Colon and rectal carcinoma

Colonic carcinoid tumors: a clinicopathologic study of 23 patients from a single institution

CONTEXT: Colonic carcinoids, excluding those arising in the appendix, have proved to be extremely rare. Due to their rarity, the characteristics and behavior of this unusual malignancy remain unclear. OBJECTIVE: To review the clinicopathologic features of patients operated on carcinoid tumors of the colon. METHODS: Twenty-three patients (12 males and 11 females) were operated on colonic carcinoids. The mean age of the patients was 63.0 ± 12.9 years (42 to 85 years). The clinical and histopathological data of patients who were pathologically diagnosed as having carcinoid tumors and submitted to surgical treatment over a 30-year period (1977-2007) were gathered. Actuarial patient survival was estimated using the Kaplan-Meier method, with carcinoid-specific death as the outcome. RESULTS: The mean time elapsed between onset of symptoms and surgical treatment was 8.3 months (1.5 to 20 months). The most frequent symptoms or signs encountered were abdominal pain followed by anorexia or weight loss, diarrhea, abdominal tenderness, palpable abdominal mass, and rectal bleeding. No carcinoid syndrome was noted. The lesion was located in the cecum in 16 (69.6%) patients, in the sigmoid in 3 patients (13.0%), in the ascending colon in 3 patients (13.0%), and in the transverse colon in one patient (4.3%). Twenty-one (91.3%) patients were operated on curative intent. Spreading of the disease to the liver and peritoneum was found in two (8.7%) patients who submitted to intestinal bypass. The mean size of the largest mass was 3.7 ± 1.2 cm (1.5 to 6.2 cm). There were multiple (two or more) lesions in three cases (13.0%). In the resected cases, the lymph nodes were compromised in 10 patients (47.6%) and disease-free in 11 (52.4%). Venous invasion and neural infiltration were both present in five (23.8%) patients. The tumors had penetrated the muscularis propria in all resected cases. Four (17.4%) patients had a second non-carcinoid primary tumor. Three (13.0%) patients died due to postoperative complications and five (21.7%) patients died from metachronous metastases or local recurrence. Fifteen patients (65.2%) remain alive without evidence of active disease. The mean follow-up period was 12 years (1.2 to 18 years), whereas the mean global survival was 50.7 ± 34.2 months and the crude survival rate at 5 years was 62.7%. CONCLUSIONS: Carcinoid tumors of the colon are frequently right-sided and may be clinically occult until an advanced stage is reached. Based on the relatively poor survival rates reported, it is recommended that, in addition to standard surgical resection, vigorous surveillance for metastatic disease must be performed, particularly during the first 2 years after surgery. In addition, these patients require evaluation of the entire gastrointestinal tract for evidence of coexisting malignancy, along with an extended period of follow-up, because tumor recurrences after 5 years are not uncommon.

Adjuvant treatment of colon and rectal cancer: impact of chemotherapy, radiotherapy, and immunotherapy on routine postsurgical patient management. Forschungsgruppe Onkologie Gastrointestinaler Tumoren (FOGT)

Colon cancer patients with UICC stage III or T4 N0 M0 stage II should receive postoperative adjuvant therapy, since relapse rates are high and surgical outcome has been improved by adjuvant treatment. The standard treatment is 5-fluourouracil plus levamisole; an alternative option is the combination of 5-fluourouracil and folinic acid. Stage II (T3 N0 M0) colon cancer patients should not receive adjuvant treatment outside of studies. Rectal cancer patients of stage II or III should receive postoperative radiochemotherapy with 45-54.4 Gy and 5-fluourouracil as standard treatment. Patients not eligible for radiotherapy may receive adjuvant chemotherapy only. Studies need to be conducted to improve adjuvant therapy in colorectal cancer. All qualified patients should be treated within these studies requiring sufficient patient numbers, as well as comparable surgical procedures, proper patient selection and stratification criteria, drug and dose intensities. Intraportal infusion may be as effective as systemic adjuvant treatment; the tumor type and stage for which benefit from this kind of treatment is consistently significant needs to be defined, since intraportal infusion of all resectable colorectal cancers is overtreatment. Both surgery and histopathological staging may be improved in some centers, and these require standardization and quality control.

