Evolution of Metastases in Space and Time under Immune Selection.

We examined how the immune microenvironment molds tumor evolution at different metastatic organs in a longitudinal dataset of colorectal cancer. Through multiplexed analyses, we showed that clonal evolution patterns during metastatic progression depend on the immune contexture at the metastatic site. Genetic evidence of neoantigen depletion was observed in the sites with high Immunoscore and spatial proximity between Ki67+ tumor cells and CD3+ cells. The immunoedited tumor clones were eliminated and did not recur, while progressing clones were immune privileged, despite the presence of tumor-infiltrating lymphocytes. Characterization of immune-privileged metastases revealed tumor-intrinsic and tumor-extrinsic mechanisms of escape. The lowest recurrence risk was associated with high Immunoscore, occurrence of immunoediting, and low tumor burden. We propose a parallel selection model of metastatic progression, where branched evolution could be traced back to immune-escaping clones. The findings could inform the understanding of cancer dissemination and the development of immunotherapeutics.

Panitumumab-FOLFOX4 treatment and RAS mutations in colorectal cancer.

BACKGROUND: Patients with metastatic colorectal cancer that harbors KRAS mutations in exon 2 do not benefit from anti-epidermal growth factor receptor (EGFR) therapy. Other activating RAS mutations may also be negative predictive biomarkers for anti-EGFR therapy. METHODS: In this prospective-retrospective analysis, we assessed the efficacy and safety of panitumumab plus oxaliplatin, fluorouracil, and leucovorin (FOLFOX4) as compared with FOLFOX4 alone, according to RAS (KRAS or NRAS) or BRAF mutation status. A total of 639 patients who had metastatic colorectal cancer without KRAS mutations in exon 2 had results for at least one of the following: KRAS exon 3 or 4; NRAS exon 2, 3, or 4; or BRAF exon 15. The overall rate of ascertainment of RAS status was 90%. RESULTS: Among 512 patients without RAS mutations, progression-free survival was 10.1 months with panitumumab-FOLFOX4 versus 7.9 months with FOLFOX4 alone (hazard ratio for progression or death with combination therapy, 0.72; 95% confidence interval [CI], 0.58 to 0.90; P=0.004). Overall survival was 26.0 months in the panitumumab-FOLFOX4 group versus 20.2 months in the FOLFOX4-alone group (hazard ratio for death, 0.78; 95% CI, 0.62 to 0.99; P=0.04). A total of 108 patients (17%) with nonmutated KRAS exon 2 had other RAS mutations. These mutations were associated with inferior progression-free survival and overall survival with panitumumab-FOLFOX4 treatment, which was consistent with the findings in patients with KRAS mutations in exon 2. BRAF mutations were a negative prognostic factor. No new safety signals were identified. CONCLUSIONS: Additional RAS mutations predicted a lack of response in patients who received panitumumab-FOLFOX4. In patients who had metastatic colorectal cancer without RAS mutations, improvements in overall survival were observed with panitumumab-FOLFOX4 therapy. (Funded by Amgen and others; PRIME ClinicalTrials.gov number, NCT00364013.).

Regorafenib induced severe toxic hepatitis: characterization and discussion.

BACKGROUND: Regorafenib is the first small-molecule multikinase inhibitor which showed survival benefits in pretreated metastatic colorectal cancer (mCRC) patients. Besides classical adverse events of this drug class, hepatotoxicity has been described as a frequent side effect. MATERIAL AND METHODS: Patients with refractory mCRC treated with regorafenib in our institution were reviewed. Severe treatment-related liver toxicity was investigated. Clinical history, liver histology and genetic assessment (sequence analysis) of cytochrome P3A4 (CYP3A4) and uridine diphosphate-glucuronosyltransferase 1A9 (UGT1A9) involved in regorafenib metabolization were here reported for patients with severe hepatotoxicity. RESULTS: Among the 93 reviewed patients, 3 presented severe and icteric toxic hepatitis which was fatal for 1 patient. Histopathological liver lesions were different depending on the onset of hepatotoxicity (acute or subacute): acinar zone 3 necrosis in case of acute symptoms, and portal tract inflammation with porto-central bridging and fibrosis in the delayed presentation. None of the patients had CYP3A4 gene mutations. Similar polymorphisms in UGT1A9 gene promoter region (UGT1A9 variant -118T9>10 [rs3832043]) were found in both patients who presented acute hepatitis. Moreover, it appears retrospectively that both of them already experienced significant toxicity under irinotecan-based chemotherapy. CONCLUSION: This is the first report of severe hepatotoxicity with available liver histology and genetic assessment of enzymes involved in regorafenib metabolization. This report also reminds the importance of close liver tests monitoring during regorafenib treatment.

