Circulating tumor DNA as a potential marker of adjuvant chemotherapy benefit following surgery for localized pancreatic cancer.

BACKGROUND: In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making. MATERIALS AND METHODS: Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data. RESULTS: Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy. CONCLUSION: ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.

Associations among prenatal stress, maternal antioxidant intakes in pregnancy, and child temperament at age 30 months.

Prenatal stress and prenatal nutrition each have demonstrable impact on fetal development, with implications for child neurodevelopment and behavior. However, few studies have examined their joint influences despite evidence of potential interactive effects. We examined associations among prenatal stress, prenatal antioxidant intakes, and child temperament in a sociodemographically diverse pregnancy cohort (N=137 mother-child dyads). In mid-pregnancy, mothers completed an assessment of recent negative life events as a measure of prenatal stress and an assessment of prenatal diet. When the children were 30 months of age, mothers completed the Early Childhood Behavior Questionnaire-Very Short form, which provides scores on child Negative Affectivity, Effortful Control, and Surgency/Extraversion. Linear regressions tested associations between maternal prenatal negative life events and child temperament, and effect modification by maternal prenatal antioxidant intakes (vitamins A, C, and E, magnesium, zinc, selenium, ß-carotene). Analyses revealed that increased maternal prenatal negative life events were associated with higher child Negative Affectivity (ß=0.08, P=0.009) but not with child Effortful Control (ß=-0.03, P=0.39) or Surgency/Extraversion (ß=0.04, P=0.14). Prenatal intakes of zinc and selenium modified this effect: Maternal exposure to prenatal negative life events was associated with higher child Negative Affectivity in the presence of lower intakes of zinc and selenium. Modification effects approached significance for vitamins A and C. The results suggest that the combination of elevated stress exposures and lower antioxidant intakes in pregnancy increases the likelihood of heightened child temperamental negative affectivity. Increased antioxidant intakes during pregnancy may protect against influences of prenatal stress on child temperament.

Prevalence of systemic anticancer therapy for patients within the last 30 days of life: experience in a private hospital oncology group.

BACKGROUND: In recent years, there has been a significant increase in the number of cancer treatments that have become available. However, it has remained difficult to choose the most appropriate time to cease active therapy in individual patients. AIMS: To determine the proportion of patients being treated with palliative intent who received systemic anticancer treatment in the last 30 days of life. METHODS: This is a retrospective cohort study conducted within the Melbourne Oncology Group at Cabrini Hospital. Patients managed with palliative intent who died between 1 January 2014 and 30 June 2014 were included. Outcomes measured were the percentage of patients who received systemic anticancer treatment in the last 30 days of life, palliative care referral status, Emergency Department presentations, hospital admissions and place of death. RESULTS: A total of 80 patients was included in the study. Of these patients, 21 (26%) received systemic anticancer treatment in the last 30 days of life. There was no statistically significant difference between patients who received treatment in the last month of life and those who did not in terms of the number of patients who were referred to palliative care, presented to an Emergency Department, were admitted to hospital or died in an acute ward. CONCLUSION: Although over a quarter of patients dying from advanced cancer received anticancer treatment in the last month of life, these patients did not present acutely to hospital more often and had the same extent of palliative care team involvement.

TACTIC: a multicentre, open-label, single-arm phase II trial of panitumumab, cisplatin, and gemcitabine in biliary tract cancer.

PURPOSE: The phase II TACTIC trial prospectively selected patients with KRAS wild-type advanced biliary tract cancer for first-line treatment with panitumumab and combination chemotherapy. METHODS: Of 78 patients screened, 85 % had KRAS wild-type tumours and 48 were enrolled. Participants received cisplatin 25 mg/m(2) and gemcitabine 1000 mg/m(2) on day 1 and day 8 of each 21-day cycle and panitumumab 9 mg/kg on day 1 of each cycle. Treatment was continued until disease progression, unacceptable toxicity, or request to discontinue. The primary endpoint was the clinical benefit rate (CBR) at 12 weeks (complete response, partial response, or stable disease). CBR of 70 % was considered to be of clinical interest. Secondary outcomes were progression-free survival, time to treatment failure, overall survival, CA19.9 response and safety. RESULTS: Thirty-four patients had a clinical benefit at 12 weeks, an actuarial rate of 80 % (95 % CI 65-89 %). 46 % had a complete or partial response. Median progression-free survival was 8.0 months (95 % CI 5.1-9.9) and median overall survival 11.9 months (95 % CI 7.4-15.8). Infection accounted for 27 % of the grade 3 or 4 toxicity, with rash (13 %), fatigue (13 %), and hypomagnesemia (10 %) among the more common grade 3 or 4 non-haematological toxicities. CONCLUSION: A marker-driven approach to patient selection was feasible in advanced biliary tract cancer in an Australian population. The combination of panitumumab, gemcitabine, and cisplatin in KRAS wild-type cancers was generally well tolerated and showed promising clinical efficacy. Further exploration of anti-EGFR therapy in a more selected population is warranted.

