Pembrolizumab in Asian patients with microsatellite-instability-high/mismatch-repair-deficient colorectal cancer.

The phase 3 KEYNOTE-177 study evaluated pembrolizumab versus chemotherapy with or without bevacizumab or cetuximab in patients with newly diagnosed, microsatellite-instability-high (MSI-H)/mismatch-repair-deficient (dMMR) metastatic colorectal cancer (mCRC). Primary endpoints were progression-free survival (PFS) per RECIST v1.1 by blinded independent central review (BICR) and overall survival (OS). Secondary endpoints were overall response rate (ORR) per RECIST v1.1 by BICR and safety. Here, we report results from the post hoc analysis of patients who were enrolled in Asia from the final analysis (FA) of KEYNOTE-177. A total of 48 patients from Japan, Korea, Singapore, and Taiwan (pembrolizumab, n = 22; chemotherapy, n = 26) were included. At FA, median time from randomization to data cutoff (February 19, 2021) was 45.3 (range 38.1-57.8) months with pembrolizumab and 43.9 (range 36.6-55.1) months with chemotherapy. Median PFS was not reached (NR; 95% confidence interval [CI] 1.9 months-NR) with pembrolizumab versus 10.4 (95% CI 6.3-22.0) months with chemotherapy (hazard ratio [HR] 0.56, 95% CI 0.26-1.20). Median OS was NR (range 13.8 months-NR) versus 30.0 (14.7-NR) months (HR 0.65, 95% CI 0.27-1.55) and ORR was 50% (95% CI 28-72) versus 46% (95% CI 27-67). Grade 3/4 treatment-related adverse events (TRAEs) were reported by two patients (9%) in the pembrolizumab arm and 20 (80%) in the chemotherapy arm. Immune-mediated adverse events or infusion reactions were reported by six patients (27%) and 10 patients (40%), respectively. No deaths due to TRAEs occurred. These data support first-line pembrolizumab as a standard of care for patients from Asia with MSI-H/dMMR mCRC. ClinicalTrials.gov identifier: NCT02563002.

Pembrolizumab versus chemotherapy for microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer (KEYNOTE-177): final analysis of a randomised, open-label, phase 3 study.

BACKGROUND: Pembrolizumab has shown improved progression-free survival versus chemotherapy in patients with newly diagnosed microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. However, the treatment's effect on overall survival in this cohort of patients was unknown. Here, we present the final overall survival analysis of the KEYNOTE-177 study. METHODS: This randomised, open-label, phase 3 study was done in 193 academic medical centres and hospitals in 23 countries. We recruited patients aged at least 18 years, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had previously untreated microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. Patients were randomly assigned (1:1) in blocks of four using an interactive voice response system or integrated web response system to intravenous pembrolizumab 200 mg every 3 weeks or to the investigator's choice of intravenous mFOLFOX6 (oxaliplatin 85 mg/m2 on day 1, leucovorin 400 mg/m2 on day 1, and fluorouracil 400 mg/m2 bolus on day 1 followed by a continuous infusion of 1200 mg/m2 per day for 2 days on days 1-2) or intravenous FOLFIRI (irinotecan 180 mg/m2 on day 1, leucovorin 400 mg/m2 on day 1, and fluorouracil 400 mg/m2 bolus on day 1 followed by a continuous infusion of 1200 mg/m2 per day for 2 days on days 1-2), every 2 weeks with or without intravenous bevacizumab 5 mg/kg every 2 weeks or intravenous weekly cetuximab (first dose 400 mg/m2, then 250 mg/m2 for every subsequent dose). Patients receiving chemotherapy could cross over to pembrolizumab for up to 35 treatment cycles after progression. The co-primary endpoints were overall survival and progression-free survival in the intention-to-treat population. KEYNOTE-177 is registered at ClinicalTrials.gov, NCT02563002, and is no longer enrolling patients. FINDINGS: Between Feb 11, 2016, and Feb 19, 2018, 852 patients were screened, of whom 307 (36%) were randomly assigned to pembrolizumab (n=153) or chemotherapy (n=154). 93 (60%) patients crossed over from chemotherapy to anti-PD-1 or anti-PD-L1 therapy (56 patients to on-study pembrolizumab and 37 patients to off-study therapy). At final analysis (median follow-up of 44·5 months [IQR 39·7-49·8]), median overall survival was not reached (NR; 95% CI 49·2-NR) with pembrolizumab vs 36·7 months (27·6-NR) with chemotherapy (hazard ratio [HR] 0·74; 95% CI 0·53-1·03; p=0·036). Superiority of pembrolizumab versus chemotherapy for overall survival was not demonstrated because the prespecified α of 0·025 needed for statistical significance was not achieved. At this updated analysis, median progression-free survival was 16·5 months (95% CI 5·4-38·1) with pembrolizumab versus 8·2 months (6·1-10·2) with chemotherapy (HR 0·59, 95% CI 0·45-0·79). Treatment-related adverse events of grade 3 or worse occurred in 33 (22%) of 153 patients in the pembrolizumab group versus 95 (66%) of 143 patients in the chemotherapy group. Common adverse events of grade 3 or worse that were attributed to pembrolizumab were increased alanine aminotransferase, colitis, diarrhoea, and fatigue in three (2%) patients each, and those attributed to chemotherapy were decreased neutrophil count (in 24 [17%] patients), neutropenia (22 [15%]), diarrhoea (14 [10%]), and fatigue (13 [9%]). Serious adverse events attributed to study treatment occurred in 25 (16%) patients in the pembrolizumab group and in 41 (29%) patients in the chemotherapy group. No deaths attributed to pembrolizumab occurred; one death due to intestinal perforation was attributed to chemotherapy. INTERPRETATION: In this updated analysis, although pembrolizumab continued to show durable antitumour activity and fewer treatment-related adverse events compared with chemotherapy, there was no significant difference in overall survival between the two treatment groups. These findings support pembrolizumab as an efficacious first-line therapy in patients with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. FUNDING: MSD.

