Colorectal cancer and high grade dysplasia complicating ulcerative colitis in Italy. A retrospective co-operative IG-IBD study

BACKGROUND

Ulcerative colitis is a well-known risk factor for colorectal cancer.

AIM

To take a census of the cases of colorectal cancer in ulcerative colitis patients observed in Italy and to evaluate the clinical presentation of neoplastic complication.

PATIENTS AND METHODS

Experts from 28 Italian centres specialised in the management of inflammatory bowel disease or malignancies participated to the study. They were invited to send clinical data of patients with ulcerative colitis complicated by colorectal cancer or high-grade dysplasia consecutively observed between 1985 and 2000. One hundred and twelve patients (92 with cancer and 20 with high-grade dysplasia) were collected. Fourteen of them had undergone colectomy and ileo-rectal anastomosis for ulcerative colitis. Data of surgical patients were analysed separately.

RESULTS

The mean age at diagnosis of ulcerative colitis and colorectal cancer patients was 39.3 and 53.2 years, respectively, and the mean duration between diagnosis of ulcerative colitis and cancer was 13.9 years (range 0-53). Inflammation was proximal to the splenic flexure in 71 cases (76.3%). One hundred and three colorectal cancers were registered (93 patients with single lesion and five patients with two synchronous cancers), with 76.7% of cancers being located in the left colon. As to the surgical patients, the mean age at diagnosis of ulcerative colitis and cancer was 28.9 and 47.0 years, respectively, and the mean diagnostic interval for ulcerative colitis and cancer was 18.1 years. Only 51 out of 112 patients were in follow-up. An early diagnosis of neoplasia (high grade dysplasia, stage A or B sec. Dukes) occurred in 72.5% of patients who were subjected to endoscopic surveillance and in 48.0% of patients who did not undergo endoscopic surveillance (p=0.02).

CONCLUSIONS

These data show an earlier diagnosis of cancer in patients who had undergone endoscopic surveillance. The poor compliance to the follow-up program, however, reduces its effectiveness. Moreover, total colectomy allows an easier follow-up, with only the rectum being controlled. Colectomy with ileo-rectal anastomosis or proctocolectomy with ileo-anal anastomosis, could represent a valid alternative in patients at high risk of cancer who refuse endoscopic surveillance.

Two mesalazine regimens in the prevention of the post-operative recurrence of Crohn's disease: a pragmatic, double-blind, randomized controlled trial

BACKGROUND

The role of mesalazine in preventing the clinical recurrence of Crohn's disease after surgery has been shown in a meta-analysis of all published studies. No clear relationship, however, has been shown between dosage and response.

AIM

To evaluate whether 4.0 g/day of mesalazine may offer therapeutic advantages over 2.4 g/day in the prevention of both endoscopic and clinical post-operative recurrence of Crohn's disease.

METHODS

The study was a double-blind, randomized, multi-centre, prospective, controlled clinical trial. Two hundred and six patients, submitted to first or second intestinal resection for Crohn's disease limited to the terminal ileum, with or without involvement of the caecum/ascending colon, were enrolled. Of these, 101 were randomly allocated to receive 4.0 g/day of mesalazine (Asacol, Giuliani SpA, Milan, Italy) and 105 to receive 2.4 g/day, starting 2 weeks after surgery. The primary outcome was endoscopic recurrence, at 12 months after surgery. Three different degrees of endoscopic recurrence were evaluated (endoscopic scores: > 0, > 1 and > 2). The secondary outcome was clinical recurrence, defined as a Crohn's disease activity index of more than 150 points or an increase in the Crohn's disease activity index of 100 points or more. For statistical analysis, chi-square, Wilcoxon and Cox regression model tests were used, when appropriate.

RESULTS

Eighty-four patients in the 4.0 g/day group and 81 patients in the 2.4 g/day group were evaluable by endoscopy. Endoscopic recurrence of > 0 was significantly higher in the 2.4 g/day group than in the 4.0 g/day group (62% vs. 46%; P < 0.04). No difference was observed between the two groups with regard to the other two endoscopic outcomes (> 1 and > 2) or clinical recurrence.

CONCLUSIONS

A 4.0 g/day regimen of mesalazine does not offer a clinically significant advantage over a 2.4 g/day regimen in the prevention of post-operative endoscopic and clinical recurrence of Crohn's disease at 1 year of follow-up.