Familial colorectal cancer.

Identifying individuals with a genetic predisposition to developing familial colorectal cancer (CRC) is crucial to the management of the affected individual and their family. In order to do so, the physician requires an understanding of the different gene mutations and clinical manifestations of familial CRC. This review summarises the genetics, clinical manifestations and management of the known familial CRC syndromes, specifically Lynch syndrome, familial adenomatous polyposis, MUTYH-associated neoplasia, juvenile polyposis syndrome and Peutz-Jeghers syndrome. An individual suspected of having a familial CRC with an underlying genetic predisposition should be referred to a familial cancer centre to enable pre-test counselling and appropriate follow up.

A phase 3 randomized, double-blind, placebo-controlled trial of ganitumab or placebo in combination with gemcitabine as first-line therapy for metastatic adenocarcinoma of the pancreas: the GAMMA trial.

BACKGROUND: This double-blind, phase 3 study assessed the efficacy and safety of ganitumab combined with gemcitabine as first-line treatment of metastatic pancreatic cancer. PATIENTS AND METHODS: Patients with previously untreated metastatic pancreatic adenocarcinoma were randomly assigned 2 : 2 : 1 to receive intravenous gemcitabine 1000 mg/m(2) (days 1, 8, and 15 of each 28-day cycle) plus placebo, ganitumab 12 mg/kg, or ganitumab 20 mg/kg (days 1 and 15 of each cycle). The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), safety, and efficacy by levels of circulating biomarkers. RESULTS: Overall, 322 patients were randomly assigned to placebo, 318 to ganitumab 12 mg/kg, and 160 to ganitumab 20 mg/kg. The study was stopped based on results from a preplanned futility analysis; the final results are reported. Median OS was 7.2 months [95% confidence interval (CI), 6.3-8.2] in the placebo arm, 7.0 months (95% CI, 6.2-8.5) in the ganitumab 12-mg/kg arm [hazard ratio (HR), 1.00; 95% CI, 0.82-1.21; P = 0.494], and 7.1 months (95% CI, 6.4-8.5) in the ganitumab 20-mg/kg arm (HR, 0.97; 95% CI, 0.76-1.23; P = 0.397). Median PFS was 3.7, 3.6 (HR, 1.00; 95% CI, 0.84-1.20; P = 0.520), and 3.7 months (HR, 0.97; 95% CI, 0.77-1.22; P = 0.403), respectively. No unexpected toxicity was observed with ganitumab plus gemcitabine. The circulating biomarkers assessed [insulin-like growth factor-1 (IGF-1), IGF-binding protein-2, and -3] were not associated with a treatment effect on OS or PFS by ganitumab. CONCLUSION: Ganitumab combined with gemcitabine had manageable toxicity but did not improve OS, compared with gemcitabine alone in unselected patients with metastatic pancreatic cancer. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01231347.

Developing a national database for metastatic colorectal cancer management: perspectives and challenges.

BACKGROUND: The changing treatment landscape for metastatic colorectal cancer creates multiple potential treatment strategies. An Australian-centric database capturing comprehensive information across a range of treatment locations would create a valuable resource enabling multiple important research questions to be addressed. AIMS: To establish a collection of a consensus dataset capturing treatment and outcomes at multiple public and private hospitals across Australia. METHODS: An electronic database was developed by a panel of clinicians, to capture an agreed dataset for patients with newly diagnosed metastatic colorectal cancer. Of particular interest were clinician decision-making, the impact of comorbidities and the frequency of major adverse events. RESULTS: Since July 2009, data collection has been established at six public and eight private hospitals across three Australian states and territories. Successful linkage and analysis, with support from BioGrid Australia, of selected data on the initial 864 patients demonstrates that data can be captured from diverse sites, including public and private practice, that multiple factors impact on treatment delivered and outcomes achieved and that comprehensive data on rare but important adverse events can be captured. As a clinical research tool, the project has been highly successful, generating multiple presentations at national and international conferences related to a diverse range of research questions. CONCLUSIONS: Multistate, project-specific data collection involving large numbers of patients is achievable. Providing invaluable insight into the routine clinical management of metastatic colorectal cancer in the era of targeted therapies, this also creates a significant resource for research, including many questions not being addressed by clinical trials.

