Capecitabine in the management of colorectal cancer

The anticancer effect of potential probiotic L. fermentum and L. plantarum in combination with 5-fluorouracil on colorectal cancer cells

5-Fluorouracil (5-FU) is an effective chemotherapy drug in the treatment of colorectal cancer (CRC). However, auxiliary or alternative therapies must be sought due to its resistance and potential side effects. Certain probiotic metabolites exhibit anticancer properties. In this study evaluated the anticancer and potential therapeutic activities of cell extracts potential probiotic strains, Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from the mule milk and the standard probiotic strain Lacticaseibacillus rhamnosus GG (LGG) against the human colon cancer cell line (HT-29) and the normal cell line (HEK-293) alone or in combination with 5-FU. In this study, L. plantarum and L. fermentum, which were isolated from mule milk, were identified using biochemical and molecular methods. Their probiotic properties were investigated in vitro and compared with the standard probiotic strain of the species L. rhamnosus GG. The MTT assay, acridine orange/ethidium bromide (AO/EB) fluorescent staining, and flow cytometry were employed to measure the viability of cell lines, cell apoptosis, and production rates of Th17 cytokines, respectively. The results demonstrated that the combination of lactobacilli cell extracts and 5-FU decreased cell viability and induced apoptosis in HT-29 cells. Furthermore, this combination protected HEK-293 cells from the cytotoxic effects of 5-FU, enhancing their viability and reducing apoptosis. Moreover, the combination treatment led to an increase in the levels of IL-17A, IFN-γ, and TNF-α, which can enhance anti-tumor immunity. In conclusion, the cell extracts of the lactobacilli strains probably can act as a potential complementary anticancer therapy.

Can immunotherapy reinforce chemotherapy efficacy? a new perspective on colorectal cancer treatment

As one of the main threats to human life (the fourth most dangerous and prevalent cancer), colorectal cancer affects many people yearly, decreases patients' quality of life, and causes irreparable financial and social damages. In addition, this type of cancer can metastasize and involve the liver in advanced stages. However, current treatments can't completely eradicate this disease. Chemotherapy and subsequent surgery can be mentioned among the current main treatments for this disease. Chemotherapy has many side effects, and regarding the treatment of this type of tumor, chemotherapy can lead to liver damage, such as steatohepatitis, steatosis, and sinus damage. These damages can eventually lead to liver failure and loss of its functions. Therefore, it seems that other treatments can be used in addition to chemotherapy to increase its efficiency and reduce its side effects. Biological therapies and immunotherapy are one of the leading suggestions for combined treatment. Antibodies (immune checkpoint blockers) and cell therapy (DC and CAR-T cells) are among the immune system-based treatments used to treat tumors. Immunotherapy targets various aspects of the tumor that may lead to 1) the recruitment of immune cells, 2) increasing the immunogenicity of tumor cells, and 3) leading to the elimination of inhibitory mechanisms established by the tumor. Therefore, immunotherapy can be used as a complementary treatment along with chemotherapy. This review will discuss different chemotherapy and immunotherapy methods for colorectal cancer. Then we will talk about the studies that have dealt with combined treatment.

S. M, Birudala G, Jamous YF, Alshargi O, Kotha KK, Sudhan HH, Mani RR, Muthumanickam A, Niranjan D, Jain NK, Agrawal A, Jadon AS, Mayasa V, Jha NK, Kolesarova A, Slama P, Roychoudhury S. Reactive oxygen species mediated apoptotic death of colon cancer cells: therapeutic potential of plant derived alkaloids

