Bruno Buecher

Preoperative Radiotherapy With or Without Concurrent Fluorouracil and Leucovorin in T3-4 Rectal Cancers: Results of FFCD 9203

PURPOSE In 1992, preoperative radiotherapy was considered in France as the standard treatment for T3-4 rectal cancers. The present randomized trial compares preoperative radiotherapy with chemoradiotherapy. PATIENTS AND METHODS Patients were eligible if they presented a resectable T3-4, Nx, M0 rectal adenocarcinoma accessible to digital rectal examination. Preoperative radiotherapy with 45 Gy in 25 fractions during 5 weeks was delivered. Concurrent chemotherapy with fluorouracil 350 mg/m2/d during 5 days, together with leucovorin, was administered during the first and fifth week in the experimental arm. Surgery was planned 3 to 10 weeks after the end of radiotherapy. All patients should receive adjuvant chemotherapy with the same fluorouracil/leucovorin regimen. The primary end point of the trial was overall survival. RESULTS A total of 733 patients were eligible. Grade 3 or 4 acute toxicity was more frequent with chemoradiotherapy (14.6% v 2.7%; P < .05). There was no difference in sphincter preservation. Complete sterilization of the operative specimen was more frequent with chemoradiotherapy (11.4% v 3.6%; P < .05). The 5-year incidence of local recurrence was lower with chemoradiotherapy (8.1% v 16.5%; P < .05). Overall 5-year survival in the two groups did not differ. CONCLUSION Preoperative chemoradiotherapy despite a moderate increase in acute toxicity and no impact on overall survival significantly improves local control and is recommended for T3-4, N0-2, M0 adenocarcinoma of the middle and distal rectum.

Genome-wide association scan identifies a colorectal cancer susceptibility locus on chromosome 8q24

Using a multistage genetic association approach comprising 7,480 affected individuals and 7,779 controls, we identified markers in chromosomal region 8q24 associated with colorectal cancer. In stage 1, we genotyped 99,632 SNPs in 1,257 affected individuals and 1,336 controls from Ontario. In stages 2–4, we performed serial replication studies using 4,024 affected individuals and 4,042 controls from Seattle, Newfoundland and Scotland. We identified one locus on chromosome 8q24 and another on 9p24 having combined odds ratios (OR) for stages 1–4 of 1.18 (trend; P = 1.41 × 10−8) and 1.14 (trend; P = 1.32 × 10−5), respectively. Additional analyses in 2,199 affected individuals and 2,401 controls from France and Europe supported the association at the 8q24 locus (OR = 1.16, trend; 95% confidence interval (c.i.): 1.07–1.26; P = 5.05 × 10−4). A summary across all seven studies at the 8q24 locus was highly significant (OR = 1.17, c.i.: 1.12–1.23; P = 3.16 × 10−11). This locus has also been implicated in prostate cancer.

Cancer Risks Associated With Germline Mutations in MLH1, MSH2, and MSH6 Genes in Lynch Syndrome