Mutations of the APC gene in human sporadic colorectal cancers

BACKGROUND

Mutations of the APC gene are reported to occur frequently in sporadic colorectal adenomas and adenocarcinomas. We studied APC gene mutations in cases of human sporadic colorectal cancer in order to evaluate their correlation with pathologic characteristics and clinical prognosis.

METHODS

Most of the mutations of the APC gene (95%) are nonsense or frame shift mutations, encoding for truncated APC proteins. For this reason, mutation detection of the APC gene was performed using the in vitro synthesized protein (IVSP) assay, analysing the region between nucleotide 2058 and nucleotide 5079 of the gene, containing the mutation cluster region.

RESULTS

Out of 58 cases of colorectal cancer, 29 presented a mutated form of APC (mutation frequency 50%). We did not find a statistically significant correlation between APC gene mutation and age, sex, localization of the primary tumour, grading, Crohn-like lymphoid reaction or presence of residual adenoma. Tumours with low invasivity (Dukes' stages A and B) were less frequently mutated (12/27, 44.5%) than tumours of Dukes' stage C (15 out of 21, 71.4%), which developed macroscopically secondary metastasis with variable latency after surgery. Highly invasive tumours with synchronous metastases (Dukes' stage D) had, instead, a low frequency of APC mutations (20%, 2/10) (P = 0.02, compared with Dukes' stages A, B and C).

CONCLUSIONS

These data suggest that more aggressive Dukes' stage D tumours develop metastasis by means of an unknown mechanism, independent of APC mutation.

Biotherapeutics and biotherapy of surgical enteropathies

Probiotic agents are living micro-organisms that, upon ingestion, exert health benefits beyond inherent general nutrition. In this context, we must differentiate between biotherapeutics as approved drugs and dietary supplements and food products containing prebiotic bacteria that are not considered drugs. At present, the only biotherapeutic agent which is prescribable in some European countries, indicated to relieve specific diseases, is the yeast Saccharomyces boulardii. In this review, we consider the various pre-clinical and clinical aspects of biotherapeutics as basic drugs and the biotherapeutic powers of their use in the treatment of some surgical enteropathies.

Cytoskeletal proteins and resident flora

Recent observations demonstrate that enteropathogenetic and enterohaemorrhagic bacteria, as well as other non enteropathogenetic bacteria (Listeria, Coxiella Burnetii), may subvert the host cell cytoskeleton. Models from enteropathogenic bacteria demonstrate that cytoskeletal proteins are required for bacteria binding to the enterocytes and that they play a role in the immune response of the host to intestinal bacteria. The cytoskeletal protein family Tropomyosins is present in all eukaryotic cells, with multiple isoforms regulated by multiple genes. Of the different Tropomyosin isoforms, TM5 has been shown to be expressed in colonic and jejunal epithelial cells, while TM1 in colonic and jejunal smooth muscle. In vitro studies have shown the presence of serum and mucosal IgG against TM5 in almost two thirds of patients with ulcerative colitis, suggesting: a. a possible autoimmune response to Tropomyosin in these patients; b. the hypothesis that the development of pouchitis may be related to the expression of TM5 in the ileal pouch; c. the use of probiotics in the treatment of pouchitis. Overall, the new expression of cytoskeletal proteins on the cell surface appears to be possibly induced by several mechanisms, including intestinal bacteria and apoptosis. The expression of cytoskeletal proteins on the cell surface may induce tolerance or autoimmune response on target cells. Further investigations are, however needed on the possible role of cytoskeletal proteins in human diseases.

Microsatellite instability in a population of sporadic colorectal cancers: correlation between genetic and pathological profiles

BACKGROUND

Tumours with high-frequency microsatellite instability exhibit unique genotype and phenotype features, whereas the difference between low-frequency microsatellite instability and apparently stable tumours is far from being clear.

AIMS

To identify distinctive genetic and pathological characteristics of low-frequency microsatellite instability tumours.

METHODS

Microsatellite instability status of 57 sporadic colorectal cancers and its correlation with genetic, pathological and clinical features was analysed.

RESULTS

High frequency microsatellite instability and low-frequency microsatellite instability and apparently stable cancers were different in terms of tumour localisation (p=0.015), frequency of APC mutations (p=0.012), occurrence of Crohn's-like/lymphoid reaction (p=0.0353) and morphological evidence of origin from an adenoma (p=0.0338). Specifically, in low-frequency microsatellite instability cancers, APC mutations were very frequent (76.9%, 10/13) and a Crohn's-like/lymphoid reaction was common (38.5%, 5/13). High-frequency microsatellite instability tumours were preferentially located in the right colon and exhibited a higher frequency of loss of heterozygosity at the FHIT locus compared with low-frequency microsatellite instability and apparently stable cases (p=0.0243). Dukes' stage (p=0.0021), tumour localisation (p=0.0410) and pattern of cancer growth (p=0.0374), were the only factors affecting patient survival. However, a borderline improvement was noted in overall survival in high-frequency microsatellite instability and low-frequency microsatellite instability cancer patients (p=0.062).