A Randomized Placebo-Controlled Phase 2 Study of Gemcitabine and Capecitabine with or without T-ChOS as Adjuvant Therapy in Patients with Resected Pancreatic Cancer (CHIPAC).

The antitumor activity of chitooligosaccharides has been suggested. This phase 2 trial evaluated the efficacy and safety of T-ChOS™, in addition to adjuvant chemotherapy, in patients after resection of pancreatic ductal adenocarcinoma (PDAC). In this single-center, randomized, double-blind, placebo-controlled trial using patients ≥18 years of age after complete macroscopic resection for PDAC, patients were randomly assigned (1:1) to either a continuous oral T-ChOS group or a placebo group, in combination with gemcitabine (GEM) and oral capecitabine (CAP), for a maximum of six cycles. The primary endpoint was disease-free survival (DFS). Recruitment was stopped prematurely in July 2018, with 21 of planned 180 patients included, due to poor accrual and because modified FOLFIRINOX replaced GEM/CAP for the target population. Nine patients received T-ChOS and twelve received the placebo. The median DFS was 10.8 months (95% CI 5.9-15.7) for the T-ChOS arm and 8.4 months (95% CI 0-21.5) in the placebo arm. Overall, seven patients (78%) in the T-ChOS arm and eight patients (67%) in the placebo arm experienced at least one grade 3-4 treatment-related adverse event, most frequently neutropenia. Altogether, the addition of T-ChOS to chemotherapy in patients after resection of PDAC seems safe. However, the clinical benefit cannot be assessed due to the premature cessation of the trial.

Health-related quality of life in patients with microsatellite instability-high or mismatch repair deficient metastatic colorectal cancer treated with first-line pembrolizumab versus chemotherapy (KEYNOTE-177): an open-label, randomised, phase 3 trial.

