool for prompt determination of HER2 status in breast cancer cytology. Rapid-CytoFISH with AC mixing will enable cancer diagnoses and HER2 status to be determined on the same day a patient comes to a clinic or hospital.

Inhibition of heat shock protein 90 sensitizes melanoma cells to thermosensitive ferromagnetic particle-mediated hyperthermia with low Curie temperature.

Heat shock protein (Hsp) 90 is a key regulator of a variety of oncogene products and cell-signaling molecules, and the therapeutic benefit of its inhibition in combination with radiation or chemotherapy has been investigated. In addition, hyperthermia has been used for many years to treat various malignant tumors. We previously described a system in which hyperthermia was induced using thermosensitive ferromagnetic particles (FMP) with a Curie temperature (Tc = 43 degrees C) low enough to mediate automatic temperature control, and demonstrated its antitumor effect in a mouse melanoma model. In the present study, we examined the antitumor effects of combining a Hsp90 inhibitor (geldanamycin; GA) with FMP-mediated hyperthermia. In cultured B16 melanoma cells, GA exerted an antitumor effect by increasing the cells' susceptibility to hyperthermia and reducing expression of Akt. In an in vivo study, melanoma cells were subcutaneously injected into the backs of C57BL/6 mice. FMP were then injected into the resultant tumors, and the mice were divided into four groups: group I, no treatment (control); group II, one hyperthermia treatment; group III, GA alone; and group IV, GA with hyperthermia. When exposed to a magnetic field, the temperature of tissues containing FMP increased and stabilized at the Tc. In group IV, complete regression of tumors was observed in five of nine mice (56%), whereas no tumor regression was seen in groups I-III. Our findings suggest that inhibition of Hsp90 with hyperthermia increases its antitumor effect. Thus, the combination of FMP-mediated, self-regulating hyperthermia with Hsp90 inhibition has important implications for the treatment of cancer.

REG1A expression is an independent factor predictive of poor prognosis in patients with breast cancer.

BACKGROUND: Regenerating gene I alpha (REG1A) is a growth factor known to affect pancreatic islet beta cells. Although REG1A expression has also been observed in various malignant tumors, the correlation between REG1A expression and the clinicopathological characteristics of breast cancer and patient prognosis has not been evaluated. METHODS: Resected breast cancer tissues obtained at surgery from 150 breast cancer patients was stained with anti-REG1A antibody, after which the relative area occupied by stained tumor cells was evaluated under a light microscope and correlated with known clinicopathological factors. RESULTS: Whereas tumor cells were frequently stained with anti-REG1A antibody, cells from normal breast tissue were not stained. REG1A expression in tumors of breast cancer patients with HER2-positive disease was higher than those with HER2-negative disease (P = .0009). The 10-year disease-specific survival rate among patients with lower levels of REG1A was significantly better than among those with higher levels (P = .0002 by log rank test). Multivariate Cox proportional hazard analyses revealed REG1A (hazard ratio, 2.07; 95% confidence interval, 1.93 to 11.29; P = .0005) and axillary lymph node status (hazard ratio, 4.44; 95% confidence interval, 1.52 to 11.29; P = .0003) to be independent factors affecting the 10-year disease-specific survival rate. CONCLUSION: High levels of REG1A expression within tumors are an independent predictor of poor prognosis in patients with breast cancer.

REG1A expression is an independent factor predictive of poor prognosis in patients with non-small cell lung cancer.

UNLABELLED: Regenerating gene I alpha (REG1A) is a known growth factor affecting pancreatic islet beta cells. Although REG1A expression also has been observed in various tumors, the correlation between REG1A expression and the clinicopathological characteristics of non-small cell lung cancer (NSCLC) and patient prognosis has not been evaluated. METHODS: We used real-time semi-quantitative reverse transcription polymerase chain reaction to assess REG1A mRNA expression in tumor samples from 86 NSCLC patients. We then correlated REG1A mRNA expression with known clinicopathological factors. We also used immunohistochemical staining to determine the source of REG1A. RESULTS: Within samples of tumor tissue, the cytosol of tumor cells was stained with anti-REG1A antibody. Cells from normal tissue were not stained. The 5-year over-all survival rate among patients expressing lower levels of REG1A was significantly better than among those expressing higher levels of REG1A (P=0.0031 by log-rank test). Multivariate Cox proportional hazard analyses revealed REG1A (hazard ratio, 2.34; 95% CI, 1.25-5.90; P=0.0055) and pathological stage III (hazard ratio, 3.46; 95% CI, 1.52-14.82; P=0.0012) to be independent factors affecting the 5-year over-all survival rate. CONCLUSION: High levels of REG1A expression by tumor cells are an independent predictor of a poor prognosis in patients with NSCLC.

