Hossein Saboorian

uPAR and HER-2 gene status in individual breast cancer cells from blood and tissues

Overexpression of urokinase plasminogen activator system or HER-2 (erbB-2) in breast cancer is associated with a poor prognosis. HER-2 overexpression is caused by HER-2 gene amplification. The anti-HER-2 antibody trastuzumab significantly improves clinical outcome for HER2-positive breast cancer. Drugs that target the uPA system are in early clinical trials. The aims of this study were to determine whether urokinase plasminogen activator receptor (uPAR) gene amplification occurs and whether analysis of individual tumor cells (TCs) in the blood or tissue can add information to conventional pathological analysis that could help in diagnosis and treatment. Analysis of individual TCs indicates that uPAR amplification occurs in a significant portion of primary breast cancers and also circulating tumor cells (CTCs) from patients with advanced disease. There was complete concordance between touch preps (TPs) and conventional pathological examination of HER-2 and uPAR gene status in primary tumors. There was also excellent concordance of HER-2 gene status between primary tumors and CTCs provided that acquisition of HER-2 gene amplification in CTCs was taken into account. Unexpectedly, gene amplification of HER-2 and uPAR occurred most frequently in the same TC and patient, suggesting a biological bias and potential advantage for coamplification. Expression of HER-2 and uPAR in primary tumors predicted gene status in 100 and 92% of patients, respectively.

Sutureless laparoscopic heminephrectomy using laser tissue soldering.

BACKGROUND AND PURPOSE Widespread application of laparoscopic partial nephrectomy has been limited by the lack of a reliable means of attaining hemostasis. We describe laser tissue welding using human albumin as a solder to control bleeding and seal the collecting system during laparoscopic heminephrectomy in a porcine model. MATERIALS AND METHODS Laparoscopic left lower-pole heminephrectomy was performed in five female domestic pigs after occluding the hilar vessels. Using an 810-nm pulsed diode laser (20 W), a 50% liquid albumin-indocyanine green solder was welded to the cut edge of the renal parenchyma to seal the collecting system and achieve hemostasis. Two weeks later, an identical procedure was performed on the right kidney, after which, the animals were sacrificed and both kidneys were harvested for ex vivo retrograde pyelograms and histopathologic analysis. RESULTS All 10 heminephrectomies were performed without complication. The mean operative time was 82 minutes, with an average blood loss of 43.5 mL per procedure. The mean warm ischemia time was 11.7 minutes. For each heminephrectomy, a mean of 4.2 mL of solder was welded to the cut parenchymal surface. In three of the five acute kidneys and all five 2-week kidneys, ex vivo retrograde pyelograms demonstrated no extravasation. In addition, no animal had clinical evidence of urinoma or delayed hemorrhage. Histopathologic analysis showed preservation of the renal parenchyma immediately beneath the solder. DISCUSSION Laser tissue welding provided reliable hemostasis and closure of the collecting system while protecting the underlying parenchyma from the deleterious effect of the laser during porcine laparoscopic heminephrectomy.

Clinical relevance of reverse transcriptase-polymerase chain reaction for the detection of axillary lymph node metastases in breast cancer

Background:The mammary sentinel lymph node procedure can increase the detection of axillary metastases by 45% compared with standard axillary dissection. Some investigators have reported that reverse transcriptase-polymerase chain reaction (RT-PCR) increases metastasis detection even more, but it is uncertain whether a positive RT-PCR test in the face of a negative histological evaluation is clinically meaningful.Methods:RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 was performed on sentinel and pooled nonsentinel axillary lymph nodes from 108 women with clinical stage I or II breast cancer who were followed up for a median of 40 months.Results:Axillary metastases were detected on standard tissue sections in 26% and by RT-PCR in 30%. Results for the two tests were concordant for 80% of the cases. RT-PCR upstaged 16%. Tumors from women whose lymph nodes were positive only by RT-PCR were phenotypically similar to those from women with no metastases detected by any method. Moreover, 4-year actuarial distant disease-free survival was 100% for women with metastases detected by RT-PCR only, as compared with 74% for those with metastases detected by routine histology (P = .03) and 93% for those with no metastases detected by either method (P = .04).Conclusions:Analysis of sentinel lymph nodes by RT-PCR for epithelial glycoprotein 2 and cytokeratin 19 is unlikely to provide clinically useful information.

Patterns of aneusomy for three chromosomes in individual cells from breast cancer tumors.

