Different Expressivity of two Adjacent Mutations of the APC Gene

Aims and background

The phenotypic expression of different APC mutations in familial adenomatous polyposis (FAP) is variable: two to three variants of the disease have been defined based on the severity of colonic manifestations. Age of onset and number of polypectomies per person-year of postsurgical follow-up were compared in two FAP families with very close mutation sites in the APC gene, in order to ascertain mutation-specific variation of expressivity.

Families and APC mutations

Family A (5 patients) carried a newly characterized mutation, a four bp deletion at codon 843. Family B (5 patients) carried a previously identified mutation at codon 835.

Results

Mean age of onset was 49.7 years in family A and 30.5 years in family B; number of polypectomies per person-year of follow-up was 1.05 for family A and 10.1 for family B (P <0.001).

Conclusions

There is significant variation of expressivity (allelic heterogeneity) in FAP between two mutations separated by only eight codons, located at the 5’ extremity of APC gene exon 15.

Clinical Aspects and Management of Hereditary Non-Polyposis Colorectal Cancer (HNPCC)

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomical dominant trasmitted disease phenotypically defined according to the “Amsterdam criteria” as follows: at least 3 affected relatives, one of whom first degree relative of other two, at least two successive generations affected. Important cardinal features are:

1 prevalent proximal location of cancers (above splenic flexure);

2 multiple synchronous or methachronous large bowel cancers;

3 early age of onset (<50 years);

4 presence of extracolonic cancers (endometrium, stomach, urinary tract, skin).

The treatment is essentially surgical and total colectomy with ileo-rectum anastomosis is already proposed as standard procedure with annual endoscopic examination of retained rectum. The screening of individuals at risk, so determined by the analysis of pedigree or the results of molecular tests, must be performed every 1-2 years by colonoscopy starting around the age of 25 years. In this review are described and analysed the spectrum of the disease with particular attention to the frequency and characteristics of extracolonic cancers. Moreover, the guidelines of the surveillance and screening are reported following the data of the literature and as proposed by the International Collaborative Group (ICG-HNPCC).

Usefulness of Breast Self-Examination for an Early Detection of Breast Cancer. Results of a Study on 500 Breast Cancer Patients and 652 Controls

The knowledge and practice of breast self-examination (BSE) was investigated among 500 women with operable breast tumors between 35 and 64 years of age (all successively operated) and 652 healthy women, matched with the previous group for 5-year age groups from 35 to 54 years. Only 39.9 % of breast cancer women and 34.5 % of the controls practiced BSE, and only a third of these did it monthly. Such practice tends to progressively decrease, starting from 45 years, and it is used less frequently by the women with a poor education and those in a lower economic bracket. Among the 500 breast cancer patients, those who practiced the self-examination had a higher number of tumors with a diameter no greater than 2 cm and a lower number with a diameter larger than 4 cm. In addition, in this group the percentage of unaffected axillary lymph nodes (N–) was 58.8 % compared to 48.8 % for the group that did not practice self-examination, and the percentage of the cases with more than 3 metastatic lymph nodes (N+ > 3) was 20.0 % in the first group and 27.3 % of the second one. These differences are statistically significant. The correlation between tumor diameter and the histologic lymph node stage is equally evident, since there is a progressive reduction in N– cases and a contemporary progressive increase in N+ (> 3) cases with increasing breast tumor diameter. Therefore, we can infer that the lack of practice of BSE causes a diagnostic and therapeutic delay, which is responsible for aggravation of the prognosis.

Risk of Colorectal Cancer following Colonoscopic Polypectomy

Aims and Background

To follow a cohort of patients who had undergone polypectomies in order to assess the overall risk of subsequent colorectal cancer in relation with various adenomas characteristics.

Methods

A total of 1,063 patients with adenomatous polyps of the large intestine were treated between 1979 and 1996 at the National Cancer Institute of Milan, during a screening program for colorectal carcinoma. Data on patients who had undergone colonoscopies were collected prospectively. The relation between colorectal cancer and adenomas characteristics was assessed by computing the hazard ratio (HR) values and corresponding confidence intervals (95% CI), according to Cox.

Results

Of the 1,063 patients who met the eligibility requirements, 672 had single adenomas (63.2%) and 391 had multiple adenomas (36.8%). Histological examination revealed 743 cases of tubular adenoma, 196 cases of tubulo-villous adenoma, and 96 cases of villous adenoma. High-grade dysplasia was found in 3.1% of the cases. During the 8,906 persons/year of follow-up, adenocarcinomas of the large bowel developed in 11 patients. Several adenomas’ characteristics at index polypectomy were significant predictors of colorectal cancer occurrence. In univariate analysis the risk of colon cancer was significantly related with multiple adenomas (HR 4.2, 95% CI 1.1-6.5), high-grade dysplasia adenomas (HR 10.0, 95% CI 2.6-38.1) and with adenomas larger than 2 cm (HR 5.0, 95% CI 1.2-20.4). A multivariate stepwise procedure confirmed that the presence of multiple adenomas and presence of high-grade dysplasia are the most important predictors of carcinomas. Hazard ratios for colorectal cancer occurrence, from multivariate Cox's model, were 5.1 (95% CI 1.2-19.9) for multiple compared to single adenomas, and 13.0 (95% CI 3.6-50.7) for adenomas with high-grade dysplasia compared to those with low-grade dysplasia.

Conclusions

High-grade dysplasia, number and size of adenomas were confirmed as the major cancer predictors. Based on this conclusion, a subgroup of patients, who may benefit from intensive surveillance colonoscopy, can be identifiable.

Abnormal Pattern of Mucin Secretion at the Resection Margin of Colorectal Carcinomas

In a retrospective study, we investigated 56 consecutive patients who had undergone radical intestinal resection for colorectal adenocarcinoma and who had developed local or distant recurrences of the disease. We found that the presence of a predominant sialomucin pattern at the margins of resection of the surgical specimen was correlated with a high percentage of local, endoluminal recurrence in the anastomotic mucosa. In contrast, no correlation could be found when the recurrences occurred in the outer tissues around the anastomosis or at some distance from it.

An Analysis of 800 Breast Cancer Patients Relapsed after Radical Mastectomy

The chronology of first recurrences, their topographic distribution and survival from mastectomy were retrospectively studied in a series of 800 mastectomized women with special reference to the relationship between these data and treatment delay, T N categories and free interval. Visceral metastases were more frequent in patients under 50 years, whereas local recurrences were more common in patients over 50. The average free interval was 26 months (over 5 years in 18% of cases) and seemed to be influenced little by the treament delay or by tumor size; it was shorter in patients under 50 years and shorter still in patients with lymph node involvement at operation. A similar correlation exists between these parameters and survival. The 5 year survival rate of the 800 cases with recurrence was 52%, which is quite different from the rate generally indicated for surgical cases, and much higher than the rate for the natural history of untreated breast cancer. The survival rate in cases with first metastases confined to the soft tissues is much higher than in those with bone and/or with visceral metastases. The survival after recurrence proves to be significantly influenced by the length of the free interval, but much more by the presence or absence of regional lymph node involvement, so that the lymph nodes status (N–- or N+) turns out to be a prognostic item of primary importance, even after the onset of recurrence.

