Sustained Disease Control in Immune Checkpoint Blockade Responders with Microsatellite Instability-high Colorectal Cancer after Treatment Termination.

Immune checkpoint inhibitors improve survival in patients with mismatch repair deficiency/microsatellite instability-high (MSI-H) colorectal cancer. The recurrence outcomes following discontinuation of immunotherapy after prolonged disease control have not been definitively reported in large series. Records from patients with advanced MSI-H colorectal cancer from The University of Texas - MD Anderson Cancer Center who received immunotherapy between 2014 and 2022 and stopped after prolonged clinical benefit were reviewed. Median progression-free and overall survival were estimated. Associations between the event of recurrence and coexisting mutations (KRAS/NRAS, BRAFV600E), metastatic organ involvement (lung, liver, lymph node, or peritoneum), metastatic timing (synchronous vs. metachronous), prior immunotherapy [anti-PD-(L)1 alone or in combination with anti-CTLA antibodies], etiology of MSI status (sporadic vs. hereditary non-polyposis colorectal cancer), and duration of immunotherapy were assessed. Sixty-four patients with MSI-H colorectal cancer without progression on immunotherapy were reviewed. Of these 48 and 16 received anti-PD(L)1 antibody alone or in combination with anti-CTLA-4 antibody, respectively. Median exposure to immunotherapy was 17.6 months (range, 1.3-51.9). After a median follow-up of 22.6 months (range, 0.3-71.7) after stopping immunotherapy, 56 of 64 patients (88%) remained without disease progression. Lung metastases were associated with recurrence/progression (OR, 6.1; P = 0.04), but coexisting mutation, primary tumor sidedness, and immunotherapy were not. These data provide a retrospective, single-institution analysis that showed that most patients with advanced MSI-H colorectal cancer do not recur after treatment cessation, regardless of the reason for stopping treatment or a variety of patient and disease features, supporting an optimistic prognosis of sustained disease control. SIGNIFICANCE: Outcomes for patients with MSI-H colorectal cancer stopping immunotherapy after disease control remain unknown. Sixty-four patients with MSI-H colorectal cancer from our institution stopping treatment for sustained benefit or toxicity were retrospectively assessed. After median follow up of 22 months and median immunotherapy exposure of 18 months, 88% patients remained without progression. All patients who recurred or progressed and were rechallenged with immunotherapy have continued to experience disease control.

Novel Clinical Tool to Estimate Risk of False-Negative KRAS Mutations in Circulating Tumor DNA Testing.

PURPOSE: In metastatic colorectal cancer, the detection of RAS mutations by circulating tumor DNA (ctDNA) has emerged as a valid and noninvasive alternative approach to determining RAS status. However, some RAS mutations may be missed, that is, false negatives can occur, possibly compromising important treatment decisions. We propose a statistical model to assess the probability of false negatives when performing ctDNA testing for RAS. METHODS: Cohorts of 172 subjects with tissue and multipanel ctDNA testing from MD Anderson Cancer Center and 146 subjects from Massachusetts General Hospital were collected. We developed a Bayesian model that uses observed frequencies of reference mutations (the maximum of APC and TP53) to provide information about the probability of KRAS false negatives. The model was alternatively trained on one cohort and tested on the other. All data were collected on Guardant assays. RESULTS: The model suggests that negative KRAS findings are believable when the maximum of APC and TP53 frequencies is at least 8% (corresponding posterior probability of false negative <5%). Validation studies demonstrated the ability of our tool to discriminate between false-negative and true-negative subjects. Simulations further confirmed the utility of the proposed approach. CONCLUSION: We suggest clinicians use the tool to more precisely quantify KRAS false-negative ctDNA results when at least one of the reference mutations (APC, TP53) is observed; usage may be especially important for subjects with a maximum reference frequency of <8%. Extension of the methodology to predict false negatives of other genes is possible. Additional reference genes can also be considered. Use of personal training data sets is supported. An open-source R Shiny application is available for public use.

