Irinotecan-based Treatment Research Articles

Gastrointestinal bleeding/ulcer among paediatric cancer patients after proton beam therapy

The details of gastrointestinal bleeding/ulcer in paediatric cancer patients treated with proton beam therapy have not been reported previously. Patients aged 15years or younger at the time of proton beam therapy and whose gastrointestinal tract was included in the irradiated field participated. A total of 124 patients participated in the study; their median age at irradiation was 5.4years. Concurrent chemotherapies were vincristine-cyclophosphamide (16 patients), irinotecan-based treatment (16 patients), vincristine-cyclophosphamide-ifosfamide-etoposide (14 patients), other chemotherapy (27 patients) and no chemotherapy (51 patients). Gastrointestinal bleeding/ulcer occurred in four patients (3.2%), with no death due to the bleeding/ulcer. The sites of the gastrointestinal bleeding/ulcer were the stomach (two patients) and the duodenum (two patients). The ages of the four patients at PBT were 5.3, 13.8, 14.2 and 14.8years, which were significantly older than those of patients without GI bleeding/ulcer (p=0.017). The maximum irradiated doses to the GI tract in the four patients were 43.2, 45, 50.4 and 50.4 gray equivalent, respectively. The concomitant chemotherapy was vincristine-cyclophosphamide-ifosfamide-etoposide 3 and vincristine-cyclophosphamide 1. Weeks from proton beam therapy to bleeding/ulcer were 15, 20, 22 and 264. Patients who developed gastrointestinal bleeding/ulcer were treated concurrently with vincristine-cyclophosphamide-ifosfamide-etoposide or vincristine-cyclophosphamide, and their ages were older than those of patients without gastrointestinal bleeding/ulcer. Bleeding occurred in the upper gastrointestinal tract in all the cases, and most cases occurred early and during chemotherapy. Upper gastrointestinal irradiation in older children undergoing intensive chemotherapy may increase the risk of developing gastrointestinal complications.

Circulating miRNA Expression Profiles and Machine Learning Models in Association with Response to Irinotecan-Based Treatment in Metastatic Colorectal Cancer

Colorectal cancer represents a leading cause of cancer-related morbidity and mortality. Despite improvements, chemotherapy remains the backbone of colorectal cancer treatment. The aim of this study is to investigate the variation of circulating microRNA expression profiles and the response to irinotecan-based treatment in metastatic colorectal cancer and to identify relevant target genes and molecular functions. Serum samples from 95 metastatic colorectal cancer patients were analyzed. The microRNA expression was tested with a NucleoSpin miRNA kit (Machnery-Nagel, Germany), and a machine learning approach was subsequently applied for microRNA profiling. The top 10 upregulated microRNAs in the non-responders group were hsa-miR-181b-5p, hsa-miR-10b-5p, hsa-let-7f-5p, hsa-miR-181a-5p, hsa-miR-181d-5p, hsa-miR-301a-3p, hsa-miR-92a-3p, hsa-miR-155-5p, hsa-miR-30c-5p, and hsa-let-7i-5p. Similarly, the top 10 downregulated microRNAs were hsa-let-7d-5p, hsa-let-7c-5p, hsa-miR-215-5p, hsa-miR-143-3p, hsa-let-7a-5p, hsa-miR-10a-5p, hsa-miR-142-5p, hsa-miR-148a-3p, hsa-miR-122-5p, and hsa-miR-17-5p. The upregulation of microRNAs in the miR-181 family and the downregulation of those in the let-7 family appear to be mostly involved with non-responsiveness to irinotecan-based treatment.

Genotyping of UGT1A1*80 as an Alternative to UGT1A1*28 Genotyping in Spain.

Background: The variant rs34983651 (UGT1A1*28) and its genotyping are used to prevent irinotecan-induced toxicity. Several variants are in close linkage disequilibrium. Our objective was to evaluate the potential correlation of genotyping UGT1A1*80 instead of UGT1A1*28 in different populations. Methods: We studied SNPs in linkage disequilibrium with UGT1A1*28 in several populations and selected rs887829 to develop an inexpensive and rapid genotyping method and compare it with the one we currently use for UGT1A1*28 genotyping. Samples from cancer patients (n = 701) already tested using PCR and electrophoresis prior to treatment with irinotecan for rs34983651 (UGT1A1*28) in a Spanish hospital were genotyped for rs887829 (UGT1A1*80) using real-time PCR with a TaqMan probe. Results: We observed a complete match for both genotypes, except in one sample. This method was 100% efficient in correctly genotyping *28/*28 patients, 99.68% efficient for *1/*28, and 100% efficient for *1/*1. Linkage disequilibrium between populations showed the Iberian population to be the most suitable for the clinical use of UGT1A1*80. This method is less expensive and the time to decision is shorter. Conclusion: Genotyping of rs887829 using the proposed method may be used to substitute genotyping of rs34983651 as a pharmacogenetics test in cancer patients prior to starting irinotecan-based treatments, mainly in the Iberian population. In addition, it is less expensive than other conventional methods and easy to implement, with a shorter time to decision than UGT1A1*28.