Analysis of circulating DNA and protein biomarkers to predict the clinical activity of regorafenib and assess prognosis in patients with metastatic colorectal cancer: a retrospective, exploratory analysis of the CORRECT trial.

BACKGROUND: Tumour mutational status is an important determinant of the response of metastatic colorectal cancer to targeted treatments. However, the genotype of the tissue obtained at the time of diagnosis might not accurately represent tumour genotype after multiple lines of treatment. This retrospective exploratory analysis investigated the clinical activity of regorafenib in biomarker subgroups of the CORRECT study population defined by tumour mutational status or plasma protein levels. METHODS: We used BEAMing technology to identify KRAS, PIK3CA, and BRAF mutations in DNA obtained from the plasma of 503 patients with metastatic colorectal cancer who enrolled in the CORRECT trial. We quantified total human genomic DNA isolated from plasma samples for 503 patients using a modified version of human long interspersed nuclear element-1 (LINE-1) quantitive real-time PCR. We also measured the concentration of 15 proteins of interest-angiopoietin 2, interleukin 6, interleukin 8, placental growth factor, soluble TIE-1, soluble VEGFR1, VEGF-A, VEGF-C, VEGF-D, VEGF-A isoform 121, bone morphogenetic protein 7, macrophage colony-stimulating factor, stromal cell-derived factor-1, tissue inhibitor of metalloproteinase 2, and von Willebrand factor-in plasma samples from 611 patients. We did correlative analyses of overall survival and progression-free survival in patient subgroups based on mutational status, circulating DNA concentration, and protein concentrations. The CORRECT trial was registered with ClinicalTrials.gov, number NCT01103323. FINDINGS: Tumour-associated mutations were readily detected with BEAMing of plasma DNA, with KRAS mutations identified in 349 (69%) of 503 patients, PIK3CA mutations in 84 (17%) of 503 patients, and BRAF mutations in 17 (3%) of 502 patients. We did not do correlative analysis based on BRAF genotype because of the low mutational frequency detected for this gene. Some of the most prevalent individual hot-spot mutations we identified included: KRAS (KRAS G12D, 116 [28%] of 413 mutations; G12V, 72 [17%]; and G13D, 67 [16%]) and PIK3CA (PIK3CA E542K, 27 [30%] of 89 mutations; E545K, 37 [42%]; and H1047R, 12 [14%]). 41 (48%) of 86 patients who had received anti-EGFR therapy and whose archival tumour tissue DNA was KRAS wild-type in BEAMing analysis were identified as having KRAS mutations in BEAMing analysis of fresh plasma DNA. Correlative analyses suggest a clinical benefit favouring regorafenib across patient subgroups defined by KRAS and PIK3CA mutational status (progression-free survival with regorafenib vs placebo: hazard ratio [HR] 0·52, 95% CI 0·35-0·76 for KRAS wild-type; HR 0·51, 95% CI 0·40-0·65 for KRAS mutant [KRAS wild type vs mutant, pinteraction=0·74]; HR 0·50, 95% CI 0·40-0·63 for PIK3CA wild-type; HR 0·54, 95% CI 0·32-0·89 for PIK3CA mutant [PIK3CA wild-type vs mutant, pinteraction=0·85]) or circulating DNA concentration (progression-free survival with regorafenib vs placebo: HR 0·53, 95% CI 0·40-0·71, for low circulating DNA concentrations; HR 0·52, 95% CI 0·40-0·70, for high circulating DNA concentrations; low vs high circulating DNA, pinteraction=0·601). With the exception of von Willebrand factor, assessed with the median cutoff method, plasma protein concentrations were also not associated with regorafenib activity in terms of progression-free survival. In univariable analyses, the only plasma protein that was associated with overall survival was TIE-1, high concentrations of which were associated with longer overall survival compared with low TIE-1 concentrations. This association was not significant in multivariable analyses. INTERPRETATION: BEAMing of circulating DNA could be a viable approach for non-invasive analysis of tumour genotype in real time and for the identification of potentially clinically relevant mutations that are not detected in archival tissue. Additionally, the results show that regorafenib seems to be consistently associated with a clinical benefit in a range of patient subgroups based on mutational status and protein biomarker concentrations. FUNDING: Bayer HealthCare Pharmaceuticals.

