Ultrasound-Assisted, Catheter-Directed Thrombolysis for Acute Intermediate/High-Risk Pulmonary Embolism: Design of the Multicenter USAT IH-PE Registry and Preliminary Results.

Catheter-based revascularization procedures were developed as an alternative to systemic thrombolysis for patients with intermediate-high- and high-risk pulmonary embolisms. USAT IH-PE is a retrospective and prospective multicenter registry of such patients treated with ultrasound-facilitated, catheter-directed thrombolysis, whose preliminary results are presented in this study. The primary endpoint was the incidence of pulmonary hypertension (PH) at follow-up. Secondary endpoints were short- and mid-term changes in the echocardiographic parameters of right ventricle (RV) function, in-hospital and all-cause mortality, and procedure-related bleeding events. Between March 2018 and July 2023, 102 patients were included. The majority were at intermediate-high-risk PE (86%), were mostly female (57%), and had a mean age of 63.7 ± 14.5 years, and 28.4% had active cancer. Echocardiographic follow-up was available for 70 patients, and in only one, the diagnosis of PH was confirmed by right heart catheterization, resulting in an incidence of 1.43% (CI 95%, 0.036-7.7). RV echocardiographic parameters improved both at 24 h and at follow-up. In-hospital mortality was 3.9% (CI 95%, 1.08-9.74), while all-cause mortality was 11% (CI 95%, 5.4-19.2). Only 12% had bleeding complications, of whom 4.9% were BARC ≥ 3. Preliminary results from the USAT IH-PE registry showed a low incidence of PH, improvement in RV function, and a safe profile.

Tumor-Associated Macrophages in Canine Oral and Cutaneous Melanomas and Melanocytomas: Phenotypic and Prognostic Assessment.

The tumor microenvironment is a complex system, where neoplastic cells interact with immune and stromal cells. Tumor-associated macrophages (TAMs) are considered among the most numerically and biologically noteworthy cellular components in tumors and the attention on this cellular population has been growing during the last decade, both for its prognostic role and as a potential future therapeutic target. Melanoma, particularly the oral form, despite being one of the most immunogenic tumors, bears a poor prognosis in dogs and humans, due to its highly aggressive biological behavior and limited therapeutic options. The aims of this study are to characterize and quantify TAMs (using CD163, CD204, Iba1, and MAC387) in canine melanocytic tumors and to evaluate the association of these markers with diagnosis, histologic prognostic features, presence of metastases, and outcome, and to provide preliminary data for possible future therapies targeting TAMs. Seventy-two melanocytic tumors (27 oral melanomas, 25 cutaneous melanomas, 14 cutaneous melanocytomas, and 6 oral melanocytomas) were retrospectively selected and submitted to immunohistochemistry and double immunofluorescence. Double immunolabeling revealed that most CD163+ and CD204+cells co-expressed Iba1, which labeled also dendritic cells. Iba1 was instead rarely co-expressed with MAC387. Nevertheless, the expression of macrophagic markers showed a mild to moderate association among the four markers, except for CD204 and MAC387. The number of CD163+, CD204+, and MAC387+ cells was significantly higher in oral melanomas compared to oral melanocytomas (p < 0.001; p < 0.05 and p < 0.01, respectively), whereas Iba1 was differentially expressed in cutaneous melanomas and melanocytomas (p < 0.05). Moreover, CD163, IBA1 and MAC387 expression was associated with nuclear atypia and mitotic count. The number of CD163+cells was associated with the presence of metastases and tumor-related death in oral melanocytic tumors (p < 0.05 and p = 0.001, respectively).

IL-8 and eNOS polymorphisms predict bevacizumab-based first line treatment outcomes in RAS mutant metastatic colorectal cancer patients.