A phase I trial of imatinib in combination with mFOLFOX6-bevacizumab in patients with advanced colorectal cancer.

PURPOSE: Platelet-derived growth factor receptor (PDGFR) inhibition by reducing tumoral interstitial fluid pressure might increase the efficacy of chemotherapy. Imatinib inhibits PDGFR kinase activity at therapeutically relevant doses. This phase I study aimed to assess the maximal tolerated dose (MTD) of imatinib in combination with mFOLFOX6-bevacizumab in patients with advanced colorectal cancer and to identify pharmacokinetic (PK) interactions and toxicities. METHODS: Eligible patients had measurable disease and adequate organ function. On day-14, patients commenced imatinib daily plus bevacizumab (5 mg/kg/2 weekly). Two weeks later (day 1), patients were also treated with full dose mFOLFOX6-bevacizumab for 12 cycles. Blood samples were taken for PK. DLTs defined in the first 6 weeks. Standard dose escalation of imatinib, with 3 patient cohorts: planned dose levels (DL): DL1; 400 mg, DL2; 600 mg, DL3; 800 mg daily. RESULTS: Ten patients enrolled. DL1 3 patients, DL2 7 patients. DLTs observed in 3 of 6 patients in DL2: febrile neutropenia (2); Grade 3 infection and Grade 4 neutropenia (1). Neutropenia was most frequent AEs: Grade 3/4 in >60 % of patients overall. In DL2 pts, imatinib clearance was reduced post-chemotherapy (P < 0.05). Oxaliplatin and 5FU PK unchanged by imatinib. CONCLUSIONS: MTD was imatinib 400 mg plus full dose mFOLFOX-bevacizumab. Dose escalation of imatinib limited by neutropenia. Further study is warranted as imatinib can be delivered at levels that inhibit PDGFR.

Different APC genotypes in proximal and distal sporadic colorectal cancers suggest distinct WNT/ß-catenin signalling thresholds for tumourigenesis.

Biallelic protein-truncating mutations in the adenomatous polyposis coli (APC) gene are prevalent in sporadic colorectal cancer (CRC). Mutations may not be fully inactivating, instead producing WNT/ß-catenin signalling levels 'just-right' for tumourigenesis. However, the spectrum of optimal APC genotypes accounting for both hits, and the influence of clinicopathological features on genotype selection remain undefined. We analysed 630 sporadic CRCs for APC mutations and loss of heterozygosity (LOH) using sequencing and single-nucleotide polymorphism microarrays, respectively. Truncating APC mutations and/or LOH were detected in 75% of CRCs. Most truncating mutations occurred within a mutation cluster region (MCR; codons 1282-1581) leaving 1-3 intact 20 amino-acid repeats (20AARs) and abolishing all Ser-Ala-Met-Pro (SAMP) repeats. Cancers commonly had one MCR mutation plus either LOH or another mutation 5' to the MCR. LOH was associated with mutations leaving 1 intact 20AAR. MCR mutations leaving 1 vs 2-3 intact 20AARs were associated with 5' mutations disrupting or leaving intact the armadillo-repeat domain, respectively. Cancers with three hits had an over-representation of mutations upstream of codon 184, in the alternatively spliced region of exon 9, and 3' to the MCR. Microsatellite unstable cancers showed hyper-mutation at MCR mono- and di-nucleotide repeats, leaving 2-3 intact 20AARs. Proximal and distal cancers exhibited different preferred APC genotypes, leaving a total of 2 or 3 and 0 to 2 intact 20AARs, respectively. In conclusion, APC genotypes in sporadic CRCs demonstrate 'fine-tuned' interdependence of hits by type and location, consistent with selection for particular residual levels of WNT/ß-catenin signalling, with different 'optimal' thresholds for proximal and distal cancers.

The TERT variant rs2736100 is associated with colorectal cancer risk.