Colorectal cancer (CRC) is one of the most deaths causing diseases worldwide. Several risk factors including hormones like insulin and insulin like growth factors (e.g., IGF-1) have been considered responsible for growth and progression of colon cancer. Though there is a huge advancement in the available screening as well as treatment techniques for CRC. There is no significant decrease in the mortality of cancer patients. Moreover, the current treatment approaches for CRC are associated with serious challenges like drug resistance and cancer re-growth. Given the severity of the disease, there is an urgent need for novel therapeutic agents with ideal characteristics. Several pieces of evidence suggested that natural products, specifically medicinal plants, and derived phytochemicals may serve as potential sources for novel drug discovery for various diseases including cancer. On the other hand, cancer cells like colon cancer require a high basal level of reactive oxygen species (ROS) to maintain its own cellular functions. However, excess production of intracellular ROS leads to cancer cell death via disturbing cellular redox homeostasis. Therefore, medicinal plants and derived phytocompounds that can enhance the intracellular ROS and induce apoptotic cell death in cancer cells via modulating various molecular targets including IGF-1 could be potential therapeutic agents. Alkaloids form a major class of such phytoconstituents that can play a key role in cancer prevention. Moreover, several preclinical and clinical studies have also evidenced that these compounds show potent anti-colon cancer effects and exhibit negligible toxicity towards the normal cells. Hence, the present evidence-based study aimed to provide an update on various alkaloids that have been reported to induce ROS-mediated apoptosis in colon cancer cells via targeting various cellular components including hormones and growth factors, which play a role in metastasis, angiogenesis, proliferation, and invasion. This study also provides an individual account on each such alkaloid that underwent clinical trials either alone or in combination with other clinical drugs. In addition, various classes of phytochemicals that induce ROS-mediated cell death in different kinds of cancers including colon cancer are discussed.

Preparation and application of patient-derived xenograft mice model of colorectal cancer

Objectives

Patient-derived xenograft (PDX) model becomes a more and more important tool for tumor research. This study aimed to establish a colorectal cancer PDX model and verify its applicability.

Materials and Methods

Fresh human colorectal cancer tissue was surgically removed and subcutaneously inoculated into immunodeficient mice to establish the PDX model. Hematoxylin and eosin (HE) staining and immunohistochemical staining were used to evaluate the model. The successful PDX model was selected to study the efficacy of capecitabine in treating colorectal cancer.

Results

HE staining showed that the PDX mice model of colorectal cancer could preserve the histological characteristics of the primary tumor. Immunohistochemistry staining showed α-fetoprotein (AFP), carcinoembryonic antigen (CEA), and E-cadherin were strongly positively expressed in primary human and PDX tumor tissues, with a high degree of similarity. Capecitabine significantly inhibited PDX tumor growth and reduced the expression of AFP and CEA proteins in the tumor tissues (all P s<0.05).

Conclusion

We successfully established a colorectal cancer PDX model, and the PDX model could retain the histological and biological characteristics of the primary tumor. Using this PDX model, we revealed that capecitabine at a dose of 300-400 mg/kg can effectively treat colorectal cancer, and no significant difference in toxicity was found among different dose groups. The current work provides a feasible framework for establishing and validating the PDX tumor model to better facilitate the evaluation of drug efficacy and safety.

Personalised, Rational, Efficacy-Driven Cancer Drug Dosing via an Artificial Intelligence SystEm (PRECISE): A Protocol for the PRECISE CURATE.AI Pilot Clinical Trial

Introduction: Oncologists have traditionally administered the maximum tolerated doses of drugs in chemotherapy. However, these toxicity-guided doses may lead to suboptimal efficacy. CURATE.AI is an indication-agnostic, mechanism-independent and efficacy-driven personalised dosing platform that may offer a more optimal solution. While CURATE.AI has already been applied in a variety of clinical settings, there are no prior randomised controlled trials (RCTs) on CURATE.AI-guided chemotherapy dosing for solid tumours. Therefore, we aim to assess the technical and logistical feasibility of a future RCT for CURATE.AI-guided solid tumour chemotherapy dosing. We will also collect exploratory data on efficacy and toxicity, which will inform RCT power calculations.

Methods and analysis: This is an open-label, single-arm, two-centre, prospective pilot clinical trial, recruiting adults with metastatic solid tumours and raised baseline tumour marker levels who are planned for palliative-intent, capecitabine-based chemotherapy. As CURATE.AI is a small data platform, it will guide drug dosing for each participant based only on their own tumour marker levels and drug doses as input data. The primary outcome is the proportion of participants in whom CURATE.AI is successfully applied to provide efficacy-driven personalised dosing, as judged based on predefined considerations. Secondary outcomes include the timeliness of dose recommendations, participant and physician adherence to CURATE.AI-recommended doses, and the proportion of clinically significant dose changes. We aim to initially enrol 10 participants from two hospitals in Singapore, perform an interim analysis, and consider either cohort expansion or an RCT. Recruitment began in August 2020. This pilot clinical trial will provide key data for a future RCT of CURATE.AI-guided personalised dosing for precision oncology.