BACKGROUND: In the KEYNOTE-177 study, pembrolizumab monotherapy provided statistically significant and clinically meaningful improvements in progression-free survival versus chemotherapy as first-line treatment in patients with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. To further support the efficacy and safety findings of the KEYNOTE-177 study, results of the health-related quality of life (HRQOL) analyses are reported here. METHODS: KEYNOTE-177 is an open-label, randomised, phase 3 trial being done at 192 cancer centres in 23 countries, in patients aged 18 years and older with microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer, with an Eastern Cooperative Oncology Group performance status of 0 or 1, and who had not received previous systemic therapy for metastatic disease. Eligible patients were randomly assigned (1:1) centrally by use of interactive voice response or integrated web response technology to receive pembrolizumab 200 mg intravenously every 3 weeks or investigator's choice chemotherapy (mFOLFOX6 [leucovorin, fluorouracil, and oxaliplatin] or FOLFIRI [leucovorin, fluorouracil, and irinotecan] intravenously every 2 weeks with or without intravenous bevacizumab or cetuximab). Patients and investigators were not masked to treatment assignment. The primary endpoints were progression-free survival (previously reported) and overall survival (data to be reported at the time of the final analysis). HRQOL outcomes were evaluated as prespecified exploratory endpoints. The analysis population comprised all randomly assigned patients who received at least one dose of study treatment and completed at least one HRQOL assessment. HRQOL outcomes were mean change from baseline to prespecified week 18 in European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and EORTC Quality of Life Questionnaire-Colorectal 29 (EORTC QLQ-CR29) scale and item scores, and in the EuroQoL 5 Dimensions 3 Levels (EQ-5D-3L) visual analogue scale and health utility scores; the proportion of patients with improved, stable, or deteriorated scores from baseline to prespecified week 18 in EORTC QLQ-C30 scales and items; and time to deterioration in EORTC QLQ-C30 global health status/quality of life (GHS/QOL), physical functioning, social functioning, and fatigue scores and EORTC QLQ-CR29 urinary incontinence scores. The threshold for a small and clinically meaningful mean difference in EORTC QLQ-C30 score was 5-8 points. This study is registered with ClinicalTrials.gov, NCT02563002 and is ongoing; recruitment is closed. FINDINGS: Between Feb 11, 2016, and Feb 19, 2018, 307 patients were enrolled and randomly assigned to receive pembrolizumab (n=153) or chemotherapy (n=154). The HRQOL analysis population comprised 294 patients (152 receiving pembrolizumab and 142 receiving chemotherapy). As of Feb 19, 2020, median time from randomisation to data cutoff was 32·4 months (IQR 27·7-37·8). Least squares mean (LSM) change from baseline to prespecified week 18 showed a clinically meaningful improvement in EORTC QLQ-C30 GHS/QOL scores with pembrolizumab versus chemotherapy (between-group LSM difference 8·96 [95% CI 4·24-13·69]; two-sided nominal p=0·0002). Median time to deterioration was longer with pembrolizumab versus chemotherapy for GHS/QOL (hazard ratio 0·61 [95% CI 0·38-0·98]; one-sided nominal p=0·019), physical functioning (0·50 [95% CI 0·32-0·81]; one-sided nominal p=0·0016), social functioning (0·53 [95% CI 0·32-0·87]; one-sided nominal p=0·0050), and fatigue scores (0·48 [95% CI 0·33-0·69]; one-sided nominal p<0·0001). INTERPRETATION: Pembrolizumab monotherapy led to clinically meaningful improvements in HRQOL compared with chemotherapy in patients with previously untreated microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer. These data, along with the previously reported clinical benefits, support pembrolizumab as a first-line treatment option for this population. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co, Kenilworth, NJ, USA.

Pre- and Perioperative Inflammatory Biomarkers in Older Patients Resected for Localized Colorectal Cancer: Associations with Complications and Prognosis.

The association between pre- and perioperative inflammatory biomarkers, major complications, and survival rates after resection of colorectal cancer (CRC) in older patients is largely unknown. The aim was to investigate age-dependent differences in these associations. Serum CRP, IL-6, and YKL-40 were measured preoperatively and on the first and second day after resection of CRC (stages I-III) in 210 older (≥70 years) and 191 younger patients (<70 years). The results from the complications was presented as an odds ratio (OR, with a 95% confidence interval (CI)) with logistic regression. Results from the mortality rates were presented as a hazard ratio (HR, with a 95% CI) using Cox proportional hazards regression. The preoperative inflammatory biomarkers were higher in the older vs. the younger patients. The risk of complications was increased in older patients with a high preoperative CRP (OR = 1.25, 95% CI 1.03-1.53), IL-6 (OR = 1.57, 95% CI 1.18-2.08), and YKL-40 (OR = 1.66, 95% CI 1.20-2.28), but not in younger patients. Mortality was higher in younger patients with high preoperative YKL-40 (HR = 1.66, 95% CI 1.06-2.60). This was not found in older patients. Elevated preoperative inflammatory biomarkers among older patients were associated with an increased risk of complications, but not mortality. Preoperative inflammatory biomarkers may be useful in assessing the risk of a complicated surgical course in older patients with CRC.

Cetuximab plus irinotecan administered biweekly with reduced infusion time to heavily pretreated patients with metastatic colorectal cancer and related RAS and BRAF mutation status.