BACKGROUND: Polymorphic variation at the 5p15.33 (TERT-CLPTM1L) locus is associated with the risk of many cancers but a relationship with colorectal cancer (CRC) risk has yet to be defined. METHODS: We used data from six genome-wide association studies (GWAS) of CRC, linkage disequilibrium mapping and imputation, to examine the relationship between 73 single-nucleotide polymorphisms at 5p15.33 and CRC risk in detail. RESULTS: rs2736100, which localises to intron 2 of TERT, provided the strongest evidence of an association with CRC (P=2.28 × 10⁻4). The association was also shown in an independent series of 10 047 CRC cases and 6918 controls (P=0.02). A meta-analysis of all seven studies (totalling 16 039 cases, 16 430 controls) provided increased evidence of association (P=2.49 × 10⁻5; per allele odds ratio=1.07). The association of rs2736100 on CRC risk was shown to be independent of 15 low-penetrance variants previously identified. CONCLUSION: The rs2736100 association demonstrates an influence of variation at 5p15.33 on CRC risk and further evidence that the 5p15.33 (TERT-CLPTM1L) locus has pleiotropic effects (reflecting generic or lineage-specific effects) on cancer risk.

Body mass index in early adulthood and colorectal cancer risk for carriers and non-carriers of germline mutations in DNA mismatch repair genes.

BACKGROUND: Carriers of germline mutations in DNA mismatch repair (MMR) genes have a high risk of colorectal cancer (CRC), but the modifiers of this risk are not well established. We estimated an association between body mass index (BMI) in early adulthood and subsequent risk of CRC for carriers and, as a comparison, estimated the association for non-carriers. METHODS: A weighted Cox regression was used to analyse height and weight at 20 years reported by 1324 carriers of MMR gene mutations (500 MLH1, 648 MSH2, 117 MSH6 and 59 PMS2) and 1219 non-carriers from the Colon Cancer Family Registry. RESULTS: During 122,304 person-years of observation, we observed diagnoses of CRC for 659 carriers (50%) and 36 non-carriers (3%). For carriers, the risk of CRC increased by 30% for each 5 kg m(-2) increment in BMI in early adulthood (hazard ratio, HR: 1.30; 95% confidence interval, CI: 1.08-1.58; P=0.01), and increased by 64% for non-carriers (HR: 1.64; 95% CI: 1.02-2.64; P=0.04) after adjusting for sex, country, cigarette smoking and alcohol drinking (and the MMR gene that was mutated in carriers). The difference in HRs for carriers and non-carriers was not statistically significant (P=0.50). For MLH1 and PMS2 (MutLα heterodimer) mutation carriers combined, the corresponding increase was 36% (HR: 1.36; 95% CI: 1.05-1.76; P=0.02). For MSH2 and MSH6 (MutSα heterodimer) mutation carriers combined, the HR was 1.26 (95% CI: 0.96-1.65; P=0.09). There was no significant difference between the HRs for MutLα and MutSα heterodimer carriers (P=0.56). CONCLUSION: Body mass index in early adulthood is positively associated with risk of CRC for MMR gene mutation carriers and non-carriers.

Case report: renal cell carcinoma segregating with a t(2;3)(q37.3;q13.2) chromosomal translocation in an Ashkenazi Jewish family.

Chromosome translocations involving chromosome 3 have previously been associated with the development of renal cell carcinoma. In this report we describe an Ashkenazi Jewish family with a previously unreported balanced constitutional translocation (t(2;3)(q37.3;q13.2)) segregating with the development of clear cell renal carcinomata in three family members spanning two generations. We outline the difficulties with the clinical utility of this finding for genetic counselling and risk management strategies. We suggest that an additional renal cancer susceptibility gene may exist at 3q13.2, and review known breakpoints in the autosomes which are associated with clear cell renal cell carcinoma.

COGENT (COlorectal cancer GENeTics): an international consortium to study the role of polymorphic variation on the risk of colorectal cancer.

It is now recognised that a part of the inherited risk of colorectal cancer (CRC) can be explained by the co-inheritance of low-penetrance genetic variants. The accumulated experience to date in identifying these variants has served to highlight difficulties in conducting statistically and methodologically rigorous studies and follow-up analyses. The COGENT (COlorectal cancer GENeTics) consortium includes 20 research groups in Europe, Australia, the Americas, China and Japan. The overarching goal of COGENT is to identify and characterise low-penetrance susceptibility variants for CRC through association-based analyses. In this study, we review the rationale for identifying low-penetrance variants for CRC and our proposed strategy for establishing COGENT.

Safety and pharmacokinetics of motesanib in combination with gemcitabine for the treatment of patients with solid tumours.