Ethics and dissemination: The National Healthcare Group (NHG) Domain Specific Review Board has granted ethical approval for this study (DSRB 2020/00334). We will distribute our findings at scientific conferences and publish them in peer-reviewed journals.

Trial registration number: NCT04522284

A Systematic Review of the Cyclooxygenase-2 (COX-2) Expression in Rectal Cancer Patients Treated with Preoperative Radiotherapy or Radiochemotherapy

The main objective of this systematic review is to investigate the expression level of the cyclooxygenase-2 (COX-2) in rectal cancer treated with either preoperative radiotherapy or radiochemotherapy. In addition, we have summarized the effects of preoperative treatment of rectal cancer with regards to the expression levels of COX-2. A systematic literature review was performed in The Cochrane Library, PubMed, Web of Science, and Scopus databases on 1 January 2021 with the usage of the following search string-(cyclooxygenase-2) OR (COX-2) AND (rectal cancer) AND (preoperative radiochemotherapy) OR (preoperative radiotherapy). Among the 176 included in the analysis, only 13 studies were included for data extraction with a total number of 2095 patients. The results of the analysis are based on the articles concerning the expression of COX-2 in rectal cancer among patients treated with preoperative radiotherapy or radiochemotherapy. A COX-2 expression is an early event involved in rectal cancer development. In cases of negative COX-2 expression, radiotherapy and radiochemotherapy might contribute to the reduction of a local recurrence. Therefore, COX-2 may be considered as a biologic factor while selecting patients for more effective, less time-consuming and less expensive preoperative treatment. However, the utility of the administration of COX-2 inhibitors to patients with COX-2 overexpression, in an attempt to improve the patients' response rate to the neoadjuvant treatment, needs an assessment in further clinical trials.

Severe and Late Acute Liver Injury Induced by Capecitabine

Capecitabine (CAP) is an antineoplastic agent that is known to cause mild hepatotoxicity. However, severe and late acute liver injury was not reported previously as an adverse reaction of CAP. This report discusses the case of a 63-year-old man with colon cancer who was receiving the fifth cycle of CAP as a monotherapy and presented with fatigue and jaundice during the fifth cycle of CAP. Laboratory tests showed markedly elevated transaminases (aspartate transaminase: 2,448 U/L; alanine transaminase: 1,984 U/L). Eventually, discontinuation of CAP was enough to reverse the delayed CAP-induced acute hepatic injury in clinical and laboratory terms.

Hyaluronic acid-doxorubicin nanoparticles for targeted treatment of colorectal cancer

Colorectal cancer, common in both men and women, occurs when tumors form in the linings of the colon. Common treatments of colorectal cancer include surgery, chemotherapy, and radiation therapy; however, many colorectal cancer treatments often damage healthy tissues and cells, inducing severe side effects. Conventional chemotherapeutic agents such as doxorubicin (Dox) can be potentially used for the treatment of colorectal cancer; however, they suffer from limited targeting and lack of selectivity. Here, we report that doxorubicin complexed to hyaluronic acid (HA) (HA-Dox) exhibits an unusual behavior of high accumulation in the intestines for at least 24 hr when injected intravenously. Intravenous administrations of HA-Dox effectively preserved the mucosal epithelial intestinal integrity in a chemical induced colon cancer model in mice. Moreover, treatment with HA-Dox decreased the expression of intestinal apoptotic and inflammatory markers. The results suggest that HA-Dox could effectively inhibit the development of colorectal cancer in a safe manner, which potentially be used a promising therapeutic option.

Pharmacogenomics of 5-fluorouracil in colorectal cancer: review and update

BACKGROUND

Colorectal cancer (CRC) is a disease with high morbidity and mortality rates. 5-fluorouracil (5-FU) is the first-line recommended drug for chemotherapy in patients with CRC, and it has a good effect on a variety of other solid tumors as well. Unfortunately, however, due to the emergence of drug resistance the effectiveness of treatment may be greatly reduced. In the past decade, major progress has been made in the field of 5-FU drug resistance in terms of molecular mechanisms, pre-clinical (animal) models and clinical trials.