Metastatic colorectal cancer (mCRC) is treated with cetuximab 250 mg/m2 administered weekly over 1 hour or biweekly (q2w) over 3.5 hours when combined with irinotecan. This prospective study investigated cetuximab 500 mg/m2 plus irinotecan 180 mg/m2 administered q2w over 1.5 hours independent of RAS or BRAF mutation status in mCRC patients in a third-line setting. The intention-to-treat population included 181 patients. No patients had complete response, 18% had partial responses (PR) and 48% stable disease (SD). For cetuximab, a relative dose intensity of ≥90% was reached in 78% and for irinotecan in 67% of the patients. Grade 3 to 4 toxicities were pain (17%), fatigue (9%), neutropenia (8%), diarrhea (8%), rash (8%), infection (7%) and hypersensitivity (3%). No deaths occurred. Next-generation sequencing in 96.7% of the patients revealed that 50.3% had RAS and BRAFV600E wild type (WT), with a mutation type (MT) in 45.1% of the RAS and 4.4% of the BRAFV600E genes. In patients with RAS-WT and RAS-MT tumors, a PR was obtained in 32% and 4% (P = .000003) and an SD in 43% and 53%, respectively, with a superior PFS (6.2 vs 3.7 months; hazard ratio [HR] 2.12, P = .00001) and OS (12.9 vs 8.8 months; HR 1.71, P = .0008). Treatment efficacy was poor in 7.4% of patients with an RAS mutation outside KRAS exon 2 and in 38% of patients with KRAS exon 2 mutations. Administration of cetuximab and irinotecan q2w, shortening treatment time from 3.5 to 1.5 hours, is recommended as standard therapy.

Pembrolizumab in Microsatellite-Instability-High Advanced Colorectal Cancer.

BACKGROUND: Programmed death 1 (PD-1) blockade has clinical benefit in microsatellite-instability-high (MSI-H) or mismatch-repair-deficient (dMMR) tumors after previous therapy. The efficacy of PD-1 blockade as compared with chemotherapy as first-line therapy for MSI-H-dMMR advanced or metastatic colorectal cancer is unknown. METHODS: In this phase 3, open-label trial, 307 patients with metastatic MSI-H-dMMR colorectal cancer who had not previously received treatment were randomly assigned, in a 1:1 ratio, to receive pembrolizumab at a dose of 200 mg every 3 weeks or chemotherapy (5-fluorouracil-based therapy with or without bevacizumab or cetuximab) every 2 weeks. Patients receiving chemotherapy could cross over to pembrolizumab therapy after disease progression. The two primary end points were progression-free survival and overall survival. RESULTS: At the second interim analysis, after a median follow-up (from randomization to data cutoff) of 32.4 months (range, 24.0 to 48.3), pembrolizumab was superior to chemotherapy with respect to progression-free survival (median, 16.5 vs. 8.2 months; hazard ratio, 0.60; 95% confidence interval [CI], 0.45 to 0.80; P = 0.0002). The estimated restricted mean survival after 24 months of follow-up was 13.7 months (range, 12.0 to 15.4) as compared with 10.8 months (range, 9.4 to 12.2). As of the data cutoff date, 56 patients in the pembrolizumab group and 69 in the chemotherapy group had died. Data on overall survival were still evolving (66% of required events had occurred) and remain blinded until the final analysis. An overall response (complete or partial response), as evaluated with Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, was observed in 43.8% of the patients in the pembrolizumab group and 33.1% in the chemotherapy group. Among patients with an overall response, 83% in the pembrolizumab group, as compared with 35% of patients in the chemotherapy group, had ongoing responses at 24 months. Treatment-related adverse events of grade 3 or higher occurred in 22% of the patients in the pembrolizumab group, as compared with 66% (including one patient who died) in the chemotherapy group. CONCLUSIONS: Pembrolizumab led to significantly longer progression-free survival than chemotherapy when received as first-line therapy for MSI-H-dMMR metastatic colorectal cancer, with fewer treatment-related adverse events. (Funded by Merck Sharp and Dohme and by Stand Up to Cancer; KEYNOTE-177 ClinicalTrials.gov number, NCT02563002.).

ABCG2 Protein Levels and Association to Response to First-Line Irinotecan-Based Therapy for Patients with Metastatic Colorectal Cancer.

In this study we investigated the use of cancer cell protein expression of ABCG2 to predict efficacy of systemic first-line irinotecan containing therapy in patients with metastatic colorectal cancer (mCRC). From a Danish national cohort, we identified 119 mCRC patients treated with irinotecan containing therapy in first-line setting. Among these, 108 were eligible for analyses. Immunohistochemistry (IHC) analyses were performed on the primary tumor tissue in order to classify samples as high or low presence of ABCG2 protein. Data were then associated with patient outcome (objective response (OR), progression free survival (PFS) and overall survival (OS)). ABCG2 protein expression in the basolateral membrane was high (score 3+) in 33% of the patients. Exploratory analyses revealed a significant interaction between ABCG2 score, adjuvant treatment and OR (p = 0.041) in the 101 patients with evaluable disease. Patients with low ABCG2 (score 0-2) and no prior adjuvant therapy had a significantly higher odds ratio of 5.6 (Confidence Interval (CI) 1.68-18.7; p = 0.005) for obtaining OR. In contrast, no significant associations between ABCG2 expression and PFS or OS were found. These results suggest that measurement of the ABCG2 drug efflux pump might be used to select patients with mCRC for irinotecan treatment. However, additional studies are warranted before conclusions regarding a clinical use can be made. Moreover, patients with high ABCG2 immunoreactivity could be candidates for specific ABCG2 inhibition treatment in combination with irinotecan.

