Role of fine needle aspiration cytology and endoscopic biopsy in the preoperative assessment of pancreatic and peripancreatic malignancies

Pancreatic Cancer: Current Options for Diagnosis, Staging and Therapeutic Management

BACKGROUND

Pancreatic cancer is characterized by frequently delayed diagnosis and aggressive tumor growth which hampers most of the current treatment modalities. This review aims to summarize the available evidence about the diagnostic and therapeutic aspects of resectable and non-resectable pancreatic cancer therapy.

SUMMARY

Embedded in the concept of multimodal therapy, surgery plays the central role in the treatment of pancreatic cancer. With advantageous tumor characteristics and complete tumor resection as the most relevant positive prognostic factors, the detection of premalignant or early invasive lesions combined with safe and oncologic adequate surgery is the major therapeutic aim. Most pancreatic adenocarcinomas are locally advanced or metastatic when diagnosed and need to be treated by the combination of surgery and (radio)chemotherapy or by palliative chemotherapy.

Is intraoperative confirmation of malignancy during pancreaticoduodenectomy mandatory?

INTRODUCTION

Differentiating between chronic pancreatitis and pancreatic adenocarcinoma can be difficult due to considerable overlap in disease presentation and radiological signs and the frequent co-existence of the two conditions. In this situation, surgeons may have to proceed to "blind" pancreaticoduodenectomy or attempt to confirm malignancy intraoperatively with frozen section (FS) histology.

METHODS

This study attempted to ascertain the false-negative and false-positive rates of undertaking pancreaticoduodenectomies (PD) based on clinical suspicion (CS) or after intraoperative confirmation of malignancy using FS histology.

RESULTS

Of patients, 13.6% (nine out of 66) underwent a benign PD in the CS group; 6.7% of patients had a missed malignancy in the FS group (n = 62), but intraoperative histology prevented PD in 35% of patients with benign disease in the FS group. Specificity and sensitivity of intraoperative FS in detecting malignancy was 100% and 89.7%, respectively. Sensitivity of clinical assessment in detecting malignancy was 86.4%.

CONCLUSIONS

In experienced hands, intraoperative confirmation of malignancy is effective and will avoid resection in patients with benign disease. However, for many surgeons the chance of missing a small tumour with a false-negative biopsy will be unacceptable and they would prefer to undertake a "blind" resection and accept the mortality risk of pancreaticoduodenectomy for benign disease.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

Diagnostic and prognostic value of plasma tumor M2 pyruvate kinase in periampullary cancer: evidence for a novel biological marker of adverse prognosis

OBJECTIVE

This prospective study examines the diagnostic and prognostic use of tumor-M2-pyruvate kinase (Tu-M2-PK) used in conjunction with carbohydrate antigen (CA) 19-9 in patients with subsequently histologically confirmed periampullary malignancy.

METHODS

Plasma Tu-M2-PK and serum CA 19-9 levels were measured at admission in a cohort of patients with suspected pancreatic cancer. Values for Tu-M2-PK and serum CA 19-9 were compared with a control group comprising jaundiced patients in whom malignancy was excluded by endoscopic retrograde cholangiopancreatography and nonjaundiced individuals undergoing laparoscopic cholecystectomy.

RESULTS

The mean (SD) plasma Tu-M2-PK level for patients with histologically proven malignancy was 40.5 (26.4) U/mL and for noncancer patients, 29.9 (20.9) U/mL (Mann-Whitney U = 1163, P = 0.006). Tumor-M2-pyruvate kinase had an area under the curve of 0.623 on receiver operating characteristic curve analysis, and at optimal cutoff of 27 U/mL, sensitivity is 66%, and specificity is 58%.However, on multivariate Cox regression modeling, elevated Tu-M2-PK (>27 U/mL) was strongly correlated with the subsequent finding of poorly differentiated cancer and/or metastatic disease and strongly predicted survival on Kaplan-Meier analysis.

CONCLUSION

An elevated Tu-M2-PK more than 27 U/mL measured on admission in suspected periampullary cancer is a predictor of adverse prognosis in periampullary cancer.

[Imaging of pancreatic adenocarcinoma]

Pancreatic cancer remains the fourth most common cause of cancer death. Surgery remains the only option for cure. Accurate diagnosis and staging are essential for appropriate management of patients with pancreatic cancer. This paper reviews the state of the art for imaging modalities in the diagnosis and staging of pancreatic adenocarcinoma. The crucial role of CT has increased with the new generation of multidetector CT.

CT–guided Transvenous or Transcaval Needle Biopsy of Pancreatic and Peripancreatic Lesions

PURPOSE

To evaluate the safety and efficacy of direct computed tomography (CT)-guided fine needle aspiration biopsy (FNAB) of pancreatic and peripancreatic masses via a posterior approach that traverses the inferior vena cava (IVC) or renal vein.