Prognosis and Treatment of Loco-Regional Breast Cancer Recurrences: Critical Considerations on 120 Cases

In the present study we report the long-term results for 120 female patients who underwent mastectomy for breast cancer, from 1955 to 1965, and in whom the first relapse was represented by a skin recurrence or a supraclavicular lymph node metastastis. Eighty-nine patients had been submitted only to local therapy, 11 had also undergone bilateral oophorectomy, and in the remaining 20 hormonal compounds had been administered in addition to local therapy. The disease-free interval between the first and the second relapse, and survival after the treatment of the first relapse were strictly related to the presence and the number of axillary lymph node metastases at the time of the mastectomy (N category). In fact, the median survival was 19.5 months for 63 cases with more than 3 metastatic lymph nodes, 29 months for 24 cases with 1–3 involved lymph nodes, and 59 months for 38 cases without axillary involvement. No significant difference in survival was observed in relation to chronological age and menopausal status of the patients or to the lenght of the disease-free interval. The association of endocrine therapies to local treatment of the recurrences also did not increase the survival rate in these cases. The present data indicate that the prognosis for patients with recurrent breast cancer is mainly related to the N category.

Double-Contrast Barium Enema and Computerised Tomography in the Pre-Operative Evaluation of Rectal Carcinoma: Are they Still Useful Diagnostic Procedures?

Purpose

In modern management of rectal carcinoma, the preoperative evaluation of disease parameters is important for selection of therapeutic options. Such parameters are currently defined through endorectal ultrasonography or endoscopic ultrasonography. A retrospective analysis of the parameters obtained with double-contrast barium enema (DCBE) and endorectal balloon computed tomography (CT) was conducted to verify the diagnostic reliability of the radiological techniques and to establish whether there is still an indication for their use.

Methods

53 consecutive patients with adenocarcinoma of the distal half of the rectal ampulla underwent double contrast barium enema examination and CT of the pelvis with endorectal balloon. On the basis of the DCBE and CT assessment we evaluated: 1) the distance between the cranial extremity of the anal canal and the distal margin of the neoplasm; 2) the radial diffusion of the tumor; 3) the metastatic involvement of the perirectal and inferior mesenteric lymph nodes.

Results

1) CT and DBCE measurements of the distal margin tended to coincide, but both tended to overestimate the measurement when compared to the pathologic examination; 2) in the identification of neoplastic infiltration of perirectal fat (T3) CT had 100% sensitivity, 78.7% specificity and 86.8% accuracy; 3) the CT sensitivity for detecting lymph node metastasis was 52.6%, specificity 85.3% and accuracy 73.6%.

Conclusions

The diagnostic information provided by the radiological examinations is comparable to that of clinical and instrumental methods currently employed for staging of rectal carcinoma, although the latter are preferred because they are more readily accessible and less costly. DCBE and CT can therefore be usefully employed for staging of cancer of the rectum in those cases in which there are limitations of the current standard methods.

Risk of desmoid tumours after open and laparoscopic colectomy in patients with familial adenomatous polyposis

BACKGROUND

Desmoid tumour (DT) is a main cause of death after prophylactic colectomy in patients with familial adenomatous polyposis (FAP). The purpose of this study was to evaluate the impact of prophylactic laparoscopic colectomy on the risk of developing DT in patients with FAP.

METHODS

The database of a single institution was reviewed. Patients with classical FAP with defined genotype who underwent either open or laparoscopic colectomy between 1947 and 2011 were included in the study. The impact of various demographic and clinical features on the risk of developing DT was assessed.

RESULTS

A total of 672 patients underwent prophylactic colectomy: 602 by an open and 70 by a laparoscopic approach. With a median (range) follow-up of 132 (0-516) months in the open group and 60 (12-108) months in the laparoscopic group, 98 patients (16·3 per cent) developed DT after an open procedure compared with three (4 per cent) following laparoscopic surgery. The estimated cumulative risk of developing DT at 5 years after surgery was 13·0 per cent in the open group and 4 per cent in the laparoscopic group (P = 0·042). In multivariable analysis, female sex (hazard ratio (HR) 2·18, 95 per cent confidence interval 1·40 to 3·39), adenomatous polyposis coli mutation distal to codon 1400 (HR 3·85, 1·90 to 7·80), proctocolectomy (HR 1·67, 1·06 to 2·61), open colectomy (HR 6·84, 1·96 to 23·98) and year of surgery (HR 1·04, 1·01 to 1·07) were independent risk factors for the diagnosis of DT after prophylactic surgery.

CONCLUSION

Laparoscopic surgery decreased the risk of DT after prophylactic colectomy in patients with FAP.

Peutz-Jeghers syndrome: a systematic review and recommendations for management

Peutz-Jeghers syndrome (PJS, MIM175200) is an autosomal dominant condition defined by the development of characteristic polyps throughout the gastrointestinal tract and mucocutaneous pigmentation. The majority of patients that meet the clinical diagnostic criteria have a causative mutation in the STK11 gene, which is located at 19p13.3. The cancer risks in this condition are substantial, particularly for breast and gastrointestinal cancer, although ascertainment and publication bias may have led to overestimates in some publications. Current surveillance protocols are controversial and not evidence-based, due to the relative rarity of the condition. Initially, endoscopies are more likely to be done to detect polyps that may be a risk for future intussusception or obstruction rather than cancers, but surveillance for the various cancers for which these patients are susceptible is an important part of their later management. This review assesses the current literature on the clinical features and management of the condition, genotype-phenotype studies, and suggested guidelines for surveillance and management of individuals with PJS. The proposed guidelines contained in this article have been produced as a consensus statement on behalf of a group of European experts who met in Mallorca in 2007 and who have produced guidelines on the clinical management of Lynch syndrome and familial adenomatous polyposis.

PI3KCA/PTEN deregulation contributes to impaired responses to cetuximab in metastatic colorectal cancer patients

BACKGROUND

It has been reported that KRAS mutations (and to a lesser extent KRAS mutations with the BRAF V600E mutation) negatively affect response to anti-epidermal growth factor receptor (EGFR) mAbs in metastatic colorectal cancer (mCRC) patients, while the biological impact of the EGFR pathway represented by PI3K/PTEN/AKT on anti-EGFR treatment is still not clear.

PATIENTS AND METHODS

We analysed formalin-fixed samples from a cohort of 32 mCRC patients treated with cetuximab by means of EGFR immunohistochemistry, EGFR and PTEN FISH analysis, and KRAS, BRAF, PI3KCA, and PTEN genomic sequencing.