Real-world clinical outcomes of patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) treated with liposomal irinotecan-based regimens: Impact of prior irinotecan (IRI) exposure.

580 Background: Subgroup analyses of the NAPOLI-1 study identified that among patients who were IRI naïve prior to entering the clinical trial, a survival benefit was observed between the study arm and control arm (overall survival (OS): 6.7 months vs 4.2 months). This treatment benefit was not observed among those previously exposed to IRI (OS: 4.6 months in study arm vs 4.8 months in control arm). This study sought to understand the impact of prior exposure to IRI on clinical outcomes among patients treated with liposomal irinotecan in the real-world setting. Methods: This retrospective observational study utilized the Flatiron Health EHR database. Data were analyzed for adult patients with mPDAC treated with liposomal irinotecan -based regimens between January 2016 and October 2020. Patient characteristics, OS and progression-free survival (PFS) were assessed. Prior IRI was defined as IRI given in a prior regimen in the metastatic setting. Cox proportional hazard (PH) methods were used to calculate hazard ratios (HRs). HRs were adjusted to account for demographics and relevant clinical covariates. Patients without prior exposure to IRI were used as the reference population for the Cox PH model (an HR < 1 represents worse survival for unexposed patients relative to the exposed). Results: 675 patients with mPDAC treated with a liposomal irinotecan-based regimen were included. Median age at treatment initiation was 69 (IQR: 62 – 75) years and among patients with available ECOG performance status (PS), 77.4% had a PS of 0-1. 181 (27%) patients were previously exposed to IRI in the metastatic setting (Table). The unadjusted OS HR was 1.3 (95% CI: 1.1 – 1.6, p < 0.001) and the unadjusted PFS HR was 1.4 (95%CI: 1.2 – 1.7, p < 0.001). After adjustment for baseline characteristics the adjusted OS HR was 1.0 (95% CI: 0.8 – 1.3, p = 0.8836) and the adjusted PFS HR was 1.1 (95%: 0.8 – 1.4, p = 0.5626). Conclusions: The results of this study suggest prior exposure to IRI is not a predictor of worse clinical outcomes for patients treated with liposomal irinotecan-based treatment when accounting for key clinical characteristics in a multivariable model. The results from this real-world study can be used to support treatment sequencing decisions for patients with mPDAC following first line therapy. This is the largest real-world evidence study to date of patients with mPDAC treated with liposomal irinotecan.[Table: see text]

Multi‐omic molecular profiling guide’s efficacious treatment selection in refractory metastatic breast cancer: a prospective phase II clinical trial

This prospective phase II clinical trial (Side Out 2) explored the clinical benefits of treatment selection informed by multi‐omic molecular profiling (MoMP) in refractory metastatic breast cancers (MBCs). Core needle biopsies were collected from 32 patients with MBC at trial enrollment. Patients had received an average of 3.94 previous lines of treatment in the metastatic setting before enrollment in this study. Samples underwent MoMP, including exome sequencing, RNA sequencing (RNA‐Seq), immunohistochemistry, and quantitative protein pathway activation mapping by Reverse Phase Protein Microarray (RPPA). Clinical benefit was assessed using the previously published growth modulation index (GMI) under the hypothesis that MoMP‐selected therapy would warrant further investigation for GMI ≥ 1.3 in ≥ 35% of the patients. Of the 32 patients enrolled, 29 received treatment based on their MoMP and 25 met the follow‐up criteria established by the trial protocol. Molecular information was delivered to the tumor board in a median time frame of 14 days (11–22 days), and targetable alterations for commercially available agents were found in 23/25 patients (92%). Of the 25 patients, 14 (56%) reached GMI ≥ 1.3. A high level of DNA topoisomerase I (TOPO1) led to the selection of irinotecan‐based treatments in 48% (12/25) of the patients. A pooled analysis suggested clinical benefit in patients with high TOPO1 expression receiving irinotecan‐based regimens (GMI ≥ 1.3 in 66.7% of cases). These results confirmed previous observations that MoMP increases the frequency of identifiable actionable alterations (92% of patients). The MoMP proposed allows the identification of biomarkers that are frequently expressed in MBCs and the evaluation of their role as predictors of response to commercially available agents. Lastly, this study confirmed the role of MoMP for informing treatment selection in refractory MBC patients: more than half of the enrolled patients reached a GMI ≥ 1.3 even after multiple lines of previous therapies for metastatic disease.