Expression and role of integrins in adhesion of human colonic carcinoma cells to extracellular matrix components

We have examined integrin expression and function in the human colon carcinoma cell line HT29, and in clonal sublines derived from the HT29 line. These cells express several different integrin subunits including beta 1, alpha 2, 3, 6 and alpha v, but do not express the classic alpha 5/beta 1 fibronectin receptor. Clonal variation in the pattern of integrin expression was quite limited. The profile of integrin expression correlates well with the adhesive behavior of HT29 cells. Thus the cells adhere well to vitronectin, laminin and type IV collagen, but not at all to fibronectin. Adhesion to collagen was completely blocked by an anti-beta 1 monoclonal antibody, indicating that beta 1 integrins mediate this process. Adhesion to laminin was strongly blocked by anti-beta 1 monoclonal or anti-beta 6 monoclonal, suggesting that the alpha 6/beta 1 complex functions in attachment to laminin; this was somewhat surprising since immunoprecipitation experiments indicate that most of the alpha 6 subunit seems to be associated with the beta 4 subunit. Despite their strong adherence to laminin, collagen and vitronectin, HT29 cells are not very motile and, in response to gradients of these proteins, do not migrate nearly as well as CHO cells tested under similar conditions. Since HT29 cells can undergo an enterocyte-like differentiation in glucose-free medium, we compared integrin expression in HT29 and its subclones during the process of differentiation. There was no correlation between the state of differentiation, as assessed by expression of brush-border hydrolases, and the level of expression of any of the integrin subunits measured. Thus the pattern of integrin expression in these colonic tumor cells seems to be a characteristic of the cell line, and is not readily modified by changes in cell growth or differentiation.

Adjuvant post-operative radiotherapy in rectal cancer: results from the ANZ Bowel Cancer Trial (Protocol 8202)

In July 1982 the Gastrointestinal Section of The Clinical Oncological Society of Australia began a multicentre randomized trial to assess the value of post-operative pelvic radiotherapy in the local control of stage B and C carcinoma of the rectum. Patients who had undergone a potentially curative resection were randomized either to no further treatment (NO RT) or to pelvic radiotherapy (RT), 45 Gy in 25 fractions (plus a perineal boost of 5 Gy in 2 fractions after abdomino-perineal resection). The trial was prematurely terminated in December 1985 owing to slow accrual after 70 patients had been randomized: 36 patients to RT and 34 patients to NO RT. Two patients in each group were found to be ineligible after randomization and, for a variety of reasons, thirteen patients who were randomized to RT did not receive that treatment. The incidence of post-operative complications were comparable in both groups, indicating that radiotherapy produced no additional problems. Radiotherapy-related morbidity comprised mainly diarrhoea (grade 1 = 2/21; grade 2 = 5/21; grade 3 = 0/21; grade 4 = 1/21). There were no deaths due to radiotherapy and only one patient, with grade 4 diarrhoea, failed to complete the prescribed course of radiotherapy. After an average follow-up period of 52 months there were 15 local recurrences, 8 in the RT group and 7 in the NO RT group, giving an actuarial 2 year local recurrence rate of 16%. There was no difference in the time to local recurrence, either by randomization group (p = 0.50) or by actual treatment received (p = 0.91).(ABSTRACT TRUNCATED AT 250 WORDS)

Linitis plastica of the colon: computed tomography findings

Primary linitis plastica of the colon is a rare entity and its radiographic findings have been described previously in the literature. We present the computed tomography findings of this unusual lesion and briefly review its pathogenesis.

Applications of molecular genetics to gastrointestinal and liver diseases. II. Clinical relevance

The use of DNA probes within or near disease genes is becoming increasingly important in clinical medicine. Probes are available for prenatal and carrier diagnosis for several of the more than 100 genetic diseases of the gastrointestinal tract and liver. These include familial adenomatous polyposis, haemochromatosis, cystic fibrosis, alpha 1-antitrypsin deficiency and the hereditary porphyrias. This review uses examples drawn from such diseases to show the relevance of these approaches to the clinician.