CONCLUSIONS

These results indicate that low-frequency microsatellite instability tumours have different genetics and histological features and suggest that they are a distinct group of colorectal cancers.

Amoxicillin/clavulanic acid versus cefotaxime for antimicrobial prophylaxis in abdominal surgery: a randomized trial

Amoxicillin/clavulanic acid (amoxicillin 2 g/clavulanic acid 200 mg) has been administered in comparison to cefotaxime (2 g) for antimicrobial prophylaxis in 476 evaluable patients undergoing abdominal surgery at high risk of septic complications. Both antibiotics were administered as a single infusion. 205 evaluable patients (110 in amoxicillin/clavulanic acid group and 95 in cefotaxime group) underwent upper gastrointestinal surgery (including gastroduodenal and biliary surgery). The wound infection rate was 4.5% for amoxicillin/clavulanic acid and 7.4% for cefotaxime, with no significant differences. Intra-abdominal abscesses were observed in 3 patients in the amoxicillin/clavulanic acid group and in 1 patient in the cefotaxime group. 271 evaluable patients (135 in amoxicillin/clavulanic acid group and 136 in cefotaxime group) underwent lower gastrointestinal surgery (including colorectal surgery). The wound infection rate was 11% for amoxicillin/clavulanic acid and 13% for cefotaxime, with no significant differences. A purulent discharge was present in 3 patients in both groups. Intra-abdominal abscesses were observed in 3 patients in the amoxicillin/clavulanic acid group and in 4 patients in the cefotaxime group. No serious adverse events and no cases of diarrhea were observed. In conclusion, in our experience amoxicillin/clavulanic acid proved to be as effective as cefotaxime in protecting patients from surgical infections in abdominal surgery. Its use in surgical prophylaxis may help decrease the cost of treatment and reduce the risk of resistance to antibiotics and superinfections.

Estrogen metabolism in human colorectal cancer cells

Epidemiological and "in vitro" studies support a direct role of estrogens in the pathogenesis and/or progression of colorectal cancer (CRC). Recent observations suggest a local synthesis of 17beta-estradiol (E(2)). In the present study, the CRC estrogen receptor beta (ERbeta) positive HCT8, HCT116, DLD-1 and LoVo cell lines were evaluated for expression of functional 17beta-hydroxysteroid dehydrogenase (17betaHSD) types 1, 2, 3, and 4. RT-PCR analysis revealed that while 17betaHSD1 and 17betaHSD4 were expressed in all the four cell lines, 17betaHSD2 and 17betaHSD3 were expressed in a cell-specific manner. The interconversion of tritiated estrone (E(1)) or E(2) evaluated by thin layer chromatography of conditioned media revealed that in HCT8, HCT116, and DLD-1 cells both reductive and oxidative activities were present, the latter showing K(m) values (approximately 10 microM) 40-fold higher than the former (approximately 250 nM). On the contrary, in LoVo cells, estrogens were almost (approximately 90%) completely metabolized to hydrophile compounds. Charcoal-dextrane (DC) stripped fetal calf serum (FCS) (10%), E(2) (10nM), Vitamin D(3) (100nM) and the combined E(2) and Vitamin D(3) treatment were evaluated for modulation of 17betaHSD isoenzymes gene expression and activity. Gene expression and activity of 17betaHSD reductive and oxidative isoenzymes were respectively inhibited and enhanced by Vitamin D(3) in HCT8 and LoVo cells. Surprisingly, DC-FCS induced a marked increase of estrogen metabolism toward hydrophile metabolites in all four cell lines. In conclusion, our results clearly show that metabolism of estrogens by 17betaHSD isoenzymes is functional and modulated by external stimuli in continuous neoplastic colonic epithelial cell lines.

Procalcitonin as an early marker of postoperative infectious complications

BACKGROUND

Procalcitonin (PCT) is a new marker for severe infection that is supposed to have a useful role in the early detection of bacterial infection in the perioperative period.

AIM OF THE STUDY

to test the hypothesis that PCT is useful as an early marker of postoperative infectious complications.

