Colorectal cancer is currently one of the most common digestive system tumors, and the liver is the most common metastatic site of colorectal cancer. In recent years, with the continuous development of the multidisciplinary treatment for colorectal cancer patients, there are quite a few cases of disappearing liver metastases (DLM) after receiving preoperative chemotherapy (or combined targeted drug therapy), and the diagnosis and treatment of DLM is currently still a very challenging and controversial topic. This article sorts out the related researches on DLM in recent years, mainly including the following 4 aspects: (1) The factors associated with DLM, including the size and number of liver metastases, chemotherapy regimens and cycles, targeted therapy drugs, and the pattern of liver metastases, Ras/Braf status and the location of the primary lesion. (2) The relationship between DLM and true complete response (pathological complete response and persistent clinical complete response), and the related predictive factors of pathological complete response. (3) Clinical evaluation of DLM: preoperative evaluation includes ultrasound, CT, MRI, and PET, while intraoperative evaluation includes intraoperative exploration, intraoperative ultrasound, and augmented reality. (4) DLM treatment strategies, including surgical treatment, local treatment, non-surgical treatment and individualized treatment.
Colorectal Neoplasms ; Humans ; Liver Neoplasms ; Magnetic Resonance Imaging ; Ultrasonography

With recent technical advances, increasing use of sonography in the initial evaluation of patients with abdominal disease may allow the detection of unexpected tumor within the abdominal cavity. Easiness of sonographic detection of bowel pathology, purposely or unexpectedly, warrants the inclusion of bowel loops during ultrasound examination when a patient complains of symptoms indicating diseases of the bowel. In patients complaining of acute abdominal symptoms or nonspecific gastrointestinal symptoms and showing signs such as abdominal pain, diarrhea, hematochezia, change of bowel habit, or bowel obstruction, sonography may reveal the primary causes and may play a definitive role in making a diagnosis. On ultrasonography, abnormal lesions may appear as fungating mass with eccentrically located bowel lumen (pseudokidney sign) or symmetrical or asymmetrical, encircling thickening of the colonic wall (target sign). In patients with mass or wall thickening detected on ultrasonography, additional work-up such as barium study, CT or endoscopy would be occasionally necessary for making a specific diagnosis.
Abdomen, Acute/ultrasonography ; Aged ; Appendicitis/ultrasonography ; Colorectal Neoplasms/ultrasonography ; Diverticulitis/ultrasonography ; Female ; Gastrointestinal Diseases/ultrasonography+ACo- ; Gastrointestinal Neoplasms/ultrasonography ; Human ; Inflammatory Bowel Diseases/ultrasonography ; Intestinal Obstruction/ultrasonography ; Intestinal Perforation/ultrasonography ; Intestines/ultrasonography ; Male ; Stomach/ultrasonography ; Ultrasonography/instrumentation

PURPOSE: Establishing the preoperative stage of colorectal cancer is of primary importance in determining the management and the operative procedure. A comparative study of preoperative evaluation of colorectal cancer is necessary for proper management. METHODS: This study reports a 7 years' experience using another two species of CT for preoperative staging. One species of CT (1989, Delta 2060, Technicare, USA) was used from January 1990 to December 1992; the other species of CT (1992, Highlight Advantage, General Electric Company, USA) was used from January 1993 to December 1997. This study included retrospective analysis of 237 cases of colorectal cancer from January 1990 to December 1997. In first group, the preoperative stage evaluation was done with a much older species of CT from January 1990 to December 1992; in the other group, the preoperative stage evaluation was done with a newer species of CT from January 1993 to December 1997. RESULT: The accuracy & sensitivity of preoperative staging between the two groups showed no significant differences. CONCLUSION: CT is recommended in the preoperative staging of rectal cancer and as an aid in choosing the appropriate therapy. In addition to CT, transrectal ultrasonography and MRI are recommend for improving the accuracy of preoperative staging in assessing local invasion by cancer.
Colorectal Neoplasms* ; Magnetic Resonance Imaging ; Rectal Neoplasms ; Retrospective Studies ; Surgical Procedures, Operative ; Ultrasonography