CONCLUSIONS

In this article we systematically review and update current knowledge on 5-FU pharmacogenomics related to drug uptake and activation, the expression and activity of target enzymes (DPD, TS and MTHFR) and key signaling pathways in CRC. Furthermore, a summary of drug combination strategies aimed at targeting specific genes and/or pathways to reverse 5-FU resistance is provided. Based on this, we suggest that causal relationships between genes, pathways and drug sensitivity should be systematically considered from a multidimensional perspective. In the design of research methods, emerging technologies such as CRISPR-Cas, TALENS and patient-derived xenograft models should be applied as far as possible to improve the accuracy of clinically relevant results.

Metronomic capecitabine as an immune modulator in glioblastoma patients reduces myeloid-derived suppressor cells

BACKGROUNDMyeloid-derived suppressor cells (MDSCs) are elevated in the circulation of patients with glioblastoma (GBM), present in tumor tissue, and associated with poor prognosis. While low-dose chemotherapy reduces MDSCs in preclinical models, the use of this strategy to reduce MDSCs in GBM patients has yet to be evaluated.METHODSA phase 0/I dose-escalation clinical trial was conducted in patients with recurrent GBM treated 5-7 days before surgery with low-dose chemotherapy via capecitabine, followed by concomitant low-dose capecitabine and bevacizumab. Clinical outcomes, including progression-free and overall survival, were measured, along with safety and toxicity profiles. Over the treatment time course, circulating MDSC levels were measured by multiparameter flow cytometry, and tumor tissue immune profiles were assessed via time-of-flight mass cytometry.RESULTSEleven patients total were enrolled across escalating dose cohorts of 150, 300, and 450 mg bid. No serious adverse events related to the drug combination were observed. Compared with pretreatment baseline, circulating MDSCs were found to be higher after surgery in the 150-mg treatment arm and lower in the 300-mg and 450-mg treatment arms. Increased cytotoxic immune infiltration was observed after low-dose capecitabine compared with untreated GBM patients in the 300-mg and 450-mg treatment arms.CONCLUSIONSLow-dose, metronomic capecitabine in combination with bevacizumab was well tolerated in GBM patients and was associated with a reduction in circulating MDSC levels and an increase in cytotoxic immune infiltration into the tumor microenvironment.TRIAL REGISTRATIONClinicalTrials.gov NCT02669173.FUNDINGThis research was funded by the Cleveland Clinic, Case Comprehensive Cancer Center, the Musella Foundation, B*CURED, the NIH, the National Cancer Institute, the Sontag Foundation, Blast GBM, the James B. Pendleton Charitable Trust, and the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation. Capecitabine was provided in kind by Mylan Pharmaceuticals.

A Sensitive and Efficient Method for Determination of Capecitabine and Its Five Metabolites in Human Plasma Based on One-Step Liquid-Liquid Extraction

Colorectal cancer is the most common critical disease both in the developed and developing countries. Capecitabine, which has served in clinical practice at least for 10 years, is a first-line antidigestive tract cancer drug for its better efficacy, patient compliance, and lower side effects. An ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method has been developed and completely validated for simultaneous determination of capecitabine and its five metabolites in human plasma from colorectal cancer patients after administration of capecitabine tablet. One-step liquid-liquid extraction was successfully applied using ethyl acetate and isopropanol (19 : 1, V : V) for sample pretreatment. Chromatographic separation was achieved within 5 min based on an Atlantis T3-C₁₈ column (3.0 µm, 2.1 × 100 mm) with gradient elution using mobile phases consisting of 0.0075% formic acid in water (pH 4) and in acetonitrile, and the flow rate was 0.3 mL/min. Linear range was approximately 20.0-5000.0 ng/mL for all analytes. Linear correlation coefficients were >0.99 for all regression curves. The intraday and interday accuracy and precision of the method were within ±15.0% and less than 15.0%, respectively. The mean recovery and matrix effect as well as stability of all the analytes ranged from 59.27% to 90.15% and from 74.84% to 114.48% as well as within ±15.0%. This simple, rapid, and sensitive method was successfully applied in 42 sparse clinical samples to verify its practicability.