Subpleural injection of tracer improves detection of mediastinal sentinel lymph nodes in non-small cell lung cancer.

BACKGROUND: The advantages and disadvantages of various tracer injection protocols for sentinel lymph node (SLN) mapping have been extensively discussed in relation to breast and gastric cancer. But no such discussion has taken place in relation to SLN mapping in non-small cell lung cancer. We therefore studied the effect of two tracer injection protocols on SLN mapping in patients with non-small cell lung cancer; of particular interest was the relationship between subpleural tracer injection and identification of mediastinal SLNs. METHODS: A quadrant injection group (n=49) received 1.6 ml of ferucarbotran by peritumoral quadrant injection after thoracotomy. In the subpleural injection group, the same amount of ferucarbotran was injected into the peritumoral quadrants plus the subpleural region (n=27). SLNs were then detected intraoperatively by measuring the magnetic force within lymph nodes using a hand-held magnetometer. After completing the SLN mapping, lobectomy and hilar and mediastinal lymph node dissection was performed. RESULTS: The incidence of mediastinal SLNs was significantly higher in the subpleural injection group (45.4%) than in the quadrant injection group (14.6%) (p=0.007). Moreover, nominal logistic regression analysis revealed subpleural injection to be a significant independent factor contributing to detection of mediastinal SLNs (p=0.024, odds ratio 5.26). In the quadrant injection group, mediastinal lymph node metastasis was detected in two patients thought to have nonmetastatic parenchymal SLNs. By contrast, there were no false-negative cases in the subpleural injection group. CONCLUSION: Subpleural tracer injection significantly improves detection of mediastinal SLNs in non-small cell lung cancer.

A novel method for sentinel lymph node mapping using magnetite in patients with non-small cell lung cancer.

OBJECTIVE: The detection rate of sentinel lymph nodes in patients with non-small cell lung cancer using isosulfan blue dye is too low for clinical use. Although exposure to radioactivity is reportedly minimal, special procedures are nonetheless required when a radioactive isotope is used as a tracer. Therefore, to eliminate the need for a radioactive tracer and to obtain a better detection rate than is obtained with isosulfan blue dye, we have developed a novel method that employs magnetite as the tracer. The aim of the present study was to test the feasibility of this technique. METHODS: The tracer employed was ferumoxides, a colloidal superparamagnetic iron oxide of nonstoichiometric magnetite. Thirty-eight non-small cell lung cancer patients participated in the study; each received 5 mL of ferumoxides, injected around the tumor intraoperatively. Fifteen minutes after injection, lung resection and lymph node dissection were carried out. The magnetic force within the lymph nodes was measured using a highly sensitive handheld magnetometer ex vivo. All lymph nodes were also subjected to conventional histological analysis. RESULTS: The rate of detection of sentinel lymph nodes was 81.6% (31/38). The accuracy, sensitivity, and false-negative rates were 96.8% (30/31), 85.7% (6/7), and 14.3% (1/7), respectively. CONCLUSION: Intraoperative sentinel lymph node mapping using ferumoxides and a highly sensitive magnetometer is a safe, accurate, and sensitive way to detect sentinel lymph nodes in non-small cell lung cancer patients.

Superior mediastinal and neck lymphatic mapping in mid- and lower-thoracic esophageal cancer as defined by ferumoxides-enhanced magnetic resonance imaging.