An open label phase 1 study evaluation safety, tolerability, and maximum tolerated dose of oral administration of irinotecan in combination with capecitabine.

PURPOSE: Oral administration of chemotherapy offers several advantages in comparison with intravenous administration. Previously, data on a new oral formulation of irinotecan have been published. The aim of the present study was to evaluate the safety, tolerability, and Maximum Tolerated Dose (MTD) of the new oral irinotecan formulation in combination with oral capecitabine. METHODS: The study was an open label, phase 1, single center, extension part in which oral irinotecan was investigated in combination with capecitabine. The MTD of irinotecan in combination with capecitabine was 17.5 mg/m2 once daily for 14 consecutive days in combination with capecitabine 800 mg/m2 twice daily. Eligible patients were adults with metastatic or unresectable solid tumors for which no standard curative or palliative therapies existed. RESULTS: 14 patients were included in the extension part. No grade 3 or 4 hematologic toxicities were observed. Non-hematological toxicities included grade 1 and 2 diarrhea, fatigue, cholinergic syndrome, vomiting, and weight loss. Totally, 3 grade 3 toxicities and no grade 4 event were reported. No objective responses were observed. Five patients had stable disease lasting median 14 weeks. CONCLUSIONS: Capecitabine in combination with oral irinotecan could be a new treatment option offering a more convenient and patient friendly treatment strategy compared to intravenous irinotecan. The combination is fairly tolerated; however, further investigations are needed to assess the efficacy of this regimen.

Systemic immune response induced by oxaliplatin-based neoadjuvant therapy favours survival without metastatic progression in high-risk rectal cancer.

BACKGROUND: Systemic failure remains a challenge in rectal cancer. We investigated the possible systemic anti-tumour immune activity invoked within oxaliplatin-based neoadjuvant therapy. METHODS: In two high-risk patient cohorts, we assessed the circulating levels of the fms-like tyrosine kinase 3 ligand (Flt3L), a factor reflecting both therapy-induced myelosuppression and activation of tumour antigen-presenting dendritic cells, at baseline and following induction chemotherapy and sequential chemoradiotherapy, both modalities containing oxaliplatin. The primary end point was progression-free survival (PFS). RESULTS: In both cohorts, the median Flt3L level was significantly higher at completion of each sequential modality than at baseline. The 5-year PFS (most events being metastatic progression) was 68% and 71% in the two cohorts consisting of 33% and 52% T4 cases. In the principal cohort, a high Flt3L level following the induction chemotherapy was associated with low risk for a PFS event (HR: 0.15; P < 0.01). These patients also had available dose scheduling and toxicity data, revealing that oxaliplatin dose reduction during chemoradiotherapy, undertaken to maintain compliance to the radiotherapy protocol, was associated with advantageous PFS (HR: 0.47; P = 0.046). CONCLUSION: In high-risk rectal cancer, oxaliplatin-containing neoadjuvant therapy may promote an immune response that favours survival without metastatic progression.

Associations between primary tumor RAS, BRAF and PIK3CA mutation status and metastatic site in patients with chemo-resistant metastatic colorectal cancer.