METHODS

Thirty-three patients were submitted to major abdominal interventions that comprehend an intestinal resection (mean age: 49.9+/-19.3 years; 19 males, 14 females). PCT was tested at 4 times: T1=preoperative; T2=6 hours after starting interventions; T3=24 hours after; T4=48 hours after.

STATISTICAL

"t"-Student test and Pearson correlation.

RESULTS

In the postoperative course 11 patients had infectious complications that were: 3 wound infections, 2 positive haemocolture, 1 pneumonia, 3 deep abdominal infections, 2 anastomotic dehiscences. In these patients only the 24 hours PCT assay at T3 was higher than in the other patients that had not complications (microgram/ml 4.74+/-3.8 vs 1.22+/-0.8; p<0.0001). The cut off value of 1 ng/ml has a sensibility of 70% and a specificity of 81%.

CONCLUSIONS

PCT detection appear to be an important aid for early diagnosis of postoperative infectious complications when it is used with the other indexes.

Guidelines for diagnosis and therapy of MEN type 1 and type 2

This is a consensus statement from an international group, mostly of clinical endocrinologists. MEN1 and MEN2 are hereditary cancer syndromes. The commonest tumors secrete PTH or gastrin in MEN1, and calcitonin or catecholamines in MEN2. Management strategies improved after the discoveries of their genes. MEN1 has no clear syndromic variants. Tumor monitoring in MEN1 carriers includes biochemical tests yearly and imaging tests less often. Neck surgery includes subtotal or total parathyroidectomy, parathyroid cryopreservation, and thymectomy. Proton pump inhibitors or somatostatin analogs are the main management for oversecretion of entero-pancreatic hormones, except insulin. The roles for surgery of most entero-pancreatic tumors present several controversies: exclusion of most operations on gastrinomas and indications for surgery on other tumors. Each MEN1 family probably has an inactivating MEN1 germline mutation. Testing for a germline MEN1 mutation gives useful information, but rarely mandates an intervention. The most distinctive MEN2 variants are MEN2A, MEN2B, and familial medullary thyroid cancer (MTC). They vary in aggressiveness of MTC and spectrum of disturbed organs. Mortality in MEN2 is greater from MTC than from pheochromocytoma. Thyroidectomy, during childhood if possible, is the goal in all MEN2 carriers to prevent or cure MTC. Each MEN2 index case probably has an activating germline RET mutation. RET testing has replaced calcitonin testing to diagnose the MEN2 carrier state. The specific RET codon mutation correlates with the MEN2 syndromic variant, the age of onset of MTC, and the aggressiveness of MTC; consequently, that mutation should guide major management decisions, such as whether and when to perform thyroidectomy.

Preclinical and clinical pharmacology of biotherapeutic agents: Saccharomyces boulardii

Probiotic agents are living microorganisms that, upon ingestion, exert health benefits beyond inherent general nutrition. In this context, we must differentiate between biotherapeutics as approved drugs and dietary supplements and food products containing probiotic bacteria that are not considered drugs. At present the only biotherapeutic agent which is prescribable in some European countries, indicated to relieve specific diseases, is the yeast Saccharomyces boulardii. In this review we consider the various preclinical and clinical aspects of biotherapeutics as basic drugs and the biotherapeutic powers of their use in the treatment of some surgical enteropathies.

[Somatostatin receptors in non-endocrine tumours]

The study of the antiproliferative action of somatostatin (ss) is important not only to understand the regulation of neuroendocrine tumours that express receptors (sst), but also non-endocrine tumours which express these receptors. We previously demonstrated the presence of sst2 in a wide panel of cell lines from human neuroblastoma. Although hypotheses have been put forward that treatment with ss or its analogs may be beneficial in oncological patients, this does not appear to be the case in neuroblastoma; patients with high sst2 levels (who are therefore sensitive to ss treatment) have per se a relatively positive outcome. Therefore, adjuvant treatment with ss is not necessary. Viceversa, patients with a poor prognosis are essentially characterized by a low expression of sst2 (and therefore are insensitive to a therapy with ss). In these patients adjuvant treatment with ss might be indicated, but would have little chance of success. Although the majority of neuroendocrine tumours expresses sst2, pancreas and prostate cancer express sst1 but not sst2, and are therefore insensitive to octreotide treatment which binds preferentially to sst2. Tumours like colorectal carcinoma and breast cancer also express sst2 in their more favourable forms. However, the concentration of sst2 in colorectal cancer is similar, if not lower than that in the surrounding normal tissue. Therefore, the probability of successful adjuvant therapy with ss is relatively low. In breast cancer, it is possible that sensitivity to estrogens may have a positive influence on the expression of sst2. This might justify clinical trials with ss in breast cancer.