BACKGROUND: Predictive biomarkers of efficacy and toxicity of bevacizumab have not yet been validated. This study assessed the influence of IL-8, eNOS and VEGF-A polymorphisms in RAS mutated metastatic colorectal cancer patients receiving bevacizumab-based chemotherapy. METHODS: 120 patients treated with first-line combination FOLFOX6 plus bevacizumab were included. A historical cohort of 112 RAS mutated colorectal cancer patients treated with FOLFOX6 alone served as control group. The following SNPs were analyzed: IL-8 c.-251T>A; eNOS c.-786T>C and c.-894G>T; VEGF-A c.936C>T, c.958T>C, c.1154A>G and c.2578C>A. Correlation of SNPs, baseline IL-8 serum levels and bevacizumab-efficacy was done. RESULTS: In the bevacizumab group, carriers of the IL-8 alleles c.-251TA+AA showed a shorter PFS (P=0.002) and OS (P=0.03) compared to TT alleles. Patients with pre-treatment IL-8 < 18.25 pg/ml showed significantly longer median PFS and OS (PFS: 10.9 vs 7.6 months, P=0.005; OS: 30.7 vs 18.2 months, P<0.001) compared to patients with IL-8 higher levels (>18,25 pg/ml). IL-8 c.-251TA+AA carriers had significantly higher IL-8 levels (P<0.0001). Multivariate analysis confirmed association of IL-8 polymorphism with PFS, and of IL-8 baseline levels with both PFS and OS. IL-8 SNP did not affect the outcome in the control group. The eNOS polymorphism c.-894G>T was found associated with higher severe toxicity (P=0.0002) in patients carrying the c.-894TT genotype. CONCLUSIONS: Although our data need prospective validation, IL-8 and eNOS SNPs may be have a role as predictive biomarkers for bevacizumab efficacy and toxicity.

Lung ultrasound for monitoring cardiogenic pulmonary edema.

Several studies address the accuracy of lung ultrasound (LUS) in the diagnosis of cardiogenic pulmonary edema (CPE) evaluating the interstitial syndrome, which is characterized by multiple and diffuse vertical artifacts (B-lines), and correlates with extravascular lung water. We studied the potential role of LUS in monitoring CPE response to therapy, by evaluating the clearance of interstitial syndrome within the first 24 h after Emergency Department (ED) admission. LUS was performed at arrival (T0), after 3 (T3) and 24 (T24) hours. Eleven regions were evaluated in the antero-lateral chest; the B-lines burden was estimated in each region (0 = no B-lines, 1 = multiple B-lines, 2 = confluent B-lines/white lung) and a mean score (B-Score, range 0-2) was calculated. Patients received conventional CPE treatment. Blood chemistry, vital signs, blood gas analysis, diuresis at T0, T3, T24 were also recorded. A complete echocardiography was obtained during hospitalization. Forty-one patients were enrolled. Respiratory and hemodynamic parameters improved in all patients between T0 and T3 and between T3 and T24. Mean B-score significantly decreased at T3 (from 1.59 ± 0.40 to 0.73 ± 0.44, P < 0.001) and between T3 and T 24 (from 0.73 ± 0.44 to 0.38 ± 0.33, P < 0.001). B-score was higher in the lower pulmonary regions at any time. At final evaluation (T24) 75 % of apical and only 38 % of basal regions were cleared. LUS allows one to assess the clearance of interstitial syndrome and its distribution in the early hours of treatment of CPE, thus representing a possible tool to guide therapy titration.

Perioperative Triplet Chemotherapy and Cetuximab in Patients With RAS Wild Type High Recurrence Risk or Borderline Resectable Colorectal Cancer Liver Metastases.

BACKGROUND: For borderline resectable colorectal cancer liver metastases (CLM), systemic treatment can help to achieve R0 resection and reduce the risk of relapse. We assessed the role of perioperative triplet chemotherapy in combination with cetuximab in patients with RAS wild type high recurrence risk and/or borderline resectable CLM. PATIENTS AND METHODS: This was a monocenter, open-label phase II study. Borderline resectability was defined technically as tumor involvement of >1 hepatic vein, or >4 hepatic segments, need for 2-stage hepatectomy or radiofrequency ablation, and/or biologically (high risk): ≥4 metastatic nodules, or synchronous metastases. Patients were treated with 4 pre- and postoperative cycles of biweekly COI-E (cetuximab 500 mg/m2 and irinotecan 180 mg/m2 on day 1, oxaliplatin 85 mg/m2 on day 2, and capecitabine 1000 mg/m2 twice per day on days 2-6). The primary end point was overall response rate. RESULTS: Forty patients were enrolled. Nine patients with KRAS mutation were excluded after amendment in 2010. In an extended RAS test we did not find additional RAS mutations. The final population was comprised of 31 patients with RAS wild type CLM (technically borderline resectable 39%; synchronous 84%; ≥4 metastatic nodules 29%). The overall response, R0 resection, and pathological response rates were 87%, 84%, and 33%, respectively. At a median follow-up of 4 years, median progression-free survival and overall survival were 17.8 and 62.5 months, respectively. Treatment toxicity was relevant but did not jeopardize the surgical plan. CONCLUSION: The COI-E regimen was associated with high response and R0 resection rates in patients with RAS wild type CLM with borderline resectability and/or high-risk features.