CONTEXT Providing accurate estimates of cancer risks is a major challenge in the clinical management of Lynch syndrome. OBJECTIVE To estimate the age-specific cumulative risks of developing various tumors using a large series of families with mutations of the MLH1, MSH2, and MSH6 genes. DESIGN, SETTING, AND PARTICIPANTS Families with Lynch syndrome enrolled between January 1, 2006, and December 31, 2009, from 40 French cancer genetics clinics participating in the ERISCAM (Estimation des Risques de Cancer chez les porteurs de mutation des gènes MMR) study; 537 families with segregating mutated genes (248 with MLH1; 256 with MSH2; and 33 with MSH6) were analyzed. MAIN OUTCOME MEASURE Age-specific cumulative cancer risks estimated using the genotype restricted likelihood (GRL) method accounting for ascertainment bias. RESULTS Significant differences in estimated cumulative cancer risk were found between the 3 mutated genes (P = .01). The estimated cumulative risks of colorectal cancer by age 70 years were 41% (95% confidence intervals [CI], 25%-70%) for MLH1 mutation carriers, 48% (95% CI, 30%-77%) for MSH2, and 12% (95% CI, 8%-22%) for MSH6. For endometrial cancer, corresponding risks were 54% (95% CI, 20%-80%), 21% (95% CI, 8%-77%), and 16% (95% CI, 8%-32%). For ovarian cancer, they were 20% (95% CI, 1%-65%), 24% (95% CI, 3%-52%), and 1% (95% CI, 0%-3%). The estimated cumulative risks by age 40 years did not exceed 2% (95% CI, 0%-7%) for endometrial cancer nor 1% (95% CI, 0%-3%) for ovarian cancer, irrespective of the gene. The estimated lifetime risks for other tumor types did not exceed 3% with any of the gene mutations. CONCLUSIONS MSH6 mutations are associated with markedly lower cancer risks than MLH1 or MSH2 mutations. Lifetime ovarian and endometrial cancer risks associated with MLH1 or MSH2 mutations were high but do not increase appreciably until after the age of 40 years.

Randomized Multicenter Phase II Trial of a Biweekly Regimen of Fluorouracil and Leucovorin (LV5FU2), LV5FU2 Plus Cisplatin, or LV5FU2 Plus Irinotecan in Patients With Previously Untreated Metastatic Gastric Cancer: A Fédération Francophone de Cancérologie Digestive Group Study—FFCD 9803

PURPOSE To determine the efficacy and safety of a biweekly regimen of leucovorin (LV) plus fluorouracil (FU) alone or in combination with cisplatin or irinotecan in patients with previously untreated metastatic gastric adenocarcinoma and to select the best arm for a phase III study. PATIENTS AND METHODS One hundred thirty-six patients (two were ineligible) were enrolled onto the randomized multicenter phase II trial. Patients received LV 200 mg/m(2) (2-hour infusion) followed by FU 400 mg/m(2) (bolus) and FU 600 mg/m(2) (22-hour continuous infusion) on days 1 and 2 every 14 days (LV5FU2; arm A), LV5FU2 plus cisplatin 50 mg/m(2) (1-hour infusion) on day 1 or 2 (arm B), or LV5FU2 plus irinotecan 180 mg/m(2) (2-hour infusion) on day 1 (arm C). RESULTS The overall response rates, which were confirmed by an independent expert panel, were 13% (95% CI, 3.4% to 23.3%), 27% (95% CI, 14.1% to 40.4%), and 40% (95% CI, 25.7% to 54.3%) for arms A, B, and C, respectively. Median progression-free survival and overall survival times were 3.2 months (95% CI, 1.8 to 4.6 months) and 6.8 months (95% CI, 2.6 to 11.1 months) with LV5FU2, respectively; 4.9 months (95% CI, 3.5 to 6.3 months) and 9.5 months (95% CI, 6.9 to 12.2 months) with LV5FU2-cisplatin, respectively; and 6.9 months (95% CI, 5.5 to 8.3 months) and 11.3 months (95% CI, 9.3 to 13.3 months) with LV5FU2-irinotecan, respectively. CONCLUSION Of the three regimens tested, the combination of LV5FU2-irinotecan is the most promising and will be assessed in a phase III trial.

Molecular analysis of the effect of short-chain fatty acids on intestinal cell proliferation.

Short-chain fatty acids (SCFA), particularly butyrate, were shown to regulate cell proliferation in vitro and in vivo. Indeed, butyrate is the major fuel for colonic epithelial cells, and it can influence cell proliferation through the release of growth factors or gastrointestinal peptides such as gastrin, or through modulation of mucosal blood flow. Lastly, SCFA can act directly on genes regulating cell proliferation, and butyrate is the main SCFA to display such an effect. Butyrate inhibits histone deacetylase, which will allow histone hyperacetylation. Such hyperacetylation leads to transcription of several genes, including p21/Cip1. Moreover, it will allow cyclin D3 hyper-expression by inhibiting its degradation. The induction of the cyclin-dependent kinase inhibitory protein p21/Cip1 accounts for cell arrest in the G1 phase of the cell cycle. However, in the absence of p21 other mechanisms are initiated, leading to inhibition of cell proliferation.

