Clinical features and risk factors for appendiceal diverticulitis: a comparative study with acute appendicitis.

PURPOSE: Despite their similar clinical characteristics, appendiceal diverticulitis (AD) and acute appendicitis (AA) are pathologically distinct. This study compared the clinical features of AD and AA and identified relevant risk factors. METHODS: Patients who underwent appendectomy with a preoperative diagnosis of either AD or AA were categorized based on histopathological findings. The two groups were compared in terms of various clinical factors. RESULTS: Among the 854 patients included in the study, a histopathological evaluation revealed 49 and 805 cases of AD and AA, respectively. A univariate analysis demonstrated that AD was more prevalent than AA among older, taller, and heavier males. A multivariate analysis revealed that male sex, a white blood cell (WBC) count < 13.5 × 103/µL, an eosinophil count ≥ 0.4%, and a mean corpuscular volume (MCV) ≥ 91.6 fL were significant factors differentiating AD from AA. In addition, pathological AD emerged as an independent risk factor for abscess and/or perforation. CONCLUSIONS: AD was associated with an older age, robust physique, and significant risk of abscess and/or perforation despite a low WBC count. In addition to imaging modalities, the preoperative factors of male sex, a WBC count < 13.5 × 103/µL, an eosinophil count ≥ 0.4%, and a MCV ≥ 91.6 fL may be useful for distinguishing AD from AA.

Long-term survivor who underwent surgical resections of repeated peritoneal oligometastases from colon cancer : a rare case report.

A 74-year-old woman underwent right hemicolectomy and partial ileal resection for ascending colon cancer with synchronous peritoneal metastasis. Histopathological examination showed moderately differentiated adenocarcinoma with mucinous component, pT4b N3 M1, and Stage IV. Postoperative chemotherapy comprising 36 courses of mFOLFOX6 with bevacizumab was administered. Twenty-two months after the surgery, computed tomography (CT) revealed a 20 mm nodular lesion adjacent to the gastric wall, and laparoscopic resection of the nodule was performed. Thirty-nine months after the second surgery, CT showed a 24 mm nodular lesion involving the liver parenchyma, and partial hepatectomy involving the nodule was performed. Histopathological examination of the nodules resected by the second and third surgeries showed the same features as the primary ascending colon cancer. The nodules were diagnosed as metachronous peritoneal metastases. The patient followed up without chemotherapy after the second and third surgery, showed no recurrence for 26 months after the third surgery. Fortunately, more than 7 years have passed since the primary tumor resection. Hence, surgical resection for synchronous and repeated metachronous peritoneal oligometastases from colon cancer can offer long-term survival. J. Med. Invest. 69 : 302-307, August, 2022.

Non-tumor forming and diffusely spreading invasive pancreatic cancer.

A 78-year-old man presented to our hospital with loss of appetite and epigastric discomfort. Computed tomography (CT) revealed dilation of the main pancreatic duct and three cystic lesions in the pancreatic neck, body, and tail. Endoscopic ultrasonography showed a mural nodule > 5 mm enhanced with Sonazoid in a cyst. Therefore, the patient was diagnosed with intra-ductal papillary mucinous neoplasm (IPMN) and underwent distal pancreatectomy. Macroscopic examination of the cut surface of the resected specimen showed no solid tumors in the pancreatic parenchyma. The histopathological diagnosis of the cysts was IPMN with low-grade dysplasia. Ten months after surgery, the serum carbohydrate antigen 19-9 level was elevated, and CT showed multiple peritoneal and pulmonary nodules, suggesting peritoneal dissemination and lung metastases. Since recurrence of pancreatic cancer was suspected, repeat histopathological examination of the resected specimen was performed, revealing small clusters of atypical epithelial cells diffusely spreading in the pancreatic tissue. The diagnosis was changed to invasive ductal carcinoma (pT2N1bM0, stage IIB). Invasive pancreatic cancer that does not form a solid mass, and shows diffuse spreading with small clusters is extremely rare. Imaging diagnosis and histopathological examination should be carefully performed in such cases.

Appendix-preserving elective herniorrhaphy for de Garengeot hernia: two case reports.

