Clinical utility of circulating DNA analysis for rapid detection of actionable mutations to select metastatic colorectal patients for anti-EGFR treatment

Background

While tumor-tissue remains the 'gold standard' for genetic analysis in cancer patients, it is challenged with the advent of circulating cell-free tumor DNA (ctDNA) analysis from blood samples. Here, we broaden our previous study on the clinical validation of plasma DNA in metastatic colorectal cancer patients, by evaluating its clinical utility under standard management care.

Patients and methods

Concordance and data turnaround-time of ctDNA when compared with tumor-tissue analysis were studied in a real-time blinded prospective multicenter clinical study (n = 140 metastatic colorectal patients). Results are presented according to STARD criteria and were discussed in regard with clinical outcomes of patients.

Results

Much more mutations were found by ctDNA analysis: 59%, 11.8% and 14.4% of the patients were found KRAS, NRAS and BRAF mutant by ctDNA analysis instead of 44%, 8.8% and 7.2% by tumor-tissue analysis. Median tumor-tissue data turnaround-time was 16 days while 2 days for ctDNA analysis. Discordant samples analysis revealed that use of biopsy, long delay between tumor-tissue and blood collection and resection of the tumor at time of blood draw, tumor site, or type of tissue analyzed seem to affect concordance. Altogether, the clinical data with respect to the anti-epidermal growth factor receptor response (RAS status) and the prognosis (BRAF status) of those discordant patients do not appear contradictory to the mutational status as determined by plasma analysis. Lastly, we present the first distribution profile of the RAS and BRAF hotspot mutations as determined by ctDNA analysis (n = 119), revealing a high proportion of patients with multiple mutations (45% of the population and up to 5 mutations) and only 24% of WT scored patients for both genes. Mutation profile as determined from ctDNA analysis with using various detection thresholds highlights the importance of the test sensitivity.

Conclusion

Our study showed that ctDNA could replace tumor-tissue analysis, and also clinical utility of ctDNA analysis by considerably reducing data turnaround time.

Tacrolimus and the risk of solid cancers after liver transplant: a dose effect relationship

Although increased rates of solid organ cancers have been reported following liver transplantation (LT), the impact of quantitative exposure to calcineurin inhibitors (CNI) remains unclear. We have therefore probed the relationship between the development of solid organ cancers following LT and the level of CNI exposure. This prospective single-center study was conducted between 1995 and 2008 and is based on 247 tacrolimus-treated liver transplant recipients who survived at least 1 year following surgery. The incidence of cancer was recorded, and the mean blood concentration of tacrolimus (TC) was determined at 1 and 3 years following LT. The study results indicate that 43 (17.4%) patients developed de novo solid cancers. Mean TC during the first year after LT was significantly higher in patients who developed solid organ tumors (10.3 ± 2.1 vs. 7.9 ± 1.9 ng/mL, p < 0.0001). Independent risks factors in multivariate analysis were tobacco consumption before LT (OR = 5.42; 95% CI [1.93-15.2], p = 0.0014) and mean annual TC during the first year after LT (p < 0.0001; OR = 2.01; 95% CI [1.57-2.59], p < 0.0001). Similar effects were observed in 216 patients who received tacrolimus continuously for ≥3 years. It appears therefore that CNI should be used with caution after LT, and that new immunosuppressive therapies could deliver significant clinical benefits in this regard.

Feasibility of biweekly combination chemotherapy with capecitabine, irinotecan, and oxaliplatin in patients with metastatic solid tumors: results of a two-step phase I trial: XELIRI and XELIRINOX

BACKGROUND

Biweekly schedule of capecitabine combined with irinotecan (XELIRI), consecutively with irinotecan and oxaliplatin (XELIRINOX), was evaluated in patients with metastatic cancer from any solid tumors.

PATIENTS AND METHODS

In this two-step phase I trial, seventeen and eleven patients were enrolled in the XELIRI and XELIRINOX stages, respectively.

