The staging of pancreatic adenocarcinoma

Surgical palliation of unresectable pancreatic head cancer in elderly patients

AIM: To determine if surgical biliary bypass would provide improved quality of residual life and safe palliation in elderly patients with unresectable pancreatic head cancer.

METHODS: Nineteen patients, 65 years of age or older, were managed with surgical biliary bypass (Group A). These patients were compared with 19 patients under 65 years of age who were managed with surgical biliary bypass (Group B). In addition, the results for group A were compared with those obtained from 17 patients, 65 years of age or older (Group C), who received percutaneous transhepatic biliary drainage to evaluate the quality of residual life.

RESULTS: Five patients (26.0%) in Group A had complications, including one intraabdominal abscess, one pulmonary atelectasis, and three wound infections. One death (5.3%) occurred on postoperative day 3. With respect to morbidity, mortality, and postoperative hospitalization, no statistically significant difference was noted between Groups A and B. The number of readmissions and the rate of recurrent jaundice were lower in Group A than in Group C, to a statistically significant degree (P = 0.019, P = 0.029, respectively). The median hospital-free survival period and the median overall survival were also significantly longer in Group A (P = 0.001 and P < 0.001, respectively).

CONCLUSION: Surgical palliation does not increase the morbidity or mortality rates, but it does increase the survival rate and improve the quality of life in elderly patients with unresectable pancreatic head cancer.

PAX6 is expressed in pancreatic adenocarcinoma and is downregulated during induction of terminal differentiation

Tumors of the exocrine pancreas are a major cause of cancer death and have among the poorest prognosis of any malignancy. Following the "cancer stem cell hypothesis," where tumors are believed to originate in tissue specific stem cells, we screened primary ductal pancreatic carcinomas and cell lines for the expression of possible stem cell factors. We find 32/46 (70%) of primary tumors and 9/10 (90%) of cell lines express PAX6. PAX6 is a transcription factor expressed throughout the pancreatic bud during embryogenesis but not in the mature exocrine pancreas. PAX proteins have also been implicated in maintaining stem cells in a committed but undifferentiated state but a role for PAX proteins in putative pancreas stem cells is not known. We induced a pancreatic carcinoma cell line, Panc-1, to differentiate by transfecting wild-type p53 and treating the cells with differentiation agents gastrin or butyrate. This treatment induces cells to terminally differentiate into a growth-arrested cell with neurite-like processes, express the terminal differentiation marker somatostatin and downregulate PAX6. This phenotype can be replicated by directly inhibiting PAX6 expression. These data support a model where PAX proteins are aberrantly expressed in tumors and downregulation leads to differentiation.

[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.

Inheritance of pancreatic cancer in pancreatic cancer-prone families

Families are being increasingly recognized as carrying an inherited susceptibility for pancreatic cancer, apparently unrelated to any currently recognized syndrome. The authors provide a review of the current evidence for familial susceptibility to pancreatic cancer. A formal segregation analysis of the pattern of inheritance of pancreatic cancer in 70 families from the National Registry for Familial Pancreatic Cancer is described. This analysis suggests a single major gene with an autosomal dominant mode of inheritance controlling susceptibility for pancreatic cancer in these families.

Spiral computed tomography for preoperative staging of potentially resectable carcinoma of the pancreatic head

BACKGROUND

Pancreatic cancer is often locally invasive. Preoperative staging attempts to identify patients suitable for resection, in order to minimize unnecessary operations. The aim of this study was to assess the improved imaging provided by spiral computed tomography (CT) in the preoperative staging of potentially resectable pancreatic head carcinoma.

METHODS

In 56 consecutive patients with pancreatic head carcinoma spiral CT findings were correlated prospectively with operative and histopathological findings. Criteria for irresectability at CT were infiltration of the peripancreatic fat and vascular ingrowth grade D, on a scale from A to F.

RESULTS

At operation 27 (48 per cent) of 56 tumours were irresectable. Small metastases were found in seven patients (12 per cent). Ingrowth (adherence) to the portal or mesenteric vein was present in 19 patients (34 per cent). The sensitivity and specificity of CT for irresectability were 78 and 76 per cent respectively. Resection rates with a vascular margin free of tumour were 100 per cent for grade A, 63 per cent for grade B, 44 per cent for grade C, 15 per cent for grade D and 0 per cent for grade E, with a predictive value for ingrowth of 88 per cent for grades D or higher. The resectability rate was 11 per cent (one of nine) when infiltration of the anterior peripancreatic fat was present and 67 per cent when infiltration was absent (P < 0.01).

CONCLUSION

Spiral CT with thin slices seems to improve detection of distant metastases and vascular ingrowth in patients with pancreatic head carcinoma.

Laparoscopic ultrasound enhances standard laparoscopy in the staging of pancreatic cancer

OBJECTIVE

To define the role of laparoscopic ultrasound (LUS) in the staging of pancreatic tumors.

SUMMARY BACKGROUND DATA

Laparoscopy has recently been established as a valuable tool in the staging of pancreatic cancer. It has been suggested that the addition of LUS to standard laparoscopy could improve the accuracy of this procedure.

METHODS

A prospective evaluation of 90 patients with pancreatic tumors undergoing laparoscopy and LUS was performed over a 27-month period. LUS equipped with an articulated curved and linear array transducer (6 to 10 MHz) was used. All patients underwent rigorous laparoscopic examination. Clinical, surgical, and pathologic data were collected.