Regorafenib monotherapy for previously treated metastatic colorectal cancer (CORRECT): an international, multicentre, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: No treatment options are available for patients with metastatic colorectal cancer that progresses after all approved standard therapies, but many patients maintain a good performance status and could be candidates for further therapy. An international phase 3 trial was done to assess the multikinase inhibitor regorafenib in these patients. METHODS: We did this trial at 114 centres in 16 countries. Patients with documented metastatic colorectal cancer and progression during or within 3 months after the last standard therapy were randomised (in a 2:1 ratio; by computer-generated randomisation list and interactive voice response system; preallocated block design (block size six); stratified by previous treatment with VEGF-targeting drugs, time from diagnosis of metastatic disease, and geographical region) to receive best supportive care plus oral regorafenib 160 mg or placebo once daily, for the first 3 weeks of each 4 week cycle. The primary endpoint was overall survival. The study sponsor, participants, and investigators were masked to treatment assignment. Efficacy analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT01103323. FINDINGS: Between April 30, 2010, and March 22, 2011, 1052 patients were screened, 760 patients were randomised to receive regorafenib (n=505) or placebo (n=255), and 753 patients initiated treatment (regorafenib n=500; placebo n=253; population for safety analyses). The primary endpoint of overall survival was met at a preplanned interim analysis; data cutoff was on July 21, 2011. Median overall survival was 6·4 months in the regorafenib group versus 5·0 months in the placebo group (hazard ratio 0·77; 95% CI 0·64-0·94; one-sided p=0·0052). Treatment-related adverse events occurred in 465 (93%) patients assigned regorafenib and in 154 (61%) of those assigned placebo. The most common adverse events of grade three or higher related to regorafenib were hand-foot skin reaction (83 patients, 17%), fatigue (48, 10%), diarrhoea (36, 7%), hypertension (36, 7%), and rash or desquamation (29, 6%). INTERPRETATION: Regorafenib is the first small-molecule multikinase inhibitor with survival benefits in metastatic colorectal cancer which has progressed after all standard therapies. The present study provides evidence for a continuing role of targeted treatment after disease progression, with regorafenib offering a potential new line of therapy in this treatment-refractory population. FUNDING: Bayer HealthCare Pharmaceuticals.

Sinusoidal obstruction syndrome (SOS) related to chemotherapy for colorectal liver metastases: factors predictive of severe SOS lesions and protective effect of bevacizumab.