Real-world Safety of Bevacizumab with First-line Combination Chemotherapy in Patients with Metastatic Colorectal Cancer: Population-based Retrospective Cohort Studies in Three Canadian Provinces

AimsTo examine the real-world safety of adding bevacizumab to first-line irinotecan-based chemotherapy for patients with metastatic colorectal cancer (mCRC). Materials and methodsPatients diagnosed with CRC in three Canadian provinces (Ontario, Saskatchewan and British Columbia) who received publicly funded bevacizumab and/or irinotecan from 2000 to 2016 were identified from cancer registries. Propensity score 1:1 matching (PSM) and inverse probability of treatment weighting (IPTW) were performed to contemporaneous and historical controls, adjusting for baseline demographic and clinical characteristics. Safety end points evaluated during first-line treatment plus 30 days included mortality within 30 days and all-cause-, chemotherapy- and bevacizumab-related hospitalisations. Chemotherapy- and bevacizumab-related visits were defined as hospitalisations for specific conditions commonly associated with chemotherapy (e.g. infections) or bevacizumab (e.g. arteriovenous thromboembolism) using most responsible diagnosis codes. In PSM and IPTW-weighted cohorts, we assessed event frequencies using odds ratios from logistic regressions and event rate ratios using negative binomial regression models. The results from each province and comparison were pooled using random-effects meta-analysis. ResultsWe identified 16 250 mCRC patients who received first-line irinotecan-based treatment. In PSM cohorts, bevacizumab was associated with fewer deaths within 30 days of treatment compared with contemporaneous (pooled odds ratio = 0.62; 95% confidence interval 0.50–0.75) and historical controls (pooled odds ratio = 0.73; 95% confidence interval 0.58–0.93). Hospitalisations were more frequent among patients treated with bevacizumab compared with historical controls but similar to contemporaneous controls. As patients receiving bevacizumab were exposed to a longer average treatment duration, across their full treatment duration, patients receiving bevacizumab had significantly lower rates of hospitalisations (contemporaneous pooled rate ratio = 0.56; 95% confidence interval 0.47–0.67; historical pooled rate ratio = 0.73; 95% confidence interval 0.56–0.95). Similar trends were observed for chemotherapy- and bevacizumab-related hospitalisations and in IPTW-weighted cohorts. DiscussionWe did not observe any increase in rates of hospitalisation or death within 30 days of treatment among mCRC patients treated with bevacizumab plus chemotherapy versus chemotherapy alone; these findings should be interpreted with caution due to the risk of residual confounding.

TLR4 deficiency upregulates TLR9 expression and enhances irinotecan-related intestinal mucositis and late-onset diarrhoea.

Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll-like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4-/-) mice were given irinotecan to investigate the severity of the induced diarrhoea. Forty-six patients treated with irinotecan-based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild-type (WT) or Tlr4-/- mice were given irinotecan (45 or 75 mg·kg-1 , i.p.) or saline (3 ml·kg-1 ). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed. All patients with TLR4 SNPs chemotherapy-treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan-related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il-18 expression along with IL-10 decreased production in Tlr4-/- mice also indicated an intensified intestinal damage and inflammatory response. TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late-onset diarrhoea during irinotecan-based treatment. Identifying patients genetically predisposed to chemotherapy-associated diarrhoea is a strategy toward precision medicine.

Treatment responses and disease dynamics in patients with untreated metastatic colorectal cancer receiving bevacizumab-based sequential versus combination chemotherapy: Analysis of a phase 3 trial (AIO KRK0110, XELAVIRI study).

