Detection Of Small Pancreatic Cancer Research Articles

Endoscopic Ultrasound for Early Diagnosis of Pancreatic Cancer.

Detection of small pancreatic cancers, which have a better prognosis than large cancers, is needed to reduce high mortality rates. Endoscopic ultrasound (EUS) is the most sensitive imaging modality for detecting pancreatic lesions. The high resolution of EUS makes it particularly useful for detecting small pancreatic lesions that may be missed by other imaging modalities. Therefore, EUS should be performed in patients with obstructive jaundice in whom computed tomography (CT) or magnetic resonance imaging (MRI) does not identify a definite pancreatic lesion. Interest in the use of EUS for screening individuals at high risk of pancreatic cancer, including those with intraductal papillary mucinous neoplasms (IPMNs) and familial pancreatic cancer is growing. Contrast-enhanced EUS can facilitate differential diagnosis of small solid pancreatic lesions as well as malignant cystic lesions. In addition, EUS-guided fine needle aspiration can provide samples of small pancreatic lesions. Thus, EUS and EUS-related techniques are essential for early diagnosis of pancreatic cancer.

Endoscopic ultrasound-guided fine-needle biopsy of small solid pancreatic lesions using a 22-gauge needle with side fenestration.

Early detection of small pancreatic cancer is important because expected survival is markedly better for tumors ≤ 2 cm. A new endoscopic ultrasound-(EUS) guided biopsy needle with side fenestration has been recently developed to enable fine-needle biopsy (FNB) under EUS guidance. The aim of this study was to evaluate the outcome of EUS-FNB using a 22-gauge ProCore needle in solid pancreatic lesions ≤ 2 cm, in terms of diagnostic accuracy and yield. From January 2011 to December 2012, all consecutive EUS-guided tissue sampling of small pancreatic lesions (≤ 2 cm) were performed using 22-gauge ProCore needles; the data of these patients were analyzed retrospectively. Sixty-eight patients with a mean age of 65.7 years were included. The mean lesion size was 16.5 mm (range 5-20). None of the patients developed complications. On pathological examination, the tissue retrieved was judged adequate in 58 out of 68 cases (85.3 %) and the presence of a tissue core was recorded in 36 out of 68 cases (52.9 %). The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80, 100, 100, 40, and 82 %, respectively. Our results suggested that EUS-FNB of small pancreatic lesions using a 22-gauge ProCore needle is effective and safe, and supports our hypothesis that EUS-FNB is highly useful in establishing the nature of small pancreatic lesions.

ROLE OF EUS IN THE EARLY DETECTION OF SMALL PANCREATIC CANCER

The prognosis of pancreatic cancer is extremely poor as a result of the difficulty in early detection of small pancreatic cancer and the intractable nature of appropriate anti-cancer therapies. Computed tomography (CT) is generally used for initial screening, but imaging sensitivities are generally insufficient to detect small masses. Endoscopic ultrasonography (EUS), in contrast, exhibits higher sensitivity than other imaging modalities for the detection of pancreatic cancers, because of the high resolution of images. The goal of this study was to evaluate the role of EUS in the early detection of small pancreatic cancer. We retrospectively reviewed the Gifu University Hospital EUS database (November 2007 to October 2010), and extracted the data of patients whose aim was to confirm the presence or absence of pancreatic cancer subsequent to no tumor detection by abdominal CT. In a 3 year period, 132 patients underwent EUS to confirm the presence or absence of small pancreatic cancer. All patients had previously tested negative for pancreatic mass using abdominal CT, but had showed pancreatic cancer risk factors, including increased serum carcinoembryonic antigen and/or CA 19-9 (n = 106), serum amylase (n = 38), and/or mild to moderate dilation of the main pancreatic duct as determined by imaging (n = 88). EUS detected pancreatic mass in three of these patients. The masses in all three patients were minute (≤10 mm) and their presence was correlated with the detection of mild dilation of the main pancreatic duct in earlier CT scans. Increase of tumor markers was observed in two patients and hyperamylasemia and aggravation of diabetes were observed in one patient. EUS is strongly recommended for early detection of small pancreatic cancer in patients in whom the dilation of the main pancreatic duct was detected in previous imaging tests, with or without increase of pancreatic enzymes or tumor markers.

