Diagnostic accuracy of K-ras mutation for pancreatic carcinoma: a meta-analysis

K-ras gene mutation analysis to diagnosis pancreatic adenocarcinoma from endoscopic ultrasound-guided tissue acquisition; a systematic review and meta-analysis

BACKGROUND

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has high sensitivity for the pathological diagnosis of pancreatic masses, but also a high false-negative rate. K-ras gene mutations occur in over 75 % of pancreatic ductal adenocarcinomas (PDAC), and this meta-analysis evaluated the utility of detecting K-ras gene mutations from EUS-TA specimens for the diagnosis of PDAC.

METHODS

Relevant studies in PubMed, the Cochrane Library, and Web of Science were systematically searched. Meta-analysis was performed on data from the selected studies using a bivariate model to provide pooled values of sensitivity, specificity, and their 95 % confidence intervals (CIs).

RESULTS

This meta-analysis included 1521 patients (from 10 eligible studies) who underwent EUS-TA with K-ras gene mutation analysis for diagnosis of pancreatic solid masses. The pooled estimates of sensitivity and specificity were 76.6 % (95 % CI, 70.9-81.5 %) and 97.0 % (95 % CI, 94.0-98.5 %), respectively, for pathological diagnosis, 75.9 % (95 % CI 69.5-81.4 %) and 95.3 % (95 % CI, 92.3-97.2 %) for K-ras gene mutation analysis, and 88.7 % (95 % CI 87.1-91.7 %) and 94.9 % (95 % CI, 91.5-97.0 %) for pathological diagnosis in combination with K-ras gene mutation analysis. The sensitivity for diagnosis of PDAC was significantly higher for pathological diagnosis in combination with K-ras gene mutation analysis than for pathological diagnosis or K-ras gene mutation analysis alone (both, p < 0.001). There was no difference in specificity between pathological diagnosis in combination with K-ras gene mutation analysis and both either (p = 0.234, 0.945, respectively).

CONCLUSIONS

K-ras gene mutation analysis in combination with to pathological diagnosis of EUS-TA increases the accuracy of differential diagnosis of PDAC.

Clinical practice guidelines for molecular tumor markers, 2nd edition review part 1

With advances in gene and protein analysis technologies, many target molecules that may be useful in cancer diagnosis have been reported. Therefore, the "Tumor Marker Study Group" was established in 1981 with the aim of "discovering clinically" useful molecules. Later, the name was changed to "Japanese Society for Molecular Tumor Marker Research" in 2000 in response to the remarkable progress in gene-related research. Currently, the world of cancer treatment is shifting from the era of representative tumor markers of each cancer type used for tumor diagnosis and treatment evaluation to the study of companion markers for molecular-targeted therapeutics that target cancer cells. Therefore, the first edition of the Molecular Tumor Marker Guidelines, which summarizes tumor markers and companion markers in each cancer type, was published in 2016. After publication of the first edition, the gene panel testing using next-generation sequencing became available in Japan in June 2019 for insured patients. In addition, immune checkpoint inhibitors have been indicated for a wide range of cancer types. Therefore, the 2nd edition of the Molecular Tumor Marker Guidelines was published in September 2021 to address the need to revise the guidelines. Here, we present an English version of the review (Part 1) of the Molecular Tumor Marker Guidelines, Second Edition.

Telomerase activity as a marker for differential diagnosis of pancreatic adenocarcinoma: a systematic review and meta-analysis

BACKGROUND

Studies evaluating the role of telomerase activity in pancreatic adenocarcinoma are inconsistent and a systemic review of the available literature may shed new light on this issue.

OBJECTIVE

To systematically review the usefulness of telomerase activity in distinguishing pancreatic cancer from other pancreatic diseases.

METHODS

A comprehensive search of the PubMed and Embase databases was conducted to identify eligible studies. Only studies evaluating telomerase activity in patients with suspected or previously diagnosed pancreatic adenocarcinomas versus nonpancreatic adenocarcinomas and published in English with a sufficient number of cases were included. The hierarchical summary receiver operating characteristic (HSROC) model was used to establish the potential value of telomerase activity in the diagnosis of pancreatic adenocarcinoma.

