The Value of Laparoscopic Staging in Upper Gastrointestinal Malignancy

Diagnostic accuracy of laparoscopy following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

BACKGROUND

Surgical resection is the only potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Laparoscopy can detect metastases not visualised on CT scanning, enabling better assessment of the spread of cancer (staging of cancer). This is an update to a previous Cochrane Review published in 2013 evaluating the role of diagnostic laparoscopy in assessing the resectability with curative intent in people with pancreatic and periampullary cancer.

OBJECTIVES

To determine the diagnostic accuracy of diagnostic laparoscopy performed as an add-on test to CT scanning in the assessment of curative resectability in pancreatic and periampullary cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, EMBASE via OvidSP (from inception to 15 May 2016), and Science Citation Index Expanded (from 1980 to 15 May 2016).

SELECTION CRITERIA

We included diagnostic accuracy studies of diagnostic laparoscopy in people with potentially resectable pancreatic and periampullary cancer on CT scan, where confirmation of liver or peritoneal involvement was by histopathological examination of suspicious (liver or peritoneal) lesions obtained at diagnostic laparoscopy or laparotomy. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment using the QUADAS-2 tool. The specificity of diagnostic laparoscopy in all studies was 1 because there were no false positives since laparoscopy and the reference standard are one and the same if histological examination after diagnostic laparoscopy is positive. The sensitivities were therefore meta-analysed using a univariate random-effects logistic regression model. The probability of unresectability in people who had a negative laparoscopy (post-test probability for people with a negative test result) was calculated using the median probability of unresectability (pre-test probability) from the included studies, and the negative likelihood ratio derived from the model (specificity of 1 assumed). The difference between the pre-test and post-test probabilities gave the overall added value of diagnostic laparoscopy compared to the standard practice of CT scan staging alone.

MAIN RESULTS

We included 16 studies with a total of 1146 participants in the meta-analysis. Only one study including 52 participants had a low risk of bias and low applicability concern in the patient selection domain. The median pre-test probability of unresectable disease after CT scanning across studies was 41.4% (that is 41 out of 100 participants who had resectable cancer after CT scan were found to have unresectable disease on laparotomy). The summary sensitivity of diagnostic laparoscopy was 64.4% (95% confidence interval (CI) 50.1% to 76.6%). Assuming a pre-test probability of 41.4%, the post-test probability of unresectable disease for participants with a negative test result was 0.20 (95% CI 0.15 to 0.27). This indicates that if a person is said to have resectable disease after diagnostic laparoscopy and CT scan, there is a 20% probability that their cancer will be unresectable compared to a 41% probability for those receiving CT alone.A subgroup analysis of people with pancreatic cancer gave a summary sensitivity of 67.9% (95% CI 41.1% to 86.5%). The post-test probability of unresectable disease after being considered resectable on both CT and diagnostic laparoscopy was 18% compared to 40.0% for those receiving CT alone.

AUTHORS' CONCLUSIONS

Diagnostic laparoscopy may decrease the rate of unnecessary laparotomy in people with pancreatic and periampullary cancer found to have resectable disease on CT scan. On average, using diagnostic laparoscopy with biopsy and histopathological confirmation of suspicious lesions prior to laparotomy would avoid 21 unnecessary laparotomies in 100 people in whom resection of cancer with curative intent is planned.

Diagnostic accuracy of laparoscopy following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

BACKGROUND

Surgical resection is the only potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Laparoscopy can detect metastases not visualised on CT scanning, enabling better assessment of the spread of cancer (staging of cancer). There has been no systematic review or meta-analysis assessing the role of diagnostic laparoscopy in assessing the resectability with curative intent in patients with pancreatic and periampullary cancer.

OBJECTIVES

To determine the diagnostic accuracy of diagnostic laparoscopy performed as an add-on test to CT scanning in the assessment of curative resectability in pancreatic and periampullary cancer.

SEARCH METHODS

We searched the Cochrane Register of Diagnostic Test Accuracy Studies, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, EMBASE via OvidSP (from inception to 13 September 2012), and Science Citation Index Expanded (from 1980 to 13 September 2012).

SELECTION CRITERIA

We included diagnostic accuracy studies of diagnostic laparoscopy in patients with potentially resectable pancreatic and periampullary cancer on CT scan, where confirmation of liver or peritoneal involvement was by histopathological examination of suspicious (liver or peritoneal) lesions obtained at diagnostic laparoscopy or laparotomy. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies.

DATA COLLECTION AND ANALYSIS

Two authors independently performed data extraction and quality assessment using the QUADAS-2 tool. The specificity of diagnostic laparoscopy in all studies was 1 because there were no false positives since laparoscopy and the reference standard are one and the same if histological examination after diagnostic laparoscopy is positive. Therefore, the sensitivities were meta-analysed using a univariate random-effects logistic regression model. The probability of unresectability in patients who had a negative laparoscopy (post-test probability for patients with a negative test result) was calculated using the median probability of unresectability (pre-test probability) from the included studies and the negative likelihood ratio derived from the model (specificity of 1 assumed). The difference between the pre-test and post-test probabilities gave the overall added value of diagnostic laparoscopy compared to the standard practice of CT scan staging alone.