Novel hybrids derived from aspirin and chalcones potently suppress colorectal cancer in vitro and in vivo

Colorectal cancer (CRC) remains the fourth leading cause of cancer deaths around the world despite the availability of many approved small molecules for treatment. The issues lie in the potency, selectivity and targeting of these compounds. Therefore, new strategies and targets are needed to optimize and develop novel treatments for CRC. Here, a group of novel hybrids derived from aspirin and chalcones were designed and synthesized based on recent reports of their individual benefits to CRC targeting and selectivity. The most active compound 7h inhibited proliferation of CRC cell lines with better potency compared to 5-fluorouracil, a currently used therapeutic agent for CRC. Importantly, 7h had 8-fold less inhibitory activity against non-cancer CCD841 cells. In addition, 7h inhibited CRC growth via the inhibition of the cell cycle in the G1 phase. Furthermore, 7h induced apoptosis by activating caspase 3 and PARP cleavage, as well as increasing ROS in CRC cells. Finally, 7h significantly retarded the CRC cell growth in a mouse xenograft model. These findings suggest that 7h may have potential to treat CRC.

Association of baseline patient characteristics with adjuvant chemotherapy toxicities in stage III colorectal cancer patients

Toxicities can affect cancer patients' quality of life resulting in poor adherence to adjuvant chemotherapy (AC). While previous studies have explored the prevalence of toxicities following AC, few have examined the associations of baseline characteristics, such as age, sex, and performance status, with toxicity outcomes. In this study, we reviewed a cohort of 371 colorectal cancer patients treated with adjuvant monotherapy (capecitabine ) or combination therapy (FOLFOX or CAPOX) within 12 weeks of curative resection, and determined the associations between baseline characteristics and toxicity outcomes. Median age was 65 years, 52% were men, and 41% received monotherapy. A number of toxicities appeared to decrease with successive AC cycles. For monotherapy, univariate analyses found that age, sex, performance status, and pre-treatment anemia were associated with hematological toxicities whereas tumor location was associated with gastrointestinal (GI) toxicities (all P < 0.05). On multivariate analyses, hematological toxicities were predicted by advanced age (≥ 70) (OR 3.30; 95% CI 1.17-9.37; P = 0.025) and pre-treatment anemia (OR 23.18; 95% CI 6.36-84.48; P < 0.001), while GI toxicities were less likely to occur among tumors at or distal to the splenic flexure (OR 0.38; 95% CI 0.15-0.99; P = 0.047). For combination therapy, sex and pre-treatment anemia were associated with hematological toxicities (all P < 0.05), but only female sex was predictive on multivariate analyses (OR 5.13; 95% CI 2.08-12.68; P < 0.001). In conclusion, few baseline characteristics were associated with treatment toxicities. These findings may better inform discussions with patients and caregivers during AC decision-making and underscore to clinicians the need for close monitoring of patients during treatment.

The SNPs in pre-miRNA are related to the response of capecitabine-based therapy in advanced colon cancer patients

The single nucleotide polymorphisms (SNPs) in the microRNA precursor (pre-miRNA) may modulate the posttranscriptional regulation of gene expression and explain individual sensitivity to chemotherapy. Here we investigated the correlation between 23 SNPs in the pre-miRNA and the efficacy of capecitabine-based chemotherapy in 274 advanced colon cancer patients. Statistical analysis indicated that much more patients with rs744591 A/C(48.03%), C/C (53.45%) or C allele (49.73%) responded to the chemotherapy than those with the A/A genotype (33.71%). The response rates of rs745666 G/C heterozygous patients (35.25%) and C allele carriers (39.69%) were apparently less than that of the G/G homozygous patients (56.25%). Moreover, three SNPs rs2114358, rs35770269, and rs73239138 were significantly associated with the occurrence of side effects of chemotherapy. The patients with rs2114358 C allele (OR = 2.016) or rs35770269 T allele (OR = 2.299) were much more prone to endure adverse events. However, the incidence of side effect was lower in the patients carrying rs73239138 A allele than those with G/G genotype (OR = 0.500). Our findings demonstrate that genetic variations in pre-miRNA may influence the efficacy of capecitabine-based chemotherapy in advanced colon cancer patients.