RESULTS

In XELIRI, a total of 136 chemotherapy cycles were administered with a median number of 8 cycles per patient (2-16). Main dose-limiting toxicities (DLT) were grade 3-4 neutropenia, with one toxicity-related death. Maximum tolerated dose (MTD) for capecitabine combined with 180 mg/m(2) of irinotecan was 3,500 mg/m(2)/day. In XELIRINOX, capecitabine starting dose was 2,500 mg/m(2)/day. Fifty-eight chemotherapy cycles were administered with a median of 4 cycles per patient (1-16). DLT included 3 grade 4 neutropenia, associated with 1 grade 3 diarrhea, and 1 grade 4 pneumopathy leading to patient death. MTD for capecitabine with 180 mg/m(2) of irinotecan and 85 mg/m(2) of oxaliplatin was 3,000 mg/m(2)/day. The recommended doses for capecitabine were 3,000 and 2,500 mg/m(2)/day D1-D7 in combination with 180 mg/m(2) of irinotecan in XELIRI, plus 85 mg/m(2) of oxaliplatin in XELIRINOX (D1 = D14), respectively.

CONCLUSION

XELIRI and XELIRINOX regimens are feasible and warrant further investigation in combination with targeted therapy in metastatic colorectal cancer patients.

Clinical impact of lymph node status in rectal cancer

Lymph node status at the time of diagnosis remains one of the principal indicators of prognosis in patients with rectal cancer. Involvement of loco-regional lymph nodes is relevant to surgical and clinical oncologists and continues to impact significantly upon local and systemic management strategies, in both neo-adjuvant and adjuvant settings. In this review, the clinical impact of lymph node status in the surgical management of rectal cancer is considered, with particular reference to the significance of lymphadenectomy and the potential implications for rectal tumours amenable to trans-anal excision. Current standards of care are reviewed and the extent to which the determination of lymph node status influences oncological decisions regarding neo-adjuvant and adjuvant therapies are discussed with areas of controversy highlighted.

A large-scale candidate gene approach identifies SNPs in SOD2 and IL13 as predictive markers of response to preoperative chemoradiation in rectal cancer

Neoadjuvant radiochemotherapy followed by total mesorectal excision is now the standard treatment for locally advanced rectal cancer. However, tumor response to chemoradiation varies widely among individuals and cannot be determined before the final pathologic evaluation. The aim of this study was to identify germline genetic markers that could predict sensitivity or resistance to preoperative radiochemotherapy (RT-CT) in rectal cancer. We evaluated the predictive value of 128 single-nucleotide polymorphisms (SNPs) in 71 patients preoperatively treated by RT-CT. The selected SNPs were distributed over 76 genes that are involved in various cellular processes such as DNA repair, apoptosis, proliferation or immune response. The SNPs superoxide dismutase 2 (SOD2) rs4880 (P=0.005) and interleukin-13 (IL13) rs1800925 (P=0.0008) were significantly associated with tumor response to chemoradiation. These results reinforce the idea of using germline polymorphisms for personalized treatment.

Endoscopic ultrasound-guided fine-needle aspiration biopsy coupled with KRAS mutation assay to distinguish pancreatic cancer from pseudotumoral chronic pancreatitis

BACKGROUND AND STUDY AIMS

Differential diagnosis between pancreatic adenocarcinoma (PADC) and pseudotumoral forms of chronic pancreatitis remains difficult. Mutation of KRAS oncogene is present in 75% to 95% of PADC. This study aimed to evaluate whether the combined analysis of KRAS mutation with cytopathological findings from endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) might improve discrimination between PADC and chronic pancreatitis.

PATIENTS AND METHODS

This prospective multicenter study included 178 patients with solid pancreatic masses (men 104, women 74; mean age 64.5 years). Cytopathological examination and KRAS mutation analysis (codon-12 and codon-13, restriction fragment length polymorphism [RFLP] and direct sequencing) were performed on EUS-FNAB material. Final diagnoses were obtained on EUS-FNAB analysis and/or a second biopsy and/or clinical follow-up and/or surgery: PADC, n = 129; chronic pancreatitis, n = 27; other pancreatic neoplasms, n = 16; and benign lesions, n = 6.

RESULTS

KRAS status analysis was successful in all EUS-FNAB samples. Codon-12 KRAS point mutation was found in 66% of PADC samples. No case of chronic pancreatitis displayed KRAS mutation. Sensitivity, specificity, positive and negative predictive values, and overall accuracy of cytopathology alone for diagnosis of PADC versus chronic pancreatitis were 83%, 100%, 100%, 56% and 86%, respectively. When KRAS mutation analysis was combined with cytopathology, these values reached 88%, 100%, 100%, 63% and 90% respectively.