BACKGROUND: Several studies have investigated correlations between metastatic pattern and mutation status in patients with colorectal cancer (CRC). However, most of the studies were small and heterogeneously designed and further research is needed to confirm previous results. In this study, we investigated the association between RAS (KRAS or NRAS), BRAF, PIK3CA mutations and metastatic pattern in patients with metastatic (m) CRC. MATERIAL AND METHODS: This study reviewed Danish biobank and database of patients with mCRC who received cetuximab and irinotecan, independent of RAS mutation status, after fluoropyrimidine, oxaliplatin and irinotecan treatment failure. The database contained information regarding tumor mutation status of KRAS, NRAS, BRAF and PIK3CA genes. RESULTS: Totally, 448 patients were included. On multivariate analyses, RAS mutations were significantly associated with increased odds of having lung metastases at diagnosis of mCRC (odds ratio (OR) = 2.04; 95% confidence interval (CI) = 1.32-3.17), and PIK3CA mutations with decreased odds of peritoneal metastases at diagnosis of mCRC (OR = 0.10; 95%CI = 0.01-0.79). On multivariate analyses of the hazard of developing metastases at any time during follow-up, RAS mutations were significantly associated with increased hazard of lung (hazard ratio (HR) = 1.34; 95%CI = 1.04-1.72) and ovarian metastases (HR = 3.12; 95%CI = 1.05-9.24), BRAF V600E mutation was associated with increased hazard of skin metastases (HR = 6.82; 95%CI = 1.86-25.02) and PIK3CA mutations with decreased hazard of peritoneal metastases (HR = 0.31; 95%CI = 0.11-0.86). CONCLUSIONS: This study indicated that in patients with mCRC, RAS mutations are associated with increased risk of lung and ovary metastases. BRAF V600E is associated with increased risk of skin metastases, and PIK3CA mutation with decreased risk of peritoneal metastases.

Risk factors for brain metastases in patients with metastatic colorectal cancer.

BACKGROUND: Brain metastases (BM) from colorectal cancer (CRC) are rare, but the incidence is suspected to rise as treatment of metastatic (m) CRC improves. The aim of this study was to identify possible biological and clinical characteristics at initial presentation of mCRC that could predict later risk of developing BM. Furthermore, we wished to estimate the incidence of BM in long-term surviving patients. MATERIAL AND METHODS: We conducted a retrospective study on a Danish multicenter cohort of patients with mCRC who received cetuximab and irinotecan (CetIri) as third-line treatment. All patients had previously progression on 5-FU, irinotecan and oxaliplatin containing regimens and received CetIri treatment independent of RAS mutations status. We subsequently performed KRAS, NRAS, BRAF, PIK3CA, PTEN, ERBB2 and EGFR sequencing of DNA extracted from primary tumor tissue. RESULTS: Totally, 480 patients were included in our study. BM were diagnosed in 42 [8.8%; 95% confidence interval (CI) 6.4-11.6%] patients. Patients with BM had a significantly longer survival from mCRC diagnosis than non-BM patients (median = 32 versus 28 months, p = 0.001). On univariate cox regression analysis, the risk of developing BM was significantly increased in patients with rectal cancer (HR = 3.9; 95% CI = 1.2-13.3), metachronous metastatic disease (HR = 2.3; 95% CI = 1.2-4.4) and lung metastases (HR = 4.2; 95% CI = 2.2-7.9). On multivariate cox regression analysis only lung metastases were significantly associated BM (HR = 3.5; 95% CI = 1.8-6.8). None of the investigated mutations were associated with BM. CONCLUSION: The incidence of BM was 8.8% in patients with mCRC who received third-line therapy. The most important risk factor for developing BM was lung metastases. Furthermore, rectal cancer, metachronous metastatic disease and long survival were linked to BM development.

Topoisomerase I copy number alterations as biomarker for irinotecan efficacy in metastatic colorectal cancer.

BACKGROUND: No biomarker exists to guide the optimal choice of chemotherapy for patients with metastatic colorectal cancer. We examined the copy numbers (CN) of topoisomerase I (TOP1) as well as the ratios of TOP1/CEN-20 and TOP1/CEN-2 as biomarkers for irinotecan efficacy in patients with metastatic colorectal cancer. METHODS: From a national cohort, we identified 163 patients treated every third week with irinotecan 350 mg/m2 as second-line therapy. Among these 108 were eligible for analyses and thus entered the study. Primary tumors samples were collected and tissue microarray (TMA) blocks were produced. FISH analysis was performed using two probe-mixes: TOP1/CEN-20 and TOP1/CEN-2. Only samples harboring all three signals (TOP1, CEN-20 and CEN-2) using FISH were included in the analyses. RESULTS: In the TOP1/CEN-20 probe-mix the median TOP1- and CEN-20 CN were 4.46 (range: 1.5-9.5) and 2.00 (range: 0.55-4.55), respectively. The median TOP1- and CEN-2 CN in the TOP1/CEN-2 probe-mix, were 4.57 (range: 1.82-10.43) and 1.98 (range: 1.22-6.14), respectively. The median TOP1/CEN-20 ratio and TOP1/CEN-2 ratio were 1.25 (range: 0.92-2.90) and 2.05 (range: 1.00-6.00), respectively. None of the markers TOP1 CN, TOP1/CEN-20-ratio or TOP1/CEN-2-ratio were associated with progression free survival, overall survival or baseline characteristics. Yet, we observed a borderline association for a stepwise increase of the TOP1 CN in relation to objective response as hazard ratio were 1.35 (95% CI 0.96-1.90; p = 0.081). CONCLUSIONS: We verified a borderline significant association between increasing TOP1 CN and objective response as previously reported. Applying the probes representing CEN-20 and CEN-2, in order to investigate the ratios of TOP1/CEN-20 and TOP1/CEN-2 provided no further information in search of a biomarker driven patient stratification. Other biomarkers to be paired with TOP1 CN are therefore highly warranted.