3571 Background: Early response parameters such as early tumor shrinkage (ETS), depth of response (DpR), and time to DpR represent exploratory endpoints that may serve as early efficacy endpoints and potential predictors of long-term outcome. We analyzed the association of these endpoints with bevacizumab-based sequential (initial fluoropyrimidines) versus combination (initial fluoropyrimidines plus irinotecan) chemotherapy within a randomized phase III trial. Methods: DpR (change from baseline to smallest tumor diameter), ETS (≥20% reduction in tumor diameter at first reassessment), and time to DpR (study randomization to DpR-image) were analyzed in the XELAVIRI-trial. Moreover, progression-free survival (PFS) and overall survival (OS) were evaluated with ETS as stratification parameter (ETS vs. no ETS) according to treatment arm, molecular subgroup, and sex. Results: 370 patients were available for analysis of early treatment response parameters. A higher rate of ETS (60.9% vs. 43.5%; p = 0.001) and significantly greater DpR (-40.0% vs. -24.7%; p < 0.001) were observed in the initial combination compared to the sequential therapy arm, respectively. The improvement of ETS and DpR was pronounced in the subpopulation of RAS/ BRAF wildtype patients. Male in contrast to female patients significantly benefitted from initial combination treatment in terms of median DpR (male: -40.0% vs. -22.2%; p < 0.001; female: -34.0% vs. -24.4%; p = 0.13) and rate of ETS (male: 64.8% vs. 40.2%; p < 0.001; female: 52.5% vs. 49.3%; p = 0.73). Achievement of ETS correlated with improved survival irrespective of treatment arm (PFS: p < 0.001; OS: p = 0.012) and molecular subgroup (PFS: p < 0.001; OS: p < 0.001). Whereas the survival benefit in male patients achieving ETS was statistically significant (PFS: p < 0.001, HR 0.532 (0.409-0.692); OS: p < 0.001, HR 0.574 (0.437-0.756)), there were no significant differences in PFS (p = 0.107) and OS (p = 0.965) of female patients depending on ETS. Conclusions: In the XELAVIRI trial, initial irinotecan-based combination therapy with bevacizumab improves ETS and DpR in mCRC patients. Improvement in early response parameters appears pronounced in patients with RAS/ BRAF wildtype tumors suggesting a high sensitivity to irinotecan-based treatment. ETS was predictive of PFS and OS regardless of treatment arm. This finding was rather driven by male than female patients, potentially indicating that ETS might be less predictive of long-term outcome in an elderly, female population.

Optimum patient selection for irinotecan-containing regimens in metastatic colorectal cancer: Literature review and lessons from clinical practice.

Metastatic colorectal cancer (mCRC) accounts for over 20% of CRC cases and is associated with a poor prognosis. Irinotecan is an important first- and second-line chemotherapy option for mCRC. In this review, we summarize the clinical efficacy and safety of irinotecan-based regimens for the treatment of mCRC and discuss various tumor- and patient-related factors that affect the clinical response, survival, and toxicity associated with these regimens. Uridine diphosphate glucuronosyltransferase (UGT) gene polymorphisms such as UGT1A1*28/*6, age, performance status, serum lactate dehydrogenase levels, and bilirubin levels could be important considerations for predicting outcomes and tolerability with irinotecan-based regimens. The role of tumor location; chemotherapy backbone; and emerging evidence on the presence of microsatellite instability-high status, consensus molecular subtype 4 tumors, and signet-ring morphology in predicting response to irinotecan-based therapy have also been highlighted. Careful consideration of these factors will help guide clinicians in optimizing the selection of mCRC patients for irinotecan-based treatment.

Predictive Value of UGT1A1 Polymorphisms in Irinotecan-Induced Toxicity and Therapeutic Efficacy in Colorectal Cancer Patients

Irinotecan-based chemotherapy is a fundamental cytotoxic regimen for advanced colorectal cancer. The disposition of irinotecan is known to vary in a fashion partially depending on genetic variations in the drug metabolic pathways. UDP-glucuronosyltransferase (UGT)1A1 is a predominant enzyme that converts the active metabolite of irinotecan to the inactive form via a glucuronidation process. Several UGT1A1 polymorphisms are linked to SN-38 glucuronidation and irinotecan-related adverse events, while the predictive role of UGT1A1 polymorphisms regarding therapeutic outcome is controversial. In this review, we will evaluate the impact of UGT1A1 genotypes on irinotecan-induced toxicity and therapeutic efficacy in colorectal cancer patients receiving irinotecan-based treatment.

PCN167 AN INTEGRATED DELIVERY NETWORK FOCUS ON COST DRIVERS IN CHEMOTHERAPY: THE ECONOMIC BURDEN OF NEUTROPENIA AND INPATIENT ADMISSIONS AMONG COMMERCIALLY INSURED METASTATIC PANCREATIC CANCER PATIENTS (MPC)