The aim of this open-label phase 1b study was to assess the safety and pharmacokinetics of motesanib in combination with gemcitabine in patients with advanced solid tumours. Eligible patients with histologically or cytologically documented solid tumours or lymphoma were enroled in three sequential, dose-escalating cohorts to receive motesanib 50 mg once daily (QD), 75 mg two times daily (BID), or 125 mg QD in combination with gemcitabine (1000 mg m(-2)). The primary end point was the incidence of dose-limiting toxicities (DLTs). Twenty-six patients were enroled and received motesanib and gemcitabine. No DLTs occurred. The 75 mg BID cohort was discontinued early; therefore, 125 mg QD was the maximum target dose. Sixteen patients (62%) experienced motesanib-related adverse events, most commonly lethargy (n=6), diarrhoea (n=4), fatigue (n=3), headache (n=3), and nausea (n=3). The pharmacokinetics of motesanib and of gemcitabine were not markedly affected after combination therapy. The objective response rate was 4% (1 of 26), and 27% (7 of 26) of patients achieved stable disease. In conclusion, treatment with motesanib plus gemcitabine was well tolerated, with adverse event and pharmacokinetic profiles similar to that observed in monotherapy studies.

Management of MUTYH-associated neoplasia in Australia.

BACKGROUND: Mutations in the MUTYH gene, which codes for a base excision repair protein, have recently been found to cause an autosomal recessive syndrome characterized by multiple colorectal adenomas and increased risk of colorectal cancer. To identify key areas for clinical research, it is necessary to understand the current management of MUTYH-associated neoplasia. METHODS: Twelve questionnaires were sent to experts from familial colorectal cancer services throughout Australia, including representatives from all Australian states. The questionnaire was designed to clarify the practical management of MUTYH-associated neoplasia in the patient and their family. RESULTS: All 12 questionnaires were returned. For patients with fewer than 100 colorectal adenomas, and no dominant family history of colorectal neoplasia, most respondents carried out MUTYH testing before or concomitantly with APC. Australian laboratories generally carried out an initial directed analysis of the MUTYH gene for the two common mutations Y165C and G382D. For patients with biallelic MUTYH mutations all respondents endorsed regular colonoscopy surveillance with an interval of 1-2 years, whereas the recommended surveillance for monoallelic mutation carriers varied. CONCLUSION: This is the first study to document current management practices for MUTYH-associated neoplasia and forms a basis for the development of evidence-based recommendations as further research becomes available. Current guidelines for testing and management of MUTYH-associated neoplasia are discussed.

Value of database linkage: are patients at risk of familial colorectal cancer being referred for genetic counselling and testing?

BACKGROUND: Unique research opportunities are being created in an era of increasingly sophisticated data collection and data linkage. There are Familial Cancer Clinics (FCC) to counsel patients and families about risk reduction strategies and to carry out genetic testing where appropriate. There is currently no objective evidence as to whether appropriate patients are being referred to the FCC. METHODS: Using a unique resource, the BIO21:MMIM informatics platform, we were able to link data from a prospective colorectal cancer (CRC) database at four Melbourne hospitals with the FCC database for the 4-year period from 2002 to 2005. We determined the number of patients that, on the basis of at least one risk factor suggestive of hereditary CRC, could have been considered for FCC referral, the number that was referred and the number that attended. RESULTS: Of the 829 new diagnoses of CRC 228 (27.5%) would potentially have benefited from FCC referral. Of these, 50 persons (21.9%) were referred and 32 (14.0%) attended. The highest referral rates were in young, early-stage CRC patients with a family history and the lowest in late-stage and multiple-polyp patients. Patient sex, language and insurance status did not influence referral or attendance. CONCLUSION: The database linkage capability provided by MMIM has enabled us to carry out a unique study. The results suggest that the rate of appropriate FCC referral is low, that certain subgroups are at particular risk of non-referral and that many referred patients do not ultimately attend. Interventions that increase referral rates and encourage attendance need to be considered.

Analysis of somatic molecular changes, clinicopathological features, family history, and germline mutations in colorectal cancer families: evidence for efficient diagnosis of HNPCC and for the existence of distinct groups of non-HNPCC families.