The importance of the unsuppressed glands in the study of intact parathyroid hormone disappearance after parathyroid adenomectomy

BACKGROUND

In the usual techniques for intraoperative intact parathyroid hormone (iPTH) monitoring for primary hyperparathyroidism, the normal glands are implicitly considered suppressed. On the contrary, we believe, as do other researchers, that they are not totally suppressed.

METHODS

For this reason, we considered the introduction of an infusion from the unsuppressed normal glands (UNG), described by an influx constant (IC (pg/ml per min)), into the formulation of a two-compartment model. For the blood compartment, we have: C(t)=A.exp(-at)+B.exp(-bt)+EV, where A+B+EV=iPTH concentration at zero time (clamping), EV (equilibrium value)=IC/k, 'a' and 'b' are reciprocals of the time constants of the two exponentials and k=rate constant of elimination from the blood. The experimental data were obtained using an IRMA standard method, collecting samples in 20 patients, during and following adenomectomy.

RESULTS

In spite of the variability among the patients, all fits were very good, thus confirming the importance of the UNG contribution to the shaping of the disappearance curve. For this reason, the relationship between the constant infusion from the UNG and the basal iPTH level at the induction of anaesthesia (BV), was studied.

CONCLUSIONS

The existence of a negative correlation, together with the determination of a regression curve (IC=6.5BV), not only confirmed our assumptions, but also revealed the theoretical possibility of a priori knowledge of the iPTH contribution from the UNG. Hence, there is a theoretical possibility of discriminating between this contribution and that of the remaining (if any) affected gland(s).

Microencapsulation of human parathyroid cells: an "in vitro" study

BACKGROUND

Patients affected by hypoparathyroidism of variable etiology are currently treated with exogenously administered vitamin D and calcium. Human parathyroid transplantation has long been investigated as a possible mean of treating these patients to prevent long-term hypocalcemia. However, the main obstacle for this treatment is represented by tissue rejection. A reliable method to efficiently protect the transplanted tissue from rejection and to allow long-term survival of the graft is the encapsulation of tissues or cells in alginate-polylysine-alginate membranes, which were successfully used for encapsulation of islets of Langerhans. The microencapsulation of parathyroid tissue fragments or of parathyroid cells becomes, therefore, a potential approach for the successful treatment of permanent symptomatic hypoparathyroidism without pharmacological immunosuppression.

MATERIALS AND METHODS

We describe microencapsulation of differentiated human parathyroid cells derived from adenoma or hyperplastic glands. Long-term viability, cell growth, and parathyroid hormone production of microencapsulated cells were evaluated together with responsiveness to extracellular Ca(2+).

RESULTS

Microencapsulated parathyroid cells maintained proliferative and differentiative properties for a long term in culture with a good response to extracellular Ca(2+) concentration.

CONCLUSIONS

These findings represent a crucial step toward the construction of functional bioartificial parathyroid organoids for the treatment of hypoparathyroidism in humans.

Substance P (neurokinin-1) and neurokinin A (neurokinin-2) receptor gene and protein expression in the healthy and inflamed human intestine

Increasing evidence suggests that tachykinins are involved in the control of pathophysiological states, such as inflammation. The precise localization of tachykinin receptors is of paramount importance in the search for their possible physiological and pathological role; in this study, therefore, we attempted to define cellular sites of substance P (NK-1R) and neurokinin A (NK-2R) receptor expression in the healthy and the inflamed human intestine by in situ hybridization and immunohistochemistry. In the normal ileum and colon, NK-1R and NK-2R were localized to smooth muscle cells of the muscularis mucosae and propria and a few inflammatory cells of the lamina propria; NK-1R expression was also found in the muscular wall of submucosal blood vessels, enteric neurons and, to a lesser degree, in surface epithelial cells. Patients with Crohn's disease and ulcerative colitis showed a dramatic increase in NK-1R density relative to controls, in both the inflamed and the uninvolved mucosa. Up-regulation of NK-1R was particularly evident on epithelial cells lining the mucosal surface and crypts, as well as on endothelial cells of capillaries and venules. Also, a marked increase in NK-2R expression was found in both groups of patients on inflammatory cells of the lamina propria, especially eosinophils. Our findings demonstrate that in the normal human intestine NK-1R and NK-2R are expressed in multiple cell types, which are endowed with different physiological functions; in addition, they demonstrate that both NK-1R and NK-2R are up-regulated in patients with Crohn's disease and ulcerative colitis. Taken together, these observations may have important physiological and pathophysiological implications, and provide the rationale for the use of NK-1R and NK-2R antagonists in the treatment of inflammatory bowel disease.

