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.

Expression of dihydropyrimidine dehydrogenase (DPD) and hENT1 predicts survival in pancreatic cancer.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD) tumour expression may provide added value to human equilibrative nucleoside transporter-1 (hENT1) tumour expression in predicting survival following pyrimidine-based adjuvant chemotherapy. METHODS: DPD and hENT1 immunohistochemistry and scoring was completed on tumour cores from 238 patients with pancreatic cancer in the ESPAC-3(v2) trial, randomised to either postoperative gemcitabine or 5-fluorouracil/folinic acid (5FU/FA). RESULTS: DPD tumour expression was associated with reduced overall survival (hazard ratio, HR = 1.73 [95% confidence interval, CI = 1.21-2.49], p = 0.003). This was significant in the 5FU/FA arm (HR = 2.07 [95% CI = 1.22-3.53], p = 0.007), but not in the gemcitabine arm (HR = 1.47 [0.91-3.37], p = 0.119). High hENT1 tumour expression was associated with increased survival in gemcitabine treated (HR = 0.56 [0.38-0.82], p = 0.003) but not in 5FU/FA treated patients (HR = 1.19 [0.80-1.78], p = 0.390). In patients with low hENT1 tumour expression, high DPD tumour expression was associated with a worse median [95% CI] survival in the 5FU/FA arm (9.7 [5.3-30.4] vs 29.2 [19.5-41.9] months, p = 0.002) but not in the gemcitabine arm (14.0 [9.1-15.7] vs. 18.0 [7.6-15.3] months, p = 1.000). The interaction of treatment arm and DPD expression was not significant (p = 0.303), but the interaction of treatment arm and hENT1 expression was (p = 0.009). CONCLUSION: DPD tumour expression was a negative prognostic biomarker. Together with tumour expression of hENT1, DPD tumour expression defined patient subgroups that might benefit from either postoperative 5FU/FA or gemcitabine.

Intratumoural expression of deoxycytidylate deaminase or ribonuceotide reductase subunit M1 expression are not related to survival in patients with resected pancreatic cancer given adjuvant chemotherapy.

BACKGROUND: Deoxycytidylate deaminase (DCTD) and ribonucleotide reductase subunit M1 (RRM1) are potential prognostic and predictive biomarkers for pyrimidine-based chemotherapy in pancreatic adenocarcinoma. METHODS: Immunohistochemical staining of DCTD and RRM1 was performed on tissue microarrays representing tumour samples from 303 patients in European Study Group for Pancreatic Cancer (ESPAC)-randomised adjuvant trials following pancreatic resection, 272 of whom had received gemcitabine or 5-fluorouracil with folinic acid in ESPAC-3(v2), and 31 patients from the combined ESPAC-3(v1) and ESPAC-1 post-operative pure observational groups. RESULTS: Neither log-rank testing on dichotomised strata or Cox proportional hazard regression showed any relationship of DCTD or RRM1 expression levels to survival overall or by treatment group. CONCLUSIONS: Expression of either DCTD or RRM1 was not prognostic or predictive in patients with pancreatic adenocarcinoma who had had post-operative chemotherapy with either gemcitabine or 5-fluorouracil with folinic acid.

The prognostic impact of consensus molecular subtypes (CMS) and its predictive effects for bevacizumab benefit in metastatic colorectal cancer: molecular analysis of the AGITG MAX clinical trial.