Early 18F-FDG-PET/CT as a predictive marker for treatment response and survival in patients with metastatic colorectal cancer treated with irinotecan and cetuximab.

BACKGROUND: To clarify if early reduction in standard uptake value (SUV) could predict metabolic response, radiologic response and overall survival (OS) in patients with metastatic colorectal cancer receiving third-line treatment. MATERIAL AND METHODS: Patients were regardless of KRAS status, included in this phase II trial. They were treated with the monoclonal antibody, cetuximab, and the chemotherapeutic drug, irinotecan, every second week. A F18-fluorodeoxy glucose positron emission tomography/computed tomography (FDG-PET/CT) was scheduled before the first and second treatment, respectively, and then after every fourth treatment. Early metabolic response after one treatment and best overall metabolic response was calculated according to EORTC criteria (responders: ≥15% decrease in ∑SUVmax) and PERCIST (responders: ≥30% decrease in SULpeak). Best overall radiologic response was calculated according to RECIST 1.0. RESULTS: By EORTC criteria, early metabolic response predicted partial metabolic response (PMR) with a high positive predictive value (PPV) of 0.875 and a high negative predictive value (NPV) of 0.714. Partial radiologic response was predicted with a low PPV of 0.368 but a high NPV of 1.0. By PERCIST, PMR was predicted with a high PPV of 0.826 and an intermediate NPV of 0.667 and partial radiologic response was predicted with a low PPV of 0.5 but a high NPV of 1.0. Median OS was nearly the same with the two criteria sets; 14.1 months for early metabolic responders and 9.9 months for non-responders using EORTC criteria and 13.5 and 10.1 months, respectively, using PERCIST. CONCLUSIONS: With both EORTC criteria and PERCIST, early reduction in FDG uptake was predictive of a later partial metabolic and partial radiologic response to treatment. It was also predictive of significantly longer survival of early metabolic responders compared to non-responders. However, the sensitivities and specificities were not high enough to support clinical routine use.

MicroRNA Expression in Formalin-fixed Paraffin-embedded Cancer Tissue: Identifying Reference MicroRNAs and Variability.

BACKGROUND: Archival formalin-fixed paraffin-embedded (FFPE) cancer tissue samples are a readily available resource for microRNA (miRNA) biomarker identification. No established standard for reference miRNAs in FFPE tissue exists. We sought to identify stable reference miRNAs for normalization of miRNA expression in FFPE tissue samples from patients with colorectal (CRC) and pancreatic (PC) cancer and to quantify the variability associated with sample age and fixation. METHODS: High-throughput miRNA profiling results from 203 CRC and 256 PC FFPE samples as well as from 37 paired frozen/FFPE samples from nine other CRC tumors (methodological samples) were used. Candidate reference miRNAs were identified by their correlation with global mean expression. The stability of reference genes was analyzed according to published methods. The association between sample age and global mean miRNA expression was tested using linear regression. Variability was described using correlation coefficients and linear mixed effects models. Normalization effects were determined by changes in standard deviation and by hierarchical clustering. RESULTS: We created lists of 20 miRNAs with the best correlation to global mean expression in each cancer type. Nine of these miRNAs were present in both lists, and miR-103a-3p was the most stable reference miRNA for both CRC and PC FFPE tissue. The optimal number of reference miRNAs was 4 in CRC and 10 in PC. Sample age had a significant effect on global miRNA expression in PC (50% reduction over 20 years) but not in CRC. Formalin fixation for 2-6 days decreased miRNA expression 30-65%. Normalization using global mean expression reduced variability for technical and biological replicates while normalization using the expression of the identified reference miRNAs reduced variability only for biological replicates. Normalization only had a minor impact on clustering results. CONCLUSIONS: We identified suitable reference miRNAs for future miRNA expression experiments using CRC- and PC FFPE tissue samples. Formalin fixation decreased miRNA expression considerably, while the effect of increasing sample age was estimated to be negligible in a clinical setting.

Improved survival with early adjuvant chemotherapy after colonic resection for stage III colonic cancer: A nationwide study.

