Association of Caveolin-1 polymorphisms with colorectal cancer susceptibility in Taiwan

AIM: To investigate the association of Caveolin-1 (Cav-1) polymorphisms with colorectal cancer (CRC) risk in a central Taiwanese population.

METHODS: Three hundred and sixty-two patients with colorectal cancer and the same number of recruited age- and gender-matched healthy controls were genotyped. And only those matches with all single nucleotide polymorphisms data (case/control = 362/362) were selected for final analyzing.

RESULTS: There were significant differences between CRC and control groups in the distributions of their genotypes (P = 1.6 × 10^-12 and 3.0 × 10^-4) and allelic frequencies (P = 2.3 × 10^-13 and 4.0 × 10^-5) in the Cav-1 G14713A (rs3807987) and T29107A (rs7804372) polymorphisms respectively. As for the haplotype analysis, those who had GG/AT or GG/AA at Cav-1 G14713A/T29107A showed a 0.68-fold (95% CI: 0.48-0.98) decreased risk of CRC compared to those with GG/TT, while those of any other combinations were of increased risk. There were joint effects of Cav-1 G14713A and T29107A genotype with smoking status on individual CRC susceptibility.

CONCLUSION: This is the first report providing evidence of Cav-1 being involved in CRC and it may be novel useful genomic markers for early detection of CRC.

Alcohol and gastrointestinal oncology

Results from several large epidemiological studies have firmly established that alcohol is associated with elevated cancer incidence and mortality. Recently the International Agency for Cancer Research stated that acetaldehyde associated with alcoholic beverages is carcinogenic to humans and confirmed the Group 1 classification of alcohol consumption and of ethanol in alcoholic beverages. Alcohol consumption causes cancers of the oral cavity, pharynx, larynx, oesophagus, colorectum, liver, pancreas and female breast. The frequency of most alcohol-induced diseases increases in a linear fashion as intake increases: oral, oesophagus and colon cancer fall into this pattern. Very little is known about safe margins of alcohol consumption. US Department of Health and Human Services suggest a maximum of 28 g of alcohol a day in man and half of this in women.

Solitary rectal ulcer syndrome presenting as polypoid mass lesions in a young girl

Solitary rectal ulcer syndrome (SRUS) is a rare condition in children. We report a case of SRUS in an 8-year old Saudi girl who presented with recurrent rectal bleeding, intermittent mucosal prolapse, and passage of mucus per rectum. Colonoscopy revealed multiple polypoid mass lesions with histopathological features of SRUS. The polypoid variant of SRUS is very rare in children and may be confused with rectal malignant or inflammatory conditions.

Recent advances in chemotherapy for advanced gastric cancer

Although medical treatment has been shown to improve quality of life and prolong survival, no significant progress has been made in the treatment of advanced gastric cancer (AGC) within the last two decades. Thus, the choice of optimum standard first-line chemotherapy regimen for AGC remains debatable, and most responses to chemotherapy are partial and of short duration, with a median survival of approximately 7-11 mo and survival at 2 years rarely more than 10%. Recently, remarkable progress in tumor biology has led to the development of new agents that target critical aspects of oncogenic pathways. For AGC, several molecular targeting agents are now under evaluation in international randomized studies, and trastuzumab, an anti-HER2 monoclonal antibody, has shown antitumor activity against HER-2 positive AGC. However, this benefit is limited to only about 20% of patients with AGC (patients with HER-2 positive AGC). Therefore, there remains a critical need for both the development of more effective agents and the identification of predictive and prognostic molecular markers to select those patients who will benefit most from specific chemotherapeutic regimens and targeted therapies.

Aberrant promoter methylation of p16 in colorectal adenocarcinoma in North Indian patients

AIM: To investigate p16 gene methylation and its expression in 30 patients with sporadic colorectal adenocarcinoma in a North Indian population.

METHODS: Methylation specific polymerase chain reaction was used to detect p16 gene methylation and immunohistochemistry was used to study the p16 expression in 30 sporadic colorectal tumors as well as adjoining and normal tissue specimens.