Background: The consensus molecular subtypes (CMS) is a transcriptome-based classification of colorectal cancer (CRC) initially described in early-stage cohorts, but the associations of CMS with treatment outcomes in the metastatic setting are yet to be established. This study aimed to evaluate the prognostic impact of CMS classification and its predictive effects for bevacizumab benefit in metastatic CRC by correlative analysis of the AGITG MAX trial. Patients and methods: The MAX trial previously reported improved progression-free survival (PFS) for the addition of bevacizumab (B) to chemotherapy [capecitabine (C)±mitomycin (M)]. Archival primary tumours from 237 patients (50% of trial population) underwent gene expression profiling and classification into CMS groups. CMS groups were correlated to PFS and overall survival (OS). The interaction of CMS with treatment was assessed by proportional hazards model. Results: The distribution of CMS in MAX were CMS1 18%, CMS2 47%, CMS3 12%, CMS4 23%. CMS1 was the predominant subtype in right-sided primary tumours, while CMS2 was the predominant subtype in left-sided. CMS was prognostic of OS (P = 0.008), with CMS2 associated with the best outcome and CMS1 the worst. CMS remained an independent prognostic factor in a multivariate analysis. There was a significant interaction between CMS and treatment (P-interaction = 0.03), for PFS, with hazard ratios (95% CI) for CB+CBM versus C arms in CMS1, 2, 3 and 4: 0.83 (0.43-1.62), 0.50 (0.33-0.76), 0.31 (0.13-0.75) and 1.24 (0.68-2.25), respectively. Conclusions: This exploratory study found that CMS stratified OS outcomes in metastatic CRC regardless of first-line treatment, with prognostic effects of CMS groups distinct from those previously reported in early-stage cohorts. In CMS associations with treatment, CMS2 and possibly CMS3 tumours may preferentially benefit from the addition of bevacizumab to first-line capecitabine-based chemotherapy, compared with other CMS groups. Validation of these findings in additional cohorts is warranted. Clinical trial number: This is a molecular sub-study of MAX clinical trial (NCT00294359).

Hope, optimism and survival in a randomised trial of chemotherapy for metastatic colorectal cancer.

PURPOSE: Psychological responses to cancer are widely believed to affect survival. We investigated associations between hope, optimism, anxiety, depression, health utility and survival in patients starting first-line chemotherapy for metastatic colorectal cancer. METHODS: Four hundred twenty-nine subjects with metastatic colorectal cancer in a randomised controlled trial of chemotherapy completed baseline questionnaires assessing the following: hopefulness, optimism, anxiety and depression and health utility. Hazard ratios (HRs) and P values were calculated with Cox models for overall survival (OS) and progression-free survival (PFS) in univariable and multivariable analyses. RESULTS: Median follow-up was 31 months. Univariable analyses showed that OS was associated negatively with depression (HR 2.04, P < 0.001) and positively with health utility (HR 0.56, P < 0.001) and hopefulness (HR 0.75, P = 0.013). In multivariable analysis, OS was also associated negatively with depression (HR 1.72, P < 0.001) and positively with health utility (HR 0.73, P = 0.014), but not with optimism, anxiety or hopefulness. PFS was not associated with hope, optimism, anxiety or depression in any analyses. CONCLUSIONS: Depression and health utility, but not optimism, hope or anxiety, were associated with survival after controlling for known prognostic factors in patients with advanced colorectal cancer. Further research is required to understand the nature of the relationship between depression and survival. If a causal mechanism is identified, this may lead to interventional possibilities.

Vascular endothelial growth factor D expression is a potential biomarker of bevacizumab benefit in colorectal cancer.

BACKGROUND: Bevacizumab prolongs progression-free survival (PFS) in patients with metastatic colorectal cancer. We analysed the protein expression levels of vascular endothelial growth factor (VEGF) ligands and receptors to determine their prognostic and predictive effects. METHODS: We graded expression of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-R1, and VEGF-R2 to assess whether overexpression predicted bevacizumab resistance in samples from 268 of 471 patients randomised to capecitabine (C), capecitabine and bevacizumab (CB), or CB and mitomycin (CBM) in the MAX trial and extended the analysis to the CAIRO-2 population. RESULTS: Patients with low expression of VEGF-D (0, 1þ) benefited from bevacizumab treatment (PFS hazard ratio (HR) (C vs CBþCBM), 0.21; 95% CI, 0.08­0.55; overall survival (OS) HR, 0.35; 95% CI, 0.13­0.90). Patients with higher VEGF-D expression received less benefit (VEGF-D 2þ PFS HR, 0.67; 95% CI, 0.45­1.00; OS HR, 0.82; 95% CI, 0.52­1.30; VEGF-D 3þ PFS HR, 0.77; 95% CI, 0.50­1.17; OS HR, 1.28; 95% CI, 0.79­2.09) (P interaction o0.05). In CAIRO-2, there was no difference in PFS or OS according to VEGF-D expression. CONCLUSIONS: The predictive value of VEGF-D expression for bevacizumab may depend on the chemotherapy backbone used. Further evaluation is required before clinical utilisation.