Pancreatic ductal adenocarcinoma is the third leading cause of cancer-related death in the US. Hospitalizations related to neutropenia are a substantial economic burden among cancer patients. This analysis assessed inpatient costs and rates of neutropenia for mPC patients enrolled in US commercial health plans. Using the IQVIA PharMetrics Plus administrative claims database, data were obtained for adult patients with mPC treated between January 1, 2014 and May 31, 2019. Treatment regimens included were: FOLFIRI, FOLFOX, FOLFIRINOX, gemcitabine+nab-paclitaxel (gem+nab-P), and liposomal irinotecan-based treatment (lip-IRI). Patients were required to have continuous health coverage for ≥ 6 months prior to and ≥ 3 months after the first treatment date post-metastatic diagnosis. All-cause inpatient per patient costs (PPC) during treatment were calculated and adjusted to 2019 US dollars. The proportions of patients with neutropenia during treatment were assessed by treatment group. 2,731 mPC patients were identified (median age: 59y; IQR 54-64). Of these patients, 1,699 (62.2%) received second line treatment, 809 (29.6%) third line and 363 (13.2%) fourth line. Among patients treated in any line, 101 (3.7%) were treated with lip-IRI, 1,316 (48.2%) were treated with gem+nab-P, 612 (22.4%) with FOLRINOX, 281 (10.3%) with FOLFOX, and 208 (7.6%) with FOLFIRI. All-cause inpatient PPC were $8,220 for lip-IRI, $13,246 for gem+nab-P, $13,872 for FOLFIRINOX, $11,393 for FOLFOX, and $12,667 for FOLFIRI. Neutropenia was reported in 12% of patients receiving lip-IRI, 24% receiving gem-nab-p, 32% receiving FOLFIRINOX, and in 19% of patients receiving FOLFOX or FOLFIRI. In this study mPC patients receiving lip-IRI experienced lower inpatient PPC and fewer neutropenia events during treatment than other common regimens. Further studies are needed to understand the impact of mPC treatment on neutropenia and inpatient admissions in the real-world.

How to improve toxicity evaluation in clinical trials? Testing new metrics from irinotecan or oxaliplatin-based treatments in metastatic colorectal cancer (mCRC): A pooled analysis from 2,349 patients in ARCAD database.

89 Background: Monitoring of adverse events (AE) is crucial in clinical trials. Maximum grade per patient (pt) is commonly used but better metrics are needed to aid describing and comparing AE profiles. Methods: We developed and evaluated 2 longitudinal AE summary metrics. 1) Onset time of max grade refers to whether a pt has max grade within pre-specified timeframes for an AE, e.g. onset can be defined as “early” (max grade before the 6th cy) or “late” (≥ 6th cy). 2) Adverse effect load (AEL) is a longitudinal score of worst grade possible excluding death over the entire treatment for an AE. Higher AEL means worst overall experience of AE. We applied these metrics to real trial data. Pts were from 6 mCRC trials included in ARCAD database and received Irinotecan-based (n = 1,119) or Oxaliplatin-based (n = 1,230) treatments that did not include biologicals. AEs were diarrhea, nausea/vomiting, neutropenia/leukopenia, and neuropathy. We used linear model to AEL and logistic model to the other metrics, adjusting for age, sex, and number of metastases. Results: For nausea/vomiting, pts in Oxali-based chemo showed a higher AEL compared to patients in Iri-based (mean (M) [standard deviation (SD)] = 0.04 [0.06] vs. 0.02 [0.04]; p < 0.001) even though less pts had gr ≥ 3 (10.4% vs. 16.2%, resp.; p < 0.001), suggesting a lower-grade but persistent nausea/vomiting for Oxali-based. Among pts with diarrhea max gr 2, pts in Iri-based had higher AEL than with Oxali-based (M [SD] = 0.11 [0.11] vs. 0.08 [0.09]; p = 0.008), indicating more persistent diarrhea for Iri-based trts even among pts with same max grade. For neutropenia/leukopenia, pts in Oxali-based trts experienced higher AEL (M [SD] = 0.09 [0.13] vs. 0.05 [0.11], p < 0.001), and more pts in Oxali-based trts had gr ≥ 3 (70.1% vs. 64.4%; p = 0.002), suggesting that pts in Oxali-based trts experienced worst overall and max grade neutropenia/leukopenia compared to pts in Iri-based. Conclusions: To improve toxicity assessment in clinical trials, AEL and onset time of max grade are new measures that describe the evolution of adverse events over time. Further validation is warranted.

Cytoplasmic E-Cadherin Expression Is Associated With Higher Tumour Level of VEGFA, Lower Response Rate to Irinotecan-based Treatment and Poorer Prognosis in Patients With Metastatic Colorectal Cancer.