Marked variation of thymidylate synthase and folylpolyglutamate synthetase gene expression in human colorectal tumors

Patients with advanced colorectal cancer are currently being treated with 5-fluorouracil (5-FU)-based chemotherapy. A growing number of patients with resectable disease receive adjuvant therapy with 5-FU/levamisole (LEV) or 5-FU/folinic acid (LV). However, many patients still fail on these treatments, due to occurrence of natural or acquired tumor resistance. Among clinically relevant mechanisms of resistance to fluoropyrimidines, increased expression of thymidylate synthase (TS) has been emphasized. Another potentially relevant mechanism involves a decrease in folylpolyglutamate synthetase (FPGS) expression. To establish the value of these genes as prognostic factors and predictors of the outcome of 5-FU-based chemotherapy in colorectal cancer, we measured their expression in colorectal tumors from patients undergoing surgery and postoperative chemotherapy and compared it with that in normal colonic mucosa. This was done by a semi quantitative, nonradioisotopic polymerase chain reaction (PCR) method using beta-actin as an internal standard and expressed as a TS/beta-actin or a FPGS/beta-actin mRNA ratio. In tumor samples from 21 colorectal cancer patients, TS gene expression varied 118-fold. The median TS/beta-actin ratio was, in fact, 41.36 x 10(-3) (range 2.49 x 10(-3) to 294.54 x 10(-3)). Little variation in TS gene expression was observed in corresponding normal colic mucosa; the TS/beta-actin gene ratio was lower (median 26.16 x 10(-3); range 8.49 x 10(-3) to 69.49 x 10(-3)). Among tumor explants from 20 patients, FPGS expression varied over 161-fold. A similar marked variation was also observed in normal colonic mucosal samples (over 185-fold). Overall and disease-free survival data suggest an inverse association between the level of tumor TS and FPGS expression and clinical prognosis. The availability of this sensitive and accurate assay for gene expression should now make it possible to extend these laboratory/clinical correlations to larger populations.

Strictureplasty in Crohn's disease: surgical option

PURPOSE

The objective of this study was to review early and late results of our personal experience with strictureplasty for patients affected by Crohn's disease.

METHOD

During a 16-year period, 44 of 383 patients underwent strictureplasty. Of the 269 strictures present at surgery, 174 were treated by performing strictureplasties (156 were closed transversely according to the Heineke-Mikulicz technique, 16 were done side-to-side in the Finney manner, and 2 were done according to Jaboulay technique), and 88 were treated with a synchronous resection. An individualized technique was used for seven other strictures, with side-to-side ileocolic (5 strictures in 3 patients) or ileoileal anastomosis (2 strictures in one patient).

RESULTS

No operative mortality was recorded, nor were septic complications caused by anastomotic leakage observed. The mean follow-up period was 47.8 +/- 42.4 (range, 3-132) months. After a median follow-up period of 50 (range, 18-89) months, a second operation for symptomatic recurrence was performed on ten patients, and two of them developed new symptomatic strictures after 3 and 36 months, requiring a third operation. Symptomatic restrictures of previous strictureplasty sites requiring surgery occurred in 8.8 percent of cases. Furthermore, no statistically significant difference (Kaplan-Meier) was observed in the reoperation rate among the patients with skip lesions or closed strictures or among patients treated by strictureplasty alone or with associated resection.

CONCLUSION

We conclude that strictureplasty is a valuable adjunct or alternative to resection in the treatment of Crohn's strictures.

Transcript dosage effect in familial adenomatous polyposis: model offered by two kindreds with exon 9 APC gene mutations

Analysis of genotype-phenotype correlations in familial adenomatous polyposis (FAP) patients demonstrated that the phenotypic heterogeneity of FAP is partly related to the mutation site. We investigated the molecular basis for the difference in severity of colorectal disease observed comparing FAP patients from two kindreds with neighbouring germline mutations in exon 9 of the APC gene. Patients from one kindred presented with a attenuated form of FAP, characterized by a low number of colorectal adenomas (up to 22). In FAP patients from this kindred, the APC gene mutation was localized at codon 367, in the portion of exon 9 that is alternately spliced. This is expected to result in the splicing-out of the mutation site in a fraction of mRNA molecules and in the residual production of wild-type transcripts from the mutant APC allele. Patients from the other kindred manifested a FAP phenotype characterized by hundreds of colorectal adenomas (320 to > 500). In these patients, the APC gene mutation abolished the donor site of exon 9a, used in both alternately spliced isoforms of the exon. The analysis of the relative levels of mutant and wild-type transcripts in unaffected colonic mucosa demonstrated that the mutant allele was not expressed. The model offered by our FAP patients with neighbouring exon 9 APC mutations supports the view that in addition to the mutation site, the type of mutation and transcript dosage effects contribute to the heterogeneity of disease phenotypes.