RESULTS: Aberrant promoter methylation of p16 gene was detected in 12 (40%) tumor specimens, whereas no promoter methylation was observed in adjoining and normal tissue. Immunohistochemistry showed expression of p16 protein in 26 (86.6%) colorectal tumors whereas complete loss of expression was seen in 4 (13.3%) and reduced expression was observed in 12 (40%) tumors. In the adjoining mucosa, expression of p16 was in 11 (36.6%) whereas no clear positivity for p16 protein was seen in normal tissue. There was a significant difference in the expression of p16 protein in tumor tissue and adjoining mucosa (P < 0.001). The methylation of the p16 gene had a significant effect on the expression of p16 protein (P = 0.021). There was a significant association of methylation of p16 gene with the tumor size (P = 0.015) and of the loss/reduced expression of p16 protein with the proximal site of the tumor (P = 0.047). Promoter methylation and expression of p16 had no relation with the survival of the patients (P > 0.05).

CONCLUSION: Our study demonstrated that promoter hypermethylation of the p16 gene results in loss/reduced expression of p16 protein and this loss/reduced expression may contribute to tumor enlargement.

Large ulcerated cecal lipoma mimicking malignancy

Colonic lipomas are relatively uncommon tumors of mesenchymal origin, composed of well-differentiated adipose tissue supported by fibrous tissue, that usually occur in cecum and ascending colon. Colonic lipomas rarely cause symptoms and are usually detected incidentally. However, if the lesion is large, it may produce symptoms, such as abdominal pain, rectal bleeding, obstruction, intussusception, and even weight loss. Large colonic lipomas can be mistaken for malignancy, which may result in extensive surgical operations. We report a large broad-based ulcerated cecal lipoma in a 68-year-old woman, who presented with abdominal pain and weight loss. The ulcerated lesion was highly suspicious for malignancy radiologically and endoscopically. The patient underwent laparoscopic right-hemicolectomy, and the lesion was diagnosed as a cecal submucosal lipoma. The surgical approach remains the treatment of choice for large and complicated cases.

Mucinous carcinoma in Crohn’s disease originating in a fistulous tract

Malignant disease, including mucinous carcinomas of the colorectum, may complicate long-standing Crohn’s disease. An 18-year-old male with extensive small and large bowel involvement with Crohn’s disease developed recurrent peri-rectal fistulous disease that persisted for more than a decade despite pharmacological and surgical therapy as well as later therapy with biological agents. Eventually, an extensive and difficult-to-detect mucinous carcinoma developed in the fistulous tract. Although fistula cancer is rarely described in Crohn’s disease, use of immunosuppressant and biological agents may play an initiating or exacerbating role in its development or progression. As potent biological agents are frequently used, often to avoid surgical treatment, clinicians should have an increasingly high index of suspicion for this potential complication, especially if fistulous drainage persists and remains refractory to medical therapy.

Complete response to preoperative chemoradiotherapy in highly advanced gastric adenocarcinoma

This report presents a case of highly advanced gastric cancer that achieved a histologically complete response (CR) to preoperative chemoradiotherapy with S-1 plus low-dose Cisplatin. A 60-year-old male patient underwent FDG positron emission tomography (PET) during a routine health examination. The patient was found to have swollen paraaortic lymph nodes. Shortly thereafter, he was diagnosed with gastric carcinoma with a type 2 tumor in the antrum with paraaortic lymph node metastases based on FDG-PET, endoscopic examination and abdominal computed tomography. After the completion of chemoradiation therapy (CRT), the tumor and the paraaortic lymph node metastases disappeared. The patient underwent surgery 5 wk after the completion of CRT, including a subtotal gastrectomy with Roux-en-Y reconstruction, D3 lymph node dissection and a left adrenalectomy. No cancer cells were detected in the resected specimen either in the primary lesion or lymph nodes, thus confirming a pathologically CR to CRT (CR grade 3). The patient has been stable and well without any evidence of recurrence for 48 mo after surgery. Such a preoperative CRT regimen might therefore be very effective for treatment of some advanced gastric cancers.