Multi-color fluorescence in situ hybridization (FISH) can determine the changes in the copy numbers of several chromosomes simultaneously and can therefore be used to identify aneusomic patterns in individual cells. Aneusomic patterns may be useful for determining the malignant nature of rare epithelial cells in the blood of cancer patients. Touch preparations from 74 primary breast tumors were evaluated for aneusomy of chromosomes 1, 8 and 17 by tri-color-FISH. In the first part of the analysis, percentages of aneusomy for individual chromosomes and their combinations were determined. In the second part of the analysis, aneusomic patterns for these three chromosomes were analyzed in individual tumor cells and compared to aneusomic patterns observed in leukocytes and in individual cells from benign and normal breast tissue to determine aneusomic patterns indicative of malignancy. Ninety-two percentage of the primary breast carcinomas showed aneusomy for one or more enumerator probes. Comparison with benign breast tissue identified six aneusomic patterns in individual carcinoma cells indicative for malignancy by statistical analysis and not observed in leukocytes. Hence, certain patterns of aneusomy in individual cells involving chromosomes 1, 8 and 17 are indicative of malignancy in individual breast tumor cells and may be useful for determining malignancy of rare epithelial cells in the blood of breast cancer patients.

Hemostatic laparoscopic partial nephrectomy: cable-tie compression

OBJECTIVES Laparoscopic partial nephrectomy (LPN) has generally been reserved for small exophytic lesions because of the limited hemostatic capabilities when excising large segments of renal parenchyma. To overcome this problem, we investigated a technique of laparoscopic reversible, regional hypoperfusion using a cable-tie to minimize blood loss and optimize exposure. METHODS Ten domestic pigs underwent LPN after securing a cable-tie around one pole of the kidney and tightening it until the distal parenchymal surface blanched completely. Eight large amputations involving the collecting system and eight smaller amputations excluding the collecting system were performed using laparoscopic scissors. Fibrin glue was applied to seal the cut surface prior to cable-tie removal. Four pigs (4 large and 4 small amputations) were killed immediately and methylene blue was injected retrograde into the ureter to identify collecting system leaks. The remaining 6 pigs (4 large and 4 small amputations) were killed 4 weeks later and retrograde urograms were performed to assess collecting system integrity. RESULTS Median cable-tie ischemia time was 15 minutes (range 7 to 48) and median blood loss was 30 mL (range 10 to 300). In each case, hemostasis was attained with fibrin glue. In the survival group, all 4 small amputations healed with a fibrotic scar. In the large amputation group, 1 animal died from urinary extravasation on postoperative day 4. The collecting systems of the remaining 3 pigs sealed completely. CONCLUSIONS In the porcine model, cable-tie-assisted LPN provides an almost bloodless surgical field that facilitates rapid resection of large renal segments and hemostasis during a short ischemic period. We anticipate that this technique will broaden the clinical application of LPN.

Detection of telomerase activity in breast masses by fine-needle aspiration

AbstractBackground: Telomerase is an RNA-dependent DNA polymerase that compensates for the telomere shortening that occurs in its absence. Reactivation of telomerase is thought to be an important step in cellular immortalization, and recent studies have indicated that telomerase activity is often detected in primary human malignancies. The clinical implications of telomerase activity in human tumors are currently under investigation. Methods: Eighty-nine samples (46 FNAs and 43 gross tissue biopsies) from 44 patients with breast masses were analyzed prospectively for the presence of telomerase activity by a modification of the telomere repeat amplification protocol (TRAP). All samples were obtained directly from the excised mass at the time of specimen removal in the operating room. Results: Telomerase activity was detected in 17 of 19 (90%) FNA samples and 15 of 18 (83%) invasive breast cancer tissue biopsies. Telomerase was also detected in 9 of 16 (56%) FNAs and 8 of 15 (53%) tissue biopsies from 16 fibroadenomas. Other benign proliferative lesions (n=5) did not have detectable telomerase activity in either FNA or tissue specimens. FNA-TRAP results correlated with the gross tissue specimen TRAP results in 95% of all cases. Conclusion: The FNA-TRAP assay for telomerase detection is a highly sensitive and accurate method for the detection of telomerase activity in breast masses. Future application of these techniques should facilitate evaluation of telomerase as a tumor marker in the clinical management of breast and other solid malignancies.

Differential roles of telomere attrition in type I and II endometrial carcinogenesis.

Endometrial cancer has been generally categorized into two broad groups of tumors, type I (TI) and type II (TII), with distinct epidemiological/clinical features and genetic alterations. Because telomere attrition appears to trigger genomic instability in certain cancers, we explored the role of telomere dysfunction in endometrial cancer by analyzing telomeres and other markers of telomere status in both tumor types. We describe a new method, telomere chromogenic in situ hybridization, which permitted us to detect cells with short telomeres relative to control (stromal) cells within the same tissue section. Using this method, we found that both types of tumor cells had short telomeres. However, only TII tumors were significantly associated with critical telomere shortening in adjacent, morphologically normal epithelium, suggesting that telomere shortening contributes to the initiation of TII but not TI tumors. To explore this hypothesis, we analyzed mice with critically short telomeres and documented distinctive endometrial lesions that histologically resembled the in situ precursor of TII serous carcinomas; these lesions have not been observed previously in TI mouse models of endometrial cancer. Based on this and previous studies, we propose a model in which telomere attrition contributes to the initiation of TII and progression of TI endometrial cancers.