Heterogeneity of Acquired Resistance to Anti-EGFR Monoclonal Antibodies in Patients with Metastatic Colorectal Cancer.

Purpose: Even if RAS-BRAF wild-type and HER2/MET-negative metastatic colorectal cancer (mCRC) patients frequently respond to anti-EGFR mAbs, acquired resistance almost invariably occurs. Mechanisms of resistance to EGFR blockade include the emergence of KRAS, NRAS, and EGFR extracellular domain mutations as well as HER2/MET alterations. However, these findings derive from retrospective studies that analyzed one single resistance mechanism at a time; moreover, it is still unclear how molecular heterogeneity affects clonal evolution in patients. In this work, we aimed at extensively characterizing and correlating the molecular characteristics of tissue- and blood-based data in a prospective cohort of patients with mCRC who received anti-EGFR antibodies.Experimental design: Twenty-two RAS-BRAF wild-type, HER2/MET-negative mCRC patients progressing on anti-EGFR therapy after initial response underwent rebiopsy. Next-generation sequencing and silver in situ hybridization (SISH)/IHC analyses were performed both on archival tumors and postprogression samples. Circulating tumor (ctDNA) molecular profiles were obtained in matched tissue-plasma samples.Results:RAS mutations and HER2/MET amplification were the most frequently detected resistance mechanisms in both tissue and blood sample analysis. On the other hand, BRAF and EGFR ectodomain mutations were much rarer. Patients with acquired MET amplification showed worse PFS on anti-EGFRs. We detected both intralesion heterogeneity, as suggested by co-occurrence of different resistance mechanisms in the same sample, and interlesion heterogeneity. The combined analysis of tissue and blood (ctDNA) results highlights the complexity of clonal evolution triggered by EGFR blockade.Conclusions: Our results indicate that it may be extremely challenging to target the complex landscape of molecular heterogeneity associated with emergence of resistance to targeted therapies in patients with mCRC. Clin Cancer Res; 23(10); 2414-22. ©2016 AACR.

Lung ultrasound and short-term prognosis in heart failure patients.

BACKGROUND: Heart failure (HF) is the leading cause of hospitalization for patients older than 65years, with a 30-day readmission rate of 20-25%. Although several markers have been evaluated to stratify timing of follow-up after an acute decompensation is mostly based on clinical judgment. Lung ultrasound (LUS) has been demonstrated to be a valid tool for the assessment and monitoring of pulmonary congestion. Aim of our study was to evaluate if LUS performed in HF patients at discharge could predict 100-day hospital readmission or death. METHODS: One-hundred fifty patients were enrolled. The anterolateral chest was scanned to evaluate the presence of B-lines. A sonographic score was calculated attributing 1 to each positive (≥3 B-lines) sector. Clinical, biochemical and echocardiographic data were recorded. A Cox proportional hazard regression analysis was performed to evaluate the association between variables and 100-day events. RESULTS: Follow-up was obtained in 149 patients. Thirty-four events were recorded. Sonographic score was significantly associated with events (HR 1.19; CI 1.05 to 1.34; p=0.005). On average, the increase of 1 point in the sonographic score was associated with an increase of approximately 24% in the risk of event within 100days. At multivariate analysis NTproBNP remained the only independent prognostic factor. CONCLUSIONS: We confirmed that B-lines at discharge are a prognostic marker for hospital readmission and death at 100days in HF patients. Nevertheless, further randomized clinical studies are needed to definitely support the routine use of LUS in the clinical management of HF patients, in combination or not with NT-proBNP.

GNAS mutations as prognostic biomarker in patients with relapsed peritoneal pseudomyxoma receiving metronomic capecitabine and bevacizumab: a clinical and translational study.