Goblet cell carcinoid tumors of the appendix: An overview

Goblet cell carcinoid is an enigmatic and rare tumor involving the appendix almost exclusively. Since its identification in 1969, understanding of this disease has evolved greatly, but issues regarding its histogenesis, nomenclature and management are still conjectural. The published English language literature from 1966 to 2009 was retrieved via PubMed and reviewed. Various other names have been used for this entity such as adenocarcinoid, mucinous carcinoid, crypt cell carcinoma, and mucin-producing neuroendocrine tumor, although none have been found to be completely satisfactory or universally accepted. The tumor is thought to arise from pluripotent intestinal epithelial crypt-base stem cells by dual neuroendocrine and mucinous differentiation. GCCs present in the fifth to sixth decade and show no definite sex predominance. The most common clinical presentation is acute appendicitis, followed by abdominal pain and a mass. Fifty percent of the female patients present with ovarian metastases. The histologic hallmark of this entity is the presence of clusters of goblet cells in the lamina propria or submucosa stain for various neuroendocrine markers, though the intensity is often patchy. Atypia is usually minimal, but carcinomatous growth patterns may be seen. These may be of signet ring cell type or poorly differentiated adenocarcinoma. Recently molecular studies have shown these tumors to lack the signatures of adenocarcinoma but they have some changes similar to that of ileal carcinoids (allelic loss of chromosome 11q, 16q and 18q). The natural history of GCC is intermediate between carcinoids and adenocarcinomas of the appendix. The 5-year overall survival is 76%. The most important prognostic factor is the stage of disease. Appendectomy and right hemicolectomy are the main modalities of treatment, followed by adjuvant chemotherapy in select cases. There is some debate about the surgical approach for these tumors, and a summary of published series and recommendations are provided.

Role of interleukin polymorphisms in gastric cancer: "Pros and cons"

Helicobacter pylori (H. pylori) infection is the leading cause of gastric cancer worldwide. Infection with this bacterium causes a chronic active immune response that persists for the life of the host. The combination of bacterial factors, environmental insults, and the host immune response drives the initiation and progression of mucosal atrophy, metaplasia, and dysplasia toward GC. Among the host factors, IL-1 gene cluster polymorphisms (IL-1B encoding IL-1β and IL-1RN encoding IL-1ra, its naturally occurring receptor antagonist) play a decisive role in modulating the risk of developing hypochlorhydria, gastric atrophy and GC in the presence of H. pylori infection. In particular, one single nucleotide polymorphism in the IL-1B promoter (IL-1B-511C⁄T), and the short allele of a 86-bp variable number of tandem repeats polymorphism in the IL-1RN second intron (IL-1RN*2) are associated with an increased risk for GC. However this hypothesis is still to be fully confirmed. This review focuses on the divergent results obtained by several epidemiological and functional in vitro and in vivo studies and show that IL-1 genotyping has still no role in the clinical management of patients with H. pylori infection.

From chronic liver disorders to hepatocellular carcinoma: Molecular and genetic pathways

Hepatocarcinogenesis is a process attributed to progressive genomic changes that alter the hepatocellular phenotype producing cellular intermediates that evolve into hepatocellular carcinoma (HCC). During the preneoplastic phase, the liver is often the site of chronic hepatitis and/or cirrhosis, and these conditions induce liver regeneration with accelerated hepatocyte cycling in an organ that is otherwise proliferatively at rest. Hepatocyte regeneration is accelerated by upregulation of mitogenic pathways involving molecular and genetic mechanisms. Hepatic growth factors, inhibitors and triggers may also play a role. This process leads to the production of monoclonal populations of aberrant and dysplastic hepatocytes that have telomerase re-expression, microsatellite instability, and occasionally structural aberrations in genes and chromosomes. Development of dysplastic hepatocytes in foci and nodules and the emergence of HCC are associated with the accumulation of irreversible structural alterations in genes and chromosomes even if the genomic basis of the malignant phenotype is largely heterogeneous. Therefore, a malignant hepatocyte phenotype may be produced by changes in genes acting through different regulatory pathways, thus producing several molecular variants of HCC. On these bases, a key point for future research will be to determine whether the deletions are specific, due to particular loci in the minimally deleted regions of affected chromosome arms, or whether they are non-specific with loss of large portions of chromosomes or entire chromosome arms leading to passive deletion of loci. The final aim is the possibility of identifying a step where carcinogenetic processes could be terminated.