OBJECTIVES: The most frequent presentation of chemotherapy-related toxicity in colorectal liver metastases (CRLM) is sinusoidal obstruction syndrome (SOS). The purpose of the present study was to identify preoperative factors predictive of SOS and to establish associations between type of chemotherapy and severity of SOS. METHODS: A retrospective study was carried out in a tertiary academic referral hospital. Patients suffering from CRLM who had undergone resection of at least one liver segment were included. Grading of SOS on the non-tumoral liver parenchyma was accomplished according to the Rubbia-Brandt criteria. A total of 151 patients were enrolled and divided into four groups according to the severity of SOS (grades 0-3). RESULTS: Multivariate analysis identified oxaliplatin and 5-fluorouracil as chemotherapeutic agents responsible for severe SOS lesions (P < 0.001 and P = 0.005, respectively). Bevacizumab was identified as having a protective effect against the occurrence of SOS lesions (P = 0.005). Univariate analysis identified the score on the aspartate aminotransferase : platelets ratio index (APRI) as the most significant biological factor predictive of severe SOS lesions. Splenomegaly is also significantly associated with the occurrence of severe SOS lesions. CONCLUSIONS: The APRI score and splenomegaly are effective as factors predictive of SOS. Bevacizumab has a protective effect against SOS.

Clinical usefulness of EGFR gene copy number as a predictive marker in colorectal cancer patients treated with cetuximab: a fluorescent in situ hybridization study.

PURPOSE: To evaluate the usefulness and the pitfalls inherent to the assessment of the epidermal growth factor receptor (EGFR) gene copy number (GCN) by fluorescence in situ hybridization (FISH) for outcome prediction to cetuximab in metastatic colorectal cancer. The value of testing KRAS mutation status, in addition to EGFR GCN, was also explored. EXPERIMENTAL DESIGN: FISH analysis of 87 metastatic colorectal cancer patients treated with cetuximab was done, recording individual GCN per cell and using different samples per tumor. Performances of published cutoff points and different summaries of EGFR GCN distribution were assessed for response prediction. RESULTS: In our data set, two published cutoff points performed less well than in their training set, yielding positive predictive values and negative predictive values between 40.0% and 48.3% and between 81.0% and 86.5%, respectively. Among summaries of GCN distribution explored, mean and right-tailed distribution of GCN yielded the highest performances. A mean EGFR GCN > or = 2.83 provided an area under the curve of 0.71. Important heterogeneity of repeated measures of mean EGFR GCN was observed within tumors (intraclass correlation, 0.61; within-class SD, 0.40), leading to potential misclassifications of FISH status in 7 of 18 (38.8%) patients if a cutoff point were used. In multivariable analysis, EGFR GCN testing provided significant information independent of the KRAS status to predict response (P = 0.016) and overall survival (P = 0.005). CONCLUSIONS: We confirm the association between increased EGFR GCN and outcome after cetuximab. However, because of reproducibility concerns, any decision making based on published cutoff points is not warranted.

Drug Insight: panitumumab, a human EGFR-targeted monoclonal antibody with promising clinical activity in colorectal cancer.

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in Western countries. Despite the progress achieved with the introduction of new cytotoxic agents, CRC recurrence rates for patients with resected stage II and/or stage III disease remain higher than 20%. Furthermore, for patients diagnosed with metastatic CRC, the median survival time remains below 2 years and cure is often an elusive goal. These data highlight the need for more-effective systemic therapies. The EGFR is frequently overexpressed in CRC and has been associated with the malignant phenotype. Numerous clinical trials are now investigating the role of EGFR-targeted agents in CRC and have produced some encouraging results. Panitumumab is a fully human IgG(2) monoclonal antibody that in a randomized phase III trial was shown to increase efficacy when added to best supportive care in patients with chemotherapy-refractory metastatic CRC. In phase I-III trials, panitumumab was safe and well tolerated, with most of its adverse effects related to some form of skin toxic effect. Early studies assessing the safety and efficacy of panitumumab alongside chemotherapy have also yielded promising results, and this combination is now being investigated in the first-line and second-line settings in randomized clinical trials.

Comprehensive Intrametastatic Immune Quantification and Major Impact of Immunoscore on Survival.