RESULTS

Ten (31%) of 32 patients showed a partial response to cetuximab and 22 (69%) did not [nonresponder (NR)]. EGFR immunophenotype and FISH-based gene status did not predict an anti-EGFR mAb response, whereas KRAS mutations (24%) and PI3K pathway activation, by means of PI3KCA mutations (13%) or PTEN mutation (10%)/loss (13%), were significantly restricted to, respectively, 41% and 37% of NRs.

CONCLUSION

These findings suggested that KRAS mutations and PI3KCA/PTEN deregulation significantly correlate with resistance to cetuximab. In line with this, patients carrying KRAS mutations or with activated PI3K profiles can benefit from targeted treatments only by switching off molecules belonging to the downstream signalling of activated EGFR, such as mammalian target of rapamycin.

Quantitative and qualitative characterization of plasma DNA identifies primary and recurrent colorectal cancer

Because plasma DNA may be a useful tool for cancer detection, we screened primary tumors and related multiple plasma samples at the time of surgery and during the follow-up period for plasma DNA level as well as for K-Ras mutations and p16INK4a promoter hypermethylation in colorectal cancer patients. At the time of surgery, DNA levels were higher in tumor patients than in healthy donors, and K-Ras and p16INK4a alterations were detected in 7 and 11 cancers respectively, and in all related plasma samples. During the follow-up, plasma DNA levels decrease progressively but rapidly increased when a relapse occurred, whereas K-Ras and p16INK4a alterations were detected only in relapsed patients. Therefore, combined quantitative and qualitative analyses of plasma DNA confirm the presence of colorectal cancer, define disease-free status and indicate the presence of relapse.

Guidelines for the clinical management of familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) is a well-described inherited syndrome, which is responsible for <1% of all colorectal cancer (CRC) cases. The syndrome is characterised by the development of hundreds to thousands of adenomas in the colorectum. Almost all patients will develop CRC if they are not identified and treated at an early stage. The syndrome is inherited as an autosomal dominant trait and caused by mutations in the APC gene. Recently, a second gene has been identified that also gives rise to colonic adenomatous polyposis, although the phenotype is less severe than typical FAP. The gene is the MUTYH gene and the inheritance is autosomal recessive. In April 2006 and February 2007, a workshop was organised in Mallorca by European experts on hereditary gastrointestinal cancer aiming to establish guidelines for the clinical management of FAP and to initiate collaborative studies. Thirty-one experts from nine European countries participated in these workshops. Prior to the meeting, various participants examined the most important management issues according to the latest publications. A systematic literature search using Pubmed and reference lists of retrieved articles, and manual searches of relevant articles, was performed. During the workshop, all recommendations were discussed in detail. Because most of the studies that form the basis for the recommendations were descriptive and/or retrospective in nature, many of them were based on expert opinion. The guidelines described herein may be helpful in the appropriate management of FAP families. In order to improve the care of these families further, prospective controlled studies should be undertaken.

Guidelines for the clinical management of Lynch syndrome (hereditary non-polyposis cancer)

Lynch syndrome (hereditary non-polyposis colorectal cancer) is characterised by the development of colorectal cancer, endometrial cancer and various other cancers, and is caused by a mutation in one of the mismatch repair genes: MLH1, MSH2, MSH6 or PMS2. The discovery of these genes, 15 years ago, has led to the identification of large numbers of affected families. In April 2006, a workshop was organised by a group of European experts in hereditary gastrointestinal cancer (the Mallorca-group), aiming to establish guidelines for the clinical management of Lynch syndrome. 21 experts from nine European countries participated in this workshop. Prior to the meeting, various participants prepared the key management issues of debate according to the latest publications. A systematic literature search using Pubmed and the Cochrane Database of Systematic Reviews reference lists of retrieved articles and manual searches of relevant articles was performed. During the workshop, all recommendations were discussed in detail. Because most of the studies that form the basis for the recommendations were descriptive and/or retrospective in nature, many of them were based on expert opinion. The guidelines described in this manuscript may be helpful for the appropriate management of families with Lynch syndrome. Prospective controlled studies should be undertaken to improve further the care of these families.

Putative common origin of two MLH1 mutations in Italian-Quebec hereditary non-polyposis colorectal cancer families

Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common inherited cancer syndromes, accounting for 3-5% of all cases of colorectal cancer. In most HNPCC families, the disease is caused by a germline mutation in MLH1 or MSH2. In some populations, founder mutations appear to explain a substantial fraction of HNPCC. We report here the identification and preliminary characterization of two putative MLH1 founder mutations. The mutation MLH1c.1831delAT was shown to segregate in two Quebec families of Italian origin who fulfilled the Amsterdam criteria for HNPCC. Haplotype analysis using five intragenic microsatellite/single nucleotide polymorphism markers spanning MLH1 on chromosome 3 showed that these two unrelated families share an identical haplotype. In addition, two other Italian kindred whose affected members carry MLH1g.IVS6 + 3A>G also share a common haplotype, suggesting that, similarly, the latter mutation has a common origin. These mutations are the first putative founder MLH1 mutations to be identified in HNPCC kindred of Italian origin.

Multiple approach to the exploration of genotype-phenotype correlations in familial adenomatous polyposis

PURPOSE

Familial adenomatous polyposis (FAP), caused by a mutation in the APC gene, is a colorectal cancer predisposition syndrome associated with several other clinical conditions. The severity of the FAP is related to the position of the inherited mutation in the APC gene. We analyzed a large series of FAP patients to identify associations among major clinical manifestations and to correlate the mutation site with specific disease manifestations.

MATERIALS AND METHODS

APC mutations were identified in 953 FAP patients from 187 families. We used unconditional logistic regression models and a method involving generalized estimating equations to investigate the association between genotype and phenotype. We used multiple correspondence analysis to represent the interrelationships of a multiway contingency table of the considered variables.

RESULTS

APC germline mutations were located between codons 156 and 2011 of the APC gene. Mutations spanning the region between codons 543 and 1309 were variable, but strongly associated with congenital hypertrophy of retinal pigment epithelium. Mutations between codons 1310 and 2011 were associated with a six-fold risk of desmoid tumors relative to the low-risk reference region (159 to 495). Mutations at codon 1309 were associated with early development of colorectal cancer. Mutations between codons 976 and 1067 were associated with a three- to four-fold increased risk of duodenal adenomas. The cumulative frequency of extracolonic manifestations was highest for mutations between codons 976 and 1067, followed by mutations between 1310 and 2011.

CONCLUSION

Analysis of the relation between APC mutation site and phenotype identifies subgroups of FAP patients at high risk for major extracolonic disease, which is useful for surveillance and prevention.