A phase I trial of the pan-ERBB inhibitor neratinib combined with the MEK inhibitor trametinib in patients with advanced cancer with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation or KRAS mutation.

PURPOSE: Aberrant alterations of ERBB receptor tyrosine kinases lead to tumorigenesis. Single agent therapy targeting EGFR or HER2 has shown clinical successes, but drug resistance often develops due to aberrant or compensatory mechanisms. Herein, we sought to determine the feasibility and safety of neratinib and trametinib in patients with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation and KRAS mutation. METHODS: Patients with actionable somatic mutations or amplifications in ERBB genes or actionable KRAS mutations were enrolled to receive neratinib and trametinib in this phase I dose escalation trial. The primary endpoint was determination of the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). Secondary endpoints included pharmacokinetic analysis and preliminary anti-tumor efficacy. RESULTS: Twenty patients were enrolled with a median age of 50.5 years and a median of 3 lines of prior therapy. Grade 3 treatment-related toxicities included: diarrhea (25%), vomiting (10%), nausea (5%), fatigue (5%) and malaise (5%). The MTD was dose level (DL) minus 1 (neratinib 160 mg daily with trametinib 1 mg, 5 days on and 2 days off) given 2 DLTs of grade 3 diarrhea in DL1 (neratinib 160 mg daily with trametinib 1 mg daily). The treatment-related toxicities of DL1 included: diarrhea (100%), nausea (55.6%) and rash (55.6%). Pharmacokinetic data showed trametinib clearance was significantly reduced leading to high drug exposures of trametinib. Two patients achieved stable disease (SD) ≥ 4 months. CONCLUSION: Neratinib and trametinib combination was toxic and had limited clinical efficacy. This may be due to suboptimal drug dosing given drug-drug interactions. TRIAL REGISTRATION ID: NCT03065387.

Feasibility and Safety of Personalized, Multi-Target, Adoptive Cell Therapy (IMA101): First-in-Human Clinical Trial in Patients with Advanced Metastatic Cancer.

IMA101 is an actively personalized, multi-targeted adoptive cell therapy (ACT), whereby autologous T cells are directed against multiple novel defined peptide-HLA (pHLA) cancer targets. HLA-A*02:01-positive patients with relapsed/refractory solid tumors expressing ≥1 of 8 predefined targets underwent leukapheresis. Endogenous T cells specific for up to 4 targets were primed and expanded in vitro. Patients received lymphodepletion (fludarabine, cyclophosphamide), followed by T-cell infusion and low-dose IL2 (Cohort 1). Patients in Cohort 2 received atezolizumab for up to 1 year (NCT02876510). Overall, 214 patients were screened, 15 received lymphodepletion (13 women, 2 men; median age, 44 years), and 14 were treated with T-cell products. IMA101 treatment was feasible and well tolerated. The most common adverse events were cytokine release syndrome (Grade 1, n = 6; Grade 2, n = 4) and expected cytopenias. No patient died during the first 100 days after T-cell therapy. No neurotoxicity was observed. No objective responses were noted. Prolonged disease stabilization was noted in three patients lasting for 13.7, 12.9, and 7.3 months. High frequencies of target-specific T cells (up to 78.7% of CD8+ cells) were detected in the blood of treated patients, persisted for >1 year, and were detectable in posttreatment tumor tissue. Individual T-cell receptors (TCR) contained in T-cell products exhibited broad variation in TCR avidity, with the majority being low avidity. High-avidity TCRs were identified in some patients' products. This study demonstrates the feasibility and tolerability of an actively personalized ACT directed to multiple defined pHLA cancer targets. Results warrant further evaluation of multi-target ACT approaches using potent high-avidity TCRs. See related Spotlight by Uslu and June, p. 865.

