REPORT ON THE InSiGHT MEETING
International Society For Gastrointestinal Hereditary Tumours - Cleveland, Ohio, USA
4-6 September 2003 by Dr Elizabeth Chow, Professor Finlay Macrae
Department of Colorectal Medicine and Genetics, Royal Melbourne Hospital, Australia

INTRODUCTION
Clinical Cancer Genetics is a multidisciplinary field which is rapidly evolving in particular due to developments in DNA based technology.
The International Society For Gastrointestinal Hereditary Tumours (InSiGHT) is a new organisation formed by the merger of The Leeds Castle Polyposis Group (established in 1985) and The International Collaborative Group on HNPCC (established in1989).
The September 2003 Cleveland Meeting provided excellent opportunities for expert discussions by leading clinical and molecular geneticists, physicians and surgeons, psycho-social workers and genetic counsellors. New and controversial topics pertinent to familial cancer syndromes were explored and debated including epidemiology, molecular analysis and diagnosis, clinical expression, treatment and prevention, counselling and health economics.
Over the three day period, there were daily collaborative studies breakfasts, 55 free paper discussions, 100 poster displays, 10 "hot" poster presentations and many moderated lectures and discussions.
This report will focus on some of these discussions with particular clinical/ genetic relevance.

HNPCC
Free Paper 11: Gastric cancer risk in HNPCC families fulfilling the Amsterdam criteria I or II (AC I or II)
L.Bertario et al, National Cancer Institute; Epidemiology Unit - Local Health Authority, Milan
The incidence of gastric cancer in 2593 subjects (2309 ACI and 284 ACII) was compared with a control group of 3883 subjects not fulfilling AC, but with a positive family history for CRC. The overall SIR in the high risk group was 1.38 (95% CI 1.04-1.79) compared with the control group overall SIR of 1.26 (95% CI 1.01-1.55). Individuals with family history of CRC, irrespective of fulfilment of AC, are at increased risk of gastric cancer.

Free Paper 14: Most patients with Muir-Torre phenotype have MSH2 germline mutations-a clear cut genotype phenotype correlation in HNPCC
E.Mangold et al, University Clinics Bonn, Germany
Muir Torre Syndrome (MTS) is a phenotypic variant of HNPCC manifest with sebaceous tumours. In 39 index cases with sebaceous tumours (35 showed MSI-H and/or loss of DNA MMR protein expression), germline mutations were found in 23 (59%), including 21 mutations located in MSH2 (accounting for 91% of the detected mutations), and 2 on MLH1. 4 of these individuals did not meet Bethesda criteria. Tumours from 10 MSH2 mutation carriers were analysed by immunohistochemistry (IHC) and all showed clear loss of MSH2 expression. Of the 16 germline mutation negative patients, IHC was performed on 12. There was loss of MSH2 in 6 tumours, loss of MLH1 in 4 , normal protein expression in 2. Sebaceous tumours are highly specific indicators for DNA MMR deficiency. The presence of sebaceous neoplasms even in those not meeting Bethesda criteria should lead to further consideration of HNPCC.

Poster 61: MSI and IHC: Two keys for selecting HNPCC families for the study of MMR gene mutations
Caldes et al, Hospital Clinico San Carlos, Madrid, Spain
Whether absence of MMR gene expression assessed by IHC screens accurately for affected gene carriers of HNPCC is a critical question. In this Spanish experience, 5 (3 MSI-H, 2 MSS) of 22 cases with germline mutations had normal MMR gene expression and therefore would have been missed if IHC were used as the sole screening test. MSI testing therefore has a place, especially where there is a high clinical index of suspicion for MMR gene mutation (eg.Amsterdam positive family).

Poster 75: Microsatellite instability and /or Immunostaining for the diagnosis of HNPCC?
B.Halvarsson et al, University Hospital, Lund, Sweden
The Swedish group addresses the same issue. 58/124 (47%) of tumours in affected members of families suspected with HNPCC were MSI-H. IHC was performed on 56 of the MSI-H cancers - 48 of these (86%) demonstrated loss of one or more MMR gene proteins. PMS2 (which dimerizes with MLH1 and whose expression is usually lost also in MLH1 gene carriers) IHC is also helpful, as technical difficulties with MLH1 staining can compromise the reliability of MLH1 IHC alone. Of the 8 discordant tumours (MSI-H with normal MMR protein expression), one had a nonsense MSH6 mutation, one had a missense MSH2 mutation, with unknown genotyping in the others. IHC is highly specific (100%) and 86% sensitive in this series for detecting tumours with defective MMR function. The Swedish group recommends both (MSI and IHC) screening analyses to be used.