OBJECTIVE: The purpose of this study was to detect lymphatic drainage into the superior mediastinum and neck in thoracic esophageal cancer patients using ferumoxides-enhanced magnetic resonance imaging (MRI), and to have this information assist in determining the appropriate extent of lymphadenectomy. METHODS: Nine male patients with T2-T3 mid- and lower-thoracic esophageal cancer with lymph node metastasis were examined. The day before surgery, ferumoxides was endoscopically injected into the submucosal layer of the peritumoral lesion. Thereafter, lymph nodes in the superior mediastinum and neck, which were shown to be ferumoxides-enhanced on MRI, were harvested and evaluated; magnetic force from all harvested lymph nodes was measured ex vivo. RESULTS: MRI of the superior mediastinum and neck revealed 1(median) ferumoxides-enhanced lymph nodes in eight (89%) patients, and there was laterality in the lymphatic mapping in both areas. Of the 15 lymph nodes into which drainage was detected by enhanced MRI, 12 (80%) were magnetite-positive. In six patients (67%), magnetic resonance enhanced lymph nodes corresponded completely with the ex vivo magnetite examination, and in 3 patients (33%) there was partial agreement. In 3 (60%) of the 5 patients that showed paratracheal and/or supraclavicular lymph node metastases, all of the affected nodes were detected by MRI; in one patient some of the affected nodes were detected. CONCLUSION: Ferumoxides-enhanced MRI is useful for visualizing lymphatic drainage to the superior mediastinum and neck in thoracic esophageal cancer. It is an adequate procedure to form an estimate on the appropriate extent of lymphadenectomy.

Radio-guided thoracoscopic surgery with (99m)Tc-methoxy-isobutylisonitrile for treating an ectopic mediastinal parathyroid adenoma in an adolescent girl.

Here we report the case of a 17-year-old girl treated for an ectopic mediastinal parathyroid adenoma using (99m)Tc-methoxy-isobutyl-isonitrile (MIBI) and radio-guided thoracoscopic surgery. Her serum calcium and intact parathyroid hormone levels were elevated, and an anterior mediastinal tumor was noted on her chest computed tomography scan. At 2 h before surgery, the patient was given an injection of 370 MBq of (99m)Tc-MIBI. Because it was not possible visually to distinguish the tumor from the mature thymic tissue in which it was embedded, a search for the tumor was carried out using a gamma probe under thoracoscopy. Thereafter, the left thymus, including the radioactivity-positive tumor, was resected. We suggest that radio-guided thoracoscopic surgery with (99m)Tc-MIBI is an excellent procedure for treating ectopic mediastinal parathyroid adenomas embedded in the mature thymus of adolescents and young adults. This approach could be especially useful for young female patients, given its cosmetic advantage.

Intraoperative sentinel lymph node mapping using a new sterilizable magnetometer in patients with nonsmall cell lung cancer.

PURPOSE: We recently developed a novel method for sentinel lymph node mapping using magnetic force. However, problems with the sterility and sensitivity of the magnetometer made intraoperative sentinel lymph node mapping impossible. The purpose of this study was to test the utility of a new, more sensitive, sterilizable magnetometer developed in our institute for in vivo sentinel lymph node mapping in patients with nonsmall cell lung cancer. DESCRIPTION: Ferumoxides (magnetite) served as the tracer. Twenty patients with nonsmall cell lung cancer participated in the study. Each received 5 mL of ferumoxides, which were injected around their tumor. Magnetic force was then measured intraoperatively using the new sterilizable magnetometer. EVALUATION: The in vivo sentinel lymph node detection rate was 80.0% (16 of 20). The accuracy, sensitivity, and false-negative rates were 100% (16 of 16), 100% (4 of 4) and 0% (0 of 12), respectively. Our preliminary study indicates that our new magnetometer enables in vivo sentinel lymph node mapping in patients with nonsmall cell lung cancer. CONCLUSIONS: This device safely and accurately detected sentinel lymph nodes in nonsmall cell lung cancer patients.

[Sentinel lymph node after intramammary injection of superparamagnetic iron oxide].

The purpose of this study was to evaluate enhancement (signal loss) of the axillary lymph nodes on MR lymphography after intramammary injection of superparamagnetic iron oxide (Ferumoxides) for detection of the sentinel lymph node. MR lymphography was performed in a total of 11 patients with breast cancer without palpable axillary lymph node swelling before operation. Coronal and axial images were obtained before and after intramammary injection of 1.5 ml Ferumoxides adjacent to the breast tumor. In all patients, decreased intensity was recognized in the axillary lymph nodes. MR lymphography could detect the sentinel lymph node with its decreased signal intensity 20 minutes after the intramammary injection of Ferumoxides.