Bintrafusp alfa, an anti-PD-L1:TGF-ß trap fusion protein, in patients with ctDNA-positive, liver-limited metastatic colorectal cancer.

Background: Identification of circulating tumor DNA (ctDNA) following curative intent therapies is a surrogate for microscopic residual disease for patients with metastatic colorectal cancer (mCRC). Preclinically, in micrometastatic microsatellite stable (MSS) CRC, increased TGF-ß signaling results in exclusion of anti-tumor cytotoxic T cells from the tumor microenvironment. Bintrafusp alfa (BA) is a bifunctional fusion protein composed of the extracellular domain of the TGF-ßRII receptor ("TGF-ß trap") and anti-PD-L1 antibody. Methods: Patients with liver-limited, MSS mCRC and with detected ctDNA after complete resection of all known tumors and standard-of-care therapy were treated with 1200 mg of BA intravenously every 14 days for six doses. The primary endpoint was ctDNA clearance. Radiographic characteristics at recurrence were compared using independent t-tests to historical data from a similar cohort of patients with liver-limited mCRC who underwent observation. Results: Only 4 of 15 planned patients received BA before the study was stopped early for loss of equipoise. There was no grade ≥3 AE. None of the patients cleared ctDNA. All patients developed radiographic recurrence by the first planned restaging. Although not detectable at prior to treatment, TGFß3 was found in circulation in all patients at cycle 2 day 1. Compared to a historical cohort, patients administered BA developed more metastases (15 versus 2, p=0.005) and greater tumor volumes (9 cm vs 2 cm, p=0.05). Conclusions: Treatment with BA in patients with ctDNA-detected, liver-limited mCRC did not clear ctDNA and was associated with large-volume recurrence, highlighting the potential context-specific complexity of dual TGF-ß and PD-L1 inhibition.

Phase II study of durvalumab (anti-PD-L1) and trametinib (MEKi) in microsatellite stable (MSS) metastatic colorectal cancer (mCRC).

BACKGROUND: Monotherapy with immune checkpoint blockade is ineffective for patients (pts) with microsatellite stable (MSS) metastatic colorectal cancer (mCRC). This study investigates whether the combination of trametinib (T) with durvalumab (D) can alter the immune tumor microenvironment (TME) by successfully priming and activating T-cells. METHODS: Open-label, single-center, phase II trial with primary endpoint of immune-related response rate for combination of T+D in refractory MSS mCRC pts (NCT03428126). T is 2 mg/day orally starting 1 week prior to D, which is given 1500 mg intravenously every 4 weeks. Simon 2-stage design used to enroll 29 pts into first stage, requiring a response in two or more pts to proceed to stage 2. Tumor biopsies were collected at baseline (BL) and early on-treatment (OT) at week 4. RESULTS: Twenty nine treated pts include 48% females, median age 48 years (range 28-75), and median prior therapies 2 (range 1-5). No grade (G) 4 or 5 treatment-related adverse events (TRAE). The most common TRAE of any grade was acneiform rash, 17% being G3. One of 29 pts had confirmed partial response (PR) lasting 9.3 months (mo) for an overall response rate of 3.4%. Seven pts had stable disease (SD) and five pts (1 PR, 4 SD) demonstrated decrease in total carcinoembryonic antigen ng/mL (best percentage reduction: 94%, 95%, 42%, 34%, and 22%, respectively). Median progression-free survival was 3.2 mo (range 1.1-9.3 months). Three pts with both liver and lung metastases demonstrated discrepant responses in which clinical benefit was present in the lung metastases but not liver metastases. Comparison of BL and 4-week OT tumor tissue flow cytometry demonstrated no changes in T-cell infiltration but upregulation expression of PD-1 and Tim3 on CD8 T cells. However, expression of PD-1 and Tim3 as single markers and as coexpressed markers was observed to increase OT relative to BL (p=0.03, p=0.06 and p=0.06, respectively). CONCLUSIONS: T+D demonstrated acceptable tolerability in pts with refractory MSS mCRC. The response rate in the first stage of the study did not meet efficacy criteria to proceed to the second stage. Specific site of metastatic disease may impact outcomes in novel immunotherapy combination trials. TRIAL REGISTRATION NUMBER: NCT03428126.