Correlation of extended RAS and PIK3CA gene mutation status with outcomes from the phase III AGITG MAX STUDY involving capecitabine alone or in combination with bevacizumab plus or minus mitomycin C in advanced colorectal cancer.

BACKGROUND: Mutations affecting RAS genes are now established predictive markers of nonresponse to anti-EGFR antibodies in advanced CRC. This analysis assessed the prognostic and predictive impact of extended RAS and PIK3CA gene mutation status in patients receiving capecitabine plus or minus bevacizumab (±mitomycin C) in the randomised phase III MAX study. METHODS: DNA was extracted from archival macrodissected formalin-fixed paraffin-embedded tumour tissue. Mutation status was determined using pyrosequencing, confirmed with Sanger sequencing (for equivocal RAS) and correlated with efficacy outcomes. Predictive analyses were undertaken using a test for interaction involving both C vs CB+CBM. RESULTS: Of the available 280 of the 471 (59.4%) patients, mutations in KRAS exons 2, 3 and 4 and NRAS 2, 3 and 4 were as follows: 32%, 2.9%, 2.2%, 1.4%, 0.7% and 0% (total RAS MT 39%). The PIK3CA MT rate was 7.5% exon 9 and 3.6% exon 20. Extended RAS gene mutation status (WT vs MT) had no prognostic impact for PFS (HR 0.91 (0.71-1.17)) or OS (HR 0.95 (0.71-1.25)). The RAS gene mutation status was not predictive of the effectiveness of bevacizumab for PFS (HR 0.56 (0.37-0.85) for RAS MT and HR 0.69 (0.5-0.97) for RAS WT; P for interaction 0.50). The PIK3CA mutation was neither predictive for bevacizumab effect nor prognostic. CONCLUSION: Of KRAS exon 2 WT patients, 10% had additional RAS mutations. Neither all RAS gene mutation status nor PIK3CA mutation status was prognostic for PFS or OS, or predictive of bevacizumab outcome in patients with advanced CRC.

The role of biological therapy in metastatic colorectal cancer after first-line treatment: a meta-analysis of randomised trials.

PURPOSE: Biologic agents have achieved variable results in relapsed metastatic colorectal cancer (mCRC). Systematic meta-analysis was undertaken to determine the efficacy of biological therapy. METHODS: Major databases were searched for randomised studies of mCRC after first-line treatment comparing (1) standard treatment plus biologic agent with standard treatment or (2) standard treatment with biologic agent with the same treatment with different biologic agent(s). Data were extracted on study design, participants, interventions and outcomes. Study quality was assessed using the MERGE criteria. Comparable data were pooled for meta-analysis. RESULTS: Twenty eligible studies with 8225 patients were identified. The use of any biologic therapy improved overall survival with hazard ratio (HR) 0.87 (95% confidence interval (CI) 0.82-0.91, P<0.00001), progression-free survival (PFS) with HR 0.71 (95% CI 0.67-0.74, P<0.0001) and overall response rate (ORR) with odds ratio (OR) 2.38 (95% CI 2.03-2.78, P<0.00001). Grade 3/4 toxicity was increased with OR 2.34. Considering by subgroups, EGFR inhibitors (EGFR-I) in the second-line setting and anti-angiogenic therapies (both in second-line and third-line and beyond settings) all improved overall survival, PFS and ORR. EGFR-I in third-line settings improved PFS and ORR but not OS. CONCLUSIONS: The use of biologic agents in mCRC after first-line treatment is associated with improved outcomes but increased toxicity.

A randomised, double-blind, placebo-controlled phase 2 study of trebananib (AMG 386) in combination with FOLFIRI in patients with previously treated metastatic colorectal carcinoma.