RESULTS

A total of 19 studies qualified for this meta-analysis. In distinguishing pancreatic adenocarcinoma from benign diseases, the pooled sensitivity and specificity of telomerase activity were 0.81 (95% CI, 0.68-0.90) and 0.97 (95% CI, 0.93-0.98), respectively; the diagnostic odds ratio (DOR) was 126.62 (95% CI, 49.94-320.99); beta was -1.16 (95% CI, -3.62-1.29), Z was -0.93, p was 0.35>0.1, and lambda was 6.86 (95% CI, 1.01-12.70). In distinguishing pancreatic adenocarcinoma from chronic pancreatitis, the pooled sensitivity and specificity of telomerase activity were 0.77 (95% CI, 0.61-0.88) and 0.97 (95% CI, 0.91-0.99), respectively; DOR was 117.28 (95% CI, 32.25-426.53); beta was -0.38 (95% CI, -1.89-1.13), Z was -0.49, p was 0.62>0.1, and lambda was 5.30 (95% CI, 3.37-7.24).

CONCLUSIONS

The present meta-analysis demonstrates that telomerase activity could be a useful biomarker for the differential diagnosis of pancreatic adenocarcinoma and benign pancreatic diseases.

Prognostic significance of K-ras mutations in pancreatic cancer: a meta-analysis

Background

K-ras gene mutations are common in patients with pancreatic cancer (PC); however, their prognostic value for PC remains inconclusive. This meta-analysis was performed to quantitatively evaluate the association between K-ras mutations and survival in patients with pancreatic cancer.

Methods

We performed a comprehensive search of electronic sources including MEDLINE (via PubMed), Web of Science, and the Cochrane Library. The search covered a publication period from inception to November 2015.

Results

Seventeen studies with a total of 2249 patients with pancreatic cancer were included in the tissue detection of this study. The meta-analysis indicated a significant association between mutant K-ras genes and overall survival (OS) (HR = 1.51, 95 % CI 1.32–1.72, P < 0.001). Moreover, further subgroup analyses by ethnicity, publication year, therapy method, cancer resectability, and gene detection method all revealed that pancreatic cancer patients with the K-ras mutation had significantly poorer OS (P < 0.05). And results from four studies with 225 patients focused on plasma K-ras mutations enhanced such association (HR = 2.23, 95 % CI 1.69–2.95, P < 0.001).

Conclusions

As a prediction of poor prognosis, the detection of K-ras mutations may be a useful prognostic factor for pancreatic cancer patients.

A meta-analysis of the diagnostic value of detecting K-ras mutation in pancreatic juice as a molecular marker for pancreatic cancer

BACKGROUND

K-ras codon 12 mutation is one of the earliest genetic changes in the development of pancreatic cancer (PC) and accurate detection of K-ras mutations is gaining increasing attention in the field of molecular diagnosis.

METHODS

Original research articles which evaluated the diagnostic accuracy of K-ras mutation detection in PC were selected. Data were presented as forest plots and summary receiver operating characteristic curve analysis was used to summarize the overall test performance.

RESULTS

We assessed 16 studies from 15 published articles. The pooled sensitivity and specificity were 59% (95%CI: 54%-64%) and 87% (95%CI: 84%-89%), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 4.13 (95%CI: 2.73-6.25) and 0.42 (95%CI: 0.32-0.56), respectively, and the pooled diagnostic odds ratio was 13.66 (95% CI: 7.25-25.74).

CONCLUSIONS

Our results indicate that the analysis of K-ras mutations in pancreatic juice has a considerable diagnostic value in PC. Further studies with rigorous design, large sample size, and multi-regional co-operation are needed.

Telomerase activity in pancreatic juice differentiates pancreatic cancer from chronic pancreatitis: A meta-analysis

BACKGROUND/OBJECTIVE

To evaluate the usefulness of genetic markers in pancreatic juice (PJ), and the combination of these markers with telomerase activity in the differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis.

METHODS

We conducted a meta-analysis for the diagnostic utility of the four major altered genes in PDAC (KRAS, CDKN2A/p16, TP53, and SMAD4/DPC4), telomerase activity, and a combination assay using PJ samples. A literature search was conducted in MEDLINE, Cochrane Library, and Web of Science. Data were pooled and presented as diagnostic sensitivity and specificity with 95% confidence intervals (CIs).