Signet ring cell colorectal cancer: genomic insights into a rare subpopulation of colorectal adenocarcinoma.

BACKGROUND: Signet ring cell carcinoma (SRCC) is a rare subtype of colorectal cancer (CRC). The aim of this study was to characterise the genomic alterations and outcomes of SRCC. METHODS: Medical records of metastatic CRC (mCRC) patients whose tumours were evaluated by NGS analysis were reviewed. SC-mCRC were classified into two groups: SRCC (>50% signet ring cells) and adenocarcinoma (AC) with SC component (≤50% signet ring cells). RESULTS: Six hundred and sixty-five mCRC patients were included. Of the 93 mCRC cases with SC features, 63 had slides for review. Of those 63 cases, 35 were confirmed SRCC, and 28 were AC with SC component. Compared with AC group, KRAS and PIK3CA mutations (mts) were found in only 11% (OR: 0.13) and 3% (OR: 0.15) of SRCC cases, respectively. In contrast to the 44% rate of APC mts in AC group, only 3% of SRCC patients had APC mts (OR = 0.04). CONCLUSIONS: SRCC has distinct molecular features, including low rates of KRAS, PIK3CA and APC mts. Further study to identify activation pathways and potential therapeutic targets are needed.

Physician interpretation of genomic test results and treatment selection.

BACKGROUND: Genomic testing is increasingly performed in oncology, but concerns remain regarding the clinician's ability to interpret results. In the current study, the authors sought to determine the agreement between physicians and genomic annotators from the Precision Oncology Decision Support (PODS) team at The University of Texas MD Anderson Cancer Center in Houston regarding actionability and the clinical use of test results. METHODS: On a prospective protocol, patients underwent clinical genomic testing for hotspot mutations in 46 or 50 genes. Six months after sequencing, physicians received questionnaires for patients who demonstrated a variant in an actionable gene, investigating their perceptions regarding the actionability of alterations and clinical use of these findings. Genomic annotators independently classified these variants as actionable, potentially actionable, unknown, or not actionable. RESULTS: Physicians completed 250 of 288 questionnaires (87% response rate). Physicians considered 168 of 250 patients (67%) as having an actionable alteration; of these, 165 patients (98%) were considered to have an actionable alteration by the PODS team and 3 were of unknown significance. Physicians were aware of genotype-matched therapy available for 119 patients (71%) and 48 of these 119 patients (40%) received matched therapy. Approximately 46% of patients in whom physicians regarded alterations as not actionable (36 of 79 patients) were classified as having an actionable/potentially actionable mutation by the PODS team. However, many of these were only theoretically actionable due to limited trials and/or therapies (eg, KRAS). CONCLUSIONS: Physicians are aware of recurrent mutations in actionable genes on "hotspot" panels. As larger genomic panels are used, there may be a growing need for annotation of actionability. Decision support to increase awareness of genomically relevant trials and novel treatment options for recurrent mutations (eg, KRAS) also are needed. Cancer 2018;124:966-72. © 2017 American Cancer Society.

FBXW7 missense mutation: a novel negative prognostic factor in metastatic colorectal adenocarcinoma.