Anastomotic configuration and mucosal 5-aminosalicyclic acid (5-ASA) concentrations in patients with Crohn's disease: a GISC study. Gruppo Italiano per lo Studio del Colon e del Retto

OBJECTIVE

Recurrence of Crohn's disease quite inevitably occurs after resection of distal small bowel and proximal colon, involving the neoterminal ileum close to the anastomosis. Oral 5-aminosalicylic acid (5-ASA) administered soon after surgery delays recurrence and reduces its severity. We recently observed that in operated patients submitted to prophylactic treatment with oral 5-ASA the rate of recurrence was significantly higher in those with end-to-end anastomosis than in those with other types of anastomosis (end-to-side, side-to-side). The hypothesis investigated in the present study was that patients with end-to-side or side-to-side anastomosis would benefit from a higher mucosal concentration of 5-ASA with respect to patients with end-to-end anastomosis. Therefore, the mucosal 5-ASA concentration was measured in the perianastomotic area of both groups.

METHODS

The study was carried out in 19 patients submitted to radical surgery for Crohn's ileitis or ileocolitis, under oral prophylactic treatment with 5-ASA (Asacol). All patients were on regular endoscopic follow-up and were free of recurrence. Two biopsies were collected 3 cm from the anastomosis, in the neoterminal ileum, and two biopsies were collected at the colonic site 3 cm below the anastomosis. 5-ASA concentrations (ng/mg) were measured in tissue homogenates by high-performance liquid chromatography (HPLC) with electrochemical detection.

RESULTS

The mucosal concentration of 5-ASA in the neoterminal ileum was significantly lower in patients with end-to-end anastomosis than in those with other types of anastomosis (median values: 29.4 ng/mg vs 92.9 ng/mg respectively; p < 0.001). Six of 10 patients (60%) with end-to-end anastomosis, but none of the nine patients with other types of anastomosis, showed 5-ASA mucosal concentrations <40 ng/mg at the neoterminal ileum. On the contrary, no patients with end-to-end anastomosis showed mucosal concentrations of 5-ASA >90 ng/mg, compared with the 57% of patients in the group with other types of anastomosis. No differences were observed for colonic biopsies.

CONCLUSIONS

The different mucosal concentrations in these two groups may be explained by the difference in segmental transit time induced by the different anastomotic configurations. A slower preanastomotic transit time, demonstrated in patients with end-to-side or side-to-side anastomosis, could offer a prolonged contact time between the intestinal content and the mucosa, resulting in an increase in drug absorption.

Clinicopathologic features and FHIT gene expression in sporadic colorectal adenocarcinomas

BACKGROUND

The putative tumour suppressor gene FHIT (fragile histidine triad) spans the common fragile site FRA3B, which is highly susceptible to breaks and deletions induced by genotoxic agents. Tumours associated with exposure to carcinogens, such as colorectal adenocarcinomas, should be particularly susceptible to alterations in the FHIT gene. We studied the frequency of FHIT alterations and their correlations with clinicopathologic features in sporadic colon carcinomas.

METHODS

FHIT expression was investigated by reverse transcription polymerase chain reaction in 56 primary sporadic colorectal carcinomas. The same tumours and matched normal tissues were also investigated for loss of heterozygosity by using two markers located inside the FHIT gene.

RESULTS

Twenty-nine of 56 tumours (51.8%) expressed aberrant FHIT transcripts. Four tumours had absence or nearly undetectable levels of the normal-sized FHIT transcript. Sequencing analysis of the altered transcripts showed FHIT mRNA lacking one or more exons, more frequent deletions of exons 4-5-6 or 4-5-6-7-8. At the genomic level 46.4% (13 of 28) of the cases showed alterations involving FHIT locus. We did not find any correlation between FHIT gene alterations and clinicopathologic characteristics of the tumours.