BACKGROUND: There is lack of evidence about systemic treatment of pseudomyxoma peritonei (PMP) relapsing after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. There is also lack of biomarkers able to predict outcomes beyond known clinical and pathological prognostic features. METHODS: Fifteen patients with relapsed PMP and progressive disease within the last 6 months were included and received metronomic capecitabine (625 mg/mq/day b.i.d.) and bevacizumab (7.5 mg/Kg three-weekly) until progressive disease/unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Ion Torrent(®) next generation sequencing technology (Hot-spot Cancer Panel) was used to characterize molecular features. RESULTS: At a median follow up of 12 months, median PFS was 8.2 months and 1-year overall survival was 91 %. Partial responses were observed in 20 % of cases, but a significant reduction of tumor markers in up to 79 %. Treatment was very well tolerated without no new safety signals. All tumor samples except one had KRAS mutations. Patients with GNAS mutations had a significantly shorter median PFS as compared to GNAS wild-type ones (5.3 months vs. not reached; p < 0.007). The results were externally validated on our previous series of PMP patients. GNAS mutations were rare in a parallel cohort of 121 advanced colorectal cancers (2.5 %), but were associated with peculiar clinical-pathological features and aggressive course. CONCLUSIONS: Metronomic capecitabine and bevacizumab is an active and well tolerated option in patients with relapsed PMP. The negative prognostic effect of GNAS mutations in gastrointestinal cancers warrants further confirmatory studies and may prompt the development of effective targeted strategies.

Factors Associated with ICU Admission following Blunt Chest Trauma.

Background. Blunt chest wall trauma accounts for over 10% of all trauma patients presenting to emergency departments worldwide. When the injury is not as severe, deciding which blunt chest wall trauma patients require a higher level of clinical input can be difficult. We hypothesized that patient factors, injury patterns, analgesia, postural condition, and positive airway pressure influence outcomes. Methods. The study population consisted of patients hospitalized with at least 3 rib fractures (RF) and at least one pulmonary contusion and/or at least one pneumothorax lower than 2 cm. Results. A total of 140 patients were retrospectively analyzed. Ten patients (7.1%) were admitted to intensive care unit (ICU) within the first 72 hours, because of deterioration of the clinical conditions and gas exchange with worsening of chest X-ray/thoracic ultrasound/chest computed tomography. On univariable analysis and multivariable analysis, obliged orthopnea (p = 0.0018) and the severity of trauma score (p < 0.0002) were associated with admission to ICU. Conclusions. Obliged orthopnea was an independent predictor of ICU admission among patients incurring non-life-threatening blunt chest wall trauma. The main therapeutic approach associated with improved outcome is the prevention of pulmonary infections due to reduced tidal volume, namely, upright postural condition and positive airway pressure.

Dose-Dense Temozolomide in Patients with MGMT-Silenced Chemorefractory Colorectal Cancer.

BACKGROUND: In a phase II study, we showed that temozolomide (TMZ) was tolerable and active in heavily pre-treated patients with advanced colorectal cancer (CRC) and MGMT methylation. A schedule of dose-dense TMZ may have enhanced activity due to the higher cumulative dose and induction of MGMT depletion, even in resistant tumors. METHODS: Thirty-two patients with chemorefractory MGMT-methylated CRC were treated with TMZ at a daily dose of 75 mg/m(2) for 21 consecutive days every 4 weeks, for up to six cycles or until the occurrence of progressive disease/unacceptable toxicity. The primary endpoint was treatment activity in terms of objective response rate (ORR). MGMT protein expression was tested by immunohistochemistry (IHC) on two pooled cohorts: patients from the previous study of standard-dose TMZ and those from the current investigation. RESULTS: From November 2013 to December 2014, 32 patients were treated at Fondazione IRCCS Istituto Nazionale dei Tumori. We observed only three episodes of grade 3 asthenia and no significant myelotoxicity. The ORR was 16 % (all partial responses occurring in RAS-BRAF-mutated tumors). Median progression-free survival (PFS) and overall survival (OS) were 2.3 and 6.7 months, respectively. Patients with MGMT-low expression by IHC had a significantly higher ORR (p < 0.0001) and PFS (p = 0.001) compared to those with MGMT-high expression, while no difference was observed in OS. CONCLUSIONS: Our data confirm the encouraging activity of TMZ in chemorefractory CRC patients selected for MGMT silencing, even in the RAS-BRAF-mutated population. The role of MGMT IHC as a biomarker for improving patient selection warrants further prospective confirmation.

BRAF in metastatic colorectal cancer: the future starts now.

BRAF mutations are detectable in about 5-15% of metastatic colorectal cancer (mCRC) patients and represent a clear negative prognostic factor. While in BRAF-mutated (BRAFmt) metastatic melanoma TKI target therapies (BRAF and MEK inhibitor), both alone or in combination, have shown significant efficacy, in BRAFmt CRC single-agent BRAF-inhibitors as well as chemotherapy seem to be ineffective. The critical role of EGFR in CRC and its multiple downstreaming pathways seem to be involved in this lack of response. In recent years, preclinical investigations and retrospective studies slowly increased our knowledge on BRAFmt CRC. This review analyses preclinical data and discusses several clinical trials in order to explore new therapeutic strategies targeting BRAFmt mCRC.