BACKGROUND: FBXW7 functions as a ubiquitin ligase tagging multiple dominant oncogenic proteins and commonly mutates in colorectal cancer. Data suggest missense mutations lead to greater loss of FBXW7 function than other gene aberrations do. However, the clinicopathologic factors and outcomes associated with FBXW7 missense mutations in metastatic colorectal cancer (mCRC) have not been described. METHODS: Data were obtained from mCRC patients whose tumors were evaluated by next-generation sequencing for hotspot mutations at The University of Texas MD Anderson Cancer Center. Alterations in FBXW7 were identified, and their associations with clinicopathologic features and overall survival (OS) were evaluated. RESULTS: Of 855 mCRC patients, 571 had data on FBXW7 status; 43 (7.5%) had FBXW7 mutations, including 37 with missense mutations. R465C mutations in exon 9 were the most common missense mutations (18.6%). PIK3CA mutations were associated with FBXW7 missense mutations (p=0.012). On univariate analysis, patients with FBXW7 missense mutations had significantly worse OS (median 28.7 mo) than those with wild-type FBXW7 (median 46.6 mo; p=0.003). On multivariate analysis including other known prognostic factors such as BRAF mutations, FBXW7 missense mutations were the strongest negative prognostic factor for OS (hazard ratio 2.0; p=0.003). CONCLUSIONS: In the largest clinical dataset of mCRC to date, FBXW7 missense mutations showed a strong negative prognostic association.

Association of SMAD4 mutation with patient demographics, tumor characteristics, and clinical outcomes in colorectal cancer.

SMAD4 is an essential mediator in the transforming growth factor-ß pathway. Sporadic mutations of SMAD4 are present in 2.1-20.0% of colorectal cancers (CRCs) but data are limited. In this study, we aimed to evaluate clinicopathologic characteristics, prognosis, and clinical outcome associated with this mutation in CRC cases. Data for patients with metastatic or unresectable CRC who underwent genotyping for SMAD4 mutation and received treatment at The University of Texas MD Anderson Cancer Center from 2000 to 2014 were reviewed. Their tumors were sequenced using a hotspot panel predicted to cover 80% of the reported SMAD4 mutations, and further targeted resequencing that included full-length SMAD4 was performed on mutated tumors using a HiSeq sequencing system. Using The Cancer Genome Atlas data on CRC, the characteristics of SMAD4 and transforming growth factor-ß pathway mutations were evaluated according to different consensus molecular subtypes of CRC. Among 734 patients with CRC, 90 (12%) had SMAD4 mutations according to hotspot testing. SMAD4 mutation was associated with colon cancer more so than with rectal cancer (odds ratio 2.85; p<0.001), female sex (odds ratio 1.71; p = 0.02), and shorter overall survival than in wild-type SMAD4 cases (median, 29 months versus 56 months; hazard ratio 2.08; p<0.001 [log-rank test]). SMAD4 mutation was not associated with age, stage at presentation, colonic location, distant metastasis, or tumor grade. A subset of patients with metastatic CRC (n = 44) wild-type for KRAS, NRAS, and BRAF who received anti-epidermal growth factor receptor therapy with mutated SMAD4 (n = 13) had shorter progression-free survival duration than did patients wild-type for SMAD4 (n = 31) (median, 111 days versus 180 days; p = 0.003 [log-rank test]). Full-length sequencing confirmed that missense mutations at R361 and P356 in the MH2 domain were the most common SMAD4 alterations. In The Cancer Genome Atlas data, SMAD4 mutation frequently occurred with KRAS, NRAS, and BRAF mutations and was more common in patients with the consensus molecular subtype 3 of CRC than in those with the other 3 subtypes. This is one of the largest retrospective studies to date characterizing SMAD4 mutations in CRC patients and demonstrates the prognostic role and lack of response of CRC to anti-epidermal growth factor receptor therapy. Further studies are required to validate these findings and the role of SMAD4 mutation in CRC.

BRAF Mutation Testing in Cell-Free DNA from the Plasma of Patients with Advanced Cancers Using a Rapid, Automated Molecular Diagnostics System.