Background: This study assesses how the metastatic immune landscape is impacting the response to treatment and the outcome of colorectal cancer (CRC) patients. Methods: Complete curative resection of metastases (n = 441) was performed for two patient cohorts (n = 153). Immune densities were quantified in the center and invasive margin of all metastases. Immunoscore and T and B cell (TB) score were analyzed in relation to radiological and pathological responses and patient's disease-free (DFS) and overall survival (OS) using multivariable Cox proportional hazards models. All statistical tests were two-sided. Results: The spatial distribution of immune cells within metastases was nonuniform. Patients, as well as metastases of the same patient, had variable immune infiltrates and response to therapy. A beneficial response was statistically significantly associated with increased immune densities. Among all metastases, Immunoscore (I) and TB score evaluated in the least immune-infiltrated metastases were the strongest predictors for DFS and OS (five-year follow-up, Immunoscore: I 3-4: DFS rate = 27.9%, 95% CI = 15.2 to 51.3; vs I 0-1-2: DFS rate = 12.3%, 95% CI = 4.9 to 30.6; HR = 0.45, 95% CI = 0.28 to 0.70, P = .02; I 3-4: OS rate = 64.6%, 95% CI = 46.6 to 89.6; vs I 0-1-2: OS rate = 32.5%, 95% CI = 17.2 to 61.4; HR = 0.32, 95% CI = 0.15 to 0.66, P = .001, C-index = 65.9%; five-year follow-up, TB score: TB 3-4: DFS rate = 25.7%, 95% CI = 14.2 to 46.6; vs TB 0-1-2: DFS rate = 5.0%, 95% CI = 0.8 to 32.4; HR = 0.36, 95% CI = 0.22 to 0.57, P < .001; TB 3-4: OS rate = 63.7%, 95% CI = 46.4 to 87.5; vs TB 0-1-2: OS rate: 21.4%, 95% CI = 9.2 to 49.8; HR = 0.25, 95% CI = 0.12 to 0.51, P < .001, C-index = 67.8%). High TB score and Immunoscore patients had a median survival of 70.5 months, while low patients survived only 25.1 to 38.3 months. Nonresponding patients with high-immune infiltrates had prolonged DFS (HR = 0.28, 95% CI = 0.15 to 0.52, P = .001) and OS (HR = 0.25, 95% CI = 0.1 to 0.62, P = .001). The immune parameters remained the only statistically significant prognostic factor associated with DFS and OS in multivariable analysis (P < .001), while response to treatment was not. Conclusions: Response to treatment and prolonged survival of metastatic CRC patients were statistically significantly associated with high-immune densities quantified into the least immune-infiltrated metastasis.

Combined BRAF, EGFR, and MEK Inhibition in Patients with BRAFV600E-Mutant Colorectal Cancer.

Although BRAF inhibitor monotherapy yields response rates >50% in BRAFV600-mutant melanoma, only approximately 5% of patients with BRAFV600E colorectal cancer respond. Preclinical studies suggest that the lack of efficacy in BRAFV600E colorectal cancer is due to adaptive feedback reactivation of MAPK signaling, often mediated by EGFR. This clinical trial evaluated BRAF and EGFR inhibition with dabrafenib (D) + panitumumab (P) ± MEK inhibition with trametinib (T) to achieve greater MAPK suppression and improved efficacy in 142 patients with BRAFV600E colorectal cancer. Confirmed response rates for D+P, D+T+P, and T+P were 10%, 21%, and 0%, respectively. Pharmacodynamic analysis of paired pretreatment and on-treatment biopsies found that efficacy of D+T+P correlated with increased MAPK suppression. Serial cell-free DNA analysis revealed additional correlates of response and emergence of KRAS and NRAS mutations on disease progression. Thus, targeting adaptive feedback pathways in BRAFV600E colorectal cancer can improve efficacy, but MAPK reactivation remains an important primary and acquired resistance mechanism.Significance: This trial demonstrates that combined BRAF + EGFR + MEK inhibition is tolerable, with promising activity in patients with BRAFV600E colorectal cancer. Our findings highlight the MAPK pathway as a critical target in BRAFV600E colorectal cancer and the need to optimize strategies inhibiting this pathway to overcome both primary and acquired resistance. Cancer Discov; 8(4); 428-43. ©2018 AACR.See related commentary by Janku, p. 389See related article by Hazar-Rethinam et al., p. 417This article is highlighted in the In This Issue feature, p. 371.

Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer.

BACKGROUND: The epidermal growth factor receptor (EGFR), which participates in signaling pathways that are deregulated in cancer cells, commonly appears on colorectal-cancer cells. Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We compared the efficacy of cetuximab in combination with irinotecan with that of cetuximab alone in metastatic colorectal cancer that was refractory to treatment with irinotecan. METHODS: We randomly assigned 329 patients whose disease had progressed during or within three months after treatment with an irinotecan-based regimen to receive either cetuximab and irinotecan (at the same dose and schedule as in a prestudy regimen [218 patients]) or cetuximab monotherapy (111 patients). In cases of disease progression, the addition of irinotecan to cetuximab monotherapy was permitted. The patients were evaluated radiologically for tumor response and were also evaluated for the time to tumor progression, survival, and side effects of treatment. RESULTS: The rate of response in the combination-therapy group was significantly higher than that in the monotherapy group (22.9 percent [95 percent confidence interval, 17.5 to 29.1 percent] vs. 10.8 percent [95 percent confidence interval, 5.7 to 18.1 percent], P=0.007). The median time to progression was significantly greater in the combination-therapy group (4.1 vs. 1.5 months, P<0.001 by the log-rank test). The median survival time was 8.6 months in the combination-therapy group and 6.9 months in the monotherapy group (P=0.48). Toxic effects were more frequent in the combination-therapy group, but their severity and incidence were similar to those that would be expected with irinotecan alone. CONCLUSIONS: Cetuximab has clinically significant activity when given alone or in combination with irinotecan in patients with irinotecan-refractory colorectal cancer.

Prognostic factors for long-term survival in patients with thoracic metastatic disease: a 10-year experience.

OBJECTIVE: To compare survival results after resection in patients with thoracic parenchymal metastatic disease versus non-parenchymal metastatic disease and to identify prognostic factors for survival. METHODS: From 1990 to 2002, we retrospectively studied 134 procedures performed on 93 patients (3-84 years old). There were 73 patients with parenchymal resection and 20 patients with non-parenchymal resection. Tumor histology was epithelial in 62 patients, sarcoma in 21 patients, and teratomas and melanoma in 6 and 4 patients, respectively. Sixty-five patients underwent a metastasectomy once, whereas 28 had their metastatic disease repeatedly resected. RESULTS: Follow-up was 100% complete with a mean time of 43 months (range 1-169). In-hospital mortality was 2.2% (3/134 procedures) and major morbidity 5.5%. Median survival was 39 months (95% CI: 21-56 months). Overall, the actuarial survival at 1, 3, and 5 years were 84%, 55%, and 44%, respectively. For the entire group, by univariate analysis, among the 13 predictor variables selected, only the number of metastases (Hazard Ratio (HR)=3.4 [95% CI: 1.9-6.1]) and completeness of resection (HR=2.3 [95% CI: 1.3-4.2]) were found to be significant for death whereas repeated metastasectomy was found to be a significant predictor for survival (HR=0.25 [95% CI: 0.12-0.55]). In the group of parenchymal metastatic disease, a size greater than 3cm was a predictor for death (HR=2 [95% CI: 1.1-3.7]). In the subgroup of patients with colorectal metastasis, bilateral disease was also found to be a significant predictor for death (HR=3.6, [95% CI: 1.2-11.1]). CONCLUSION: This study supports our current aggressive approach to metastatic thoracic disease. Indeed, patient's survival is improved while a low mortality and morbidity is achieved. The most beneficial impact on long-term survival is correlated to the completeness of the surgery whereas the increasing number and size of the metastasis inversely correlate with survival.

Prospective Evaluation of First-Line Erlotinib in Advanced Non-Small Cell Lung Cancer (NSCLC) Carrying an Activating EGFR Mutation: A Multicenter Academic Phase II Study in Caucasian Patients (FIELT).