Early goal-directed therapy vs usual care in the treatment of severe sepsis and septic shock: a systematic review and meta-analysis.

Sepsis is a common and high-burden healthcare problem with a mortality exceeding 20 % in severe sepsis and nearly 50 % when septic shock is present. Early goal-directed therapy (EGDT) is recommended by sepsis guidelines as the standard of care following a landmark study by Rivers et al. alongside other observational studies. Three recent randomized controlled trials have questioned the Rivers' results. The objective of our systematic review was to assess the effectiveness of EGDT in reducing the mortality of severe sepsis or septic shock. Relevant primary studies were identified by searching the MEDLINE and EMBASE databases and the Cochrane Central Register of Controlled Clinical Trials to identify randomized controlled trials assessing the effectiveness of EGDT for sepsis. Data from all trials were combined and analyzed using a random effects model. Five studies, enrolling a total of 4033 patients, were included in the meta-analysis. In-hospital mortality did not differ between the two treatment groups (RR 0.93, 95 % CI 0.77-1.11, P = 0.42), although moderate heterogeneity between studies was noted (I (2) = 48 %). A non-significant trend toward reduction in 60-day mortality in the EGDT group was noted (RR 0.93, 95 % CI 0.82-1.05, P = 0.22, I (2) = 24 %). Heterogeneity between trials precludes a definitive conclusion on the utility of EGDT in severe sepsis. Until further evidence is available, it is reasonable to consider EGDT in the care of patients with severe sepsis and septic shock.

Undetected toxicity risk in pharmacogenetic testing for dihydropyrimidine dehydrogenase.

Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%-30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients' homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies' results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer.

DPD and UGT1A1 deficiency in colorectal cancer patients receiving triplet chemotherapy with fluoropyrimidines, oxaliplatin and irinotecan.

AIMS: Triplet chemotherapy with fluoropyrimidines, oxaliplatin and irinotecan is a standard therapy for metastatic colorectal cancer (CRC). Single nucleotide polymorphisms (SNPs) in DPYD and UGT1A1 influence fluoropyrimdines and irinotecan adverse events (AEs). Low frequency DPYD variants (c.1905 + 1G > A, c.1679 T > G, c.2846A > T) are validated but more frequent ones (c.496A > G, c.1129-5923C > G and c.1896 T > C) are not. rs895819 T > C polymorphism in hsa-mir-27a is associated with reduced DPD activity. In this study, we evaluated the clinical usefulness of a pharmacogenetic panel for patients receiving triplet combinations. METHODS: Germline DNA was available from 64 CRC patients enrolled between 2008 and 2013 in two phase II trials of capecitabine, oxaliplatin and irinotecan plus bevacizumab or cetuximab. SNPs were determined by Real-Time PCR. We evaluated the functional variants in DPYD (rare: c.1905 + 1G > A, c.1679 T > G, c.2846A > T; most common: c.496A > G, c.1129-5923C > G, c.1896 T > C), hsa-mir-27a (rs895819) and UGT1A1 (*28) genes to assess their association with grade 3-4 AEs. RESULTS: None of the patients carried rare DPYD variants. We found DPYD c.496A > G, c.1129-5923C > G, c.1896 T > C in heterozygosity in 19%, 5% and 8%, respectively, homozygous rs895819 in hsa-mir-27a in 9% and homozygous UGT1A1*28 in 8%. Grade 3-4 AEs were observed in 36% patients and were associated with DPYD c.496A > G (odds ratio (OR) 4.93, 95% CI 1.29, 18.87; P = 0.021) and homozygous rs895819 in hsa-mir-27a (OR 11.11, 95% CI 1.21, 102.09; P = 0.020). Carriers of DPYD c.1896 T > C and homozygous UGT1A1*28 showed an OR of 8.42 (95% CI 0.88, 80.56; P = 0.052). Multivariate analysis confirmed an independent value for DPYD c.496A > G and c.1896 T > C. CONCLUSIONS: Concomitant assessment of DPYD variants and the UGT1A1*28 allele is a promising strategy needing further validation for dose personalization.

Circulating tumor cells as a longitudinal biomarker in patients with advanced chemorefractory, RAS-BRAF wild-type colorectal cancer receiving cetuximab or panitumumab.