CONCLUSION

Although the value of KRAS analysis in addition to EUS-FNAB is limited for distinguishing pancreatic mass lesions, when chronic pancreatitis presented as a pseudotumor a negative finding (wild-type KRAS), was useful in strongly suggesting a benign lesion.

A multicenter, randomized phase II trial of gemcitabine and oxaliplatin (GEMOX) alone or in combination with biweekly cetuximab in the first-line treatment of advanced biliary cancer: Interim analysis of the BINGO trial

4520

Background: There is no standard regimen for palliative chemotherapy of advanced biliary cancers. The GEMOX regimen is an option (BJC 2008). EGFR over-expression has been observed in advanced biliary cancers suggesting that the combination with anti-EGFR monoclonal antibodies may be appropriate. Methods: Patients with advanced biliary cancer, WHO performance status 0–1, and without prior palliative chemotherapy were eligible for this international, open-label, two-stage, randomized phase II trial. Patients received GEMOX (gemcitabine, 1000 mg/m2 [10 mg/m2/min] at day [D]1; oxaliplatin, 100 mg/m2 at D2) alone (arm A) or with cetuximab (500 mg/m2 at D1 or 2, arm B), every 2 weeks. Randomization was stratified according to tumor stage and location, center, and prior treatments. The primary endpoint was 4-month crude progression-free survival (PFS) rate (H0 hypothesis, < 40%; H1, ≥ 60%; planned sample size, 50 patients per arm). Secondary endpoints were response rate, PFS, overall survival, toxicity, early response assessment by PET, and blood/tumor EGFR signalling pathway member analyses. A data safety monitoring board-approved interim analysis was performed at the end of the first stage (18 patients per arm, minimal follow- up 4 months). Results: From October 2007 to October 2008, we enrolled 101 patients (median age, 62 yrs; male, 60%; metastatic, 86%; non-gallbladder, 76%). Among the 36 patients at the time of the interim analysis, the median number of treatment cycles was 6 and 8 in arms A and B, respectively. 76% (arm A) and 67% (arm B) had NCI-CTC grade 3–4 toxicity, mainly cytopenia (41%/39%), peripheral neuropathy (modified Levi's scale grade 2–3: 29%/33%), fatigue (6%/22%), gastrointestinal toxicity (12%/17%), and rash/hypersensitivity (0%/17%). The 4-month PFS rate was 44% (95% CI, 20–70) and 61% (95% CI, 36–83) in arms A and B, respectively. Conclusions: The GEMOX-cetuximab regimen seems well tolerated in patients with advanced biliary cancer. Adding cetuximab to GEMOX showed promising activity and therefore the trial was continued. Updated results on the whole population for primary and secondary endpoints will be available at the meeting.

[Table: see text]

A phase I trial of a bi-weekly combination of capecitabine/irinotecan (XELIRI) then capecitabine/irinotecan/oxaliplatin (XELIRINOX) in solid tumors

e15075

Background: Oral fluoropyrimidines, notably capecitabine, are increasingly replacing IV 5-FU/LV as the backbone of therapy for metastatic colorectal cancer. The bi-weekly combination of capecitabine/irinotecan warrants further examination. Methods: We conducted a phase I trial, in metastatic cancer patients treated for solid tumors, to determine the recommended dose of capecitabine administered orally bid from day 1 to 8 in combination with a bi-weekly fixed-dose of IV irinotecan 180 mg/m2 delivered on day 1 and 14 (FIRST STAGE: XELIRI); and + a bi-weekly fixed-dose of IV oxaliplatin (L-OHP) 85 mg/m2 delivered on day 1 and 14 (Second STAGE: XELIRINOX). Five increasing dose levels (DL1–5) of capecitabine were planned: 1000, 1250, 1500, 1750, and 2000 mg/m2 bid. A pharmacokinetic study of this association was performed. Results: In the first stage, a total of 17 patients were enrolled, with a median age of 60 (range 52–73) years. All patients had an ECOG PS of either 0 (59%), 1 (35%), or 2 (6%). Four patients experienced dose-limiting toxicity: 2 developed grade 4 neutropenia (at DL 1 and 4) and 2 others grade 4 febrile neutropenia (at DL3 and 4). One toxicity-related death occurred following febrile neutropenia (DL4). Maximal tolerated dose (MTD) was DL4, and the recommended dose regimen was bi-weekly irinotecan 180 mg/m2 combined with capecitabine 1500 mg/m2 bid (administered from days 1 to 8). In the second stage, the starting dose level of capecitabine in the bi- weekly association with irinotecan and L-OHP was defined as two dose levels below the MTD level reached in the first stage of the study (DL4 - 2 = DL2). Height patients were enrolled with a median age of 56 (35–75) and ECOG 0 for 62%, ECOG 1 for 38%. Chemotherapy is ongoing for three of them. Three patients experienced dose-limiting toxicity: 1 grade 4 neutropenia ( DL2), 1 grade 4 febrile neutropenia ( DL3) and 1 grade 4 pneumopathy ( DL3). The MTD of XELIRINOX was DL3, and the recommended dose regimen will be presented at the meeting. Conclusions: Bi-weekly combination of capecitabine/irinotecan/oxaliplatin (XELIRI / XELIRINOX) is feasible and could be tested in patients with metastatic colorectal cancer in combination with a targeted therapy.