Tissue localization of TGFalpha and apoptosis are inversely related in colorectal tumors

Expression of TGFalpha and the EGF receptor was studied in relation to apoptosis in human colorectal mucosa and premalignant and malignant tumors. In normal mucosa the proteins colocalized both in the proliferation compartment and at the luminal pole of the crypts in cells committed to undergo apoptosis. While staining for the EGF receptor was increased in premalignant and malignant lesions, TGFalpha was undetectable in aberrant crypt foci as well as large areas of adenomas. Incidence of apoptosis (AI) was high in these areas ranging from 8.83-24.59. Adenomas did, however, contain islands of high TGFalpha expression where AI was decreased to a range of 0.76-4.00 (decreased at P=0.0027). In carcinomas TGFalpha expression was increased above both normal and adenoma levels corresponding to the decrease in apoptosis in the malignant tumors. Tissue localization of TGFalpha and AI were still inversely related ( P=0.022), but interpatient variability was much larger than for adenomas. The data indicate that TGFalpha is the main survival factor in premalignant tumor cells of the colon, while additional factors moderate its effect in carcinomas. This suggests the possibility of targeting the EGF receptor pathway not only for treatment but also for the reversal of adenoma growth and the prevention of malignant colorectal tumors.

Effect of lifestyle, smoking, and diet on development of intestinal metaplasia in H. pylori-positive subjects

OBJECTIVES

This study aimed to evaluate the influence of environmental and sociodemographic factors and the effect of smoking, alcohol, and dietary habits on the risk of gastric intestinal metaplasia (IM) in Helicobacter pylori-infected subjects.

METHODS

The investigation was based on 2598 consecutive volunteer blood donors tested for the presence of antibodies against H. pylori from March 1995 to March 1997. Endoscopy with multiple biopsies was offered to all H. pylori-positive, symptomatic subjects. The presence or absence of IM was diagnosed by gastric biopsies. A serologically H. pylori-positive subject with gastric IM was defined as a case, whereas serologically H. pylori-positive subjects without IM were used as controls. All patients answered a detailed questionnaire collecting sociodemographic characteristics and smoking, alcohol drinking, and dietary habits. Odds ratios (ORs) and their 95% CIs were estimated by unconditional logistic regression, including terms for age and sex, to assess the association between the data collected and IM.

RESULTS

Three hundred forty-four subjects with serological H. pylori infection and upper-GI symptoms underwent GI endoscopy, during which biopsies were taken for histological diagnosis. Histology revealed metaplasia in 74 subjects (21.5%). Incomplete IM was found in 37.8% of these cases. No significant associations were found between IM and anthropometric or sociodemographic factors. There was a significant association between age and IM (chi2 for trend, 6.67; p value, 0.009). Current smokers of over 20 cigarettes per day had a 4-fold risk of IM (OR, 4.75, 95% CI, 1.33-16.99). A 2-fold increased risk was found for high butter consumers (OR, 2.17; 95% CI, 1.14-4.11). No significant specific associations were found between the variables studied and complete or incomplete IM.

CONCLUSIONS

This study found that smoking and high butter consumption may increase the risk of having gastric IM in H. pylori-positive subjects.

Genotype and phenotype factors as determinants of desmoid tumors in patients with familial adenomatous polyposis

Desmoids represent the most important cause of death, after colorectal cancer, in patients affected with familial adenomatous polyposis (FAP), an inherited disease due to mutations in the APC gene. The aims of our study were to estimate the risk of developing desmoids in FAP patients and to evaluate the association between desmoids and different risk factors. The occurrence of desmoids, colorectal cancer and other extra-colonic manifestations were assessed in 897 FAP patients, 653 of whom were also investigated for APC mutations. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed using an unconditional multiple logistic regression model. Desmoids developed in 107 patients (11.9%), with a cumulative risk of 20.6%. Females had a significantly higher risk than males (OR = 2.1; 95% CI 1.4-3.1). Family history of desmoids (OR = 8.75; 95% CI 5.66-13.51), osteomas (OR = 2.9; 95% CI 1.8-4.8) and epidermoid cysts (OR = 1.8; 95% CI 1.1-3.2) was also significantly associated with the occurrence of disease. Subjects with APC mutations beyond codon 1444 had a 12-fold increased risk, compared with patients with mutations located upstream. Mutations beyond codon 1309 conferred a 17-fold higher risk, compared with mutations upstream codon 452. Multivariate analysis identified as independent predictors mutation beyond codon 1444 (OR = 6.2; 95% CI 2.5-15.8), family history of desmoids (OR = 5.8; 95% CI 3.1-10.6), female gender (OR = 2.1; 95% CI 1.1-3.8) and the presence of osteomas (OR = 1.9; 95% CI 1.1-3.4). Our results indicate that integrating genetic and clinical data is helpful in defining subgroups of patients at higher risk for desmoids, who may benefit from specific prevention programs.

Surgical treatment of gastric cancer invading the oesophagus

INTRODUCTION

There is controversy regarding which type of surgical treatment is most appropriate for upper gastric cancer invading the oesophagus.

METHODS

A review of the pertinent literature was carried out regarding oesophageal involvement in gastric cancer.

RESULTS

Invasion of the oesophagus occurred in 26-63% of Western surgical series. It was more frequent in Borrmann IV type, linitis plastica, pT3-pT4, diffuse type by Lauren, N+ or tumours exceeding 5 cm in diameter. Lymphatic tumour spread was caudad (coeliac nodes, hepatoduodenal nodes, paraortic nodes) but mediastinal nodes were also involved if tumour growth in the oesophagus exceeded 3 cm or if there was transmural oesophageal infiltration. In Western countries there was less than 30% 5-year survival and no long-term survivors when hepatoduodenal or mediastinal nodes were metastatic. Mediastinal dissection through thoracotomy did not provide any benefit.

CONCLUSIONS

A rational approach involves total gastrectomy plus partial oesophagectomy. Abdominal transhiatal resection may be performed in the case of a localized, non-infiltrating tumour and oesophageal involvement <2 cm. However, infiltrating, poorly differentiated or Borrmann III-IV tumours require a right thoracotomy to achieve a longer margin of clearance. When oesophageal involvement is >3 cm, or hepatoduodenal or mediastinal nodes are positive, no surgical procedure is curative and the literature demonstrates that extended aggressive surgery has no benefits.

Colorectal cancer: how does it start? How does it metastasize?

Colorectal carcinogenesis is a multistep process with an apparently orderly progression from benign tissue to invasive malignancy and metastases. Yet at the genome level, a considerably more chaotic situation exists, with order arising through the process of natural selection in the midst of genomic instability. Major pathways for colorectal carcinogenesis begin with suppressor loss or acquisition of a mutator phenotype, but there are other pathways known and yet to be described. These pathways result in the natural selection of cells with unstable genomes leading to malignancy and metastases.