A still relevant number of patients with RAS-BRAF wild-type colorectal cancer (CRC) do not respond to treatment with antiepidermal growth factor receptor (EGFR) monoclonal antibodies cetuximab and panitumumab, suggesting that additional biomarkers to guide patient selection are urgently needed. Circulating tumor cells (CTCs) may represent such a biomarker. In this prospective study, 38 patients with advanced RAS-BRAF-wild-type CRC received third-line therapy with cetuximab-irinotecan or panitumumab. Peripheral blood samples for CTC status determination were collected at baseline, during treatment at early (2-4 weeks) and at later (8-10 weeks) times. CTC enrichment was done with the AdnaTest ColonCancerSelect kit, whereas CTC detection was done with the AdnaTest ColonCancerDetect kit. CTC status positivity was defined according to the kit manufacturer's thresholds. Fifty percent of patients were defined as CTC positive at baseline and the overall RECIST response rate was 26%. CTC baseline status was not associated with treatment response, whereas early CTC status and CTC status changes during treatment were significantly associated with tumor response. Kaplan-Meier analysis showed a significantly shorter progression-free survival (median, 2.0 versus 4.0 months, p = 0.004) and overall survival (4.7 versus11.4, p = 0.039) in patients with early CTC + status compared with CTC - ones. In multivariable analysis including classical prognostic factors, the CTC status changes profile during treatment was an independent predictor of both progression-free survival (p < 0.001) and overall-survival (p = 0.001). CTC status assessed early during treatment with anti-EGFR monoclonal antibodies may predict treatment failure in advance compared to imaging-based tools.

Predictive role of BRAF mutations in patients with advanced colorectal cancer receiving cetuximab and panitumumab: a meta-analysis.

BACKGROUND: Wild type RAS (RAS-wt) status is predictive of the activities of the anti-epidermal growth factor receptor (EGFR) monoclonal antibodies cetuximab (C) and panitumumab (P). We examined the impact of C and P on progression-free survival (PFS), overall survival (OS) and overall response rate (ORR) in advanced colorectal cancer (CRC) patients who have RAS-wt/BRAF-mutant (BRAF-mut) status. METHODS: Randomised trials that compared C or P plus chemotherapy (or C or P monotherapy) with standard therapy or best supportive care (BSC) were included. We used published hazard ratios (HRs) if they were available, or we derived treatment estimates from other survival data. Pooled estimates of the treatment efficacy of anti-EGFR-based therapy with C or P for the RAS-wt/BRAF-mut subgroup were calculated with the random-effect inverse variance weighted method. All statistical tests were two-sided. RESULTS: Nine phase III trials and one phase II trial (six first-line and two second-line trials, plus two trials involving chemorefractory patients), that included 463 RAS-wt/BRAF-mut CRC patients, were analysed. Overall, the addition of C or P treatment in the BRAF-mut subgroup did not significantly improve PFS (HR, 0.88; 95% confidence interval (CI), 0.67-1.14; p=0.33), OS (HR, 0.91; 95% CI, 0.62-1.34; p=0.63) and ORR (relative risk, 1.31; 95% CI 0.83-2.08, p=0.25) compared with control regimens. CONCLUSIONS: C- or P-based therapy did not increase the benefit of standard therapy or the BSC in RAS-wt/BRAF-mut CRC patients. These findings support BRAF mutation assessment before initiation of treatment with anti-EGFR monoclonal antibodies.

Role of MGMT as biomarker in colorectal cancer.

O(6)-methylguanine DNA methyltransferase (MGMT) gene promoter methylation plays an important role in colorectal carcinogenesis, occurring in about 30%-40% of metastatic colorectal cancer. Its prognostic role has not been defined yet, but loss of expression of MGMT, which is secondary to gene promoter methylation, results in an interesting high response to alkylating agents such as dacarbazine and temozolomide. In a phase 2 study on heavily pre-treated patients with MGMT methylated metastatic colorectal cancer, temozolomide achieved about 30% of disease control rate. Activating mutations of RAS or BRAF genes as well as mismatch repair deficiency may represent mechanisms of resistance to alkylating agents, but a dose-dense schedule of temozolomide may potentially restore sensitivity in RAS-mutant patients. Further development of temozolomide in MGMT methylated colorectal cancer includes investigation of synergic combinations with other agents such as fluoropyrimidines and research for additional biomarkers, in order to better define the role of temozolomide in the treatment of individual patients.