Cell-free (cf) DNA from plasma offers an easily obtainable material for BRAF mutation analysis for diagnostics and response monitoring. In this study, plasma-derived cfDNA samples from patients with progressing advanced cancers or malignant histiocytosis with known BRAF(V600) status from formalin-fixed paraffin-embedded (FFPE) tumors were tested using a prototype version of the Idylla BRAF Mutation Test, a fully integrated real-time PCR-based test with turnaround time about 90 minutes. Of 160 patients, BRAF(V600) mutations were detected in 62 (39%) archival FFPE tumor samples and 47 (29%) plasma cfDNA samples. The two methods had overall agreement in 141 patients [88%; κ, 0.74; SE, 0.06; 95% confidence interval (CI), 0.63-0.85]. Idylla had a sensitivity of 73% (95% CI, 0.60-0.83) and specificity of 98% (95% CI, 0.93-1.00). A higher percentage, but not concentration, of BRAF(V600) cfDNA in the wild-type background (>2% vs. ≤ 2%) was associated with shorter overall survival (OS; P = 0.005) and in patients with BRAF mutations in the tissue, who were receiving BRAF/MEK inhibitors, shorter time to treatment failure (TTF; P = 0.001). Longitudinal monitoring demonstrated that decreasing levels of BRAF(V600) cfDNA were associated with longer TTF (P = 0.045). In conclusion, testing for BRAF(V600) mutations in plasma cfDNA using the Idylla BRAF Mutation Test has acceptable concordance with standard testing of tumor tissue. A higher percentage of mutant BRAF(V600) in cfDNA corresponded with shorter OS and in patients receiving BRAF/MEK inhibitors also with shorter TTF. Mol Cancer Ther; 15(6); 1397-404. ©2016 AACR.

Erratum: Actionable mutations in plasma cell-free DNA in patients with advanced cancers referred for experimental targeted therapies.

The Abstract is incorrect in PubMed. The corrected Abstract is provided here.

Capecitabine-induced leukocytoclastic vasculitis under neoadjuvant chemotherapy for locally advanced colorectal cancer.

We describe a case of capecitabine-induced leukocytoclastic vasculitis in a patient with locally advanced rectal cancer under curative neoadjuvant concurrent chemoradiation using capecitabine. After 5 days of the initiation of capecitabine the patient developed a pruritic maculopapular rash in her extremities consistent with vasculitis which was confirmed on skin biopsy without any signs of systemic involvement. Capecitabine was held and the rash was treated with topical steroids with complete resolution of both rash and pruritus. Due to a lack of other alternative chemotherapeutic options and the cutaneous-only involvement of vasculitis, the capecitabine was re-introduced. Two days later, the patient developed an identical maculopapular rash with a similar distribution. Prednisone was initiated while the capecitabine was continued with complete resolution of the rash. The patient successfully completed her curative neoadjuvant chemoradiation therapy treatment without the need to permanently discontinue the capecitabine.

Actionable mutations in plasma cell-free DNA in patients with advanced cancers referred for experimental targeted therapies.

Cell-free (cf) DNA in the plasma of cancer patients offers an easily obtainable source of biologic material for mutation analysis. Plasma samples from 157 patients with advanced cancers who progressed on systemic therapy were tested for 21 mutations in BRAF, EGFR, KRAS, and PIK3CA using the BEAMing method and results were compared to mutation analysis of archival tumor tissue from a CLIA-certified laboratory obtained as standard of care from diagnostic or therapeutic procedures. Results were concordant for archival tissue and plasma cfDNA in 91% cases for BRAF mutations (kappa = 0.75, 95% confidence interval [CI] 0.63 - 0.88), in 99% cases for EGFR mutations (kappa = 0.90, 95% CI 0.71- 1.00), in 83% cases for KRAS mutations (kappa = 0.67, 95% CI 0.54 - 0.80) and in 91% cases for PIK3CA mutations (kappa = 0.65, 95% CI 0.46 - 0.85). Patients (n = 41) with > 1% of KRAS mutant cfDNA had a shorter median survival compared to 20 patients with 1% of mutant cfDNA (BRAF, EGFR, KRAS, or PIK3CA) had a shorter median survival compared to 33 patients with

Dose-finding study of hepatic arterial infusion of irinotecan-based treatment in patients with advanced cancers metastatic to the liver.

