Colorectal liver metastases: Radiological diagnosis and staging

Frequency of Neuroendocrine Tumor Studies: Using Latent Dirichlet Allocation and HJ-Biplot Statistical Methods

Background: Neuroendocrine tumors (NETs) are severe and relatively rare and may affect any organ of the human body. The prevalence of NETs has increased in recent years; however, there seem to be more data on particular types, even though, despite the efforts of different guidelines, there is no consensus on how to identify different types of NETs. In this review, we investigated the countries that published the most articles about NETs, the most frequent organs affected, and the most common related topics. Methods: This work used the Latent Dirichlet Allocation (LDA) method to identify and interpret scientific information in relation to the categories in a set of documents. The HJ-Biplot method was also used to determine the relationship between the analyzed topics, by taking into consideration the years under study. Results: In this study, a literature review was conducted, from which a total of 7658 abstracts of scientific articles published between 1981 and 2020 were extracted. The United States, Germany, United Kingdom, France, and Italy published the majority of studies on NETs, of which pancreatic tumors were the most studied. The five most frequent topics were t_21 (clinical benefit), t_11 (pancreatic neuroendocrine tumors), t_13 (patients one year after treatment), t_17 (prognosis of survival before and after resection), and t_3 (markers for carcinomas). Finally, the results were put through a two-way multivariate analysis (HJ-Biplot), which generated a new interpretation: we grouped topics by year and discovered which NETs were the most relevant for which years. Conclusions: The most frequent topics found in our review highlighted the severity of NETs: patients have a poor prognosis of survival and a high probability of tumor recurrence.

Risk of Infectious Complications After Simultaneous Gastrointestinal and Liver Resections for Neuroendocrine Tumor Metastases

BACKGROUND

Neuroendocrine tumors (NETs) are a relatively rare category of cancers that arise in the gastrointestinal (GI) tract and other organs. Extended hepatectomies including resection of multiple organs are often necessary to achieve negative margins.

METHODS

We performed a review of patients undergoing liver resection for NET liver metastases from 2005 to 2015 using National Surgical Quality Improvement Program. We compared patients undergoing hepatectomy alone (HA) versus hepatectomy and a concomitant GI surgery procedure (colorectal, small bowel, and pancreatic) to evaluate postoperative infectious complications.

RESULTS

During the study period, 354 patients underwent liver resection for metastatic NET. Hepatectomy alone was performed in 98 patients, and concomitant GI surgery was performed in 256 patients, including 83 colorectal resections (HCCR), 68 small bowel resections, 75 distal pancreatectomies, and 35 pancreaticoduodenectomies (HCPD). Infectious complications were more likely to occur in those undergoing HCPD (60%, P < 0.001), and HCCR (32.5%, P < 0.05) than in those undergoing HA (16.3%). Patients undergoing HCPD and HCCR had a 7.69-fold and 2.52-fold increased risk of infectious complication, respectively, compared with HA after adjustment for other infection risk factors.

CONCLUSIONS

Neuroendocrine liver metastases requiring liver resection with concomitant colorectal resection or pancreaticoduodenectomy are at significantly increased risk of developing infectious complications.

Current status of imaging and emerging techniques to evaluate liver metastases from colorectal carcinoma

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. Liver is a common site of tumor spread and in approximately 30% of the cases; synchronous liver disease is present at the time of diagnosis. Early detection of liver metastases is crucial to appropriately select patients who may benefit from hepatic resection among those needing chemotherapy, to improve 5-year survival. Advances in imaging techniques have contributed greatly to the management of these patients. Multidetector computed tomography is the most useful test for initial staging and in posttreatment surveillance settings. Magnetic resonance imaging is considered superior to multidetector computed tomography and positron emission tomography for the detection and characterization of small lesions and for liver evaluation in the presence of background fatty liver changes. Positron emission tomography-computed tomography has a problem-solving role in the detection of distant metastasis and in posttreatment evaluation. The advanced imaging methods also serve a role in selecting appropriate patients for radiologically targeted therapies and in monitoring response to conventional and novel therapies.

Magnetic resonance imaging for extramammary Paget's disease: radiological and pathological correlations

Extramammary Paget's disease (EMPD) is a rare cutaneous neoplasm that is thought to represent intraepithelial adenocarcinoma developing in an area rich in apocrine glands. Magnetic resonance imaging (MRI) findings for this disease are not well established. We report three cases of pathologically confirmed EMPD in which MRI was performed before surgery. The lesions were widespread in the epidermis and the dermis. Lesions were sharply well enhanced on gadolinium-enhanced T1-weighted imaging and appeared hyperintense on diffusion-weighted imaging in all cases. Areas with enhancement in depth corresponded well with the pathological lesion. In addition, different malignant legions were found on the same images from MRI in two cases, indicating potential associations with other malignancies. We describe the MRI findings and their pathological correlation. MRI could be useful for preoperative evaluation of disease spread and detection of associated malignancies.