Pharmacogenomics DNA Biomarkers in Colorectal Cancer: Current Update

Colorectal cancer (CRC) remains as one of the most common cause of worldwide cancer morbidity and mortality. Improvements in surgical modalities and adjuvant chemotherapy have increased the cure rates in early stage disease, but a significant portion of the patients will develop recurrence or advanced disease. The efficacy of chemotherapy of recurrence and advanced CRC has improved significantly over the last decade. Previously, the historical drug 5-fluorouracil was used as single chemotherapeutic agent. Now with the addition of other drugs such as capecitabine, irinotecan, oxaliplatin, bevacizumab, cetuximab, panitumumab, vemurafenib, and dabrafenib, the median survival of patients with advanced CRC has significantly improved from less than a year to the current standard of almost 2 years. However, the side effects of systemic therapy such as toxicity may cause fatal complications and have a major consequences on the patients' quality of life. Hence, there is an urgent need for key biomarkers which will enable the selection of optimal drug singly or in combination for an individual patient. The application of personalized therapy based on DNA testing could aid the clinicians in providing the most effective chemotherapy agents and dose modifications for each patient. Yet, some of the current findings are controversial and the evidences are conflicting. This review aims at summarizing the current state of knowledge about germline pharmacogenomics DNA variants that are currently used to guide therapeutic decisions and variants that have the potential to be clinically useful in the future. In addition, current updates on germline variants conferring treatment sensitivity, drug resistance to existing chemotherapy agents and variants affecting prognosis and survival will also be emphasized. Different alteration in the same gene might confer resistance or enhanced sensitivity; and while most of other published reviews generally stated only the gene name and codon location, we will specifically discuss the exact variants to offer more accurate information in this mini review.

Phase I/II trial of dose-reduced capecitabine in elderly patients with advanced colorectal cancer

BACKGROUND

Combination chemotherapy is associated with improved outcomes in trials of selected fit patients with advanced colorectal cancer (acrc). For older or less-fit patients, combination chemotherapy is associated with greater toxicity and less benefit. Capecitabine monotherapy is a reasonable option for those patients, but the optimal dose remains controversial.

METHODS

A multicentre phase i/ii trial of reduced-dose capecitabine (2000 mg/m², days 1-14 every 21 days) was conducted in 221 patients representing one or more of the following subsets: age greater than 65 years (n = 167), Eastern Cooperative Oncology Group (ecog) performance status of 1 or greater (n = 139), elevated lactate dehydrogenase (ldh) (n = 105), or prior pelvic radiation (n = 54). Based on phase i results, patients with prior pelvic radiation received capecitabine 750 mg/m² twice daily. The goal was to ascertain efficacy in a design that was unlikely to cause high levels of toxicity.

RESULTS

Median age in the patient cohort was 72 years. A median of 5 and a mean of 8 capecitabine cycles were given (range: 0-50 cycles). Grade 3 or 4 toxicity occurred in 25% of patients during the first 3 cycles (8.1% hand-foot syndrome, 7.7% diarrhea). The response rate was 13.6%, with a 69.7% disease control rate. Median progression-free survival (pfs) was 5.6 months. Post progression, 56 patients received further capecitabine monotherapy (median of 4 additional cycles). Median overall survival duration for the patients was 14.3 months. Median survival was significantly higher for those who, at baseline, had an ecog performance status of 0 (compared with 1 or more) and normal ldh (compared with elevated ldh).

CONCLUSIONS

Toxicity is less with dose-reduced capecitabine than with historical full-dose capecitabine, with only a small trade-off in efficacy, seen as a lower objective response rate. The improved tolerability could lead to an increased number of cycles of therapy, and pfs appears to be consistently higher at the lower dose. Those observations should, in the absence of a head-to-head clinical trial, be viewed as compelling evidence that 1000 mg/m², or even 750 mg/m², twice daily is an appropriate dose in elderly or frail patients with acrc.

Rs7911488 modified the efficacy of capecitabine-based therapy in colon cancer through altering miR-1307-3p and TYMS expression