18F-fluorodeoxyglucose positron emission tomography in the diagnosis of small pancreatic cancer

To investigate the role of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis of small pancreatic cancer. This study involved 31 patients with proven invasive ductal cancer of the pancreas. The patients were divided into 3 groups according to the maximum diameter of the tumor: TS1 (maximum tumor size ≤ 2.0 cm), TS2 (> 2.0 cm and ≤ 4.0 cm) or TS3-4 (> 4.0 cm). The relationships between the TS and various diagnostic tools, including FDG-PET with dual time point evaluation, were analyzed. The tumors ranged from 1.3 to 11.0 cm in diameter. Thirty of the 31 patients (97%) had a positive FDG-PET study. There were 5 patients classified as TS1, 15 as TS2 and 11 as TS3-4. The sensitivity of FDG-PET, computed tomography (CT) and magnetic resonance imaging (MRI) were 100%, 40%, 0% in TS1, 93%, 93%, 89% in TS2 and 100%, 100%, 100% in TS3-4. The sensitivity of FDG-PET was significantly higher in comparison to CT and MRI in patients with TS1 (P < 0.032). The mean standardized uptake values (SUVs) did not show a significant difference in relation to the TS (TS1: 5.8 ± 4.5, TS2: 5.7 ± 2.2, TS3-4: 8.2 ± 3.9), respectively. All the TS1 tumors (from 13 to 20 mm) showed higher SUVs in FDG-PET with dual time point evaluation in the delayed phase compared with the early phase, which suggested the lesions were malignant. These results indicate that FDG-PET with dual time point evaluation is a useful modality for the detection of small pancreatic cancers with a diameter of less than 20 mm.

Imaging study of pancreatic ductal adenocarcinomas in Syrian hamsters using X‐ray micro‐computed tomography (CT)

X-ray computed tomography (CT) has been used for diagnoses of human pancreatic cancer. Although micro-CT is a useful approach to evaluate macromorphology of organs/tissue also in animal models, reports on pancreatic tumors are limited. In this study, the utility of micro-CT was assessed in characterizing chemically induced pancreatic tumors in Syrian hamsters. Hamsters treated with or without N-nitrosobis(2-oxopropyl)amine (BOP) were injected with the antispasmodic agent, scopolamine butylbromide, and contrast agents, 5 or 10 mL/kg body weight of iopamidol or Fenestra VC at 18-38 weeks, then examined by micro-CT scanning with a respiratory gating system. Both peristaltic and respiratory movements were substantially suppressed by the combination of scopolamine butylbromide treatment and the respiratory gating system, resulting in improvements of image qualities. Iopamidol clearly visualized the pancreatic parenchyma and contrasted the margins among the pancreas and other abdominal organs/tissue. Meanwhile Fenestra VC predominantly contrasted abdominal vascular systems, but the margins among pancreas and other organs/tissue remained obscure. Six pancreatic tumors of 4-13 mm in diameter were detected in four of 15 animals, but not the five tumors of 1-4 mm in diameter. The inner tumor images were heterogeneously or uniformly visualized by iopamidol and Fenestra VC. Overall, iopamidol could clearly contrast between pancreatic parenchyma and the tumors as compared with Fenestra VC. All tumors confirmed were histopathologically diagnosed as pancreatic ductal adenocarcinomas. Thus, micro-CT could be useful to evaluate the carcinogenic processes and preventive methods of pancreatic cancer in hamsters and to assess the novel contrast agents for detection of small pancreatic cancer in humans.