OBJECTIVE: To analyse somatic molecular changes, clinicopathological features, family history, and germline mutations in families with colorectal cancer (CRC). METHODS: Molecular changes (K-ras and beta-catenin mutations, chromosome 18q allele loss (LOH), APC LOH, microsatellite instability (MSI), and expression of beta-catenin and p53) were examined in four series of CRC patients with proven or probable hereditary disease: hereditary non-polyposis colon cancer (HNPCC); MYH associated polyposis (MAP); multiple (>5) colorectal adenomas without familial adenomatous polyposis (FAP); and other families/cases referred to family cancer clinics (FCC series). HNPCC was diagnosed using a combination of germline mutation screening and tumour studies. A series of unselected CRC patients was also studied. RESULTS: There was overlap between genetic pathways followed by each type of CRC, but significant differences included: increased frequency of K-ras mutation and reduced frequency of APC LOH in cancers from MAP, but not from multiple adenoma patients; reduced frequency of LOH in HNPCC CRCs; and increased MSI in CRCs from HNPCC, but not from FCC or multiple adenoma patients. HNPCC was apparently detected efficiently by combined germline and somatic analysis. Cancers from the FCC, unselected, and multiple adenoma series shared similar molecular characteristics. In the FCC and multiple adenoma series, hierarchical cluster analysis using the molecular features of the cancers consistently identified two distinct groups, distinguished by presence or absence of K-ras mutation. CONCLUSIONS: While K-ras mutation status is known to differentiate hereditary bowel cancer syndromes such as MAP and FAP, it may also distinguish groups of non-HNPCC, FCC patients whose disease has different, as yet unknown, genetic origins.

Refining the Amsterdam Criteria and Bethesda Guidelines: testing algorithms for the prediction of mismatch repair mutation status in the familial cancer clinic.

PURPOSE: Hereditary nonpolyposis colon cancer (HNPCC) is a Mendelian dominant syndrome of bowel, endometrial, and other cancers and results from germline mutations in mismatch repair (MMR) genes. HNPCC is now best diagnosed on molecular grounds using MMR mutation screening, aided by microsatellite instability (MSI) and immunohistochemistry in tumors. Selection of families for molecular investigation of HNPCC is usually based on suboptimal methods (Amsterdam Criteria or Bethesda Guidelines), but these can be improved using additional clinical data (mean ages of affected persons and presence of endometrial cancer) in a quantitative model. METHODS: We have verified the performance of the Wijnen model and have shown that it remains valid when HNPCC is diagnosed using mutation screening, MSI, and immunohistochemistry. We have also set up and verified our own models (Amsterdam-plus and Alternative), which perform at least as well as the Wijnen model. RESULTS: The Amsterdam-plus model improves on the Amsterdam Criteria by using five extra variables (numbers of colorectal and endometrial cancers in the family, number of patients with five or more adenomas, number with more than one primary cancer of the colorectum or endometrium, and mean age of presentation) and performs better than the Wijnen model. The Alternative model avoids the need to evaluate the Amsterdam Criteria and performs nearly as well as the other models. CONCLUSION: We believe that a quantitative model, such as the Amsterdam-plus model, should be the first choice for selecting families or patients for evaluation of HNPCC using molecular tests. We present an algorithm for this process.

Whole-gene APC deletions cause classical familial adenomatous polyposis, but not attenuated polyposis or "multiple" colorectal adenomas.

Familial adenomatous polyposis (FAP) is a dominantly inherited colorectal tumor predisposition that results from germ-line mutations in the APC gene (chromosome 5q21). FAP shows substantial phenotypic variability: classical polyposis patients develop more than 100 colorectal adenomas, whereas those with attenuated polyposis (AAPC) have fewer than 100 adenomas. A further group of individuals, so-called "multiple" adenoma patients, have a phenotype like AAPC, with 3-99 polyps throughout the colorectum, but mostly have no demonstrable germ-line APC mutation. Routine mutation detection techniques fail to detect a pathogenic APC germ-line mutation in approximately 30% of patients with classical polyposis and 90% of those with AAPC/multiple adenomas. We have developed a real-time quantitative multiplex PCR assay to detect APC exon 14 deletions. When this technique was applied to a set of 60 classical polyposis and 143 AAPC/multiple adenoma patients with no apparent APC germ-line mutation, deletions were found exclusively in individuals with classical polyposis (7 of 60, 12%). Fine-mapping of the region suggested that the majority (6 of 7) of these deletions encompassed the entire APC locus, confirming that haploinsufficiency can result in a classical polyposis phenotype. Screening for germ-line deletions in APC mutation-negative individuals with classical polyposis seems warranted.