BACKGROUND: Liver metastases are associated with a poor prognosis. We investigated the use of hepatic arterial infusion (HAI) of irinotecan combination therapy in patients with liver metastases. PATIENTS AND METHODS: Patients with histologically confirmed advanced cancer with liver metastases that was refractory to standard therapy were eligible. A standard "3 + 3" phase I study design was used to determine the dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD). Three cohorts were evaluated: HAI of irinotecan with systemic intravenous (IV) (a) bevacizumab, (b) oxaliplatin and bevacizumab, or (c) bevacizumab and cetuximab. RESULTS: From October 2009 through December 2013, 98 patients with various tumor types were enrolled (median age, 62 years, range, 34-85; and median number of prior therapies, 4, range, 1-11). In cohorts A and C, dose escalation continued until the highest dose level-considered the MTD-was reached. In cohort B, dose escalation continued until dose level 3, and dose level 2 was considered the MTD. Rates of grade 3/4 adverse events were as follows: diarrhea, 8 %; fatigue, 4 %; neutropenia, 4 %; thrombocytopenia, 2 %; and skin rash, 2 %. Seventy-seven patients were evaluable for response. Partial response was noted in 5 (6.5 %) patients (neuroendocrine cancer, n = 2; CRC, n = 2; NSCLC, n = 1); and stable disease ≥ 6 months in 17 (22.1 %) patients (CRC, n = 13; breast, n = 1; neuroendocrine, n = 1; NSCLC, n = 1; pancreatic, n = 1). CONCLUSIONS: HAI irinotecan in combination with bevacizumab; oxaliplatin plus bevacizumab; or cetuximab plus bevacizumab was safe and may be a treatment option for selected patients with advanced cancer and liver involvement.

A phase II, randomized, double blind trial of calcium aluminosilicate clay versus placebo for the prevention of diarrhea in patients with metastatic colorectal cancer treated with irinotecan.

PURPOSE: Calcium aluminosilicate clay (CASAD) is a naturally occurring clay that serves as a cation exchange absorbent. We hypothesized that oral administration of CASAD would reduce the rate of grade 3/4 diarrhea associated with irinotecan use for metastatic colorectal cancer (CRC) by adsorbing the SN-38 metabolite. METHODS: Patients receiving irinotecan-based chemotherapy were randomized equally between CASAD and placebo arms in this multicenter trial in order to assess differences in the proportions of patients with grade 3/4 diarrhea within 6 weeks. Additionally, we compared symptom severity between the two arms using the M.D. Anderson Symptom Inventory. RESULTS: Between May 2009 and May 2012, 100 patients were enrolled. In evaluable patients, 7 of 43 (16 %) on the CASAD arm compared to 3 of 32 (9 %) on the placebo arm experienced grade 3/4 diarrhea (P = 0.70). The rate of any diarrhea among all patients was similar (CASAD arm, 64 % vs. placebo arm, 70 %). The rate of study dropout was 14 % in the CASAD arm and 38 % in the placebo arm (P = 0.01). No differences were found in symptom severity, individual symptom items, and in serious adverse events between the two arms. CONCLUSION: Compared to placebo, CASAD use was safe but ineffective in preventing diarrhea in metastatic CRC patients treated with irinotecan-containing chemotherapy regimens. There were no distinct signals in terms of patient symptoms between arms, but there was significantly more patient dropout in the placebo arm. Future CASAD trials will focus on the active treatment of diarrhea.

High prevalence of recurrent thrombosis in subsets of cancer patients with isolated gonadal vein thrombosis: a single center retrospective study.