RESULTS

Thirty-nine studies fulfilled the inclusion criteria. Pooled estimates of KRAS analysis were as follows: sensitivity was 0.67 (95% CI, 0.63-0.71) and specificity, 0.82 (95% CI, 0.79-0.85). For telomerase activity analysis, sensitivity was 0.82 (95% CI, 0.76-0.87) and specificity, 0.96 (95% CI, 0.90-0.99). The other three tumor suppressors demonstrated low sensitivity. The data did not suggest any publication bias. A combined analysis of KRAS and telomerase activity showed a higher diagnostic sensitivity (0.94; 95% CI, 0.83-0.99) than KRAS alone. A combined analysis of telomerase activity and cytology revealed more reliable diagnostic accuracy than telomerase activity alone, with high sensitivity (0.88; 95% CI, 0.74-0.96) and specificity (1.00; 95% CI, 0.91-1.00).

CONCLUSIONS

The most reliable marker in PJ samples for diagnosis of PDAC was telomerase activity. Telomerase activity can play a central role in diagnostic analysis using PJ samples, and can increase diagnostic accuracy when combined with KRAS mutations or cytological examination.

Standardized uptake value on positron emission tomography/computed tomography predicts prognosis in patients with locally advanced pancreatic cancer

BACKGROUND

The aim of the present study was to investigate the use and value of maximum standardized uptake value (SUV max) on positron emission tomography/computed tomography (PET/CT) images as a prognostic marker for patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

The medical records of all consecutive patients who underwent PET/CT examination in our institution were retrospectively reviewed. Inclusion criteria were histologically or cytologically proven LAPC. Patients with distant metastasis were excluded. For statistical analysis, the SUV max of primary pancreatic cancer was measured. Survival rates were calculated using the Kaplan-Meier method, and multivariable analysis was performed to determine the association of SUV max with overall survival (OS) and progression-free survival (PFS) using a Cox proportional hazards model.

RESULTS

Between July 2006 and June 2013, 69 patients were enrolled in the present study. OS and PFS were 14.9 months [95% confidence interval (CI) 13.1-16.7] and 8.3 months (95% CI 7.1-9.5), respectively. A high SUV max (>5.5) was observed in 35 patients, who had significantly worse OS and PFS than the remaining patients with a low SUV max (P = 0.025 and P = 0.003). Univariate analysis showed that SUV max and tumor size were prognostic factors for OS, with a hazard ratio of 1.90 and 1.81, respectively. A high SUV max was an independent prognostic factor, with a hazard ratio of 1.89 (95% CI 1.015-3.519, P = 0.045).

CONCLUSION

The present study suggests that increased SUV max is a predictor of poor prognosis in patients with LAPC.

Clinicopathological Significance of CDKN2A Promoter Hypermethylation Frequency with Pancreatic Cancer

The prognosis of pancreatic cancer patients is very poor, with a 5-year survival of less than 6%. Previous studies demonstrated that the loss of function of CDKN2A is mainly caused by the hypermethylation of CDKN2A gene promoter; however, whether or not it is associated with the incidence of pancreatic cancer still remains unclear. In this study, we systematically reviewed the association between CDKN2A promoter methylation and pancreatic cancer using meta-analysis methods. The pooled data were analyzed by Review Manager 5.2. Fourteen studies eligible studies, including 418 pancreatic cancer, 155 pancreatic intraepithelial neoplasia (PanINs) and 45 chronic pancreatitis (CP) patients were analyzed. We observed that the frequency of CDKN2A methylation was significantly higher in pancreatic cancer patients than in normal healthy controls, the pooled OR = 17.19, 95% CI = 8.72–33.86, P < 0.00001. The frequency of CDKN2A methylation was also significantly higher in PanINs patients than that in normal individual controls, OR = 12.35, 95% CI = 1.70–89.89, P = 0.01. In addition, CDKN2A methylation was associated with worse survival in pancreatic cancer, HR = 4.46, 95% CI = 1.37–14.53, P = 0.01. The results strongly suggest that CDKN2A methylation is correlated with an increased risk of pancreatic cancer. CDKN2A methylation plays a critical role in pancreatic carcinogenesis and may serve as a prognostic marker.