PURPOSE: The aim of this study was to evaluate the tissue stiffness of solid pancreatic lesions by using acoustic radiation force impulse (ARFI) elastography to differentiate benign from malignant pancreatic lesions. METHODS: ARFI elastography was performed in 26 patients who had 27 focal solid pancreatic lesions, including 8 benign lesions (mass-forming pancreatitis, 5; autoimmune pancreatitis, 3) and 19 malignant lesions (pancreatic adenocarcinoma, 16; metastasis from colorectal cancer, 2; malignant neuroendocrine tumor, 1). On the elastographic images of virtual touch tissue imaging (VTI), the echogenicity of the mass was categorized on a 5-grade scale. On the elastographic image of virtual touch tissue quantification (VTQ), the shear wave velocities (SWVs) of the lesion and surrounding parenchyma were measured. RESULTS: On the VTI images, the mean echogenicity score of the malignant lesions (3.7+/-1.0) was higher than that of the benign lesions (3.1+/-0.4; P=0.023). On the VTQ images, there were no statistical differences in the mean SWV between the benign (2.4+/-1.1 m/sec) and malignant (3.3+/-1.0 m/sec) lesions (P=0.101). However, the mean SWV difference values between the lesion and background parenchyma of the malignant lesions (1.5+/-0.8 m/sec) were higher than those of the benign lesions (0.4+/-0.3 m/sec; P=0.011). CONCLUSION: ARFI elastography can determine the relative stiffness between a lesion and the background pancreatic parenchyma using VTI and VTQ, which is helpful in the differentiation between benign and malignant solid pancreatic lesions.
Acoustics* ; Adenocarcinoma ; Colorectal Neoplasms ; Diagnosis, Differential* ; Elasticity Imaging Techniques* ; Humans ; Neoplasm Metastasis ; Neuroendocrine Tumors ; Pancreas ; Pancreatic Neoplasms ; Pancreatitis ; Ultrasonography

PURPOSE: Pharmacologic thromboprophylaxis is routinely recommended for Western cancer patients undergoing major surgery for prevention of venous thromboembolism (VTE). However, it is uncertainwhetherroutine administration of pharmacologic thromboprophylaxis is necessary in all Asian surgical cancer patients. This prospective study was conducted to examine the incidence of and risk factors for postoperative VTE in Korean colorectal cancer (CRC) patients undergoing major abdominal surgery. MATERIALS AND METHODS: This study comprised two cohorts, and none of patients received perioperative pharmacologic thromboprophylaxis. In cohort A (n=400), patients were routinely screened for VTE using lower-extremity Doppler ultrasonography (DUS) on postoperative days 5-14. In cohort B (n=148), routine DUS was not performed, and imaging was only performed when there were symptoms or signs that were suspicious for VTE. The primary endpoint was the VTE incidence at 4 weeks postoperatively in cohort A. RESULTS: The postoperative incidence of VTE was 3.0% (n=12) in cohort A. Among the 12 patients, eight had distal calf vein thromboses and one had symptomatic thrombosis. Age ≥ 70 years (odds ratio [OR], 5.61), ≥ 2 comorbidities (OR, 13.42), and white blood cell counts of > 10,000/μL (OR, 17.43) were independent risk factors for postoperative VTE (p < 0.05). In cohort B, there was one case of VTE (0.7%). CONCLUSION: The postoperative incidence of VTE, which included asymptomatic cases, was 3.0% in Korean CRC patients who did not receive pharmacologic thromboprophylaxis. Perioperative pharmacologic thromboprophylaxis should be administered to Asian CRC patients on a risk-stratified basis.
Asia ; Asian Continental Ancestry Group ; Cohort Studies ; Colorectal Neoplasms* ; Colorectal Surgery ; Comorbidity ; Humans ; Incidence* ; Leukocyte Count ; Prospective Studies* ; Risk Factors ; Thrombosis ; Ultrasonography, Doppler ; Veins ; Venous Thromboembolism*