BACKGROUND: Emergency appendectomy is often performed for de Garengeot hernia. However, in some cases, there may be a chance to perform an appendix-preserving elective surgery. CASE DESCRIPTION: A 76-year-old woman presented to our hospital with complaints of a right inguinal swelling, which we diagnosed as a de Garengeot hernia using computed tomography (CT). B-mode ultrasonography (US) of the mass showed an appendix 4-6 mm in diameter with a clear wall structure; color Doppler US showed pulsatile blood flow signal in the appendiceal wall. Twenty-eight days later, herniorrhaphy with transabdominal preperitoneal repair (TAPP) was performed without appendectomy. Another 70-year-old woman presented to our hospital with complaints of a painful bulge in the right inguinal region. The diagnosis of de Garengeot hernia was made using CT. B-mode US showed an appendix 5 mm in diameter with a clear wall structure. Color Doppler US showed a pulsatile blood signal in the appendiceal wall. Seven days later, herniorrhaphy with TAPP was performed without appendectomy. CONCLUSION: De Garengeot hernia is often associated with appendicitis; however, an appendix-preserving elective herniorrhaphy can be performed if US and intraoperative findings do not suggest appendicitis or circulatory compromise in the appendix.

Optimal cutoff value of preoperative CEA and CA19-9 for prognostic significance in patients with stage II/III colon cancer.

PURPOSE: This unicentric, retrospective cohort study aimed to identify the optimal cutoff values of preoperative serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) for the prognosis in patients with stage II/III colon cancer. METHODS: After excluding 43 patients with CA19-9 levels < 0.2 U/mL, 588 were included. Receiver operating characteristic curves were constructed to determine the optimal cutoff values of CEA and CA 19-9 for disease relapse. RESULTS: The median CEA and CA19-9 values were 3.6 (interquartile range: 2.1-7.2 ng/mL) and 14.3 (interquartile range: 8.1-30.0) U/mL, respectively. The optimal cutoff values of CEA and CA19-9 were 5.4 ng/mL and 22.4 U/mL, respectively. A multivariate analysis of relapse-free survival (RFS) showed that cancer stage, CEA, and CA19-9 were significant independent factors. The RFS of patients with stages II and III colon cancer was significantly stratified by CEA (< 5.4/ ≥ 5.4 ng/mL) and CA19-9 (< 22.4/ ≥ 22.4 U/mL). Prognostication based on the reference values (< 5.0 ng/mL for CEA and < 37.0 U/mL for CA19-9) was less significant than that based on the optimal cutoff values. Both elevated CEA and CA19-9 had no value dependency on RFS: RFS curves were similar between extremely elevated CEA (≥ 54.0 ng/ml) and intermediate CEA (5.4-54.0 ng/ml) and between extremely elevated CA19-9 (≥ 224.0 U/ml) and intermediate CA19-9 (22.4-224.0 U/ml). CONCLUSION: The optimal cutoff values of preoperative CEA and CA19-9 for RFS were 5.4 ng/ml and 22.4 U/mL, respectively, in patients with stages II and III colon cancer. Further relapse risk stratification is possible using these values.

CA19-9 is a significant prognostic marker of patients with stage III gastric cancer.

BACKGROUND: Due to prognostic heterogeneity within a stage of gastric cancer (GC), identification of patients with a high risk for recurrence after resection is important. We aimed to identify the prognostic significance of preoperative serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels in patients with Stage I, II, and III GC who underwent R0 gastrectomy. METHODS: A total of 794 patients were included in this study after excluding 72 patients with CA19-9 <1.0 U/mL. Receiver operating characteristic curves were drawn to assess the optimal cut-off values of CEA and CA19-9 for disease recurrence. RESULTS: The optimal cut-off values of CEA and CA19-9 levels were 2.9 ng/mL and 46.3 U/mL, respectively. Multivariate analysis for relapse-free survival (RFS) showed that stage of GC, CA19-9 levels, postoperative adjuvant chemotherapy, and venous invasion were significant independent factors. The RFS and overall survival (OS) of patients with CA19-9 ≥ 46.3 U/mL were significantly lower than those with CA19-9 < 46.3 U/mL in Stage III GC. However, the RFS of GC patients with CA19-9 ≥ 463 U/mL tended to be better than those with CA19-9 levels between 46.3 and 463 U/mL. CONCLUSIONS: The RFS and OS of patients with CA19-9 ≥ 46.3 U/mL were significantly lower than those with CA19-9 < 46.3 U/mL in Stage III GC. However, there was no value dependency of extremely elevated CA19-9 on RFS. Further risk stratification can be obtained by measuring preoperative serum CA19-9 in stage III GC.