The prognostic value of vascular endothelial growth factor-A (VEGFA) and epithelial cadherin (E-cadherin) expression in patients with metastatic colorectal cancer (mCRC) is controversial. In this prospective study, patients diagnosed with mCRC between August 1, 1998, and August 30, 2003, at the Turku University Hospital, Finland were included. Expression of E-cadherin (membranous and cytoplasmic pattern) and VEGFA in tumour samples was assessed by immunohistochemistry. Tumours were classified as E-cadherin expressers if they demonstrated moderate or strong cytoplasmic or membranous staining, while those positive for VEGFA expression showed a moderate or strong cytoplasmic staining. Of particular interest was the association between membranous or cytoplasmic expression of E-cadherin and VEGFA. The value of strong VEGF-A staining and membranous or cytoplasmic expression of E-cadherin as a predictor of disease outcome over a 6-year period was another point of interest in this study. Of the 67 patients with mCRC, 43 (64%) had tumours positive for cytoplasmic E-cadherin, while in 24 cases (36%), E-cadherin expression was membranous. Strong VEGFA staining was present in half of the cases (n=36, 54% of all 67 mCRC cases). VEGFA expression was significantly correlated with cytoplasmic E-cadherin expression in that 28/36 cases of VEGFA-positive tumours were also positive for cytoplasmic E-cadherin (p=0.012). In addition, among the patients with intense VEGFA expression (n=36), those who had positive cytoplasmic E-cadherin in their tumours had a lower response-rate to first-line therapy with irinotecan, fluorouracil and leucovorin regimen: 5 out of 36 (14%) were chemosensitive. This is in contrast to the patients with VEGFA-positive tumours and membranous E-cadherin (8/36, 22% chemosensitive (p=0.004). The former group also had more ominous prognosis (p<0.001). Reduced membranous expression of E-cadherin and increased cytoplasmic E-cadherin expression predict poor survival in mCRC.

Clinical utility of ABCB1 genotyping for preventing toxicity in treatment with irinotecan.

Preventing severe irinotecan-induced adverse reactions would allow us to offer better treatment and improve patients' quality of life. Transporters, metabolizing enzymes, and genes involved in the folate pathway have been associated with irinotecan-induced toxicity. We analyzed 12 polymorphisms in UGT1A1, ABCB1, ABCG2, ABCC4, ABCC5, and MTHFR in 158 patients with metastatic colorectal cancer treated with irinotecan and studied the association with grade >2 adverse reactions (CTCAE). Among the most frequent ADRs, the SNPs rs1128503, rs2032582, and rs1045642 in ABCB1 and rs1801133 in MTHFR were associated with hematological toxicity and overall toxicity. The SNP rs11568678 in ABCC4 was also associated with overall toxicity. After correction of P values using a false discovery rate, only ABCB1 variants remained statistically significant. Haplotype analysis in ABCB1 showed an 11.3-fold and 4.6-fold increased risk of hematological toxicity (95% CI, 1.459-88.622) and overall toxicity (95% CI, 2.283-9.386), respectively. Consequently, genotyping of the three SNPs in ABCB1 can predict overall toxicity and hematological toxicity with a diagnostic odds ratio of 4.40 and 9.94, respectively. Genotyping of ABCB1 variants can help to prevent severe adverse reactions to irinotecan-based treatments in colorectal cancer.

Potential role of PIN1 genotypes in predicting benefit from oxaliplatin-based and irinotecan-based treatment in patients with metastatic colorectal cancer.

PIN1-mediated substrate isomerization plays a role in the repair of DNA double-strand breaks. We hypothesized that genetic polymorphisms in PIN1-related pathways may affect tumor sensitivity to oxaliplatin or irinotecan in metastatic colorectal cancer (mCRC) patients. We analyzed genomic DNA from five cohorts of mCRC patients (total 950) treated with different first-line treatments: oxaliplatin cohorts 1 (n=146) and 2 (n=70); irinotecan cohorts 1 (n=228) and 2 (n=276); and combination cohort (n=230). Single nucleotide polymorphisms of candidate genes were analyzed by PCR-based direct sequencing. In the oxaliplatin cohort 1, patients carrying any PIN1 rs2233678 C allele had shorter progression-free survival (PFS) and overall survival (OS) than the G/G variant (PFS, 7.4 vs. 15.0 months, hazard ratio [HR] 3.24, P<0.001; OS, 16.9 vs. 31.5 months, HR: 2.38, P=0.003). In contrast, patients with C allele had longer median PFS than patients with G/G (11.9 vs. 9.4 months, HR: 0.64, 95%CI: 0.45–0.91, P=0.009) in the irinotecan cohort 1. No significant differences were observed in the combination cohort. In comparison between the irinotecan cohort 1 and combination cohort, the patients carrying the G/G variant benefit greatly from the combination compared with irinotecan-based regimen (PFS, 11.6 vs. 9.4 months, HR 0.61, 95%CI: 0.47–0.78, P<0.001; OS, 30.6 vs. 24.0 months, HR 0.79, 95%CI: 0.62–1.02, P=0.060), while no significant difference was shown in any C allele. Germline PIN1 polymorphisms may predict clinical outcomes in mCRC patients receiving oxaliplatin- or irinotecan-based therapy, and identify specific populations favorable to oxaliplatin plus irinotecan combination therapy.

SNPs in predicting clinical efficacy and toxicity of chemotherapy: walking through the quicksand.