BACKGROUND/AIMS: Gallbladder polyps and colorectal adenomas share many common risk factors; however, their association has never been studied. The aim of this study was to investigate this association in asymptomatic healthy subjects. METHODS: Consecutive asymptomatic subjects who underwent both screening colonoscopy and abdominal ultrasonography at Kyung Hee University Hospital in Gang Dong between July 2010 and April 2011 were prospectively enrolled. The prevalence of colorectal adenoma was compared between subjects with or without gallbladder polyps. Furthermore, a logistic regression analysis was performed to determine the independent risk factors for colorectal adenoma in these subjects. RESULTS: Of the 581 participants, 55 presented with gallbladder polyps and 526 did not have gallbladder polyps. Participants with gallbladder polyps showed a trend toward a higher prevalence of colorectal adenoma than those without gallbladder polyps (52.7% vs. 39.2%, P=0.051). Although the result was not statistically significant, gallbladder polyps were found to be a possible risk factor for colorectal adenoma (odds ratio=1.796, 95% confidence interval=0.986-3.269, P=0.055), even after adjusting for potential confounding factors. There was no difference observed in colorectal adenoma characteristics between the two groups. CONCLUSIONS: Our results suggest a possible association between gallbladder polyps and colorectal adenomas. Future studies with larger cohorts are warranted to further investigate this matter.
Adenoma* ; Cohort Studies ; Colonoscopy ; Colorectal Neoplasms ; Gallbladder* ; Logistic Models ; Mass Screening ; Polyps* ; Prevalence ; Prospective Studies ; Risk Factors ; Ultrasonography

PURPOSE: The aim of this study is to describe the safety and efficacy of radiofrequency ablation (RFA) in the treatment of unresectable liver metastasis from colorectal cancer. METHODS: From January 1999 to December 2000, we undertook 48 RFA procedures in 36 patients with unresectable metastatic liver tumor from colorectal cancer. RFA was performed either via celiotomy (n=23) or using a percutaneous approach (n=25) under ultrasound guidance using a LeVeen needle electrode and a RF 2000 generator. Patients were followed with spiral computed tomographic scans at 1 week after RFA. RESULTS: RFA was performed in 15 patients with synchronous hepatic metastasis and 21 with metachronous hepatic metastasis. The mean tumor size was 3.1 cm (range; 0.5~7.2 cm). In 2 patients, complete ablation failed due to anatomic tumor location. Nine patients (25%) exhibited post RFA complications (9 cases of fever, 8 of abdominal pain, and 1 of hematoma) which showed spontaneous resolution and there was no treatment-related death. At a mean follow up of 10.1 months, 12 patients (33.3%) had recurred in the liver and 3 (8.6%) at the RFA site, while 16 (44.4%) remained clinically free of disease. CONCLUSION: Although RFA is a relatively safe procedure in patients with unresectable hepatic metastasis from colorectal cancer, the possible development of new metastatic disease after RFA is currently a limitation in this form of treatment. Further study on the efficacy of RFA versus other treatment modalities is needed.
Abdominal Pain ; Catheter Ablation* ; Colorectal Neoplasms* ; Electrodes ; Fever ; Follow-Up Studies ; Humans ; Liver ; Needles ; Neoplasm Metastasis* ; Ultrasonography