Capecitabine is an orally administered prodrug of 5-fluouracil (5-FU) and is used in first-line treatment of metastatic colorectal cancer. Studies have demonstrated that polymorphisms in 5-FU related ADME genes are associated with the efficacy of capecitabine. However, the relationship between the polymorphisms within the microRNA precursors and the efficacy of capecitabine is still largely unknown. We detected six polymorphisms in 274 colon cancer patients and statistically analyzed the association of the genotypes with the efficacy of capecitabine-based chemotherapy. The mechanisms underlying the effect of genotypes on the efficacy of capecitabine were also studied. We identified a polymorphism rs7911488 T>C in pre-miR-1307 to be significantly associated with the efficacy of capecitabine chemotherapy in colon cancer patients. The response rates of capecitabine chemotherapy for the patients with TT, TC, and CC genotypes were 44.35% (55/124), 51.33% (58/113), and 24.32% (9/37), respectively. In the C-allelic patients, miR-1307-3p is down-regulated and TYMS, a direct target of miR-1307-3p, is over-expressed, which leads to insensitivity of cancer cells to capecitabine chemotherapy. The cancer cells with rs7911488 C allele were further observed to be resistant to 5-FU treatment in vitro and in vivo. Our findings show that rs7911488 C-allelic pre-miR-1307 leads to attenuated miR-1307-3p and elevated TYMS, thus insensitive to capecitabine chemotherapy in colon cancer.

Low Incidence of the DPD IVS14+1G>A Polymorphism in Jordanian Breast and Colorectal Cancer patients

Background:

Dihydropyrimidine dehydrogenase (DPD) is a crucial enzyme in the catabolism of 5-fluorouracil (5-FU), a drug that is frequently used in cancer therapy. Patients with deficient DPD activity are at risk of developing severe 5-FU–associated toxicity. One possible cause of deficiency is genetic polymorphisms in the DPD gene, such as IVS14+1G>A.

Aim:

The present study was conducted to screen for the IVS14+1G>A polymorphism in cancer patients receiving 5-FU and a control group.

Methods:

A total of 40 cancer patients (30 colorectal cancer (CRC) and 10 breast cancer patients) were enrolled in this study. One hundred healthy controls were also tested using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). DNA sequence analysis was carried out to confirm the presence of the IVSI14+1G>A polymorphism.

Results:

Only one CRC patient showed heterozygous IVS14+1G>A polymorphism in the DPD gene.

Conclusion:

The results of this study demonstrated a very low frequency of the IVS14+1G>A polymorphism among Jordanian patients with colorectal and breast cancer.

Association of thymidylate synthase polymorphisms with the tumor response to preoperative chemoradiotherapy in rectal cancer: a systematic review and meta-analysis

Preoperative chemoradiotherapy (pCRT) followed by surgery is currently the standard therapy for patients with locally advanced rectal cancer. It is very important to develop biomarkers to prior identify the patients who have a higher likelihood of responding to pCRT. Recently, a series of studies have been conducted to investigate the association of thymidylate synthase (TYMS) polymorphisms with the tumor response to pCRT in rectal cancer, but the results were not consistent and conclusive. In the present study, we performed a systematic literature search for relevant studies up to 30 March 2015 and conducted a meta-analysis to summarize and clarify the association between the TYMS polymorphisms and the tumor response to pCRT in rectal cancer. Finally, 7 studies containing 892 cases for TYMS 2R/3R polymorphism, 7 studies involving 715 cases for TYMS 1494del6 polymorphism and 6 studies containing 616 cases for TYMS 5' untranslated region (UTR) expression allele polymorphism were analyzed in the meta-analysis. The results suggested that TYMS 2R/3R was associated with the response and the patients with 2R/2R or 2R/3R genotype with rectal cancer might benefit more from pCRT than others. On the contrary, neither 1494del6 nor 5'UTR expression allele polymorphisms was associated with the response to pCRT.

Variants in CDA and ABCB1 are predictors of capecitabine-related adverse reactions in colorectal cancer

Adverse reactions to capecitabine-based chemotherapy limit full administration of cytotoxic agents. Likewise, genetic variations associated with capecitabine-related adverse reactions are associated with controversial results and a low predictive value. Thus, more evidence on the role of these variations is needed. We evaluated the association between nine polymorphisms in MTHFR, CDA, TYMS, ABCB1, and ENOSF1 and adverse reactions, dose reductions, treatment delays, and overall toxicity in 239 colorectal cancer patients treated with capecitabine-based regimens. The ABCB1*1 haplotype was associated with a high risk of delay in administration or reduction in the dose of capecitabine, diarrhea, and overall toxicity. CDA rs2072671 A was associated with a high risk of overall toxicity. TYMS rs45445694 was associated with a high risk of delay in administration or reduction in the dose of capecitabine, HFS >1 and HFS >2. Finally, ENOSF1 rs2612091 was associated with HFS >1, but was a poorer predictor than TYMS rs45445694. A score based on ABCB1-CDA polymorphisms efficiently predicts patients at high risk of severe overall toxicity (PPV, 54%; sensitivity, 43%) in colorectal cancer patients treated with regimens containing capecitabine. Polymorphisms in ABCB1, CDA, ENOSF1,and TYMS could help to predict specific and overall severe adverse reactions to capecitabine.