Free Paper 20: Survival after adjuvant 5-FU treatment for stage III colon cancer in hereditary non polyposis colorectal cancer
W.H.de Vos et al, Leiden University Medical Centre; Groningen University Hospital; Nijmegen University Hospital; VU Medical Centre Amsterdam; The Netherlands Cancer Institute, Amsterdam; The Netherlands Foundation for the detection of Hereditary Tumours.
Selection of patients with CRC for adjuvant therapy with 5 FU has been based on stage rather than the biology of the tumour. In vitro studies show deficient MMR system reduces 5 FU cytotoxicity. However, clinical studies on efficacy of 5 FU in MSI high tumours are contradictory. This paper described a retrospective study of the Dutch HNPCC family registry comparing survival of subjects with stage III CRC from HNPCC families treated with and without 5 FU. 28 (17 males) out of 92 patients had 5 FU. Over a median follow up of 4 years, 8 subjects died of CRC giving a 5 year survival of 70%. 64 subjects (36 males) did not have adjuvant therapy. Over a median follow up of 6 years, 20 died from CRC giving 5 year survival in this group of 70%. So in this study, the five year survival of subjects treated with and without adjuvant 5 FU did not differ.

Poster 2:Clinico-pathological features and cancer survival in a prospective cohort of early onset colorectal cancer probands categorised by DNA mismatch repair gene mutation status
M.G.Dunlop et.al, Colon Cancer Genetics Group, Edingburgh University, UK.
In a population based study of 579 patients aged <55 years diagnosed with colorectal cancer, MSH2, MLH1 and MSH6 were sequenced irrespective of family history. 56 (9.7%) had germline variants (24 MSH2, 23 MLH1, 9MSH6), including 5 frameshift mutations, 6 splice mutations, 7 small insertions or deletions, and 38 missense variants. Mean age in carriers was 45.7 years and 48.6 years in non carriers. There was no difference in tumour location or Duke's stage or survival (follow up 48 months) in mutation carriers compared to non carriers.

MYH
MYH is a base excision repair (BER) gene on 1p34.1 responsible for repair of oxidative DNA damage. Biallelic germline mutations in MYH gene lead to somatic mutations of the APC gene. Mutations are both missense and truncating. Tumours in these patients are characterised by excess of G:C-T:A transversion mutations in the APC gene. MYH mutations cause an autosomal recessive syndrome that predisposes to multiple adenoma phenotype with and without progression to CRC. There is considerable overlap of the phenotype with FAP and attenuated FAP (AFAP). This syndrome may account for >10% of APC negative FAP patients. The risk of CRC in heterozygous carriers is still to be ascertained.

Free Paper 23: Mono- and bi-allelic mutations in the human Mut Y homologue, MYH, predispose for hereditary colorectal polyps and carcinoma in a large Dutch cohort
Frederik Hes et al, Leiden University Medical Centre, Netherlands Foundation for the detection of Hereditary Tumours, Leiden; Free University Medical Centre; University of Groningen; Erasmus Medical Centre, Rotterdam, The Netherlands.
250 families affected by FAP or AFAP, previously not shown to carry APC germline mutations were studied. Mutation screening by DGGE was performed in 4 of 16 MYH exons. 34 MYH germline mutation carriers were identified, 15 were homozygous for Y165C or G382D missense mutations. 6 probands were compound heterozygotes for the Y165C mutation and the G382D missense mutation. Probands had young age of diagnosis of CRC (mean 45 years,). Pedigree studies of families suggest a late onset CRC in parents of probands.

FAP
Free Paper 45: Is there an increased risk of gastric cancer in FAP?
K.Moozar et al, Mount Sinai Hospital, Toronto, Canada
A survey of 30 registries (including the Victorian registry) of the epidemiology and histology of gastric neoplasia in FAP patients was reported. 161 antral adenomas, and 32 gastric cancers were registered. The median age of diagnosis was 54 yrs, 17/20 Caucasian. 5/20 had family history of gastric cancer. Dominant sites were the antrum (7), lesser curve (4), fundus (3); 4 cases were associated with fundic gland polyps. The cancer risk appears to increase with age, particularly in antrum. Helicobacter status was not consistently reported.

Free Paper 29: The use of capsule endoscopy to detect small bowel polyps in patients with FAP
C. Bourke et al, Cleveland Clinic Foundation, Cleveland, USA
Capsule endoscopy was used in 10 FAP patients with known duodenal adenomas to study polyp location, size, and number. All patients had previous major intestinal surgery. 60% had polyps beyond duodenum. Jejunal and ileal polyps were common. No complications were reported.

