Improvement of the rapid immunoperoxidase staining method for intraoperative pathological diagnosis of pancreatic cancer using microwave irradiation

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis

OBJECTIVES

The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies.

METHODS

MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively.

RESULTS

A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001).

CONCLUSIONS

Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

Novel rapid immunohistochemistry using an alternating current electric field identifies Rac and Cdc42 activation in human colon cancer FFPE tissues

It is important to determine the activation status of Rac and Cdc42 in cancer tissues for the prediction of metastasis and patient prognosis. However, it has been impossible to detect their spatial activation on formalin-fixed paraffin embedded (FFPE) surgical specimens thus far. Here, we established a novel detection technique for activated Rac/Cdc42 in human colon cancer FFPE tissues by using a p21-activated kinase (PAK)-Rac binding domain (RBD) detection probe fused with glutathione S-transferase (GST), designated GST-PAK-RBD, and novel rapid-immunohistochemistry (R-IHC) systems using noncontact alterating-current electric field mixing, although there is a technical limitation in that it may not distinguish between Rac members and Cdc42. In 50 cases of colon cancer, various activation patterns of Rac/Cdc42 were observed, which were designated plasma membrane, cytoplasm, mixed pattern, and polarized distribution. The activity was striking in the invasive fronts of tumors and significantly correlated with tumor invasion properties evaluated by TNM classification. Of note, in tissue microarray (TMA) samples, 29 of 33 cases demonstrated higher Rac1/Cdc42 activity in the tumor area than the corresponding normal mucosa. In addition, positive correlations were detected between Rac/Cdc42 activity and clinicopathological factors such as venous and lymphatic vessel invasion. These results suggest that understanding Rac and Cdc42 activations in cancer tissues would be valuable as an option for molecular therapy as personalized medicine.

Indications and techniques of extended resection for pancreatic cancer

INTRODUCTION

The resectability rate and postoperative survival rate for pancreatic carcinoma are poor. Aggressive resection including vascular resection and extended lymphadenectomy represent one strategy for improving survival. This study was carried out to clarify the indications for extended resection, especially vascular resection, for pancreatic carcinoma.

METHODS

From July 1981 to March 2005, we performed curative resection in 289 of 443 patients with pancreatic carcinoma in our department (65.2%). Vascular resection was performed in 201 (69.5%) patients and portal vein resection without arterial resection in 186 patients. Combined portal and arterial resection was performed in 14 patients and arterial resection without portal vein resection in 1. Extended lymphadenectomy including paraaortic lymph nodes was done. The postoperative survival rate was stratified according to operative and pathology findings.

RESULTS

Operative mortality (any death within 30 days after surgery) occurred in 11 of the 289 curative resection patients (3.8%), including 1 of 88 patients without vascular resection (1.1%), 5 of 186 portal vein resection patients without arterial resection (2.7%), and 5 of 14 (35.7%) arterial resection patients undergoing portal vein arterial resection as well. Most patients who survived for 2 to 3 years had carcinoma-free surgical margins.

CONCLUSIONS

The most important indication for vascular resection in patients with pancreatic cancer is the ability to obtain cancer-free surgical margins. Otherwise, vascular resection is contraindicated. Extended lymphadenectomy may be not of benefit.

Rapid Intraoperative Immunohistochemical Evaluation of Sentinel Lymph Nodes for Metastatic Breast Carcinoma

OBJECTIVE

Sentinel lymph node (SLN) biopsy is an integral part of the surgical management of patients with breast cancer. Rapid immunohistochemistry (RIHC) has the potential to increase detection of metastatic carcinoma at the time of frozen section consultation. The authors assessed the accuracy and turnaround time of a newly developed RIHC method for pancytokeratin (RIHC-CK).

METHODS

Sixty-six SLNs from 32 patients with breast carcinoma were examined for metastasis using the Zymed Sentinel Lymph Node Rapid IHC Kit. Intraoperative frozen sections (6 mum) of the SLNs were incubated with Zymed anti-pan-cytokeratin/HRP conjugate, diaminobenzidine (DAB), and stained with hematoxylin. Slides were ready within 8 minutes and were interpreted as positive or negative for metastatic carcinoma. Results were compared with previous intraoperative touch preparations, frozen sections, hematoxylin and eosin (Perm H&E), and AEl/3-immunostained permanent sections (Perm CK).