INTRODUCTION: Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibition is the preferred first-line treatment of advanced adenocarcinoma of the lung that harbors EGFR activating tyrosine kinase domain mutations. Most data available pertain to Asian populations in which such mutations are more prevalent. We report on the long-term results of first-line treatment with erlotinib in Caucasian patients with advanced adenocarcinoma of the lung that have a somatic EGFR mutation in their tumor. METHODS: Multicenter academic prospective phase II study with erlotinib in patients with an activating EGFR tyrosine kinase (TK) domain somatic mutation (any exon encoding the kinase domain) in the tumor and no prior treatment for their advanced disease. RESULTS: Phenotypic preselecting of 229 patients led to a high EGFR mutation detection rate of 24% of which 46 patients were included in the phase II study. With a progression free survival (PFS) of 81% at three months the study met its primary endpoint for presumed superiority over chemotherapy. With an overall median PFS of 11 months and a median overall survival (OS) of 23 months, the results compare favorably with results obtained in randomized studies using TKI in first line in EGFR mutation positive adenocarcinoma of the lung. CONCLUSION: The present study reinforces the use of EGFR tyrosine kinase inhibition (TKI) as a first line treatment of choice for advanced adenocarcinoma of the lung carrying an activating EGFR mutation. The mutation rate in preselected Caucasian patients is higher than previously reported. Issues relevant for clinical practice are discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT00339586.

Aflibercept Plus FOLFIRI vs. Placebo Plus FOLFIRI in Second-Line Metastatic Colorectal Cancer: a Post Hoc Analysis of Survival from the Phase III VELOUR Study Subsequent to Exclusion of Patients who had Recurrence During or Within 6 Months of Completing Adjuvant Oxaliplatin-Based Therapy.

The aim of this post hoc analysis of the VELOUR study (ClinicalTrials.gov NCT00561470) was to investigate the treatment effect of adding aflibercept to second-line infusional 5-fluorouracil (5-FU), leucovorin and irinotecan (FOLFIRI) in patients with metastatic colorectal cancer (mCRC) who had failed any prior oxaliplatin-containing regimen. Adjuvant rapid relapsers (ARR), who were enrolled directly following relapse during or within 6 months of completion of oxaliplatin-containing adjuvant chemotherapy (N = 124, including 17 patients who also received bevacizumab as part of their adjuvant therapy), were excluded from the original VELOUR intention-to-treat (ITT) population (N = 1226). After exclusion of the ARR, overall survival (OS) in the ITT minus ARR (ITT-ARR) population (N = 1102) was longer in the aflibercept plus FOLFIRI arm than in the placebo plus FOLFIRI arm [hazard ratio (HR) 0.78, 95 % confidence interval (CI) 0.68-0.90; median survival difference 1.87 months]. In the subgroup of patients assigned to the prior bevacizumab stratum at randomization, OS was numerically longer in the aflibercept plus FOLFIRI arm than in the placebo plus FOLFIRI arm (HR 0.81; 95 % CI 0.63-1.04; median survival difference 2.14 months). Comparison of the post hoc analysis results with the primary analysis from VELOUR suggests that the inclusion of the directly enrolled ARR may have understated the aflibercept treatment benefit for both bevacizumab-pretreated and bevacizumab-naïve patients in the strictly second-line setting although no definitive conclusion may be inferred. The benefit associated with the addition of aflibercept to second-line FOLFIRI in patients with mCRC was observed whatever the timing of first-line disease progression. There were no unexpected safety concerns.

Radiological imaging markers predicting clinical outcome in patients with metastatic colorectal carcinoma treated with regorafenib: post hoc analysis of the CORRECT phase III trial (RadioCORRECT study).