PURPOSE: Cancer patients are a high-risk population for venous thromboembolism (VTE); the natural history of gonadal vein thrombosis (GVT) occurring in cancer patients is not well described in the medical literature. METHODS: Utilizing a software program the computerized tomographic scan reports of patients at a single cancer center from January 1, 2004 to June 30, 2011 were searched for the term GVT. Patients included in this analysis had a diagnosis of cancer, an isolated GVT (i.e. no evidence of thrombosis at another site), no symptoms referable to the GVT, and at least six months of follow-up information. All subsequent recurrent VTE events were confirmed by imaging studies. RESULTS: 196 cancer patients with GVT were identified. The majority of patients in this analysis had metastatic disease (118, 61.2%) as well as active cancer (167, 85.2%). Twenty patients (10.8%) developed recurrent VTE (median follow-up 14.5 months); median time to recurrent VTEs was 5.5 months (range 0-19 months). When considering only patients with without a recent history of gynecologic surgery, VTE recurrence rates were 14.3%. Active cancer was the only risk factor significantly associated with recurrent VTE (P=0.047). CONCLUSIONS: Based upon the patient's risk factors for VTE, treatment of an incidentally detected GVT in cancer patients with anticoagulation, as per guidelines for other VTE sites, may be indicated in certain high risk subgroups, especially those patients with active cancer who have not had prior pelvic surgery.

Rare Though Not Mutually Exclusive: A Report of Three Cases of Concomitant KRAS and BRAF Mutation and a Review of the Literature.

KRAS mutations occur frequently in colorectal cancers (CRC) and predict lack of response to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy. CRC BRAF mutations, most commonly at V600E, occur less than 10% of the time, and occur usually in KRAS wild-type tumors, and more frequently in microsatellite instable tumors. Concomitant KRAS and BRAF mutant CRCs are rare (occurring in 0.001%); BRAF mutations should not be routinely tested in patients with KRAS mutant tumors, unless the patients is participating in a clinical trial enriching for the presence of a KRAS or BRAF tumor. Clinical trials treating patients with either KRAS or BRAF mutant tumors should address eligibility of patients with concomitant KRAS and BRAF mutations.

A Primer on the Current State-of-the-Science Neoadjuvant and Adjuvant Therapy for Patients with Locally Advanced Rectal Adenocarcinomas.

Patients with rectal cancers, due to the unique location of the tumor, have a recurrence pattern distinct from colon cancers. Advances in adjuvant therapy over the last three decades have played an important role in improving patient outcomes. This article serves to review the clinical studies that lay the basis for our current standard-of-care treatment of patients with locally advanced rectal cancer, as well as touch upon future ongoing experimental clinical trials of adjuvant chemoradiation therapy.

Survival benefit associated with surgical oophorectomy in patients with colorectal cancer metastatic to the ovary.

BACKGROUND AND OBJECTIVES: The purpose of this study was to determine the outcome of patients with colorectal cancer metastatic to the ovary and the impact of surgical oophorectomy on the outcome. METHODS: We conducted a retrospective evaluation of patients with metastatic colorectal cancer to the ovary. Of 3776 female patients with colorectal cancer seen at MD Anderson from 2001-2008, 110 (2.9%) were identified as having metastases to the ovary. The Kaplan-Meier method and log-rank test were used to examine the survival functions. RESULTS: Seventy-one patients (64.5%) had disease metastatic to the ovary at the time of initial presentation; in 39 patients (35.5%) the ovaries were a site of relapse after previous curative colorectal surgical resection. Patients who presented with ovarian relapse after previous colorectal surgery and who underwent oophorectomy had a median survival of 50 months compared with 12 months for those who did not (P < .0001). Patients with metastatic disease at the time of presentation who underwent oophorectomy had a median survival of 39.4 months vs. 18.2 months for those who did not. CONCLUSIONS: This retrospective analysis suggests that women with metastatic colorectal cancer metastatic to the ovary may derive a survival benefit from palliative oophorectomy.