CONCLUSIONS

Since the FHIT gene is frequently altered, its role in the molecular pathogenesis of sporadic colon carcinoma deserves further investigation.

Long-term treatment with sulindac in familial adenomatous polyposis: is there an actual efficacy in prevention of rectal cancer?

BACKGROUND AND OBJECTIVES

Ileorectal anastomosis (IRA) is still used in the treatment of familial adenomatous polyposis (FAP). Sulindac appears to induce regression of colorectal adenomas; however, its effects in long-term therapy and in preventing carcinoma remain unclear.

METHODS

Fifteen FAP patients treated by IRA received sulindac (200 mg/day) for a mean period of 48.6 +/- 28.7 (range 12-124) months. Number, size, and type of rectal polyps were assessed by endoscopic and histological evaluation every 6 months.

RESULTS

Significant regression of polyps was observed in all patients after 6 months (P < 0.02). However, after a mean of 48.6 +/- 28.7 months, both number and size of polyps increased again, showing no statistical difference with baseline values. Minute polyps appeared reddish, while the largest lesions were flat or slightly elevated. Endoscopic polypectomy was necessary in 9 patients and transanal surgical excision in 3. Two patients were submitted to restorative proctectomy because of a large polyp with severe dysplasia and a rectal cancer, respectively.

CONCLUSIONS

Sulindac appears to influence the morphological appearance of polyps in FAP patients, inducing apparent regression. However, at a dose of 200 mg, it does not influence the progression of polyps toward a malignant pattern.

Intraoperative parathormone measurement in patients with multiple endocrine neoplasia type I syndrome and hyperparathyroidism

Total or subtotal parathyroidectomy is considered the treatment of choice for multiple endocrine neoplasia type I (MEN-I)-associated primary hyperparathyroidism (HPT). However, persistent or recurrent HPT is frequently observed. The development of a rapid two-site immunoradiometric assay (IRMA) method for measuring intact parathormone (PTH) has provided a valuable tool for recognizing possible surgical failures. Our experience includes 16 MEN-I patients (10 females, 6 males) of mean age 35.5 years operated on between 1990 and 1996. Total parathyroidectomy (TPTX) with autotransplantation of parathyroid tissue was the standard treatment. Blood samples for PTH measurement were drawn at the induction of anesthesia (basal value), 10 and 20 minutes after the removal of each gland, and 60 minutes after TPTX. Rapid PTH measurement, which required only 15 minutes of incubation at 37 degrees C, showed a highly significant correlation (p < 0.0001) with the standard method. Circulating PTH levels exhibited a stepwise decrease during TPTX, reaching a mean value of 22.3% of the baseline 20 minutes after removal of the last gland. Two patients showed a prompt decrease of PTH after removal of the single enlarged gland, featuring the kinetics observed in the adenomas. One of these two patients was successfully treated with more conservative surgery. None of the patients showed persistence or recurrence of HPT. In our experience, intraoperative measurement of PTH seems to be a valuable adjunct in both the diagnosis of multiglandular involvement and the prediction of surgical treatment in patients with primary parathyroid hyperplasia.

Parathyroid glands: combination of (99m)Tc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules

PURPOSE

To determine the appropriate choice of imaging techniques for localization of nodular lesions of parathyroid glands.

MATERIALS AND METHODS

First, computed tomographic (CT), magnetic resonance (MR), ultrasonographic (US), and technetium 99m methoxyisobutyl-isonitrile (MIBI) scintigraphic images in 49 patients with primary hyperparathyroidism were retrospectively evaluated. A single-blind, prospective study that included 16 patients with primary hyperparathyroidism was then conducted. MR, US, scintigraphic, and color Doppler US images of the neck were obtained and analyzed.

RESULTS

In the retrospective study, CT, MR imaging, and US had low sensitivity (13%, 17%, and 27%, respectively) and specificity (39%, 65%, and 65%, respectively). Scintigraphy had 57% sensitivity and 85% specificity. In the prospective study, the use of latest-generation MR and US equipment and the participation of experienced operators led to improved sensitivity and specificity for these techniques. The combination of US and scintigraphy resulted in improved sensitivity (96%), specificity (83%), and positive and negative predictive values (88% and 94%, respectively), relative to the results obtained with either method alone. Doppler US was of little help in the setting of small glands.

CONCLUSIONS

The combination of (99m)Tc MIBI scintigraphy and US performed by well-trained operators with up-to-date instruments appeared to be the best diagnostic tool for the preoperative diagnosis of parathyroid disease.