OBJECTIVE: To identify imaging markers predicting clinical outcomes to regorafenib in metastatic colorectal carcinoma (mCRC). METHODS: The RadioCORRECT study is a post hoc analysis of a cohort of patients with mCRC treated within the phase III placebo-controlled CORRECT trial of regorafenib. Baseline and week 8 contrast-enhanced CT were used to assess response by RECIST 1.1, changes in the sum of target lesion diameters (ΔSTL), lung metastases cavitation and liver metastases density. Primary and secondary objectives were to develop ex novo univariable and multivariable models to predict overall survival (OS) and progression-free survival (PFS), respectively. RESULTS: 202 patients were enrolled, 134 (66.3%) treated with regorafenib and 68 (33.7%) with placebo. In the univariate analysis, PFS predictors were lung metastases cavitation at baseline (HR 0.50, 95% CI 0.27 to 0.92, p=0.03) and at week 8 (HR 0.58, 95% CI 0.36 to 0.93, p=0.02). Baseline cavitation (HR 0.23, 95% CI 0.08 to 0.66, p=0.007), RECIST 1.1 (HR 0.23, 95% CI 0.14 to 0.4, p <0.0001) and ΔSTL (HR 1.16, 95% CI 1.06 to 1.27, p=0.002) predicted OS. We found an increase of 9% of diameter as the best threshold for discriminating OS (HR 2.64, 95% CI 1.61 to 4.34, p <0.001). In the multivariate analysis, baseline and week 8 cavitation remained significant PFS predictors. Baseline cavitation, RECIST 1.1 and ΔSTL remained predictors of OS in exploratory multivariable models. Assessment of liver metastases density did not predict clinical outcome. CONCLUSIONS: RECIST 1.1 and ΔSTL predict favourable outcome to regorafenib. In contrast to liver metastases density that failed to be a predictor, lung metastases cavitation represents a novel radiological marker of favourable outcome that deserves consideration.

Ossification of a rectal tumor: an uncommon finding.

The authors report the case of a 29-year-old woman with partially calcified stage cT4N2M0 mucoid adenocarcinoma of the mid-rectum. Concomitant neoadjuvant chemoradiotherapy was administered. Preoperative CT scan and MRI demonstrated stable disease with a marked increase of its mineralized component. Histology confirmed a mucoid adenocarcinoma with ossified matrix. Osteocytes were identified in the tumor. TNM (5th edition) staging was ypT3N2M1. This case illustrates heterotopic ossification of a rectal tumor, a fairly uncommon finding. The mechanism of heterotopic bone formation within gastrointestinal adenocarcinoma has not been fully elucidated. The impact of this particular feature on patient outcome is unknown.

Panitumumab as a radiosensitizing agent in KRAS wild-type locally advanced rectal cancer.

Our goal was to optimize the radiosensitizing potential of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies, when given concomitantly with preoperative radiotherapy in KRAS wild-type locally advanced rectal cancer (LARC). Based on pre-clinical studies conducted by our group, we designed a phase II trial in which panitumumab (6 mg/kg/q2 weeks) was combined with preoperative radiotherapy (45 Gy in 25 fractions) to treat cT3-4/N + KRAS wild-type LARC. The primary endpoint was complete pathologic response (pCR) (H0 = 5%, H1 = 17%, α = 0.05, ß = 0.2). From 19 enrolled patients, 17 (89%) were evaluable for pathology assessment. Although no pCR was observed, seven patients (41%) had grade 3 Dworak pathological tumor regression. The regimen was safe and was associated with 95% of sphincter-preservation rate. No NRAS, BRAF, or PI3KCA mutation was found in this study, but one patient (5%) showed loss of PTEN expression. The quantification of plasma EGFR ligands during treatment showed significant upregulation of plasma TGF-α and EGF following panitumumab administration (p < 0.05). At surgery, patients with important pathological regression (grade 3 Dworak) had higher plasma TGF-α (p = 0.03) but lower plasma EGF (p = 0.003) compared to those with grade 0-2 Dworak. Our study suggests that concomitant panitumumab and preoperative radiotherapy in KRAS wild-type LARC is feasible and results in some tumor regression. However, pCR rate remained modest. Given that the primary endpoint of our study was not reached, we remain unable to recommend the use of panitumumab as a radiosensitizer in KRAS wild-type LARC outside a research setting.