BACKGROUND: This phase 2 study evaluated trebananib (AMG 386), an investigational peptide-Fc fusion protein that neutralises the interaction between angiopoietins-1/2 and the Tie2 receptor, plus FOLFIRI as second-line treatment for patients with metastatic colorectal cancer. METHODS: Patients had adenocarcinoma of the colon or rectum with progression within 6 months of receiving only one prior fluoropyrimidine/oxaliplatin-based chemotherapy regimen for metastatic disease. All patients received FOLFIRI and were randomised 2:1 to also receive intravenous trebananib 10 mg kg(-1) once weekly (QW) (Arm A) or placebo QW (Arm B). The primary end point was investigator-assessed progression-free survival (PFS). RESULTS: One hundred and forty-four patients were randomised (Arms A/B, n=95/49). Median PFS in Arms A and B was 3.5 and 5.2 months (hazard ratio (HR) 1.23; 95% CI, 0.81-1.86; P=0.33) and median overall survival (OS) was 11.9 and 8.8 months, respectively (HR 0.90; 95% CI; 0.53-1.54; P=0.70). Objective response rate (ORR) was 14% and 0% in Arms A and B, respectively. Incidence of grade ≥3 adverse events was similar between treatment arms (Arm A, 61%; Arm B, 65%) and included pulmonary embolism (1%/4%), deep vein thrombosis (5%/2%), and hypertension (1%/0%). CONCLUSION: Administration of trebananib plus FOLFIRI did not prolong PFS compared with placebo plus FOLFIRI. Toxicities were manageable and consistent with those known for FOLFIRI and trebananib.

Docetaxel plus cetuximab as second-line treatment for docetaxel-refractory oesophagogastric cancer: the AGITG ATTAX2 trial.

BACKGROUND: Cetuximab can reverse chemotherapy resistance in colorectal cancer. This study evaluated the efficacy and safety of the combination of docetaxel and cetuximab as a second-line treatment in docetaxel-refractory oesophagogastric cancer. METHODS: Patients received docetaxel 30 mg m(-2) on days 1 and 8, every 3 weeks and cetuximab 400 mg m(-2) on day 1, then 250 mg m(-2) weekly. Biomarker mutation analysis was performed. RESULTS: A total of 38 patients were enrolled. Response rates were PR 6% (95% CI 2-19%), s.d. 43% (95% CI 28-59%). Main grade 3/4 toxicities were febrile neutropenia, anorexia, nausea, diarrhoea, stomatitis, and acneiform rash. Median progression-free and overall survival were 2.1 and 5.4 months, respectively. A landmark analysis showed a trend to improved survival times with increased grade of acneiform rash. No KRAS, BRAF or PIK3CA mutations were observed. CONCLUSION: Cetuximab and docetaxel achieve modest responses rates, but maintain comparable survival times to other salvage regimens with low rates of toxicity.

Phase II randomized, double-blind, placebo-controlled study of AMG 386 (trebananib) in combination with cisplatin and capecitabine in patients with metastatic gastro-oesophageal cancer.

BACKGROUND: We evaluated AMG 386, an investigational peptibody that neutralizes the interaction between angiopoietins-1 and -2 and the Tie2 receptor, combined with cisplatin/capecitabine (CX) as first-line treatment for metastatic gastro-oesophageal cancer. PATIENTS AND METHODS: Patients with metastatic gastric, gastro-oesophageal junction, or distal oesophageal adenocarcinoma were randomized 1:1:1 to CX (cisplatin 80 mg/m(2) IV Q3W; capecitabine 1000 mg/m(2) P.O. BID for 14 days Q3W) plus intravenous AMG 386 10 mg/kg QW (Arm A) or 3 mg/kg QW (Arm B), or placebo QW (Arm C). The primary end point was estimated progression-free survival (PFS). RESULTS: A total of 171 patients were enrolled. Median estimated PFS in Arms A, B, and C was 4.2, 4.9, and 5.2 months, respectively (hazard ratio for Arms A+B combined versus Arm C, 0.98; 95% CI 0.67-1.43; P = 0.92). Objective response rates were 27% (Arm A), 43% (Arm B), and 35% (Arm C). Incidence of grade ≥3 adverse events was 80% in Arm A, 84% in Arm B, and 75% in Arm C. There was no evidence of pharmacokinetic interactions. CONCLUSIONS: In this study, PFS and ORR were estimated to be similar with AMG 386 plus CX and placebo plus CX treatment. Compared with placebo, toxicity of AMG 386 plus CX was greater but manageable. PREVIOUS PRESENTATION: The results of this study have not been previously published or submitted for publication elsewhere. The results were presented in part at the Gastrointestinal Cancers Symposium, San Francisco, CA, January 20-22, 2011. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT00583674.