[A Case of Ascending Colon Cancer with Synchronous Unresectable Liver Metastasis Maintaining a Long-Term Stable Disease State after Discontinuing Chemotherapy].

A 73-year-old woman presenting with weight loss was diagnosed as having ascending colon cancer with synchronous liver metastasis. The liver metastasis was solitary but it occupied the medial and anterior segments. The size was over 9 cm in diameter and was located adjacent to the left, middle, and right hepatic veins, making it initially unresectable. Following surgical resection of the primary tumor, she received mFOLFOX6 plus bevacizumab chemotherapy, resulting in a decrease in size of the liver metastasis. During the 15 courses of chemotherapy, an allergic reaction to oxaliplatin occurred and oxaliplatin administration was stopped. Although the liver metastasis was considered to be in a stable disease state according to the RECIST criteria at the time following 32 courses of chemotherapy, we discontinued chemotherapy due to various reasons of the patient. However, the liver metastasis continues to be in the stable disease state, and has not grown for over 5 years since initiating mFOLFOX6 plus bevacizumab chemotherapy and for over 3 years since discontinuing the chemotherapy.

Chronological Changes in Appendiceal Pathology Among Patients Who Underwent Appendectomy for Suspected Acute Appendicitis.

BACKGROUND: Given recent advances in imaging and the development of diagnostic parameters, the rate of unnecessary appendectomy (i.e., negative appendectomy) has been decreasing. However, the incidence of acute appendicitis (AA) in elderly patients is rising due to the aging of society. We aimed to identify chronological changes in demographics and appendiceal pathology among patients who underwent appendectomy for suspected AA. METHODS: Data from 881 patients who underwent appendectomy for suspected AA between January 2006 and December 2017 were analyzed. The final diagnosis was based on intraoperative findings, pathological reports, and clinical course. Negative appendectomy was defined as the absence of appendiceal diseases including inflammation, fibrosis, and neoplasm. We compared demographics and appendiceal pathology between early (2006-2011) and late study phases (2012-2017). RESULTS: The mean age of patients with pathologically proven AA (n = 761) was significantly greater in the late phase than in the early phase (38.6 ± 19.8 years vs. 44.0 ± 20.3 years, p = 0.0002), and the ratio of patients with AA aged ≧ 75 years was also increased (from 5.6 to 8.6%, p = 0.1120). The incidences of complicated appendicitis (defined as perforated or gangrenous appendicitis) and appendiceal diverticulitis (AD) were increased in the late phase compared to those in the early phase (61.3% vs. 77.2% and 3.7% vs. 6.6%, respectively). The negative appendectomy rate was significantly reduced in the late phase compared to that in the early phase (10.0% vs. 2.5%, p < 0.0001). CONCLUSIONS: During a 12-year period, the mean age of patients with AA and the incidences of complicated appendicitis and AD increased, whereas the negative appendectomy rate decreased.

In vivo18F-fluorodeoxyglucose-positron emission tomography/computed tomography imaging of pancreatic tumors in a transgenic rat model carrying the human KRASG12V oncogene.

A novel KRAS-mediated transgenic rat model has previously been demonstrated, in which animals develop multiple pancreatic ductal adenocarcinoma (PDAC) that is histologically similar to human PDAC within two weeks. Positron emission tomography (PET)/computed tomography (CT) is commonly used for the diagnosis and staging of PDAC in humans, and can be adopted for optimal use in animal experiments. The aim of the present study was to evaluate the carcinogenic process in a rat pancreatic carcinoma model using small-animal multimodality imaging systems. The utility of fluorodeoxyglucose (FDG)-PET/CT in detecting the location and size of PDAC during tumor development in the present transgenic rat model was assessed. A small animal multimodality PET/CT system and contrast-enhanced CT (CECT) system were used for the imaging analysis of KRASG12V male transgenic rats (n=6), which developed pancreatic tumors following the administration of an injection of Cre recombinase (Cre)-carrying adenovirus. Laparotomies performed at six weeks post-treatment revealed that all three (100%) Cre-expressing rats developed pancreatic tumors that were <2 mm in diameter, none of which were detected by 18F-FDG PET/CT or CECT. At eight weeks post-treatment, the pancreatic tumors were heterogeneously visualized by 18F-FDG-PET/CT and CECT in two of the three rats. Furthermore, the autopsies confirmed that all three rats had developed pancreatic tumors. These novel findings provide evidence that the FDG-PET/CT imaging system is a valuable tool for the evaluation of the carcinogenic process, and one which may aid in treatment and preventive methods for pancreatic tumors in mammalian models. A limitation associated with the early detection of PDACs warrants further investigation.