RESULTS

Fourteen lymph nodes (19%) in 13 patients tested positive for metastatic carcinoma in Perm H&E, the gold standard. RIHC-CK had the highest sensitivity (92%) of the intraoperative tests, compared with touch preparations (64%) and frozen sections (80%). RIHC-CK showed 94% accuracy, compared with 96% (frozen section) and 93% (touch preparation). The RIHC technique took 8 minutes and was easy to perform and interpret.

CONCLUSIONS

Zymed RIHC is a sensitive method for detecting breast cancer metastases in SLNs. The speed, accuracy, and ease of interpretation of the test allow for recognition of micrometastases (<2 mm) that might otherwise be undetectable by current methods of intraoperative evaluation. The prognostic significance and effect on surgical management of micrometastases in SLNs have yet to be determined.

Ultrarapid Ki-67 immunostaining in frozen section interpretation of gliomas

BACKGROUND

Astrocytic tumours, the most common gliomas, are often classified intraoperatively using standard morphological staining. The final diagnosis and grading of gliomas on paraffin wax sections is often assisted by Ki-67 immunohistochemistry, but standard immunostaining protocols take too long to be used intraoperatively.

AIMS

To investigate a new rapid Ki-67 immunohistochemical test for its use in an intraoperative setting.

METHODS

The new Ki-67 immunostaining (Ultrarapid-Ki67) method on frozen sections can be carried out in 10 minutes. Thirty four pilocytic and diffuse astrocytomas were immunostained by rapid Ki-67 and results were compared with corresponding MIB-1 staining, histological grading, and prognosis.

RESULTS

The staining protocol was practical to perform and the results were morphologically and quantitatively indistinguishable from those after immunostaining with MIB-1, an antibody recognising Ki-67 in paraffin wax embedded tissue. A comparison of Ultrarapid-Ki67 and MIB-1 immunostaining of paraffin wax sections showed almost identical quantitative correlation in astrocytic gliomas (r = 0.916; p<0.001). The Ultrarapid-Ki67 indices (percentage of positive cells) of low grade (I/II) astrocytomas ranged from 0% to 6.1%, whereas those of representative high grade (III/IV) tumours were significantly higher (range, 5.6-45%; p<0.001). The best prognostic cutoff point for Ultrarapid-Ki67 was 7.5%, which divided diffuse grade II-IV astrocytomas into significantly differing subsets (p = 0.0008).

CONCLUSION

Ultrarapid-Ki67 immunostaining is a useful adjunct to morphological diagnosis and grading of astrocytic tumours, and as a fast test (approximately 10 minutes for staining plus three to four minutes for scoring), it could be used in routine intraoperative diagnosis of gliomas and other neoplastic diseases.

Extended radical resection versus standard resection for pancreatic cancer: the rationale for extended radical resection

OBJECTIVES

This clinical study was carried out to clarify the indications for extended radical resection for pancreatic carcinoma.

METHODS

From July 1981 to September 2003, 250 of 391 (63.9%) patients with pancreatic carcinoma underwent tumor resection in our department. Portal vein resection was performed in 171 of these 250 (68.4%) resected cases. The postoperative survival rate was studied using the operative and histologic findings.

RESULTS

Most of the patients who survived for 2 or 3 years were in the carcinoma-free surgical margins group.

CONCLUSION

The most important indication for an extended radical resection combined with portal vein resection for pancreatic cancer is the ability to obtain surgical cancer-free margins. There is no indication for an extended resection in patients in whom the surgical margins will become cancer positive if such an operation is employed.

Rapid immunohistochemistry for cytokeratin in the intraoperative evaluation of sentinel lymph nodes for metastatic breast carcinoma