Association of hypomagnesemia with inferior survival in a phase III, randomized study of cetuximab plus best supportive care versus best supportive care alone: NCIC CTG/AGITG CO.17.

BACKGROUND: Cetuximab-induced hypomagnesemia has been associated with improved clinical outcomes in advanced colorectal cancer (CRC). We explored this relationship from a randomized clinical trial of cetuximab plus best supportive care (BSC) versus BSC alone in patients with pretreated advanced CRC. PATIENTS AND METHODS: Day 28 hypomagnesemia grade (0 versus ≥1) and percent reduction (<20% versus ≥20%) of Mg from baseline was correlated with outcome. RESULTS: The median percentage Mg reduction at day 28 was 10% (-42.4% to 63.0%) for cetuximab (N = 260) versus 0% (-21.1% to 25%) for BSC (N = 251) [P < 0.0001]. Grade ≥1 hypomagnesemia and ≥20% reduction from baseline at day 28 were associated with worse overall survival (OS) [hazard ratio, HR 1.61 (95% CI 1.12-2.33), P = 0.01 and 2.08 (95% CI 1.32-3.29), P = 0.002, respectively] in multivariate analysis including grade of rash (0-1 versus 2+). Dyspnea (grade ≥3) was more common in patients with ≥20% versus < 20% Mg reduction (68% versus 45%; P = 0.02) and grade 3/4 anorexia were higher in patients with grade ≥1 hypomagnesemia (81% versus 63%; P = 0.02). CONCLUSIONS: In contrast to prior reports, cetuximab-induced hypomagnesemia was associated with poor OS, even after adjustment for grade of rash.

Bevacizumab is equally effective and no more toxic in elderly patients with advanced colorectal cancer: a subgroup analysis from the AGITG MAX trial: an international randomised controlled trial of Capecitabine, Bevacizumab and Mitomycin C.

BACKGROUND: In an ageing population, a greater proportion of geriatric patients will be considered for systemic chemotherapy. Colorectal cancer (CRC) is a common malignancy and will be a major health issue in geriatrics. We used the MAX population to investigate whether age affected the improved outcome found in CRC when bevacizumab is added to capecitabine chemotherapy. PATIENTS AND METHODS: MAX, a three arm study of Capecitabine (C) versus CBevacizumab (CB) versus CBMitomycin C (CBM), found an improvement in progression-free survival (PFS), with addition of B [+/- mitomycin C (MMC)] to C. This analysis assesses the effect of adding B (+/- MMC) to C on PFS, overall survival (OS), response rate (RR), toxicity and dose intensity in geriatric patients (age ≥ 75 years). RESULTS: Ninety-nine patients (21%) were aged 75-86 years. Baseline characteristics were well balanced. Eighty-eight per cent commenced C at the lower optional dose of 2000 mg/m(2)/day; days 1-14, q21 (61% for <75 years) and 88% were Eastern Cooperative Oncology Group 0-1. Co-morbidities were as expected in this population. The addition of B significantly improved PFS in geriatric patients(C 5.8 months versus CB 8.8 months, Hazard ratio (HR) 0.65 and C versus CBM 10.4 months HR 0.38). The interaction test for OS, RR and PFS revealed no impact of age. Dose intensity was maintained >90% in all patients. There were no major differences in toxicity patterns between age cohorts. CONCLUSIONS: Addition of B to C significantly improved PFS in this geriatric population, with similar benefits to those aged <75 years. Treatment was well tolerated with no signal of increased toxicity (including thromboembolism) when compared with those aged <75 years.

A phase II open-label randomized study to assess the efficacy and safety of selumetinib (AZD6244 [ARRY-142886]) versus capecitabine in patients with advanced or metastatic pancreatic cancer who have failed first-line gemcitabine therapy.