Screening for mutations of the APC gene in 66 Italian familial adenomatous polyposis patients: evidence for phenotypic differences in cases with and without identified mutation

Germline mutations in the APC gene are responsible for familial adenomatous polyposis (FAP), a dominantly inherited syndrome characterized by the development of hundreds to thousands of polyps in the colon and in the rectum of affected individuals and by variable extracolonic manifestations (gastric and duodenal polyps, osteomas, retinal lesions, and desmoid tumors). Through the combined use of single-strand conformation polymorphism (SSCP) analysis and the protein truncation test (PTT), we have screened 66 Italian FAP patients and found 29 different APC mutations in a total of 34 cases. Of the identified mutations, 15 were nonsense, 12 were 1- to 5-bp deletions or insertions and two were complex rearrangements, all leading to the formation of premature stop codons. Only 10 mutations had been already previously described at the germline level, confirming the high heterogeneity of the APC mutational spectrum. The mean age of diagnosis in mutation positive cases and their affected relatives was significantly lower than in cases without identified mutation (30.6 vs 39.1 years, respectively; p = 0.003). In addition, among patients without a family history of polyposis, all mutation-positive cases displayed at least one of the extracolonic manifestations usually associated with FAP, whereas in one-half of the cases without identified mutation, none of these phenotypes was observed. Although a fraction of apparently mutation-negative cases were likely to be due to limitations of the mutation screening strategy, our results suggest, in agreement with previous reports, that allelic and/or genetic heterogeneity might be responsible for the phenotypic variability observed in FAP patients.

A prospective multicenter evaluation of new fecal occult blood tests in patients undergoing colonoscopy

OBJECTIVE

Guaiac-based fecal occult blood (FOB) tests, in particular, Hemoccult II (HO), are commonly used to detect colorectal neoplasia. Because the sensitivity and specificity of these tests are critical to cost-effective screening programs, we aimed to investigate the improved performance characteristics of new FOB tests for known colonic lesions.

METHODS

Nine centers worldwide performed FOB testing with guaiac-based tests (Hemoccult II [HO] and Hemoccult II SENSA [SENSA]) and immunochemical tests (HemeSelect [HS] and FlexSure OBT [FS]) on 554 patients referred for colonoscopy for predetermined indications. A combination testing strategy consisting of SENSA followed by HS or FS (which was considered positive only when both tests were positive) was also evaluated. Results of FOB tests were compared to findings on colonoscopy.

RESULTS

Cancers were identified in 2.9% of subjects, whereas adenomas > or =10 mm were found in 39 patients. Small adenomas, colitis, and other lesions were identified in 141 patients. The positivity rate of HO for adenomas > or =10 mm was less than for SENSA (20.5% vs 35.9%, p < 0.05), whereas the positivity rate of HO, SENSA, FS, HS, or the combination tests for cancers was not statistically different. The overall positivity rates were significantly greater for FS (15.9%, p = 0.0002) and significantly lower using the combination tests (SENSA/FS 6.0%, p = 0.01; SENSA/HS 6.2%, p = 0.02) compared to HO (9.4%). In this study population, the relative specificity (i.e., true-negative tests/true-negatives + false-positives in patients without adenomas > or =10 mm or cancers) of HO (93.9%; 95% CI, 91.7-96.1) was similar to that of SENSA (92.8%; 95% CI, 90.4-95.2) and HS (90.1%; 95% CI, 87.4-92.8), and greater than FS (88.0%; 95% CI, 85.1-90.9, p < 0.001). When considering adenomas > or =10 mm, cancers alone or cancers and adenomas combined, the combination test using SENSA/FS was associated with significantly fewer false-positive tests than any of the individual tests.

CONCLUSIONS

Compared to single tests, the combination test with the highly sensitive SENSA and an immunochemical test had slightly reduced sensitivity but significantly fewer false-positive tests than any single test. These data raise the possibility that a combination test (i.e., highly sensitive guaiac plus immunochemical) could reduce the costs of screening for colon cancer, and suggest that further study of combination test strategies is warranted.

Genotype and phenotype factors as determinants for rectal stump cancer in patients with familial adenomatous polyposis. Hereditary Colorectal Tumors Registry

OBJECTIVE

To identify factors influencing the occurrence of cancer in the rectal remnant in patients with familial adenomatous polyposis (FAP) after colectomy and ileorectal anastomosis (IRA).

SUMMARY BACKGROUND DATA

The risk for rectal cancer in patients with FAP after colectomy and IRA remains a major concern.

METHODS

Between 1955 and 1997, 371 patients (206 men, 165 women) from the Registry of Hereditary Colorectal Tumors underwent colectomy and IRA as a primary surgical procedure. Survival was estimated using the Kaplan-Meier method. Cox proportional hazard models were fitted to assess the relative excess risk of rectal cancer and to control for confounding factors. A multivariate analysis was performed to assess the relation between cancer risk in the rectum and sex, age, number of rectal polyps, colon cancer, and APC germline mutation.

RESULTS

Median follow-up was 81 months. Eighty-nine patients (24%) had colon cancer at the time of surgery. The APC mutation was found in 200 patients. In 27 patients, cancer developed in the retained rectum 1 to 26 years after surgery. The incidence of rectal carcinoma appears to increase with time: at 10, 15, and 20 years after surgery, the cumulative risk was 7.7%, 13.1%, and 23.0%, respectively. Multivariate analysis identified as independent predictors the presence of colon cancer at IRA and a mutation occurring between codons 1250 and 1464; both factors increased the risk nine times.

CONCLUSIONS

The presence of cancer at IRA and APC mutation type are the most important risk factors for the future development of cancer in the rectal remnant in patients with FAP.

Microsatellite instability in colorectal-cancer patients with suspected genetic predisposition

Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited syndrome linked to DNA-mismatch-repair (MMR) gene defects, which also account for microsatellite instability (MSI) in tumour tissues. Diagnosis is based mainly on family history, according to widely accepted criteria (Amsterdam Criteria: AC). Aim of this work was to assess MSI in colorectal-cancer patients with suspected genetic predisposition, and to verify whether MSI represents a tool to manage MMR gene (hMSH2 and hMLH1) mutation analysis. We investigated 13 microsatellites (including the 5 NCI/ICG-HNPCC markers) in 45 patients with suspected hereditary predisposition (including 16 subjects from HNPCC families fulfilling the AC). We found MSI-H (high frequency of instability, i.e., in > or =30% of the markers) in 85% of the HNPCC patients and in 16% of the non-HNPCC subjects. The 5 NCI/ICG-HNPCC microsatellites proved to be the most effective in detecting MSI, being mononucleotide repeats the most unstable markers. We investigated the association between hMSH2- and hMLH1 gene mutations and MSI. Our results indicate that AC are highly predictive both of tumour instability and of MMR-gene mutations. Therefore, as the most likely mutation carriers, HNPCC subjects might be directly analyzed for gene mutations, while to test for MSI in selected non-HNPCC patients and to further investigate MMR genes in MSI-H cases, appears to be a cost-effective way to identify subjects, other than those from kindred fulfilling AC, who might benefit from genetic testing.