The sensitivity and specificity of detecting metastatic breast carcinoma in sentinel lymph nodes using a rapid immunohistochemistry technique was determined and compared with methods currently used at the authors' institution. At the time of intraoperative consultation, after routine diagnostic touch preparations and frozen sections were prepared, 6-microm frozen sections of 72 sentinel lymph nodes from 32 patients with breast carcinoma were placed on plus slides, fixed in cold acetone for 2 or 3 minutes, and stored at -70 degrees C. These sections were immunostained with a prediluted broad-spectrum anticytokeratin monoclonal antibody coupled to an inert polymer with horseradish peroxidase (DAKO EPOS). Slides were ready for interpretation within 16 minutes and were scored as positive, negative, or equivocal for metastatic carcinoma. Results were compared with those of the intraoperative touch preparations and frozen sections and with paraffin-embedded, hematoxylin and eosin-stained, and AE1/AE3 immunostained permanent sections. Fourteen (19%) sentinel lymph nodes were positive for metastatic carcinoma in 13 patients. All methods tested were 100% specific. The rapid immunohistochemistry method was the least sensitive (57% sensitivity) of all methods used to detect metastasis. Routine diagnostic touch preparations, frozen sections, and permanent sections had sensitivities of 69%, 86%, and 100% respectively. In conclusion, this rapid immunohistochemistry method would not be helpful in intraoperative assessment of sentinel lymph nodes in breast cancer patients due to its low sensitivity.

A new rapid immunohistochemical staining technique using the EnVision antibody complex

Rapid immunohistochemical investigation, in addition to staining with hematoxylin and eosin, would be useful during intraoperative frozen section diagnosis in some cases. This study was undertaken to investigate whether the recently described EnVision system, a highly sensitive two-step immunohistochemical technique, could be modified for rapid immunostaining of frozen sections. Forty-five primary antibodies were tested on frozen sections from various different tissues. After fixation in acetone for 1 min and air-drying, the sections were incubated for 3 min each with the primary antibody, the EnVision complex (a large number of secondary antibodies and horseradish peroxidase coupled to a dextran backbone), and the chromogen (3,3'diaminobenzidine or 3-amino-9-ethylcarbazole). All reactions were carried out at 37C. Specific staining was seen with 38 antibodies (including HMB-45 and antibodies against keratin, vimentin, leukocyte common antigen, smooth muscle actin, synaptophysin, CD34, CD3, CD20, and prostate-specific antigen). A modification of the EnVision method allows the detection of a broad spectrum of antigens in frozen sections in less than 13 min. This method could be a useful new tool in frozen section diagnosis and research. (J Histochem Cytochem 49:623-630, 2001)

Problems in pancreatic cancer surgery

Despite the development of more sophisticated diagnostic techniques, it remains difficult to detect pancreatic carcinoma in the early stage. However, the resection rate has been increasing due to recent advances in surgical techniques and the application of extensive surgery. In 1995, statistics of the Pancreatic Cancer Register Committee of Japan Pancreas Society showed a 44.5% rate of resection. Further, according to Japan Pancreas Society staging, the 5-year survival rate of Stage I, II, III, and IV after surgical resection was 46.3, 27.5, 20.4, and 8.3%, respectively. This paper will review the Japanese experience of pancreatic carcinoma and several problems in pancreatic cancer surgery.

Clinical usefulness of CA-19-9 in pancreatic carcinoma

Preoperative and postoperative serum levels of carbohydrate antigen-(CA)19-9 in 148 patients with carcinoma of the pancreas were studied. All 18 patients with carcinoma of the pancreas of Stage I, II, and III were resectable, and their pre-operative serum levels of CA-19-9 were under 1,344 U/ml. Pre-operative serum levels of CA-19-9 in patients with Stage IV ranged widely between 5 and 32,240 U/ml. The postoperative survival rate was significantly superior in patients (n = 15) whose CA-19-9 pre-operative serum levels were less than 2,000 U/ml compare to those (n = 64) whose levels were over that level. Fifteen resectable patients who showed serum levels of CA-19-9 over 2,000 U/ml pre-operatively died within 2 years postoperatively due to recurrence, especially by liver metastasis in spite of aggressive surgery. Intraoperative quick immunostaining of CA-19-9 and carcinoembryonic antigen (CEA) was useful to diagnose intrapancreatic carcinoma development on frozen sections of cut margin of the pancreas and also useful in abdominal washing cytology combined with conventional staining.

Enhanced polymer one-step staining for proliferating cell nuclear antigen in squamous cell carcinoma of the tongue

A rapid enhanced polymer one-step staining for proliferating cell nuclear antigen (EPOS-PCNA) in formalin fixed, paraffin embedded sections of tongue squamous cell carcinoma is described. EPOS-PCNA was compared with PCNA immunohistochemistry using the avidin-biotin complex (ABC) method, with or without autoclave pretreatment. Significant correlation of PCNA labeling index (percentage of labeled cells/total cells counted) was observed between EPOS-PCNA and the immunohistochemical protocol using autoclave pretreatment. We consider this method a reliable, timesaving technique that would be useful in quantitative histopathology and in performing double immunostaining.