In the “precision medicine” era, chemotherapy still remains the backbone for the treatment of many cancers, but no affordable predictors of response to the chemodrugs are available in clinical practice. Single nucleotide polymorphisms (SNPs) are gene sequence variations occurring in more than 1% of the full population, and account for approximately 80% of inter-individual genomic heterogeneity. A number of studies have investigated the predictive role of SNPs of genes enrolled in both pharmacodynamics and pharmacokinetics of chemotherapeutics, but the clinical implementation of related results has been modest so far. Among the examined germline polymorphic variants, several SNPs of dihydropyrimidine dehydrogenase (DPYD) and uridine diphosphate glucuronosyltransferases (UGT) have shown a robust role as predictors of toxicity following fluoropyrimidine- and/or irinotecan-based treatments respectively, and a few guidelines are mandatory in their detection before therapy initiation. Contrasting results, however, have been reported on the capability of variants of other genes as MTHFR, TYMS, ERCC1, XRCC1, GSTP1, CYP3A4/3A5 and ABCB1, in predicting either therapy efficacy or toxicity in patients undergoing treatment with pyrimidine antimetabolites, platinum derivatives, irinotecan and taxanes. While formal recommendations for routine testing of these SNPs cannot be drawn at this moment, therapeutic decisions may indeed benefit of germline genomic information, when available. Here, we summarize the clinical impact of germline genomic variants on the efficacy and toxicity of major chemodrugs, with the aim to facilitate the therapeutic expectance of clinicians in the odiern quicksand field of complex molecular biology concepts and controversial trial data interpretation.

Association of STAT-3 rs1053004 and VDR rs11574077 With FOLFIRI-Related Gastrointestinal Toxicity in Metastatic Colorectal Cancer Patients.

Pharmacogenomics has largely been applied to the personalization of irinotecan-based treatment, focusing mainly on the study of genetic variants in adsorption, distribution, metabolism, and excretion (ADME) genes. The transcriptional control of ADME gene expression is mediated by a set of nuclear factors responding to cancer-related inflammation, which could have pharmacological implications. The aim of the present study was to uncover novel genetic predictors of neutropenia and gastrointestinal toxicity risk among 246 haplotype-tagging polymorphisms in 22 genes encoding inflammation-related cytokines and transcriptional regulators of ADME genes. The study comprised overall more than 400 metastatic colorectal cancer (mCRC) patients treated with first-line FOLFIRI, grouped in a discovery and a replication cohorts. A concordant protective effect of STAT-3 rs1053004 polymorphism against the risk of grade 3–4 gastrointestinal toxicity was observed in both the cohorts of patients (OR = 0.51, p = 0.045, q = 0.521 and OR = 0.39, p = 0.043, respectively). VDR rs11574077 polymorphism was demonstrated to affect both irinotecan biliary index (BI) and glucuronidation ratio (GR) by a pharmacokinetic analysis. This effect was consistent with an increased risk of grade 3–4 gastrointestinal toxicity in the discovery cohort (OR = 4.46, p = 0.010, q = 0.305). The association was not significant in the replication cohort (OR = 1.44, p = 0.601). These findings suggest an effect of STAT-3 and VDR polymorphisms on FOLFIRI-related gastrointestinal toxicity. If prospectively validated as predictive markers, they could be used to improve the clinical management of mCRC.

Implications of ABCG2 Expression on Irinotecan Treatment of Colorectal Cancer Patients: A Review.

Background: One of the main chemotherapeutic drugs used on a routine basis in patients with metastatic colorectal cancer ((m)CRC) is the topoisomerase-1 inhibitor, irinotecan. However, its usefulness is limited by the pre-existing or inevitable development of resistance. The ATP-binding cassette (ABC) transporter ABCG2/breast cancer resistance protein (BRCP) through its function in xenobiotic clearance might play an important role in irinotecan resistance. With a goal to evaluate the clinical significance of ABCG2 measurements, we here review the current literature on ABCG2 in relation to irinotecan treatment in CRC patients. Results: Few studies have evaluated the association between ABCG2 gene or protein expression and prognosis in CRC patients. Discordant results were reported. The discrepancies might be explained by the use of different criteria for interpretation of results in the immunohistochemistry studies. Only one large study evaluated the ABCG2 protein expression and efficacy of irinotecan in mCRC (CAIRO study, n = 566). This study failed to demonstrate any correlation between ABCG2 protein expression in the primary tumor and response to irinotecan-based treatment. We recently raised questions on how to evaluate ABCG2 immunoreactivity patterns, and the results in the CAIRO study might be influenced by using a different scoring protocol than the one proposed by us. In contrast, our recent exploratory study of ABCG2 mRNA expression in 580 patients with stage III primary CRC (subgroup from the randomized PETACC-3 study) indicated that high ABCG2 tumor tissue mRNA expression might be predictive for lack of efficacy of irinotecan. Conclusion: The biological role of ABCG2 in predicting clinical irinotecan sensitivity/resistance in CRC is uncertain. In particular, the significance of ABCG2 cellular localization needs to be established. Data concerning ABCG2 mRNA expression and prediction of adjuvant irinotecan efficacy are still sparse and need to be confirmed.