MAIN RESULTS

Fifteen studies with a total of 1015 patients were included in the meta-analysis. Only one study including 52 patients had a low risk of bias and low applicability concern in the patient selection domain. The median pre-test probability of unresectable disease after CT scanning across studies was 40.3% (that is 40 out of 100 patients who had resectable cancer after CT scan were found to have unresectable disease on laparotomy). The summary sensitivity of diagnostic laparoscopy was 68.7% (95% CI 54.3% to 80.2%). Assuming a pre-test probability of 40.3%, the post-test probability of unresectable disease for patients with a negative test result was 0.17 (95% CI 0.12 to 0.24). This indicates that if a patient is said to have resectable disease after diagnostic laparoscopy and CT scan, there is a 17% probability that their cancer will be unresectable compared to a 40% probability for those receiving CT alone.A subgroup analysis of patients with pancreatic cancer gave a summary sensitivity of 67.9% (95% CI 41.1% to 86.5%). The post-test probability of unresectable disease after being considered resectable on both CT and diagnostic laparoscopy was 18% compared to 40% for those receiving CT alone.

AUTHORS' CONCLUSIONS

Diagnostic laparoscopy may decrease the rate of unnecessary laparotomy in patients with pancreatic and periampullary cancer found to have resectable disease on CT scan. On average, using diagnostic laparoscopy with biopsy and histopathological confirmation of suspicious lesions prior to laparotomy would avoid 23 unnecessary laparotomies in 100 patients in whom resection of cancer with curative intent is planned.

Patients with laparoscopically staged unresectable pancreatic adenocarcinoma do not require subsequent surgical biliary or gastric bypass

BACKGROUND

Laparoscopic staging is an effective and accurate means of staging pancreatic cancer. But, the frequency of subsequent surgical bypass to treat biliary or gastric obstruction in laparoscopically staged patients with unresectable adenocarcinoma is unknown. The development of biliary and gastric obstruction in patients with unresectable pancreatic adenocarcinoma has been reported to occur in as many as 70% and 25% of patients, respectively. Previously, staging for patients with pancreatic cancer was achieved by laparotomy and the anticipated high rate for these patients to develop obstruction led to prophylactic bypass procedures. As laparoscopic staging for pancreatic cancer becomes a standard modality, the need for prophylactic bypass procedures in these patients needs to be examined.

STUDY DESIGN

Analyses of laparoscopically staged patients (n = 155) with unresectable, histologically proved pancreatic adenocarcinoma, from a single institution treated between 1993-1997 were performed. The frequency of surgical bypass in a prospective cohort of patients with unresectable pancreatic adenocarcinoma who did not undergo open enteric or biliary bypass at the time of laparoscopic staging was determined.

RESULTS

Laparoscopic staging revealed that 40 patients had locally advanced disease and 115 had metastatic disease. Median survival for patients with locally advanced and metastatic disease was 6.2 and 7.8 months, respectively. Postlaparoscopy followup revealed that 98% (152 of 155) of these patients did not require a subsequent open surgical procedure to treat biliary or gastric obstruction.

CONCLUSIONS

These results do not support the practice of routine prophylactic bypass procedures. As such, we propose that surgical biliary bypass can be advocated only for those patients with obstructive jaundice who fail endoscopic stent placement, and gastroenterostomy should be reserved for patients with confirmed gastric outlet obstruction.

Positive peritoneal cytology predicts unresectability of pancreatic adenocarcinoma

BACKGROUND

Peritoneal cytology is clinically useful in gastric and gynecologic malignancies. Its role in pancreatic adenocarcinoma remains less well defined. Controversy exists as to the relationship between percutaneous fine needle aspiration (FNA) of the pancreas and shedding of malignant cells with the peritoneum. The aim of this study was to determine whether positive peritoneal cytology (PPC) predicts unresectability of pancreatic adenocarcinoma and impacts on overall survival. In addition, the study aimed to determine whether antecedent FNA increases the incidence of PPC.

STUDY DESIGN

Between January 1993 and June 1996, 228 patients with radiographically resectable pancreatic adenocarcinoma underwent laparoscopic staging. Specimens were taken from right and left upper quadrants at the beginning of laparoscopy. Various prognostic factors were analyzed.

RESULTS

PPC was identified in 34 patients (15%). Of patients that had an antecedent FNA, 20% had PPC, and 13% of those without an antecedent FNA had PPC (p = 0.22). The majority of patients with PPC had stage IV disease (26 of 34 [76%]) and only 8 (24%) had no evidence of metastases. Overall survival was significantly higher in patients with negative peritoneal cytology (NPC) compared with PPC (p<0.0006). PPC had a positive predictive value of 94.1%, specificity of 98.1%, and a sensitivity of 25.6% for determining unresectability of pancreatic adenocarcinoma. PPC was not an independent prognostic variable for survival on multivariate analysis.

CONCLUSIONS

PPC is associated with advanced disease and is highly specific in predicting unresectability of pancreatic adenocarcinoma, resulting in decreased survival. Antecedent FNA is not associated with an increased the incidence of PPC, nor does it significantly impact on overall survival.