Endoscopic ultrasonography in the diagnosis and management of cancer

Since its development and introduction to clinical practice, endoscopic ultrasonography (EUS) has progressed rapidly from being a purely imaging modality with limited use in the detection of small pancreatic cancers to one that can provide a tissue diagnosis by fine-needle aspiration (FNA) and deliver therapy. EUS has now firmly established a place as the investigation of choice in the diagnosis, locoregional staging and management of a wide range of gastrointestinal cancers. With the increasing use of FNA, the accuracy of EUS has substantially improved and may become a stand-alone investigation in some situations. However, it is recommended that a combination of information obtained from other imaging modalities and EUS is needed to maximize the accuracy, in particular to complete staging beyond locoregional stage. In addition to well-established indications, newer applications of EUS are emerging and are no longer limited to the gastrointestinal system. In lung cancer, EUS combined with endobronchial ultrasonography is emerging as an accurate, minimally invasive, nonsurgical alternative to staging of the mediastinum. Furthermore, the ability of EUS to acquire tissue safely and conveniently results in a potential role of the molecular diagnostics to enhance the performance of EUS-guided FNA. Besides a diagnostic role of EUS, there continues to be technological advances in the field of interventional EUS, with many potential applications under investigation. This review focuses on the current and future roles of EUS in the diagnosis and management of cancers.

Detection of small pancreatic cancers: Diagnostic potential of tumor markers, oncogenes, and tumor-suppressor genes

The development of the monoclonal antibody technique has made it possible to use various tumor markers, such as CA 19-9, to detect pancreatic cancer. Although it has been reported that these markers are not sensitive or specific enough to detect small pancreatic cancers, nearly 70% of small pancreatic cancers (<4.0 cm) release pancreatic-cancer associated antigens. In addition, the use of serum tumor markers and ultrasound (US) as screening tools in the outpatient clinic is very effective in detecting pancreatic cancer, including small pancreatic cancers. Recently, observations of carcinogenesis in the pancreas in humans and in experimental models have suggested several cellular pathways for carcinoma of the pancreas. There is increasing evidence that pancreatic cancer results from an accumulation of dominant and recessive mutations in oncogenes and tumor-suppressor genes. Identification of the mutations that occur in pancreatic cancer may provide important information concerning the early stage of this disease. Although there are currently no methods of detecting the premalignant stages of pancreatic cancer, the study of genetic markers may play a central role in the development of techniques for the early detection of pancreatic cancer in the future. (For more detailed information on genetic changes in pancreatic cancer, see: PG Terhune and DS Longnecker,Do Oncogene and Tumor Suppressor Gene Abnormalities Vary with Type of Carcinoma of the Pancreas? J Hep Bil Pancr Surg (1995) 2:1–7.)

Endoscopic Ultrasonography Diagnosis of Pancreatic Cancer

Endoscopic ultrasound (EUS) was developed for the detection of small pancreatic cancer because the complete demonstration of the pancreas by conventional ultrasonography (US) was sometimes prevented by intestinal gas and echoic reduction due to the deeper position of the pancreas head and tail. In this article, the diagnosis, staging, limitations, and hazards of EUS for diagnosing pancreatic cancer are described.

Various Tumor Markers for Small Pancreatic Cancer with Special Reference to the Present Status of Pancreatic Cancer in Japan and Our Experience Over the Past 2 Years

Various tumor markers for detection of small pancreatic cancer less than 4.0 cm of diameter were evaluated and our recent 2 year experience is presented. Even in T1 cancer, 62.5% of the patients (N = 24) had elevated serum CA 19-9 and 56.5% of the patients also had elevated serum SPan-1. However, that of other markers was less than 30% except for CA 50 (60%). In T2 cancer, the highest sensitivity was observed for SPan-1 (79.6%, N = 54) and that of Ca 19-9 (N = 54) was also high (77.7%). That of other markers was less than 50%. The combination assay of CA 19-9 and SPan-1 in T1 cancer increased sensitivity from a single assay of 62.5% and 56.5%, respectively, to 70%. In T2 cancer, the sensitivity of the combination was 97.1%. All of our cases showed positive results using serum SPan-1 and/or CA 19-9 before confirming the diagnosis with imaging procedures. By applying measurements accurately, the test is a very useful adjunct to the diagnosis of small pancreatic cancer and therefore improves its prognosis.