Free Paper 46: Duodenal Adenomatosis Study - Final results
S.Bulow et al, The Danish Polyposis Register, Copenhagen, Denmark
In a prospective follow up study in Denmark, Finland, Holland, Norway, Sweden, 367 patients aged 20+ had gastroduodenoscopy with a forward viewing endoscopy at 2 yearly intervals in 1990-2001. At first endoscopy, 236 (64%) had duodenal adenomas at a median age of 32 years. In 290 patients with at least 2 endoscopies the median follow up was 7.6 years. The lifetime risk of duodenal adenomatosis was 95%; the cumulative risk of Spigelman Stage IV duodenal polyposis was 31% at age 60. Lifetime risk of duodenal cancer was 6%. The risk of cancer was higher in patients with Spigelman stage IV at first endoscopy than in those with stage 0-III (p<0.01).

Free Paper 47: Duodenal Cancer in FAP
J.Bjork et al, Karolinska Hospital, Stockholm, Sweden
430 Swedish FAP patients born after 1920 were tracked through the national cancer registry. Duodenal cancer was diagnosed in 22 patients, with cumulative risk of 15% at age 60 years. The comprehensive nature of the tracking process in Sweden makes this a study of special interest.

Poster 32: Large duodenal adenomas in FAP - should endoscopic resection be first line therapy?
M.C.Gallagher et al, St Mark's Hospital, London
Duodenal polyps were located with side viewing endoscopy and therapy performed with the forward viewing scope. Technically successful saline assisted polypectomies with or without supplementary argon plasma coagulation were performed in 14 patients. Endoscopic follow up has revealed a reduction in the diameter of the largest polyp in 12 cases (initial average size of polyps 2.3cm reduced to 0.82cm). Two patients required post polypectomy transfusion, five had melaena, and one had post procedure abdominal pain. Endoscopic therapy debulked the majority of large duodenal polyps. However it was associated with a significant complication rate.

Free Paper 48: Surgical management of severe duodenal adenomatosis in FAP- a worldwide survey among polyposis registries
W.H. de Vos et al, The Netherlands Foundation for Detection of Hereditary Tumours, Leiden; Leiden University Medical Centre; University Central Hospital, Finland; Swedish Polypsosis Registry; Familial GI Cancer Registry, Canada; University of Vienna, Austria; University Medical Centre Nijmegen; Heine-Universitat, Dusseldorf, Germany; Rigshospitalet, Denmark; Herford Klinikum- Academic Teaching Hospital, Germany; National Cancer Institute, Italy; Groote Schuur Hospital and University of Cape Town, South Africa; Danish Polyposis Register
Surgical intervention to prevent death from invasive duodenal cancer is controversial. A survey of members of the Leeds Castle Polyposis Group was conducted for information on FAP patients treated for duodenal cancer or severe duodenal polyposis after 1990. 69 patients were included. Indications for surgery were: invasive cancer (13 patients, 6 died from metastatic disease), severe duodenal adenomatosis (56 patients, 5 died from metastatic disease). In surviving patients, adenomas recurred after ampullectomy (6/8, mean follow up 11 months), after duodenectomy with polypectomy (17/21 at mean 29 months) and after pancreaticoduodenectomy (6/25 mean 47 months). No recurrence of adenomas was reported in 6 patients after pancreas-sparing duodenectomy (mean follow up 11 months). The recommendation is of prophylactic surgery for duodenal adenomatosis before biopsies reveal invasive cancer.

Poster 24: Prophylactic pylorus preserving pancreatoduodenectomy for advanced duodenal disease in FAP
M.C.Gallagher et al; St Mark's Hospital, London
16 patients with Spigelman Stage IV duodenal polyposis underwent PPPDR over 8 years. One died post operatively, 6 had major complications from surgery. 5/16 had cancer in the surgical specimen, and 4 of these died within 3 years of surgery. Two others died (PE in one and brain tumour in the other). Large ampullary adenomas are likely to harbour carcinoma in situ. If pylorus and pancreas preserving duodenectomy had been performed, 5 would have had their unanticipated cancers incompletely resected. PPPDR has the advantage of permanent ablation of abnormal duodenal mucosa and resection of unexpected duodenal invasive disease, but carries significant morbidity/mortality.

Free Paper 51: Results of national registration of FAP
S. Bulow, The Danish Polyposis Register, Denmark
The Danish Polyposis Registry, established in 1975, offers collection of information on probands, pedigree construction, prophylactic endoscopic and molecular genetic examination for at risk patients, and colectomy for affected patients. The prevalence of CRC has reduced from 60% in 1900-75 to 27% in 1976-2001. The 10 year cumulative crude survival rate increased from 47% in 1900-75 to 78% in 1976-2001. The Danish Polyposis Registry improved patient's; prognosis and reduced CRC prevalence. This important study confirms the value of FAP registries.