Microsatellite instability in colorectal-cancer patients with suspected genetic predisposition

Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited syndrome linked to DNA-mismatch-repair (MMR) gene defects, which also account for microsatellite instability (MSI) in tumour tissues. Diagnosis is based mainly on family history, according to widely accepted criteria (Amsterdam Criteria: AC). Aim of this work was to assess MSI in colorectal-cancer patients with suspected genetic predisposition, and to verify whether MSI represents a tool to manage MMR gene (hMSH2 and hMLH1) mutation analysis. We investigated 13 microsatellites (including the 5 NCI/ICG-HNPCC markers) in 45 patients with suspected hereditary predisposition (including 16 subjects from HNPCC families fulfilling the AC). We found MSI-H (high frequency of instability, i.e., in > or =30% of the markers) in 85% of the HNPCC patients and in 16% of the non-HNPCC subjects. The 5 NCI/ICG-HNPCC microsatellites proved to be the most effective in detecting MSI, being mononucleotide repeats the most unstable markers. We investigated the association between hMSH2- and hMLH1 gene mutations and MSI. Our results indicate that AC are highly predictive both of tumour instability and of MMR-gene mutations. Therefore, as the most likely mutation carriers, HNPCC subjects might be directly analyzed for gene mutations, while to test for MSI in selected non-HNPCC patients and to further investigate MMR genes in MSI-H cases, appears to be a cost-effective way to identify subjects, other than those from kindred fulfilling AC, who might benefit from genetic testing.

Determinants of Helicobacter pylori seroprevalence among Italian blood donors

BACKGROUND/AIM

Helicobacter pylori is a worldwide infection. It is estimated that approximately 50% of the general population is affected, but this percentage varies considerably between countries. To investigate the prevalence of H. pylori infection, a cross-sectional epidemiological study, based on the serological determination of the IgG antibodies against H. pylori, was carried out in healthy Italian blood donors by using a commercially available kit.

METHODS

From March 1995 to March 1997, a total of 2598 consecutive volunteer blood donors were tested for the presence of antibodies against H. pylori. All patients answered a detailed questionnaire which collected sociodemographic characteristics, and smoking, alcohol drinking and dietary habits. Test-positive subjects with gastrointestinal symptoms underwent endoscopy, with biopsies taken for histological diagnosis.

RESULTS

The global prevalence of H. pylori infection in our study was 1161/2598 (45%). It was directly correlated with age (67% in subjects aged > or = 50 years). The prevalence of H. pylori infection was higher in men (46.4%) than women (38.4%), and more frequent in patients with a low educational level, in the lower quintile of height and in the upper quintile of body mass index (BMI). No significant association with smoking and alcohol drinking was found. Inverse associations were found with elevated consumption of milk (chi-square for trend 5.49, P < 0.05), but not other examined food groups. Multivariate analysis selected sex, age, BMI and educational level as the variables independently related to H. pylori infection.

CONCLUSION

This study confirms relatively high prevalence of H. pylori seropositivity among Italian healthy adults and points to sex, age, BMI and sociocultural class as persisting determinant features of H. pylori infection.

Preoperative radiation therapy for patients with T2-T3 carcinoma of the middle-to-lower rectum

BACKGROUND

The aim of this study was to determine the effects of preoperative radiation therapy (RT) on the objective responses of patients with rectal carcinoma to their treatment. These effects were assessed with endorectal ultrasound (EUS) evaluation, histopathologic grading of postirradiation tumor mass reduction in the surgical specimen, and analysis of local and distant recurrences.

METHODS

Fifty-nine consecutive patients with palpable adenocarcinoma of the rectum, classified by EUS examination as uT2-uT3 (which meant involvement of the muscular layer and the perirectal adipose tissue, respectively), received 45 grays (Gy) over 3 weeks (2 fractions per day of 1.5 Gy each) given as photons supplied through a high-energy linear accelerator (18 MeV) through 3 fields: 1 posterior and 2 opposed lateral. Surgery was scheduled 2-3 weeks after the end of RT and included a sphincter-saving resection (39 patients) and an abdominoperineal resection (20 patients).

RESULTS

Greatest tumor dimension, which was evaluated with rectal endoscopy before RT and measurement of the lesion in the fresh specimen, showed a decrease among two-thirds of the patients; the decrease amounted to approximately one-third of the initial measurement. An echoendoscopic downstaging of the T component was observed among 24.5% of the patients. Complete tumor regression occurred in 8.5% of patients, whereas in 69% only the presence of rare residual cancer cells and prominent fibrosis were found at the pathologic examination of the specimen. Finally, the tumor regressed to pT0 and pT1 in 13.6% of the patients. The overall and disease free 2-year survival rates were 94.0% and 73.7%, respectively, for pT2 and pT3 patients, and 100% for those whose tumors regressed to pT0-pT1 after a median follow-up of 2 years.

CONCLUSIONS

Hyperfractionated preoperative RT appears to be efficient in achieving tumor shrinkage and destroying the tumor. In this study, the subset of patients with a good response to RT therapy had an excellent clinical outcome at the time of a 2-year follow-up.

Reducing colorectal cancer mortality by repeated faecal occult blood test: a nested case-control study

Randomised trials have shown the efficacy of faecal occult blood testing (FOBT) in reducing colorectal cancer mortality, but observational studies are needed to monitor such efficacy in population programmes. We conducted a nested case-control study on a cohort of 21,879 subjects who participated in a colorectal screening programme from 1978 to 1995, undergoing at least one FOBT test. 95 fatal cases of colorectal cancer were eligible for the study. For each fatal case, 5 non-fatal matched controls were randomly selected from the cohort. FOBT screening history was less common among cases than controls. The odds ratio of colorectal cancer mortality among 'attenders' (defined as those who underwent a second FOBT within 2 years of study entry) with respect to 'non-attenders' was 0.64 (95% confidence interval 0.36-1.15). We also computed odds ratios defining exposure as one or more tests in the detectable preclinical period, hypothesising various lengths for the latter, which, however, yielded an efficacy estimate biased towards the null. A strong inverse relationship was observed between mortality and the number of tests, but this phenomenon is interpretable as 'healthy screenee bias'. The results suggest that the potential efficacy in preventing colorectal cancer mortality through annual FOBT screening may be of the order of one third.