A large-scale meta-analysis to refine colorectal cancer risk estimates associated with MUTYH variants

Background:Defective DNA repair has a causal role in hereditary colorectal cancer (CRC). Defects in the base excision repair gene MUTYH are responsible for MUTYH-associated polyposis and CRC predisposition as an autosomal recessive trait. Numerous reports have suggested MUTYH mono-allelic variants to be low penetrance risk alleles. We report a large collaborative meta-analysis to assess and refine CRC risk estimates associated with bi-allelic and mono-allelic MUTYH variants and investigate age and sex influence on risk.Methods:MUTYH genotype data were included from 20 565 cases and 15 524 controls. Three logistic regression models were tested: a crude model; adjusted for age and sex; adjusted for age, sex and study.Results:All three models produced very similar results. MUTYH bi-allelic carriers demonstrated a 28-fold increase in risk (95% confidence interval (CI): 6.95–115). Significant bi-allelic effects were also observed for G396D and Y179C/G396D compound heterozygotes and a marginal mono-allelic effect for variant Y179C (odds ratio (OR)=1.34; 95% CI: 1.00–1.80). A pooled meta-analysis of all published and unpublished datasets submitted showed bi-allelic effects for MUTYH, G396D and Y179C (OR=10.8, 95% CI: 5.02–23.2; OR=6.47, 95% CI: 2.33–18.0; OR=3.35, 95% CI: 1.14–9.89) and marginal mono-allelic effect for variants MUTYH (OR=1.16, 95% CI: 1.00–1.34) and Y179C alone (OR=1.34, 95% CI: 1.01–1.77).Conclusions:Overall, this large study refines estimates of disease risk associated with mono-allelic and bi-allelic MUTYH carriers.

Combinations of cytochrome P450 gene polymorphisms enhancing the risk for sporadic colorectal cancer related to red meat consumption.

Susceptibility to sporadic colorectal cancers (CRC) is generally thought to be the sum of complex interactions between environmental and genetic factors, all of which contribute independently, producing only a modest effect on the whole phenomenon. However, to date, most research has concealed the notion of interaction and merely focused on dissociate analyses of risk factors to highlight associations with CRC. By contrast, we have chosen a combinative approach here to explore the joint effects of several factors at a time. Through an association study based on 1,023 cases and 1,121 controls, we examined the influence on CRC risk of environmental factors coanalyzed with combinations of six single nucleotide polymorphisms located in cytochrome P450 genes (c.−163A>C and c.1548T>C in CYP1A2, g.−1293G>C and g.−1053C>T in CYP2E1, c.1294C>G in CYP1B1, and c.430C>T in CYP2C9). Whereas separate analyses of the SNPs showed no effect on CRC risk, three allelic variant combinations were found to be associated with a significant increase in CRC risk in interaction with an excessive red meat consumption, thereby exacerbating the intrinsic procarcinogenic effect of this dietary factor. One of these three predisposing combinations was also shown to interact positively with obesity. Provided that they are validated, our results suggest the need to develop robust combinative methods to improve genetic investigations into the susceptibility to CRC. (Cancer Epidemiol Biomarkers Prev 2007;16(7):1460–7)

CDH1 germline mutations and the hereditary diffuse gastric and lobular breast cancer syndrome: a multicentre study