Intraoperative peritoneal washing cytology with the rapid immunoperoxidase method using microwave irradiation

The rapid immunocytochemical staining of gastrointestinal cancer-associated antigens, carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), for intraoperative peritoneal washing cytology of pancreatic or biliary carcinoma can be completed in only 25 minutes by using microwave irradiation to accelerate incubation of the primary antibody. Only 3-second irradiation at 500 W for fresh smears produced specific antigen staining of malignant cells similar to that obtained with longer incubation, and the sensitivity of intraoperative cytology was greater than by the conventional staining method. The rapid immunocytochemical staining method of peritoneal washings at laparotomy can provide sensitive information for determining more aggressive therapy for intraperitoneal spread of malignant cells before closing the abdominal wall.

Enhanced polymer one-step staining (EPOS) for proliferating cell nuclear antigen (PCNA) and Ki-67 antigen: application to intra-operative frozen diagnosis

Enhanced polymer one-step staining (EPOS) is a novel, highly sensitive one-step immunostaining method. This simple and rapid technique was applied to intra-operative frozen diagnosis. The markers of choice were proliferating cell nuclear antigen (PCNA) and Ki-67 antigen. These cell proliferation markers were both identifiable in fresh frozen sections of the human tonsil in approximately 7 min. The suitable staining sequences are as follows. Frozen sections prepared using 3-aminopropyltrimethoxysilane-coated glass slides are immediately fixed, without air drying, for 15 s in a mixture of 50% formalin and 50% methanol for PCNA, and in 10% formalin for Ki-67 antigen. After a brief rinse in phosphate-buffered saline (PBS), sections are incubated with the EPOS antibody for 3 min, followed by PBS rinse for 1 min. The peroxidase activity is visualized in diaminobenzidine-H2O2 solution containing 10 mmol/L imidazole for 2 min. After a light rinse in tap water, the nuclei are briefly counterstained with 5% methyl green. When necessary, endogenous peroxidase blockage in 1% periodic acid solution for 1 min is added before the EPOS antibody incubation. This procedure is applicable to frozen sections of gastric cancers, malignant lymphomas, and brain, liver and peritoneal lesions in which differential diagnosis between benignancy and malignancy was required.

Clinical significance of portal invasion by pancreatic head carcinoma

BACKGROUND

The purpose of the present study was to clarify the indication of aggressive surgery for pancreatic head carcinoma.

METHODS

Laparatomy was performed in 153 patients with carcinoma, 101 of whom underwent resection of the carcinoma. With histologic examination the degree of carcinoma invasion into the portal vein was classified into grades 0, I, or II according to the depth of invasion by the carcinoma. Macroscopic carcinoma invasion into portal vein was classified into types A, B, C, or D according to preoperative findings on the portal phase of superior mesenteric angiography or intraoperative portography.

RESULTS

Macroscopic findings correlated with the histologic invasion grades. The 1-year survival rate was 39.6% in grade 0, 11.3% in grade I, and 5.5% in grade II cases. The survival rates of patients with type A (p < 0.01), B (p < 0.05), and C invasion (p < 0.01) were higher than those of patients who did not undergo resection; however, no significant difference in the survival rates between patients who did not undergo resection and patients with type D invasion was observed.

CONCLUSIONS

For locally advanced carcinoma of the pancreatic head or entire pancreas, patients with type D invasion have no indication of aggressive surgery.

Microwaves for immunohistochemistry

Microwaves are now widely used in immunohistochemistry for fixing and stabilizing tissue prior to embedding and cutting, for antigen retrieval and for immunoincubations. These techniques can be used for frozen sections and for material embedded in paraffin and plastic. Material prepared in this way shows high contrast in light microscopy. In principle, these microwave methods can also be used for electron microscopy. To be successful in the application of these techniques, insight into the physics of exposure to microwaves and the effects of microwaves on the material is a must. Microwave immunohistochemistry depends on optimal temperature control. To guarantee this, special measures should be taken and dedicated laboratory ovens should be used. The recently developed Coverplate units facilitate immunoincubations in the microwave oven. We show that the total microwave approach, combining microwave fixation, embedding and immunoincubations, is very useful for confocal microscopy.