Cumulative risk of developing polyps or malignancy at the ileal pouch-anal anastomosis in patients with familial adenomatous polyposis

Restorative proctocolectomy with an ileal pouch-anal anastomosis is performed in an increasing number of patients with familial adenomatous polyposis (FAP). Two techniques are currently used to construct an ileal pouch-anal anastomosis: (1) a double-stapled anastomosis between the pouch and the anal canal and (2) mucosectomy with a hand-sewn ileoanal anastomosis at the dentate line. Although this procedure is thought to abolish the risk of colorectal adenoma, an increasing number of case reports have been published concerning the development of adenoma at the anastomotic site. The purpose of this study was to evaluate the overall cumulative risk of developing adenomatous polyps after ileal pouch-anal anastomosis and to compare the cumulative risk after either anastomotic technique. A total of 126 consecutive FAP patients undergoing a restorative proctocolectomy were identified from polyposis registries in The Netherlands, Denmark, Italy, Germany, and New York. Life-table analysis was used to calculate the cumulative risk of developing polyps in 97 patients with at least 1 year of endoscopic follow-up (median 66 months, range 12 to 188 months). A double-stapled anastomosis was used in 35 patients, whereas in 62 patients a hand-sewn anastomosis with a mucosectomy was performed. In 13 patients polyps developed at the anastomotic site, four with severe and four with moderate dysplasia. None of the patients developed a carcinoma at the anastomotic site. The cumulative risk of developing a polyp at the anastomotic site was 8% (95% confidence interval 2% to 14%) at 3.5 years and 18% (95% confidence interval 8% to 28%) at 7 years, respectively. The risk of developing a polyp at the anastomotic site within 7 years was 31% for patients with a double-stapled vs. 10% for patients with a hand-sewn anastomosis with mucosectomy (P = 0.03 [log-rank test]). Because FAP patients undergoing a restorative proctocolectomy with either a double-stapled or hand-sewn anastomosis have a substantial risk of developing adenomatous polyps at the anastomotic site, lifelong endoscopic surveillance is mandatory in both groups.

Survival of patients with hereditary colorectal cancer: comparison of HNPCC and colorectal cancer in FAP patients with sporadic colorectal cancer

Conflicting data exist on the prognosis of hereditary colorectal cancer. HNPCC patients, in particular, are often reported to have a better survival. We examined 2,340 colorectal-cancer patients treated in our Institution: 144 HNPCC patients (Amsterdam Criteria), 161 FAP patients and 2,035 patients with sporadic cancer. Data on hereditary-cancer patients treated between 1980 and 1995 was collected in a registry. The 2,035 sporadic colorectal-cancer patients (controls) included all new cases treated in the Department of Gastrointestinal-Tract Surgery during the same period. Observed survival was estimated using the Kaplan-Meier method. Cumulative survival probability was estimated at 5 years within each group and stratified by various clinical and pathological variables. The age distribution at diagnosis of sporadic patients was significantly higher than that of FAP and HNPCC patients (median 60 years vs. 43 and 49 years; p < 0.0001). In the HNPCC group, 40% had a right cancer location, vs. 14% in the FAP group and 13% in the sporadic-cancer group. In the sporadic group, 51% were early-stage cancers (Dukes A or B) vs. 48.4% and 52.1% in the FAP and HNPCC groups respectively. In the HNPCC, FAP and sporadic-cancer groups, the 5-year cumulative survival rate was 56.9%, 54.4% and 50.6% respectively. Survival analysis by the Cox proportional-hazards method revealed no substantial survival advantage for HNPCC and FAP patients compared with the sporadic group, after adjustment for age, gender, stage and tumor location. The hazard ratio for HNPCC was 1.01 (95% CI 0.72-1.39) and 1.27 (95% CI 0.95-1.7) for FAP patients compared with the sporadic-colorectal-cancer group.

Survival of patients with hereditary colorectal cancer: comparison of HNPCC and colorectal cancer in FAP patients with sporadic colorectal cancer

Conflicting data exist on the prognosis of hereditary colorectal cancer. HNPCC patients, in particular, are often reported to have a better survival. We examined 2,340 colorectal-cancer patients treated in our Institution: 144 HNPCC patients (Amsterdam Criteria), 161 FAP patients and 2,035 patients with sporadic cancer. Data on hereditary-cancer patients treated between 1980 and 1995 was collected in a registry. The 2,035 sporadic colorectal-cancer patients (controls) included all new cases treated in the Department of Gastrointestinal-Tract Surgery during the same period. Observed survival was estimated using the Kaplan-Meier method. Cumulative survival probability was estimated at 5 years within each group and stratified by various clinical and pathological variables. The age distribution at diagnosis of sporadic patients was significantly higher than that of FAP and HNPCC patients (median 60 years vs. 43 and 49 years; p < 0.0001). In the HNPCC group, 40% had a right cancer location, vs. 14% in the FAP group and 13% in the sporadic-cancer group. In the sporadic group, 51% were early-stage cancers (Dukes A or B) vs. 48.4% and 52.1% in the FAP and HNPCC groups respectively. In the HNPCC, FAP and sporadic-cancer groups, the 5-year cumulative survival rate was 56.9%, 54.4% and 50.6% respectively. Survival analysis by the Cox proportional-hazards method revealed no substantial survival advantage for HNPCC and FAP patients compared with the sporadic group, after adjustment for age, gender, stage and tumor location. The hazard ratio for HNPCC was 1.01 (95% CI 0.72-1.39) and 1.27 (95% CI 0.95-1.7) for FAP patients compared with the sporadic-colorectal-cancer group.

STK11 mutations in Peutz-Jeghers syndrome and sporadic colon cancer

A potential tumor suppressor gene, STK11 , encoding a serine threonine kinase, has recently been identified on chromosome 19p13. Germ-line mutations of this gene have been found in patients with Peutz-Jeghers syndrome (PJS). To further investigate the relevance of STK11 mutations in PJS, we analyzed its coding sequence in nine patients and identified two deletions and three missense mutations. Because intestinal carcinomas have been observed to develop in association with PJS, we analyzed tumors from 71 patients for allelic deletions (loss of heterozygosity) and STK11 gene mutations, to elucidate the etiological role of STK11 gene in sporadic colorectal cancer. Loss of heterozygosity, evaluated using the microsatellite D19S886, was observed in 10 of 52 informative cases. No somatic mutations were detected except for a missense alteration in one tumor. Our data indicate the heterogeneity of PJS and the infrequent involvement of the STK11 gene in colorectal cancer.

Mutations of adenomatous polyposis coli (APC) gene are uncommon in sporadic desmoid tumours

Desmoids are locally aggressive, non-metastasizing soft-tissue tumours, whose aetiology is still unclear. In patients affected with familial adenomatous polyposis (FAP), the incidence of desmoids is much higher than in the general population. The APC gene, which is responsible for FAP, is involved in the development of desmoids associated with this syndrome. In this study 16 sporadic and four FAP-related desmoids were analysed in order to investigate the possible involvement of APC in non-syndromic cases also. The 5' end (exons 1-11) and the coding portion of exon 15 of APC were screened using the in vitro synthesized-protein assay (IVSP). Exons 5, 6, 8-14, and a region of exon 15 spanning codons 1036-1634 were investigated by single-strand conformation polymorphism (SSCP) analysis. APC germline mutations were identified in all FAP patients, but not in sporadic cases. Somatic mutations were found in three FAP-associated desmoids (75%) and two sporadic tumours (12.5%). In one of the latter cases, both alleles were affected. These findings indicate a limited role of the gene in the development of desmoid tumours outside FAP.