Introduction CDH1 predisposes primarily to diffuse gastric cancer (DGC). Multiple DGC cases in a family, DGC at a young age in an individual or the combination of DGC andlobular breast cancer (LBC) in an individual or a family define the hereditary DGC syndrome (HDGC), and testing for germline CDH1 mutations is warranted in HDGC. Methods and results We report all index cases from Ile-de-France in which a germline CDH1 mutation has been identified. Out of 18 cases, 7 do not fulfil the HDGC-defining criteria. Three of them are women who presented initially with bilateral LBC below age 50, without personal or family history of DGC, and who subsequently developed symptomatic DGC. Discussion Our series of CDH1 mutation carriers is the largest to date and demonstrates that LBC might be the first manifestation of HDGC. A personal or family history of multiple LBCs at a young age, even without DGC, should prompt CDH1 mutation screening. It is paramount to identify mutation carriers early, so that they can benefit from prophylactic gastrectomy before they develop symptomatic, highly lethal DGC. We recommend a revision of the HDGC-defining criteria and propose for consideration the name ‘Hereditary Diffuse Gastric and Lobular Breast Cancer’ instead of HDGC.

Fine deletion mapping of chromosome 8p in non‐small‐cell lung carcinoma

Several somatic genetic alterations have been described in non‐small‐cell lung carcinomas (NSCLC). Recurrent chromosomal deletions have suggested the presence of tumor‐suppressor genes specifically involved in lung carcinogenesis. For one of these, 2 non‐overlapping regions have been proposed on the short arm of chromosome 8, encompassing the LPL and NEFL genes. The LPL region has been extensively studied in NSCLC and other cancer types. Two genes, N33 and PRLTS, have been identified, but the small number of mutations excludes their involvement in the vast majority of tumors. In order to delineate a reliable region of deletional overlap on chromosome 8p in NSCLC, a series of 77 NSCLC was studied for 34 microsatellite polymorphisms distributed on chromosome 8p, using multiplex‐PCR amplification. After purification of tumor nuclei by flow cytometry based on either the abnormal DNA index or the presence of a high expression of cytokeratin, allelic losses on chromosome 8p were observed in 39% of cases. Measurement of DNA index showed that 62% of tumors were hyperploid; allelic losses were more frequent in hyperploid than in diploid tumors (54% vs. 14%; p < 10−4). Deletions of part of the short arm were observed in 7 instances. Our data allow definition of an interval of common deletion, flanked by the loci D8S511 and D8S1992, where the putative tumor‐suppressor gene might be localized. Int. J. Cancer 81:854–858, 1999.

Circulating tumor DNA changes for early monitoring of anti-PD1 immunotherapy: a proof-of-concept study

Background Recent clinical results support the use of new immune checkpoint blockers (ICB), such as anti-PD-1 (e.g. nivolumab and pembrolizumab) and anti-PD-L1 antibodies. Radiological evaluation of ICB efficacy during therapy is challenging due to tumor immune infiltration. Changes of circulating tumor DNA (ctDNA) levels during therapy could be a promising tool for very accurate monitoring of treatment efficacy, but data are lacking with ICB. Patients and methods This prospective pilot study was conducted in patients with nonsmall cell lung cancer, uveal melanoma, or microsatellite-instable colorectal cancer treated by nivolumab or pembrolizumab monotherapy at Institut Curie. ctDNA levels were assessed at baseline and after 8 weeks (w8) by bidirectional pyrophosphorolysis-activated polymerization, droplet digital PCR or next-generation sequencing depending on the mutation type. Radiological evaluation of efficacy of treatment was carried out by using immune-related response criteria. Results ctDNA was detected at baseline in 10 out of 15 patients. At w8, a significant correlation (r = 0.86; P = 0.002) was observed between synchronous changes in ctDNA levels and tumor size. Patients in whom ctDNA levels became undetectable at w8 presented a marked and lasting response to therapy. ctDNA detection at w8 was also a significant prognostic factor in terms of progression-free survival (hazard ratio = 10.2; 95% confidence interval 2.5-41, P < 0.001) and overall survival (hazard ratio = 15; 95% confidence interval 2.5-94.9, P = 0.004). Conclusion This proof-of-principle study is the first to demonstrate that quantitative ctDNA monitoring is a valuable tool to assess tumor response in patients treated with anti-PD-1 drugs.