Parenchyma-sparing pancreatectomies for benign or border-line tumors of the pancreas

Standard pancreatic resections, such as pancreaticoduodenectomy, distal pancreatectomy, or total pancreatectomy, result in an important loss of normal pancreatic parenchyma and may cause impairment of exocrine and endocrine function. Whilst these procedures are mandatory for malignant tumors, they seem to be too extensive for benign or border-line tumors, especially in patients with a long life expectancy. In recent years, there has been a growing interest in parenchyma-sparing pancreatic surgery with the aim of achieving better functional results without compromising oncological radicality in patients with benign, border-line or low-grade malignant tumors. Several limited resections have been introduced for isolated or multiple pancreatic lesions, depending on the location of the tumor: central pancreatectomy, duodenum-preserving pancreatic head resection with or without segmental duodenectomy, inferior head resection, dorsal pancreatectomy, excavation of the pancreatic head, middle-preserving pancreatectomy, and other multiple segmental resections. All these procedures are technically feasible in experienced hands, with very low mortality, although with high morbidity rate when compared to standard procedures. Pancreatic endocrine and exocrine function is better preserved with good quality of life in most of the patients, and tumor recurrence is uncommon. Careful patient selection and expertise in pancreatic surgery are crucial to achieve the best results.

Embryonal sarcoma of the liver with chondroid differentiation

A 31-year-old female complained of upper abdominal and back pain. Laboratory tests showed elevated levels of aspartate aminotransferase, alanine aminotransferase and α-fetoprotein. Computed tomography revealed that the tumor, measuring 14.5 cm × 10.4 cm, occupied the anterior and medial segments of the liver and consisted of multicystic and solid lesions. The preoperative diagnosis was a hepatic cystadenocarcinoma. The operation was performed urgently because of tumor rupture. Histopathologically, spindle and asteroid cells were found to have proliferated diffusely. There were no neoplastic epithelial tumor cells. Tumor cells had periodic acid-Schiff-positive hyalin globules. At the periphery, trapped normal bile duct cells were observed. The final diagnosis was embryonal sarcoma of the liver (ESL). Interestingly, irregular islands of chondrosarcoma-like lesions were found in the tumor and the tumor-associated vascular endothelium showed immunoreactivity for KIT. Two months after the operation, the tumor recurred. At 6 mo follow-up, the patient is alive with the disease and undergoing chemotherapy. This is the first report of ESL with chondroid differentiation.

Intermittent gastric outlet obstruction caused by a prolapsing antral gastric polyp

Most gastric polyps have an asymptomatic presentation and are an incidental finding on upper endoscopy. Symptomatic presentations can range from an ulcerated polyp leading to anemia and occult bleed to complete gastric outlet obstruction. We report a case of an 89-year-old woman who presented with postprandial nausea and early satiety. Her upper endoscopy revealed a 2 cm pedunculated hyperplastic polyp arising from the antrum of the stomach which was seen prolapsing into the pylorus causing intermittent gastric outlet obstruction. In the present report, we statistically analyzed 39 prolapsing gastric polyps previously reported in the English literature and demonstrate the current utility of monopolar snare polypectomy in establishing a histological diagnosis while offering simultaneous treatment. Additionally, we review the literature for the management of all hyperplastic gastric polyps in relation to advancements in digestive endoscopy.

Perspectives on the treatment of colorectal carcinoma

Colorectal cancer includes cancerous growths in the colon, rectum and appendix. With 655000 deaths worldwide per year, it is the third most common form of cancer and the second leading cause of cancer-related death in the Western world. Advances in imaging, genetics, molecular diagnostics, surgical techniques and chemotherapy are now making significant gains in our ability to prevent, diagnose, and treat this serious disease. This article reviews some of these recent successes and shares a vision of future care based on current research.