Selumetinib is a potent, selective MEK inhibitor with efficacy in several tumor models. This study compared selumetinib with capecitabine in patients with advanced or metastatic pancreatic cancer who had been pretreated with a gemcitabine-based regimen. In this randomized, multicenter phase II study (NCT00372944), patients received either 100 mg oral selumetinib twice daily or 1,250 mg/m(2) oral capecitabine twice daily for 2 weeks followed by a 1-week break, given in 3-weekly cycles. The primary endpoint was overall survival. In all 70 patients were randomized. The median survival was 5.4 months in the selumetinib group and 5.0 months in the capecitabine group (hazard ratio 1.03; two-sided 80% confidence interval = 0.68,1.57; P = 0.92). Disease progression events occurred in 84% and 88% of patients in the selumetinib and capecitabine treatment groups, respectively. Gastrointestinal adverse events (nausea, vomiting and diarrhea) were commonly observed in both treatment groups. Other frequently reported adverse events were acneiform dermatitis and peripheral edema with selumetinib, and palmar-plantar erythrodysaesthesia with capecitabine. There was no statistically significant difference in overall survival between selumetinib and capecitabine as second-line treatment in patients with advanced pancreatic cancer. Selumetinib was well tolerated with a manageable safety profile.

Risk of arterial thromboembolic events in patients with advanced colorectal cancer receiving bevacizumab.

BACKGROUND: Bevacizumab is an antiangiogenic mAb with efficacy against several cancers, but it is associated with risk of arterial thromboembolism (ATE). Further data are needed to determine the safety of bevacizumab. PATIENTS AND METHODS: We recorded grade 3, 4, or 5 ATE events and other data (including age, baseline cardiovascular risk factors, history of ATE, and aspirin use) from 471 patients with metastatic colorectal cancer in the MAX (Mitomycin, Avastin, Xeloda) trial of capecitabine monotherapy versus capecitabine with bevacizumab with or without mitomycin C. RESULTS: Bevacizumab-treated patients had 12 grade 3, 4, or 5 ATEs (3.8% incidence). ATEs occurred in 2.1% of patients >65 years, 5% of those with a history of ATE, and 5% of those with cardiac risk factors. Age, history of ATE, or vascular risk factors did not increase risk. Aspirin users had a higher incidence than nonusers (8.9% versus 2.7%) but had higher rates of vascular risk factors. CONCLUSIONS: Bevacizumab was associated with a modestly higher risk of ATE, but safety was not significantly worse in older patients or patients with a history of ATE or vascular risk factors. The effect of aspirin in preventing ATE in patients receiving bevacizumab could not be determined from this study.

Randomised, non-comparative phase II study of weekly docetaxel with cisplatin and 5-fluorouracil or with capecitabine in oesophagogastric cancer: the AGITG ATTAX trial.

BACKGROUND: Docetaxel administered 3-weekly with cisplatin and 5-fluorouracil leads to better survival than does standard therapy in patients with oesophagogastric cancer, but leads to high rates of haematological toxicity. Weekly docetaxel is associated with less haematological toxicity. This randomised phase II study tested weekly docetaxel-based combination chemotherapy regimens, with the aim of maintaining their activity while reducing toxicity. METHODS: Patients with histologically confirmed metastatic oesophageal or gastric carcinoma were randomised to receive weekly docetaxel (30 mg m(-2)) on days 1 and 8, cisplatin (60 mg m(-2)) on day 1, and 5-fluorouracil (200 mg m(-2) per day) continuously, every 3 weeks (weekly TCF, wTCF); or docetaxel (30 mg m(-2)) on days 1 and 8 and capecitabine (1600 mg m(-2) per day) on days 1-14, every 3 weeks (weekly TX, wTX). RESULTS: A total of 106 patients were enrolled (wTCF, n=50; wTX, n=56). Response rates, the primary end point, were 47% with wTCF and 26% with wTX. Rates of febrile neutropenia were low in each arm. Median progression-free and overall survival times were 5.9 and 11.2 months for wTCF and 4.6 and 10.1 months for wTX, respectively. CONCLUSION: Weekly TCF and TX have encouraging activity and less haematological toxicity than TCF administered 3-weekly. Weekly docetaxel-based combination regimens warrant further evaluation in this disease.