BACKGROUND AND OBJECTIVES: In stage III colonic cancer, time from surgery to start of adjuvant chemotherapy may influence survival. In this study, we evaluated the effect of timing of adjuvant therapy on survival. METHODS: Database study from the Danish Colorectal Cancer Group's national database. Data on patients with stage III colonic cancer operated between January 1, 2005 and August 31, 2012 were retrieved. Perioperative variables, surgical modality, and time to adjuvant therapy (<4, 4-8, or >8 weeks) were evaluated and Cox regression was performed to identify factors influencing survival. RESULTS: The final population included 1,827 patients scheduled for adjuvant chemotherapy. Adjuvant therapy started within 4 and 8 weeks improved survival when compared to start later than 8 weeks (HR [95%CI]: 1.7 [1.1-2.6]; P = 0.024 and 1.4 [1.07-1.8]; P = 0.013, respectively), whereas there was no significant difference in survival with start after 4 versus 8 weeks (1.2 [0.8-1.8]; P = 0.37). CONCLUSIONS: Survival increased when adjuvant therapy was started within 8 weeks after surgery for stage III colonic cancer.

FCGR polymorphisms and cetuximab efficacy in chemorefractory metastatic colorectal cancer: an international consortium study.

OBJECTIVE: We aimed to better clarify the role of germline variants of the FCG2 receptor, FCGR2A-H131R and FCGR3A-V158F, on the therapeutic efficacy of cetuximab in metastatic colorectal cancer (mCRC). A large cohort with sufficient statistical power was assembled. DESIGN: To show a HR advantage of 0.6 in progression-free survival (PFS) for FCGR2A-HH versus the rest and FCGR3A-VV versus the rest, with an 80% power, 80 Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) wild-type (KRAS-WT) and 52 KRAS-WT patients are required, respectively. This leads to a total sample size of 952 and 619 patients, respectively. Samples were collected from 1123 mCRC patients from 15 European centres treated with cetuximab alone or in combination with chemotherapy. Fc gamma receptor (FCGR) status was centrally genotyped. Two additional externally genotyped series were included. RESULTS: Incidences of FCGR2A-HH and FCGR3A-VV in KRAS-WT patients were 220/660 (33%) and 109/676 (16.1%) respectively. There was no difference in median PFS (mPFS) for KRAS-WT patients with FCGR2A-HH (22.0 weeks; 95% CI18.8 to 25.2) versus non-HH (22.0 weeks; 95% CI 19.4 to 24.6) or for FCGR3A-VV (16.4 weeks; 95% CI 13.0 to 19.8) versus non-VV (23 weeks; 95% CI 21.1 to 24.9) (p=0.06). Median overall survival, response rate and disease control rate assessments showed no benefit for either HH or VV. CONCLUSIONS: No differences in mPFS were found between the FCGR polymorphisms HH and the others and VV versus the others in KRAS-WT mCRC patients refractory to irinotecan, oxaliplatin and 5-fluorouracil treated with cetuximab. We cannot confirm the effects of other IgG1 antibodies, which may be weaker than previously suggested. Other markers may be needed to study the actual host antibody response to cetuximab.

CT versus FDG-PET/CT response evaluation in patients with metastatic colorectal cancer treated with irinotecan and cetuximab.

We compared morphologic computed tomography (CT)-based to metabolic fluoro-deoxy-glucose (FDG) positron emission tomography (PET)/CT-based response evaluation in patients with metastatic colorectal cancer and correlated the findings with survival and KRAS status. From 2006 to 2009, patients were included in a phase II trial and treated with cetuximab and irinotecan every second week. They underwent FDG-PET/CT examination at baseline and after every fourth treatment cycle. Response evaluation was performed prospectively according to Response Evaluation Criteria in Solid Tumors (RECIST 1.0) and retrospectively according to Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST). Best overall responses were registered. Sixty-one patients were eligible for response evaluation. Partial response (PR) rate was 18%, stable disease (SD) rate 64%, and progressive disease (PD) rate 18%. Partial metabolic response (PMR) rate was 56%, stable metabolic disease rate 33%, and progressive metabolic disease (PMD) rate 11%. Response agreement was poor, κ-coefficient 0.19. Hazard ratio for overall survival for responders (PR/PMR) versus nonresponders (PD/PMD) was higher for CT- than for FDG-PET/CT evaluation. Within patients with KRAS mutations, none had PR but 44% had PMR. In conclusion, morphologic and metabolic response agreement was poor primarily because a large part of the patients shifted from SD with CT evaluation to PMR when evaluated with FDG-PET/CT. Furthermore, a larger fraction of the patients with KRAS mutations had a metabolic treatment response.