Peroxisome proliferator activated receptor-γ and the ubiquitin-proteasome system in colorectal cancer

Peroxisome proliferator activated receptor-γ (PPARγ), a transcription factor of the nuclear receptor superfamily plays a significant role in colorectal cancer pathogenesis. In most experimental systems PPARγ activation has tumor suppressing effects in the colon. PPARγ is regulated at multiple levels by the ubiquitin-proteasome system (UPS). At a first level, UPS regulates PPARγ transcription. This regulation involves both PPARγ transcription specific factors and the general transcription machinery. At a second level UPS regulates PPARγ and its co-factors themselves, as PPARγ and many co-factors are proteasome substrates. At a third level of regulation, transduction pathways working in parallel but also having interrelations with PPARγ are regulated by the UPS, creating a network of regulation in the colorectal carcinogenesis-related pathways that are under UPS control. Activation of PPARγ transcription by direct pharmacologic activators and by stabilization of its molecule by proteasome inhibitors could be strategies to be exploited in colorectal cancer treatment.

Positron emission tomography as predictor of rectal cancer response during or following neoadjuvant chemoradiation

Positron emission tomography (PET) shows great promise as a tool to evaluate the effectiveness of rectal cancer neoadjuvant therapy as it has demonstrated high predictive value in several studies. Creating a standardized method of using PET has the potential to reduce ineffective treatments. However, relevant studies have been heterogenous in approach, making any unified standard difficult to establish. PET related parameters used to assess treatment response include magnitude and change of standard uptake value, total lesion glycolysis, and visual response. Finding the best evaluation interval and parameters to use for interpreting PET results in the neo-adjuvant treatment of rectal cancer needs additional study.

New progress in CT and MRI examination and diagnosis of small intestinal tumors

Precise examination and diagnosis of small intestinal tumors is difficult because of the curved course and overlapping canal of the small intestine. Traditional technology for intestinal canal examination and endoscopy cannot exhibit the intestinal wall and extra-luminal structure well. With the development and advancement of multi-slice spiral computed tomography and magnetic resonance imaging (MRI), computed tomography enteroclysis (CTE) and magnetic resonance enteroclysis (MRE) are widely used in the examination and diagnosis of small intestinal tumors. CTE and MRE, with three-dimensional imaging capabilities and excellent soft-tissue contrast, can analyze the abnormalities of peripheral intestinal structure as well as the tunica mucosa. In addition, these two technologies can clearly reveal the localization, appearance, degree of mesenteric infiltration and remote tumor metastasis, which increases our cognition of the imaging diagnosis for intestinal tumors. Here we review recent progress in imaging (CT and MRI) examination and diagnosis of small intestinal tumors.

Tumor stem cell, or its niche, which plays a primary role in tumorigenesis?

Cancer research over the past decades has focused on neoplastic cells, or a fraction of them, i.e. tumor stem cells, as the ultimate causes of tumorigenesis. However, during recent years, scientists have come to realize that tumorigenesis is not a solo act of neoplastic cells, but rather a cooperative process in which the roles of numerous types of non-neoplastic cells should be recognized. These tumor-residing non-neoplastic cells constitute the so-called tumor-associated stroma, which in certain cases even greatly surpasses the neoplastic cellular compartment that was previously thought of as a sole determiner leading to a seemingly autonomous growth pattern. In this review, we summarize several recent research highlights that have unveiled many previously unappreciated roles for microenvironmental factors, especially during the initiation stage of tumorigenesis. It is becoming increasingly clear that the stroma’s regulatory effects constitute not only an essential force for maintaining tumor growth, but also primary causes initiating tumorigenesis.

Isolated pancreatic metastasis of hepatocellular carcinoma after curative resection

Hepatocellular carcinoma (HCC) is a highly malignant tumor and extrahepatic metastasis is not rare. The most common organ of HCC metastasis is lung, followed by bone and adrenal gland. To the best of our knowledge, isolated pancreatic metastasis of HCC that developed after curative resection has not been described previously. We report a case of solitary pancreatic metastasis of HCC, which was found 28 mo after left hemihepatectomy for HCC. The lesion was successfully resected with the pancreas, and no other metastatic lesions have been found in follow-up.