Meta-Analysis of Oxaliplatin-Based Chemotherapy Combined With Traditional Medicines for Colorectal Cancer: Contributions of Specific Plants to Tumor Response

This meta-analysis evaluates the clinical evidence for the addition of traditional medicines (TMs) to oxaliplatin-based regimens for colorectal cancer (CRC) in terms of tumor response rate (TRR). Eight electronic databases were searched for randomized controlled trials of oxaliplatin-based chemotherapy combined with TMs compared to the same oxaliplatin-based regimen. Data on TRR from 42 randomized controlled trials were analyzed using Review Manager 5.1. Studies were conducted in China or Japan. Publication bias was not evident. The meta-analyses suggest that the combination of the TMs with oxaliplatin-based regimens increased TRR in the palliative treatment of CRC (risk ratio [RR] 1.31 [1.20-1.42], I(2) = 0%). Benefits were evident for both injection products (RR 1.36 [1.18-1.57], I(2) = 0%) and orally administered TMs (RR 1.27 [1.15-1.41], I(2) = 0%). Further sensitivity analysis of specific plant-based TMs found that Paeonia, Curcuma, and Sophora produced consistently higher contributions to the RR results. Compounds in each of these TMs have shown growth-inhibitory effects in CRC cell-line studies. Specific combinations of TMs appeared to produce higher contributions to TRR than the TMs individually. Notable among these was the combination of Hedyotis, Astragalus, and Scutellaria.

The HSP90 inhibitor ganetespib has chemosensitizer and radiosensitizer activity in colorectal cancer

The integration of targeted agents to standard cytotoxic regimens has improved outcomes for patients with colorectal cancer (CRC) over recent years; however this malignancy remains the second leading cause of cancer mortality in industrialized countries. Small molecule inhibitors of heat shock protein 90 (HSP90) are one of the most actively pursued classes of compounds for the development of new cancer therapies. Here we evaluated the activity of ganetespib, a second-generation HSP90 inhibitor, in models of CRC. Ganetespib reduced cell viability in a panel of CRC cell lines in vitro with low nanomolar potency. Mechanistically, drug treatment exerted concomitant effects on multiple oncogenic signaling pathways, cell cycle regulation, and DNA damage repair capacity to promote apoptosis. Combinations of ganetespib and low-dose ionizing radiation enhanced the radiosensitivity of HCT 116 cells and resulted in superior cytotoxic activity over either treatment alone. In vivo, the single-agent activity of ganetespib was relatively modest, suppressing HCT 116 xenograft tumor growth by approximately half. However, ganetespib significantly potentiated the antitumor efficacy of the 5-Fluorouracil (5-FU) prodrug capecitabine in HCT 116 xenografts, causing tumor regressions in a model that is intrinsically resistant to fluoropyrimidine therapy. This demonstration of combinatorial benefit afforded by an HSP90 inhibitor to a standard CRC adjuvant regimen provides an attractive new framework for the potential application of ganetespib as an investigational agent in this disease.

Clinical management of localized colon cancer with capecitabine

Large randomized trials demonstrated a benefit of adjuvant chemotherapy after resection of the primary colon cancer. It improves overall survival and reduces the risk of death, by 5% in UICC (Union Internationale Contre le Cancer) stage II and approximately 15%-20% in stage III. Fluoropyrimidines have been the standard drugs for the treatment of colon cancer since large randomized controlled trials demonstrated their efficacy and safety in treating patients suffering from this disease. Capecitabine is an orally administered fluoropyrimidine, which is preferably activated in tumor tissue to the active moiety 5-fluorouracil (5FU) and is cytotoxic through inhibition of DNA synthesis. It has proven equivalent efficacy and tolerability despite a changed toxicity profile compared to 5FU with less myelosuppression but more hand-and-foot syndrome. Capecitabine is well tolerated in elderly patients. The oral route of administration avoids frequent clinical visits as well as insertion of central venous catheters. The impact of the particular drug features on daily clinical practice is discussed in this review.