Chain-terminating mutations in the APC gene lead to alterations in APC RNA and protein concentration

APC mutations introduce premature stop codons into the open reading frame of the gene, leading to the formation of truncated tumor suppressor proteins. Both RNA and protein levels are likely to be profoundly altered by such nonsense mutations. To test this hypothesis, Western blotting and RT-PCR strategies were used to characterize mutant and normal APC protein and APC RNA concentrations in lymphoblastoid cell lines from 22 unrelated polyposis patients carrying different APC mutations. Variable levels of truncated APC peptides were observed in 14 of 14 cell lines with APC mutations within exon 15. No truncated APC protein was detected in six of eight cell lines with APC mutations located 5' of exon 15. Mutations located in exon 15 showed mutant RNA underrepresentation in four of eight cell lines, whereas mutations located 5' of exon 15 showed RNA reduction in five of six cell lines. These findings indicate that a two- to threefold decrease in RNA concentration is common when APC alleles carry chain-terminating mutations. They also suggest that the severe decrease of truncated APC protein observed in some cell lines is due to mechanisms acting at the protein level.

Characteristics of small bowel carcinoma in hereditary nonpolyposis colorectal carcinoma. International Collaborative Group on HNPCC

BACKGROUND

Small bowel carcinoma is uncommon. However, hereditary nonpolyposis colorectal carcinoma (HNPCC) patients are at increased risk of small bowel carcinoma. The purpose of this study was to characterize small bowel tumors in HNPCC patients.

METHODS

A questionnaire was mailed to the members of International Collaborative Group on HNPCC (ICG-HNPCC) requesting clinicopathologic data in their registries on HNPCC patients with small bowel carcinoma. Survival was estimated utilizing the Kaplan-Meier method.

RESULTS

Forty-two individuals from 40 HNPCC families developed 42 primary and 7 metachronous small bowel tumors. There were 46 adenocarcinomas and 3 carcinoid tumors. The median age at diagnosis of the index small bowel tumor was 49 years. Mismatch repair gene mutations were present in 15 of 42 patients (36%). There were nine hMLH1 and six hMSH2 mutations. The small bowel was the first site of carcinoma in 24 patients (57%). The median survival for the 42 patients was 47 months (range, 0-447 months). The overall 5- and 10-year survival rates were 44% and 33%, respectively.

CONCLUSIONS

Small bowel tumors can be the presenting neoplasms in HNPCC patients. Similar to colorectal carcinoma in HNPCC, small bowel adenocarcinomas in HNPCC patients occur at an earlier age and appear to have a better prognosis than those occurring in the general population.

Characteristics of small bowel carcinoma in hereditary nonpolyposis colorectal carcinoma. International Collaborative Group on HNPCC

BACKGROUND

Small bowel carcinoma is uncommon. However, hereditary nonpolyposis colorectal carcinoma (HNPCC) patients are at increased risk of small bowel carcinoma. The purpose of this study was to characterize small bowel tumors in HNPCC patients.

METHODS

A questionnaire was mailed to the members of International Collaborative Group on HNPCC (ICG-HNPCC) requesting clinicopathologic data in their registries on HNPCC patients with small bowel carcinoma. Survival was estimated utilizing the Kaplan-Meier method.

RESULTS

Forty-two individuals from 40 HNPCC families developed 42 primary and 7 metachronous small bowel tumors. There were 46 adenocarcinomas and 3 carcinoid tumors. The median age at diagnosis of the index small bowel tumor was 49 years. Mismatch repair gene mutations were present in 15 of 42 patients (36%). There were nine hMLH1 and six hMSH2 mutations. The small bowel was the first site of carcinoma in 24 patients (57%). The median survival for the 42 patients was 47 months (range, 0-447 months). The overall 5- and 10-year survival rates were 44% and 33%, respectively.

CONCLUSIONS

Small bowel tumors can be the presenting neoplasms in HNPCC patients. Similar to colorectal carcinoma in HNPCC, small bowel adenocarcinomas in HNPCC patients occur at an earlier age and appear to have a better prognosis than those occurring in the general population.

The familial adenomatous polyposis region exhibits many different haplotypes

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation.

Rapid assessment of replication error phenotype in gastric cancer

Forty gastric tumors were investigated for microsatellite instability at the D2S119 and L-myc loci. These tumors and 143 other gastrointestinal cancers were previously analyzed for instability at several different microsatellites. By evaluating previous and present results, repeated sequences were selected that frequently underwent replication errors (RERs). To coamplify these sequences, the following multiplex polymerase chain reactions (PCRs) were performed: 1) D2S119/L-myc/D18S59; 2) D2S119/L-myc/D3S1076; and 3) D2S177/L-myc/BAT-RII. Therefore, the 40 gastric tumors in the present survey were rescreened using multiplex PCRs. Each multiplex allowed detection of nearly all RER+ tumors (80% for multiplex 3 and 87% for multiplexes 1 and 2) that had been previously identified by amplifying 9 different loci with independent reactions. Moreover, for multiplexes 1 and 2, the size differences between normal and RER alleles were sufficient to be detected by electrophoresis on conventional polyacrylamide gels after DNA staining with ethidium bromide. This approach allows a rapid and easy assessment of RER phenotype in gastric tumors.

Surgical treatment of locally recurrent rectal carcinoma

PURPOSE

This study was performed to analyze the outcomes of patients with local (pelvic) recurrence (following radical surgery for rectal cancer) who subsequently underwent a new operation.

METHODS

Forty-five patients (19 percent of 213 local recurrences) were explored surgically because the disease was deemed to be confined to the pelvis with a limited extension and, therefore, amenable to surgical cure.

RESULTS

Only 21 of the 45 patients who underwent surgical exploration had an oncologically radical operation (R0). In the remaining 24 patients, either a simple exploration or palliation or a nonradical procedure (R1-R2) was performed. In the R0 group, there was a 19 percent five-year survival rate vs. a 0 percent rate in the R1-R2 group (median survival, 4 months). Site of recurrence (anastomosis vs. other sites) was statistically associated with a higher chance of long-term survival for those who underwent an R0 operation.

CONCLUSIONS

The prognosis of locally recurrent rectal cancer is dismal; less than 10 percent of all patients who underwent surgical treatment benefit from reoperation with an overall survival for five years. On the basis of these results, we no longer consider the surgical approach as the primary option for treating locally recurrent rectal cancer.