RESULTS

The median age was 65 years (range 43 to 85 years). Sixty-four patients had tumors in the head, 19 in the body, and 3 in the tail of the pancreas. Four patients had ampullary tumors. LUS was able to image the primary tumor (98%), portal vein (97%), superior mesenteric vein (94%), hepatic artery (93%), and superior mesenteric artery (93%) in these patients. LUS was particularly helpful in determining venous involvement (42%) and arterial involvement (38%) by the tumor. This resulted in a change in surgical treatment for 13 (14%) of the 90 patients in whom standard laparoscopic examination was equivocal.

CONCLUSIONS

LUS is useful in evaluating the primary tumor and peripancreatic vascular anatomy. When standard laparoscopic findings are equivocal, LUS allowed accurate determination of resectability. Supplementing laparoscopy with LUS offers improved assessment and preoperative staging of pancreatic cancer.

Spiral CT and the pre-operative assessment of pancreatic adenocarcinoma

AIM

To determine the value of spiral computed tomography (CT) in the pre-operative assessment of pancreatic carcinoma.

PATIENTS AND METHODS

Fifty patients with proven pancreatic carcinoma referred for pancreatoduodenectomy underwent pre-operative spiral CT using a dedicated pancreatic protocol to determine tumour resectability. Twenty-eight patients subsequently underwent surgical exploration.

RESULTS

Pre-operative imaging suggested that 15 tumours were resectable, and macroscopic clearance was complete in 13 giving a positive predictive value (PPV) of 87%. PPV of irresectability was 92%. CT underestimated locally advanced disease (n = 2), missed small hepatic metastases (n = 1), and lymphadenopathy (n = 1). CT overestimated SMV encasement in 1 case, otherwise prediction of vascular patency and compromise was correct. The conspicuity of small resectable carcinomas was improved by spiral scanning.

CONCLUSION

The optimised pancreatic parenchymal enhancement and vascular opacification achieved by spiral CT improves tumour detection of small carcinomas, allows accurate assessment of peripancreatic vessels, and reliably predicts both resectable and irresectable disease. CT remains inherently limited in the prediction of early extrapancreatic non-vascular spread and of lymphatic metastases.

The value of minimal access surgery in the staging of patients with potentially resectable peripancreatic malignancy

OBJECTIVE

The purpose of this study was to determine if an endosurgical approach that mimics open exploration would improve the accuracy of simple diagnostic laparoscopy. SUMMARY BACKGROUND DATA; Most patients with peripancreatic malignancy are found at exploration to be unable to undergo resection. Laparoscopy has been suggested as a sensitive method for detecting metastatic disease in this group of patients. However, the ability to assess resectability with simple diagnostic laparoscopy remains relatively low (<40%).

METHODS

Between December 1992 and August 1994, 115 patients with radiologically resectable peripancreatic tumors underwent extended laparoscopy before undergoing a planned curative resection. This technique required assessment of the peritoneal cavity, liver, lesser sac, porta hepatis, duodenum, transverse mesocolon, and celiac and portal vessels.

RESULTS

Sixty male and 55 female patients were included in the current study. The pancreatic head was involved in 74 patients (64%), followed by the body in 21 (18%), tail in 8 (7%), ampulla in 8 (7%), duodenum in 3 (3%), and distal bile duct in 1 (1%). An abdominal computed tomography (CT) scan was performed for all patients before laparoscopy, ultrasonography for 74 patients (64%), endoscopic retrograde choleangiopancreatography for 59 patients (51%), and mesenteric angiography for 9 patients (8%). Pneumoperitoneum was established successfully in all but 2 cases (98%). A complete examination of 108 patients was performed. Sixty-seven patients were considered to have resectable disease, and 61 resections were performed. Laparoscopy failed to identify hepatic metastases in 5 patients and portal venous encasement in 1 patient. Unresectable disease was identified in 41 patients. Hepatic metastases were observed in 20 patients, mesenteric vascular encasement in 14, extrapancreatic/peritoneal involvement in 16, and celiac or portal lymphatic metastases in 8. There were no intraoperative or postoperative complications related to the laparoscopic procedure. The positive predictive index, negative predictive index, and accuracy of laparoscopy were 100%, 91%, and 94%, respectively.

CONCLUSIONS

This study demonstrates that extended laparoscopy is accurate and safe and makes exploration unnecessary in many patients with potentially resectable peripancreatic malignancy. In this series, 76% of patients explored were resected, compared with the authors' experience between 1983 and 1993 of 35%. The authors believe that laparoscopy is an important component in the staging of this group of patients and should be performed before exploration.

Pancreatic carcinoma

The management of patients with pancreatic carcinoma poses many problems. The diagnosis is usually made late, generally because the patients present late, but it is not unusual to find patients who have had many negative investigations for vague upper abdominal symptoms only to be diagnosed as having pancreatic carcinoma many months later. Staging the disease is equally difficult and often inaccurate. The results of treatment are to date discouraging even in those patients diagnosed early. But the outlook is not totally dismal; in recent years the results for surgical resection of pancreatic lesions have improved; adjuvant treatment may finally be having an effect, although small, on this relentless disease. The most notable inroad made in the management of pancreatic cancer in the last 10 years is the improvement in palliation due to the use of the endoprosthesis. In spite of the poor results we must continue to search actively for more accurate methods of diagnosis and better methods of treatment.