[Table: see text]

[Systematic review: value of perioperative chemotherapy in the management of resectable rectal adenocarcinoma (brief report)]

At the request of the National Thesaurus of Gastrointestinal Cancer (TNCD), the SOR program undertaken by the French federation of cancer centers and now led by the French National Cancer Institute, completed a systematic review to evaluate the value of perioperative chemotherapy in the management of resectable rectal adenocarcinoma in collaboration with clinician experts.

METHODS

Results of a systematic literature search using Medline and Embase (from January 1996 to October 2007) were completed by a survey of Evidence- Based Medicine websites. All phase III randomized trials and systematic reviews comparing surgery (alone or associated with adjuvant therapy) to the same treatment plus chemotherapy, or comparing different perioperative chemotherapy modalities in patients with resectable rectal adenocarcinoma, were included in the study. The quality and clinical relevance of the trials were evaluated using validated checklists, allowing to associate each result with its level of evidence. Data synthesis was performed taking into account both efficacy and toxicity outcomes for each intervention. Finally, research recommendations were formulated.

RESULTS

Of 29 studies meeting the selection criteria, 19 were included after critical methodological and clinical appraisal. As compared with preoperative radiotherapy, preoperative chemoradiotherapy with 5-fluorouracil and folinic acid does not improve overall or relapse-free survivals but decreases local recurrence rates. Postoperative chemotherapy with 5-fluorouracil and folinic acid does not improve overall or relapse-free survivals, whether the patients received preoperative radiotherapy or preoperative chemoradiotherapy, whereas it seems to decrease local recurrence rates after preoperative radiotherapy but not after preoperative chemoradiotherapy. As compared with postoperative chemoradiotherapy, preoperative chemoradiotherapy with continuous infusion of 5-fluorouracil does not improve overall or relapse-free survivals, but decreases local recurrence rates as well as acute and long-term toxicities. In the absence of preoperative radiotherapy, fluoropyrimidine-based postoperative chemotherapy improves both overall and relapse-free survivals and decreases local recurrence rates.

CONCLUSIONS

Preoperative chemoradiotherapy reduces the risk of local recurrence as compared with preoperative radiotherapy or postoperative chemoradiotherapy.

[Value of MRCP for diagnosis of biliary complications after liver transplantation]

PURPOSE

To assess the value of MRCP in the detection of biliary complications after orthotopic liver transplantation.

MATERIALS AND METHODS

27 transplanted patients with suspected biliary complication underwent a total of 34 MR and direct cholangiography procedures. MRCP were reviewed by 2 independent reviewers blinded to clinical and laboratory findings. The biliary tract was divided into 7 segments, and all lesions were evaluated using this segmental anatomy. Each segment was evaluated for the presence of dilatation, stenosis and intra-ductal debris. MRCP results were compared to results frpm direct cholangiography.

RESULTS

216 (98%) of 221 biliary segments could be evaluated on MRCP, with good to excellent visualization in 179 (80%) cases. Segmental analysis showed sensitivity, specificity and accuracy values of 85%, 81% and 83% for the detection of biliary stenosis, 82%, 81% and 81% for the detection of biliary dilatation, and 60%, 88% and 80% for the detection of inyraductal debris.

CONCLUSION

MRCP is accurate for the detection of biliary stenosis and dilatation in patients after liver transplantation and provides an alternative to direct cholangiography.