Examination of multiple UGT1A and DPYD polymorphisms has limited ability to predict the toxicity and efficacy of metastatic colorectal cancer treated with irinotecan-based chemotherapy: a retrospective analysis

BackgroundTo evaluate a new UGT1A and DPYD polymorphism panel to better predict irinotecan-induced toxicity and the clinical response in Chinese patients with metastatic colorectal cancer (mCRC).MethodsThe genotypes of UGT1A (UGT1A1*6, UGT1A1*27, UGT1A1*28, UGT1A7*2, UGT1A7*3, UGT1A7*4 and UGT1A9*22) and DPYD (DPYD*5, DPYD c.1896 T > C, and DPYD*2A) were examined by direct sequencing in 661 mCRC patients receiving irinotecan-based chemotherapy. The influences of UGT1A and DPYD polymorphisms on severe irinotecan-induced toxicities and clinical outcomes were assessed.ResultsIn the cohort studied here, the incidence of UGT1A1*6, UGT1A1*28, UGT1A7*2, UGT1A7*3, UGT1A9*22, DPYD*5, and DPYD c.1896 T > C variants were 34.8%, 24.2%, 34.3%, 39.4%, 81.8%, 48.4% and 20.4%, respectively. UGT1A1*27 and DPYD*2A had low frequencies and UGT1A7*4 was not found. A total of 59 patients (8.9%) suffered severe diarrhea and 136 patients (20.6%) suffered severe neutropenia. UGT1A1*28 heterozygotes (OR = 2.263, 95%CI 1.395–3.670), UGT1A1*28 homozygotes (OR = 5.910, 95%CI 1.138–30.672) and UGT1A1*6 homozygotes (OR = 4.737, 95%CI 1.946–11.533) were independent risk factors for severe neutropenia. UGT1A polymorphisms were not found to relate to severe diarrhea. DPYD*5 was determined to be an independent risk factor for severe diarrhea (OR = 2.143, 95%CI 1.136–4.041). Neither DPYD*5 nor DPYD c.1896 T > C was found to relate to severe neutropenia. In the first-line irinotecan-based treatment, UGT1A1*28 and DPYD*5 contributed to higher response rates (P = 0.043 and P = 0.019, respectively), while DPYD*5 was found to associate with better progression-free survival (P = 0.015). UGT1A1*27 contributed to worse overall survival (P < 0.001).ConclusionResults still showed UGT1A1*6 and UGT1A1*28 to be partially associated with irinotecan-induced toxicity and clinical response. An examination of more UGT1A loci, except for UGT1A1*6 and UGT1A1*28, was not helpful to improve the predictive value of irinotecan-based toxicity and efficacy. An examination of DPYD*5 assisted in the prediction of severe diarrhea.

Pseudocirrhosis caused by regorafenib in an advanced rectal cancer patient with multiple liver metastases.

A 70-year-old man who was diagnosed with unresectable advanced rectal cancer with multiple liver metastases, received oxaliplatin-based treatment with bevacizumab as first-line chemotherapy and irinotecan-based treatment with bevacizumab as second-line chemotherapy for a total of 17 months. The patient was treated with regorafenib (160 mg/day for 3 weeks) as third-line chemotherapy. Following completion of one course of regorafenib treatment, the patient complained of abdominal distension. Computed tomography (CT) examination identified liver atrophy and massive ascites, while no such symptoms were observed prior to the regorafenib treatment. Blood testing revealed increases in the aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels. The patient was admitted to the Aizu Medical Center (Aizuwakamatsu, Japan). Approximately 2,000 ml of ascitic fluid were aspirated daily for 1 week by abdominal puncture. The patient was administered oral diuretics, including 20 mg/day of furosemide and 25 mg/day of spironolactone. Albumin was administered to correct the albumin deficit. The levels of AST, ALT and ALP were decreased from the peak value reported on admission and the patient was discharged from our hospital 16 days following treatment initiation. The CT examination after 1 month revealed that the volume of the liver had been restored and the ascites had disappeared. Furthermore, almost all the liver metastases were reduced in size. The carcinoembryonic antigen level, which was elevated prior to regorafenib treatment, also decreased to normal.