Circulating galectin-3 in the bloodstream: An emerging promoter of cancer metastasis

Increased concentrations of free circulating galectin-3 are commonly seen in the blood circulation of patients with many types of cancers including colorectal cancer. Recent studies have shown that changes in circulating galectin-3 levels in cancer patients may contribute significantly to the metastatic spread of disseminating cancer cells by enhancing their ability to adhere to blood vessel endothelium and by helping their avoidance of immune surveillance. Thus, targeting the galectin-3 actions in the circulation may hold significant promise for future development of novel therapeutic agents to prevent metastasis and reduce cancer-associated fatality.

Early postoperative feeding in resectional gastrointestinal surgical cancer patients

Malnutrition is present in the majority of patients presenting for surgical management of gastrointestinal malignancies, due to the effects of the tumour and preoperative anti-neoplastic treatments. The traditional practice of fasting patients until the resumption of bowel function threatens to further contribute to the malnutrition experienced by these patients. Furthermore, the rationale behind this traditional practice has been rendered obsolete through developments in anaesthetic agents and changes to postoperative analgesia practices. Conversely, there is a growing body of literature that consistently demonstrates that providing oral or tube feeding proximal to the anastomosis within 24 h postoperatively, is not only safe, but might be associated with significant benefits to the postoperative course. Early post operative feeding should therefore be adopted as a standard of care in oncology patients undergoing gastrointestinal resections.

Appendiceal neuroendocrine tumors: Recent insights and clinical implications

New insights emerged last decade that enriched our knowledge regarding the biological behavior of appendiceal neuroendocrine tumors (NETs), which range from totally benign tumors less than 1cm to goblet cell carcinomas which behave similarly to colorectal adenocarcinoma. The clinical implication of that knowledge reflected to surgical strategies which also vary from simple appendicectomy to radical abdominal procedures based on specific clinical and histological characteristics. Since the diagnosis is usually established post-appendicectomy, current recommendations focus on the early detection of: (1) the subgroup of patients who require further therapy; (2) the recurrence based on the chromogranin a plasma levels; and (3) other malignancies which are commonly developed in patients with appendiceal NETs.

Perivascular epithelioid cell neoplasm of the colon

A 17-year-old female presented with rectal bleeding from an ulcerated sigmoid mass in 1994. Initial pathological evaluation revealed a rare clear cell neoplasm of the colon, possibly originating from kidneys, adrenals, lung or a gynecologic source as a metastatic lesion. Extensive imaging studies were negative, and over the next 15 years, she remained well with no recurrence. The original resected neoplasm was reviewed and re-classified as a perivascular epithelioid cell neoplasm (PEComa). Although the long-term natural history of PEComas requires definition, increased clinical and pathological awareness should lead to increased recognition of an apparently rare type of colonic neoplasm that likely occurs more often than is currently appreciated.

Gastric low-grade mucosal-associated lymphoid tissue-lymphoma: Helicobacter pylori and beyond

The stomach is the most frequently involved site for extranodal lymphomas, accounting for nearly two-thirds of all gastrointestinal cases. It is widely accepted that gastric B-cell, low-grade mucosal-associated lymphoid tissue (MALT)-lymphoma is caused by Helicobacter pylori (H. pylori) infection. MALT-lymphomas may engender different clinical and endoscopic patterns. Often, diagnosis is confirmed in patients with only vague dyspeptic symptoms and without macroscopic lesions on gastric mucosa. H. pylori eradication leads to lymphoma remission in a large number of patients when treatment occurs at an early stage (I-II₁). Neoplasia confined to the submucosa, localized in the antral region of the stomach, and without API2-MALT1 translocation, shows a high probability of remission following H. pylori eradication. When both bacterial infection and lymphoma recur, further eradication therapy is generally effective. Radiotherapy, chemotherapy and, in selected cases, surgery are the available therapeutic options with a high success rate for those patients who fail to achieve remission, while data on immunotherapy with monoclonal antibodies (rituximab) are still scarce. The 5-year survival rate is higher than 90%, but careful, long-term follow-up is required in these patients since lymphoma recurrence has been reported in some cases.