MATERIALS AND METHODS

From January 2000 to July 2003, 55 patients underwent 58 biopsies of masses located within the pancreas (n = 28) or in a peripancreatic location (n = 30) with use of a posterior approach that crossed the IVC or renal vein. Biopsies were performed with needles ranging in size from 18 to 22. Cytology reports and medical records of all patients were retrospectively reviewed to evaluate diagnostic accuracy and complication rates.

RESULTS

Masses were safely accessed with a direct (noncoaxial) pathway traversing the IVC (n = 54), renal vein (n = 4), or both (n = 3). Overall diagnostic accuracy was 86% (50 of 58). Cytologic examination was positive for malignancy in 39 of 58 biopsies (67%). Benign lesions were demonstrated in 12 of 58 biopsies. In seven cases (12%), the sample was deemed nondiagnostic. Of those, four were diagnosed later by endoscopy (n = 1), surgical biopsy (n = 2), or repeat FNAB (n = 1). A false-negative result was noted in one case, which was later diagnosed by repeat biopsy. A total of four inadvertent passes through the right renal artery were recorded. CT evidence of perilesional blood was seen in eight of 55 patients (eight of 58 cases). Three of these occurred after a passage via the right renal artery. All patients remained asymptomatic, and no transfusion or change in management was necessary. No other complications occurred.

CONCLUSION

CT-guided noncoaxial FNAB with an approach that traverses the IVC or renal vein is safe and effective in obtaining diagnostic specimens from pancreatic and peripancreatic masses.

Low sensitivity of the ki-ras polymerase chain reaction for diagnosing pancreatic cancer from pancreatic juice and bile: a multicenter prospective trial

PURPOSE

Early detection of pancreatic cancer using molecular markers may improve outcome. Mutations of the ki-ras oncogene are detected in 70% to 90% of pancreatic adenocarcinomas. A prospective, partially blinded, multicenter diagnostic trial was performed to test the sensitivity and specificity of the ki-ras polymerase chain reaction (PCR) analysis of pancreatic juice and bile specimens.

PATIENTS AND METHODS

Specimens of pancreatic juice and bile were collected from 532 consecutive patients. Mutations in codon 12 of the ki-ras gene were identified by two independent enrichment PCRs and confirmed by direct sequencing.

RESULTS

One hundred seventy-four of 532 patients were excluded from the final analysis (reasons: no amplifiable DNA, no specimen or only duodenal juice sent, lost to follow-up). Sixty-three of 358 patients had ductal pancreatic cancer. In 24 (38.1%) of 63 patients, a mutated ki-ras gene was identified in pancreatic juice and/or bile. Ki-ras mutations were found in four (8%) of 50 cases of chronic pancreatitis, in 10 (18.7%) of 53 cases of other malignancies of the pancreaticobiliary tree, and in 14 (7.3%) of 192 cases of benign diseases or normal findings. Sensitivity and specificity of the ki-ras PCR analysis for the detection of pancreatic cancer was 38.1% and 90.5%, respectively.

CONCLUSION

In this prospective trial performed in nonselected patients, mutations of the ki-ras gene were detected in 38.1% of cases with pancreatic cancer. This test in its present form is not appropriate to confirm or screen for pancreatic cancer. More sensitive and/or quantitative PCR tests may improve the molecular diagnosis of pancreatic cancer.

Abdominal US for diagnosis of pancreatic tumor: prospective cohort analysis

PURPOSE

To elucidate the accuracy of abdominal ultrasonography (US) in the diagnosis of pancreatic tumors.

MATERIALS AND METHODS

In all patients referred for pancreatic US during 1988-1990, data on malignant disease and survival were analyzed by using the Swedish Death and Cancer Registries. Nine hundred nineteen patients were entered into the analysis. In 140 of them, a clinical diagnosis of tumor in the pancreatic area was confirmed within 1 year after US. These tumors were primary pancreatic tumors (n = 102), common bile duct and duodenal cancers (n = 17), and metastases in the pancreatic area (n = 21).

RESULTS

The sensitivity of US in the detection of all tumors in the pancreatic area was 88.6% (124 of 140 patients), which was similar to that for the detection of exocrine pancreatic cancer, 90% (79 of 88 patients). There were nine false-positive US examinations, for a specificity of 98.8% (770 of 779 patients). Systematic sampling of 94 investigations confirmed an association between US accuracy and presence of clinical symptoms of pancreatic cancer. Significant differences in the sensitivity (P < .05) and accuracy (P < .01) of diagnosis were observed between three experienced investigators.

CONCLUSION

Study results support the use of US as a first-line diagnostic examination in patients suspected of having pancreatic tumor. Dependency on the investigator's experience with US mandates continuous evaluation of its performance.