Rat N-ERC/mesothelin as a marker for in vivo screening of drugs against pancreas cancer.

Pancreatic ductal adenocarcinoma (PDA) is a highly lethal disease, which is usually diagnosed in an advanced stage. We have established transgenic rats carrying a mutated K-ras gene controlled by Cre/loxP activation. The animals develop PDA which is histopathologically similar to that in humans. Previously, we reported that serum levels of N-ERC/mesothelin were significantly higher in rats bearing PDA than in controls. In the present study, to determine whether serum levels of N-ERC/mesothelin correlated with tumor size, we measured N-ERC/mesothelin levels in rats bearing PDA. Increased serum levels of N-ERC/mesothelin correlated with increased tumor size. This result indicates an interrelationship between the serum level of N-ERC/mesothelin and tumor size. We next investigated the effect of chemotherapy on serum N-ERC/mesothelin levels. Rat pancreatic cancer cells were implanted subcutaneously into the flank of NOD-SCID mice. In the mice treated with 200 mg/kg gemcitabine, tumor weight and the serum level of N-ERC/mesothelin were significantly decreased compared to controls. These results suggest that serum N-ERC/mesothelin measurements might be useful for monitoring response to therapy.

Relationship of detection rate of PET cancer screening examinees and risk factors: analysis of background of examinees.

OBJECTIVE: PET cancer screening is performed widely in Japan as opportunistic screening, but no study has focused on the correlation with various cancer risk factors and the seeking bias of examinees and cancer detection rate. Analyzing our large series of PET cancer screening data, correlations with cancer detection rates according to general cancer risk factors and PET detection survey were reviewed, and the selection bias of the medical examinees was determined. METHODS: 19189 examinees who underwent PET cancer screening were enrolled. Using logistic-regression analysis, we analyzed correlations between smoking history/drinking history/cancer family history and detection rates of thyroid cancer/breast cancer/colorectal cancer/lung cancer, which are the main malignancies detected in PET cancer screening. In addition, we evaluated seeking bias of examinees, analyzing correlations between the presence of cancer risk factors and prior screening checkups at other institutions to our PET cancer screening using a matched case-control study. RESULTS: Cancer detection rates by FDG-PET were 1.17% (224/19189), being much higher than those of standard cancer mass screenings. In males, statistically significant correlations were seen between lung cancer and smoking, and between prostate cancer and a family history of prostate cancer, but not between the detection rates of three other types of cancer (thyroid cancer/lung cancer/colorectal cancer) and other cancer risk factors. In females, detection rates of four types of cancer (thyroid cancer/lung cancer/colorectal cancer/breast cancer) were significantly higher in the examinees without cancer risks, and subgroup analysis according to types of cancer did not indicate significant correlations either. The matched case-control study evaluating seeking bias indicated that a significant proportion of the examinees with cancer risks had undergone prior cancer screening at other institutions. CONCLUSIONS: Our study indicated that there was significant seeking bias for prior screening of examinees, with this accounting for the fact that this study did not find a significant correlation between cancer risks and cancer detection rates. The results of our study indicated that PET cancer screening can provide high cancer detection rates.

[Imaging of cancer activity and range of tumor involvement--applying to breast cancer].

In recent years, PET using mainly fluorine-18 fluorodeoxyglucose (FDG) has played a very large role in the management of breast cancer. Systemic, functional images can be obtained by whole body PET and can provide information that is not obtained by anatomical imaging modalities such as conventional X-ray computed tomography, X-ray mammography, or ultrasonography. The utility of FDG-PET for breast cancer patients has been established in every phase of the management of breast cancer, such as the differential diagnosis of breast cancer primary lesion, cancer staging, and posttreatment monitoring. For whole body FDG-PET that can assess the spread of systemic disease in a single examination, postoperative monitoring is one of the most useful applications in particular. In addition, the usefulness of PET for prediction of prognosis and assessment of treatment response has been reported along with the medical economical effect of FDG-PET for breast cancer patients. Moreover, it is expected that a new tracer other than FDG, such as fluorine-18 ion and [18F]-fluoro-17beta; estradiol (FES), and the new instruments such as PET-CT and positron emission mammography (PEM) can further contribute to the management of breast cancer. In this report, we will outline the benefits, limitations, and future prospects of PET for breast cancer.