Surgical management of colorectal liver metastases

Colorectal cancer is the third most commonly diagnosed cancer with approximately half of the patients developing liver metastases during the course of their disease. Modern multimodal therapies have improved the overall survival. Liver resection remains the most important modality in the treatment of colorectal liver metastases. The evolution of the criteria for resectability has resulted in more patients being offered a hepatectomy. This is further augmented with the utilization of adjuncts to liver resection, including portal vein embolization and local ablative techniques. Two-stage hepatectomy is also being used to increase resectability. Overall survival is improved by the deployment of new chemotherapeutic agents and the use of combination chemotherapy. Neoadjuvant chemotherapy is a promising development in the treatment of colorectal liver metastases. Patients with colorectal liver metastases can achieve long-term survival. A multidisciplinary approach is essential in the management of these patients.

Surgical management of colorectal liver metastases

Colorectal cancer is the third most commonly diagnosed cancer with approximately half of the patients developing liver metastases during the course of their disease. Modern multimodal therapies have improved the overall survival. Liver resection remains the most important modality in the treatment of colorectal liver metastases. The evolution of the criteria for resectability has resulted in more patients being offered a hepatectomy. This is further augmented with the utilization of adjuncts to liver resection, including portal vein embolization and local ablative techniques. Two-stage hepatectomy is also being used to increase resectability. Overall survival is improved by the deployment of new chemotherapeutic agents and the use of combination chemotherapy. Neoadjuvant chemotherapy is a promising development in the treatment of colorectal liver metastases. Patients with colorectal liver metastases can achieve long-term survival. A multidisciplinary approach is essential in the management of these patients.

Diffusion-weighted MRI and liver metastases

Liver metastases are the most frequently encountered malignant liver lesions in the Western countries. Accurate diagnosis of liver metastases is essential for appropriate management of these patients. Multiple imaging modalities, including ultrasound, CT, positron emission tomography, and MRI, are available for the evaluation of patients with suspected or known liver metastases. Contrast-enhanced MRI has a high accuracy for detection and characterization of liver lesions. Additionally, diffusion-weighted MRI (DWI) has been gaining increasing attention. It is a noncontrast technique that is easy to perform, could be incorporated in routine clinical protocols, and has the potential to provide tissue characterization. This article discusses the basic principles of DWI and discusses its emerging role in the detection of liver metastases in patients with extrahepatic malignancies.

Hepatic resection for colorectal liver metastases

Colorectal adenocarcinoma remains the third most common cause of cancer death in the United States, with an estimated 146,000 new cases and 50,000 deaths annually. Survival is stage dependent, and the presence of liver metastases is a primary determinant in patient survival. Approximately 25% of new cases will present with synchronous colorectal liver metastases (CLM), and up to one-half will develop CLM during the course of their disease. The importance of safe and effective therapies for CLM cannot be overstated. Safe and appropriately aggressive multimodality therapy for CLM can provide most patients with liver-dominant colorectal metastases with extended survival and an improved quality of life.

Use of modified multidetector CT colonography for the evaluation of acute and subacute colon obstruction caused by colorectal cancer: a feasibility study

PURPOSE

This study was designed to evaluate the feasibility of using CT colonography with a modified procedural protocol for diagnosis and cancer staging in patients with suspected acute or subacute colon obstruction caused by colorectal cancer.

METHODS

Following colonic cleansing with lukewarm water enemas, thin-collimation CT colonography was performed on 47 patients (15 women and 32 men, mean age, 68 years) in the precontrast prone position and in the supine position after the intravenous administration of a contrast agent. The surgical and pathologic findings served as a reference standard.

RESULTS

In 44 of 47 patients, colon distention was caused by obstruction, and pathologic examination confirmed colorectal cancer in 41 of these 44 patients. CT colonography correctly located all tumors and successfully identified noncancerous causes of colon distention in five patients. The overall accuracy of staging was 97.6 percent for the T category, 73.2 percent for N, and 100 percent for M. Two synchronous colorectal cancers were correctly identified.

CONCLUSIONS

When appropriate protocol modifications regarding colon cleansing and air insufflation are made to take the clinical situation into account, CT colonography is a technically feasible, accurate, and well-tolerated method for tumor evaluation and cancer staging in patients with acute and subacute colon obstruction.

Chemotherapy for colorectal cancer liver metastases

Colorectal cancer (CRC) is a highly prevalent malignant disease in industrialized nations. The annual incidence of invasive CRC in the U.S. is among the highest in the world, and the liver is the only metastatic site in approximately one third of patients. Without treatment, patients with metastatic disease have a poor prognosis; however, long-term survival benefits and even cure have been reported in patients undergoing surgical resection of metastases. In addition, advances in chemotherapy, imaging, and surgical techniques have increased the proportion of patients who are eligible for resection. Combination therapy with fluorouracil and leucovorin has been the mainstay of treatment for metastatic CRC; however, the introduction of newer agents, such as oxaliplatin and irinotecan, and targeted agents, such as cetuximab and bevacizumab, has yielded improvements in response rates (RRs) and survival. Maximizing the exposure of hepatic metastases to high target concentrations of cytotoxic drugs using hepatic arterial infusion (HAI) increases RRs further than with systemic chemotherapy; however, the impact of HAI on survival is unclear. As the goals of chemotherapeutic treatment for metastatic CRC increasingly shift from palliation to prolongation of survival, improvement in RRs, and downsizing of tumors in order to enable or optimize resection, treatment in a multidisciplinary environment involving a medical oncologist, radiologist, and surgical oncologist with hepatobiliary expertise will become central to deciding the best course of therapy and timing of surgery.