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.

The murine A33 antigen is expressed at two distinct sites during development, the ICM of the blastocyst and the intestinal epithelium.

The expression pattern of the murine A33 antigen has been defined during development using wholemount immunohistochemistry. Two temporally and spatially distinct sites of expression were identified: the inner cell mass of the blastocyst and the endoderm cell layer of the intestinal tract where expression is initiated at E14.5 in the hindgut and subsequently extends throughout the length of the intestine. The onset of mA33 antigen expression in the gut occurs at the beginning of an extensive phase of cell movement involved in the conversion of the endoderm cell layer to a single cell layer of polarized epithelium. Expression of mA33 antigen is then maintained into adulthood, where it is a definitive marker of intestinal epithelium.

Location of colon cancer (right-sided versus left-sided) as a prognostic factor and a predictor of benefit from cetuximab in NCIC CO.17.

BACKGROUND: Right- and left-sided colon cancers (RC, LC) differ with respect to biology, pathology and epidemiology. Previous data suggest a mortality difference between RC and LC. We examined if primary tumour side also predicts for outcome in chemotherapy refractory, metastatic colon cancer (MCC). We also compared RC versus LC as a predictor of efficacy of epidermal growth factor receptor (EGFR) inhibition with cetuximab. METHODS: Reanalyzing NCIC CO.17 trial (cetuximab versus best supportive care [BSC]), we coded the primary tumour side as RC (caecum to transverse colon) or LC (splenic flexure to rectosigmoid). The association between tumour side and baseline characteristics was assessed. Cox regression models determined factors affecting overall survival (OS) and progression free survival (PFS). RESULTS: Patients with RC (150/399) had more poorly differentiated, mutant KRAS, mutated PIK3CA and wild-type BRAF tumours, fewer liver and lung metastases, and shorter interval between diagnosis and study entry. Among BSC patients, tumour side was not prognostic for PFS (hazard ratios (HR) 1.07 [0.79-1.44], p = 0.67) or OS (HR 0.96 [0.70-1.31], p = 0.78). Among wild-type KRAS patients, those with LC had significantly improved PFS when treated with cetuximab compared to BSC (median 5.4 versus 1.8 months, HR 0.28 [0.18-0.45], p < 0.0001), whereas those with RC did not (median 1.9 versus 1.9 months, HR 0.73 [0.42-1.27], p = 0.26), [interaction p = 0.002]. CONCLUSION: In refractory MCC, tumour location within the colon is not prognostic, but is strongly predictive of PFS benefit from cetuximab therapy. Additional research is needed to understand the molecular differences between RC and LC and their interaction with EGFR inhibition.

Systemic treatment of colorectal cancer.

Palliative and adjuvant treatment for colorectal cancer has been, until recently, largely dependent on 5-fluorouracil (5-FU)-based chemotherapy. Oral fluoropyrimidines have been evaluated in the advanced disease setting and they appear to be as effective as 5-FU, but are safer and more convenient for most patients. Irinotecan and oxaliplatin are new cytotoxic agents, which are active in 5-FU-resistant disease, but which may also be combined with 5-FU as initial therapy in advanced disease. Initial combination therapy leads to improved response rates and more prolonged progression-free survival compared with 5-FU monotherapy. Standard regimens for adjuvant therapy usually involve 6 months of chemotherapy using 5-FU and folinic acid. Recent trials of capecitabine, oxaliplatin and irinotecan in the adjuvant setting are ongoing, or have recently completed accrual, and may lead to a change in future clinical practice. Biological therapies are playing an increasing role in the management of colorectal cancer. Farnesyl transferase inhibition, inhibition of the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF) are undergoing evaluation in advanced disease. In the adjuvant setting, both passive and active immunotherapeutic approaches have been studied. In addition, a large trial will evaluate the role of cyclo-oxygenase(COX)-2 inhibitors as adjuvant therapy. Further research is required in order to define the optimal sequence and combination of these different cytotoxic and biological therapies, in order to secure the best possible outcome for various subgroups of patients with both early and advanced stage colorectal cancer.