Free Paper 40: High gene transfer efficiency in an APC mutated colon cancer cell line: application to gene therapy for FAP
N. Stuart et al, Polyposis Registry, St Mark's Hospital, Harrow, UK
Reintroduction of the APC gene into an APC deficient CRC cell can downregulate Beta Catenin expression and induce apoptosis. The Beta-galactosidase reporter gene and the liposome Lipofectamine 2000T were used to quantify the transfection efficiency in the APC deficient SW-480 CRC cell line. Cells were transfected with a plasmid containing the APC gene or an empty control plasmid. Using Lipofectamine 200T, a high transfection efficiency of >50% cells was achieved. Cell lines transfected with the APC gene showed a decreased total number of cells, decreased Beta-catenin expression, and increased apoptosis with an increase in active caspase 3 expression. This study suggests liposomal gene therapy for FAP may be effective.

Free Paper 43: Results of CAPP1 study: aspirin and resistant starch are beneficial in FAP
J. Burn et al, CAPP group
This study is the sister study to the CAPP2 study active in Australia in HNPCC gene carriers. Carriers of FAP were recruited in a randomised placebo controlled trial of 600mg aspirin and/or 30g resistant starch. 206 FAP carriers received treatment, with complete data on 133 subjects followed for at least 1 year. Neither intervention resulted in significant reduction in polyp number, but the mean size of the largest polyps was significantly reduced in the aspirin only group. Secondary analysis using data from patients staying on trial for > 1 year, (likely higher compliance) showed significant results for both the aspirin alone and the combined aspirin/resistant starch group. The starch group had shorter crypts. The aspirin group had longer crypts and a 37% increase in crypt cell proliferation.

HAMARTOMATOUS POLYPS
Free Paper 27: Clinical aspects of Peutz Jeghers Syndrome (PJS)
T.Vogel et al, Chirurgische Universitatsklinik Dusseldorf, Germany
87 PJS patients from 49 families were studied. 15 cancers were documented in 13 patients from 10 families (5 pancreatic, 2 CUP, 2 small bowel, colon, lung stomach), Polyps occurred in SB followed by colon and stomach. Positive mutational analysis of STK 11 gene was found in 27 of 38 families. There was no genotype-phenotype correlation. It is recommended that regular screening of the GI tract, pancreas and the gynaecological organs be performed. Regular small bowel examinations (capsule endoscopy, Sellink-MRT) and prophylactic polyp removal were also recommended.

Free Paper 28: Cancer risk in Peutz Jeghers Syndrome patients in the Netherlands
F.Menko et al, VU University Medical Centre, Amsterdam, The Netherlands
Registry based investigations of 93 patients from 31 families. This is one of the largest reports of cancer risk in PJS published to date. 26 cancers were diagnosed in 25 patients, 59% were gastrointestinal cancers. Non gastrointestinal tumours included breast, pancreas, ovary (cystadenoma), testis (seminoma), kidney (nephroblastoma), skin (melanoma) and nasal cavity. The mean age of diagnosis was 45 yrs (SD 14.9yrs). The cumulative risk for cancer for both sexes was 5% to age 30 years, 25% to age 40 years, 43% to age of 50 years, 63% to age 60 years.

SUMMARY
Numerous discussions at The September Cleveland InSiGHT meeting will have significant impact on clinical management of patients with familial cancer syndromes.
In HNPCC, gastric cancer prevalence was addressed with implications for cancer screening. In improving the accuracy of screening for gene carriers, papers by the Spanish and Swedish group indicate that both MSI and IHC tests need to be performed, but with centre stage for IHC. In the area of management of stage III CRC in HNPCC, a study showed no difference in 5 year survival between patients treated with and without 5 FU.

The new base excision repair gene MYH has been discussed in detail. It will be important to test this gene in families with multiple adenomas, FAP with no germline mutations and Attenuated FAP.

In FAP. a series of gastric cancers was reported for the first time; duodenal polyposis and associated duodenal cancer risks were discussed, and therapeutic options such as endoscopic polyp resection, and prophylactic pylorus preserving pancreatoduodenectomy were explored. Capsule endoscopy has a proven role in diagnosis of small bowel polyposis in FAP. The Danish polyposis Registry demonstrated that the registry has contributed significantly to improving FAP patient's; prognosis and reducing CRC prevalence. Aspirin and resistant starch use were beneficial in FAP patients.

Large series of Peutz Jeghers Syndrome study explored the risks of GIT/non GIT cancers and are useful in consideration of appropriate cancer screening.