The optimal management of hepatic metastases in colorectal carcinoma patients has become increasingly complex with the myriad of available treatment options. Because the timing of any therapy has become integral to the success of the treatment, a collaborative approach involving multiple specialties is needed for achieving the best patient outcome. Surgical resection is the most effective therapy for metastatic colorectal cancer isolated to the liver. Liver resection of colorectal metastases is associated with three- and five-year survival rates close to 40~60% and 30~50%, respectively. Because the technique for hepatic resection has improved, patients with multiple, biloba, and huge metastases can undergo resection. Every liver resection should be planned after intraoperative ultrasonography, and an anatomical surgical procedure should be preferred instead of wedge resection. Since some of patients diagnosed with metastatic colorectal disease are initially classified as unresectable, neoadjuvant chemotherapy is being increasingly employed to downsize colorectal metastasis. The greatest benefit of the preoperative approach is the potential to convert patients with initially unresectable metastatic disease to a resectable state. Although various prognostic risk factors have been identified, there has been no dependable staging or prognostic scoring system for metastatic hepatic tumor. As surgeons become more proficient in the technical aspects of resection, the patient selection criteria as based on the biologic determinants of the outcome are becoming increasingly important. The goal of this review is to provide the optimal management, treatment and follow-up for patients with colorectal metastasis to the liver.
Colorectal Neoplasms ; Drug Therapy ; Follow-Up Studies ; Humans ; Liver* ; Neoplasm Metastasis* ; Patient Selection ; Risk Factors ; Survival Rate ; Ultrasonography

Pancreatic cancer (PC) is the third most common cause of cancer-related death in the United States and the 12th most common worldwide. Mortality is high, largely due to late stage of presentation and suboptimal treatment regimens. Approximately 10% of PC cases have a familial basis. The major genetic defect has yet to be identified but may be inherited by an autosomal dominant pattern with reduced penetrance. Several known hereditary syndromes or genes are associated with an increased risk of developing PC and account for approximately 2% of PCs. These syndromes include the hereditary breast-ovarian cancer syndrome, Peutz-Jeghers syndrome, familial atypical multiple mole melanoma, Lynch syndrome, familial polyposis, ataxia-telangiectasia, and hereditary pancreatitis. Appropriate screening using methods such as biomarkers or imaging, with endoscopic ultrasound and magnetic resonance imaging, may assist in the early detection of neoplastic lesions in the high-risk population. If these lesions are detected and treated before the development of invasive carcinoma, PC disease morbidity and mortality may be improved. This review will focus on familial PC and other hereditary syndromes implicated in the increased risk of PC; it will also highlight current screening methods and the future of new screening modalities.
Ataxia Telangiectasia ; Biomarkers ; Colorectal Neoplasms, Hereditary Nonpolyposis ; Dysplastic Nevus Syndrome ; Magnetic Resonance Imaging ; Mass Screening* ; Mortality ; Pancreatic Neoplasms* ; Pancreatitis ; Penetrance ; Peutz-Jeghers Syndrome ; Ultrasonography ; United States

The incidence of colorectal cancer has been increased gradually and it was about 6.9% of all malignancies in Korea. Early diagnosis was recognized as the most important factor influencing the prognosis of colorectal cancer and the incidence of early colorectal cancer was increasing. Thus great change was observed in the treatment of early colorectal cancer, endoscopic therapy as well as curative surgical resection is being accepted. We report a case of effective and safe endoscopic therapy for early rectal cancer in 5S-year-old male patient. He presented with rectal prolapse and bleeding of a year's duration. A large polypoid mass with fine nodular surface and thick, short stalk was seen in the rectum at 4cm above the anal verge during flexible sigmoidoscopy. After the histologic examination of specimen obtained by bite biopsy, CT scan of pelvic cavity and ultrasonogram of abdomen, the tumor was removed safe and completely by 2 sessions of piecemeal polypectomies and strip biopsy. He has been well without symptoms and signs of recurrence of rectal cancer for 20 months.
Abdomen ; Biopsy* ; Colorectal Neoplasms ; Early Diagnosis ; Hemorrhage ; Humans ; Incidence ; Korea ; Male ; Prognosis ; Rectal Neoplasms* ; Rectal Prolapse ; Rectum ; Recurrence ; Sigmoidoscopy ; Tomography, X-Ray Computed ; Ultrasonography