5-fluorouracil and other fluoropyrimidines in colorectal cancer: Past, present and future

5-Fluorouracil (5-FU) is an essential component of systemic chemotherapy for colorectal cancer (CRC) in the palliative and adjuvant settings. Over the past four decades, several modulation strategies including the implementation of 5-FU-based combination regimens and 5-FU pro-drugs have been developed and tested to increase the anti-tumor activity of 5-FU and to overcome the clinical resistance. Despite the encouraging progress in CRC therapy to date, the patients' response rates to therapy continue to remain low and the patients' benefit from 5-FU-based therapy is frequently compromised by the development of chemoresistance. Inter-individual differences in the treatment response in CRC patients may originate in the unique genetic and epigenetic make-up of each individual. The critical element in the current trend of personalized medicine is the proper comprehension of causes and mechanisms contributing to the low or lack of sensitivity of tumor tissue to 5-FU-based therapy. The identification and validation of predictive biomarkers for existing 5-FU-based and new targeted therapies for CRC treatment will likely improve patients' outcomes in the future. Herein we present a comprehensive review summarizing options of CRC treatment and the mechanisms of 5-FU action at the molecular level, including both anabolic and catabolic ways. The main part of this review comprises the currently known molecular mechanisms underlying the chemoresistance in CRC patients. We also focus on various 5-FU pro-drugs developed to increase the amount of circulating 5-FU and to limit toxicity. Finally, we propose future directions of personalized CRC therapy according to the latest published evidence.

Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for clear cell renal cell carcinoma (KEYNOTE-564): 30-month follow-up analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

The first interim analysis of the KEYNOTE-564 study showed improved disease-free survival with adjuvant pembrolizumab compared with placebo after surgery in patients with clear cell renal cell carcinoma at an increased risk of recurrence. The analysis reported here, with an additional 6 months of follow-up, was designed to assess longer-term efficacy and safety of pembrolizumab versus placebo, as well as additional secondary and exploratory endpoints.

METHODS

In the multicentre, randomised, double-blind, placebo-controlled, phase 3 KEYNOTE-564 trial, adults aged 18 years or older with clear cell renal cell carcinoma with an increased risk of recurrence were enrolled at 213 hospitals and cancer centres in North America, South America, Europe, Asia, and Australia. Eligible participants had an Eastern Cooperative Oncology Group performance status of 0 or 1, had undergone nephrectomy 12 weeks or less before randomisation, and had not received previous systemic therapy for advanced renal cell carcinoma. Participants were randomly assigned (1:1) via central permuted block randomisation (block size of four) to receive pembrolizumab 200 mg or placebo intravenously every 3 weeks for up to 17 cycles. Randomisation was stratified by metastatic disease status (M0 vs M1), and the M0 group was further stratified by ECOG performance status and geographical region. All participants and investigators involved in study treatment administration were masked to the treatment group assignment. The primary endpoint was disease-free survival by investigator assessment in the intention-to-treat population (all participants randomly assigned to a treatment). Safety was assessed in the safety population, comprising all participants who received at least one dose of pembrolizumab or placebo. As the primary endpoint was met at the first interim analysis, updated data are reported without p values. This study is ongoing, but no longer recruiting, and is registered with ClinicalTrials.gov, NCT03142334.

FINDINGS

Between June 30, 2017, and Sept 20, 2019, 994 participants were assigned to receive pembrolizumab (n=496) or placebo (n=498). Median follow-up, defined as the time from randomisation to data cutoff (June 14, 2021), was 30·1 months (IQR 25·7-36·7). Disease-free survival was better with pembrolizumab compared with placebo (HR 0·63 [95% CI 0·50-0·80]). Median disease-free survival was not reached in either group. The most common all-cause grade 3-4 adverse events were hypertension (in 14 [3%] of 496 participants) and increased alanine aminotransferase (in 11 [2%]) in the pembrolizumab group, and hypertension (in 13 [3%] of 498 participants) in the placebo group. Serious adverse events attributed to study treatment occurred in 59 (12%) participants in the pembrolizumab group and one (<1%) participant in the placebo group. No deaths were attributed to pembrolizumab.

INTERPRETATION

Updated results from KEYNOTE-564 support the use of adjuvant pembrolizumab monotherapy as a standard of care for participants with renal cell carcinoma with an increased risk of recurrence after nephrectomy.

FUNDING

Merck Sharp & Dohme LLC, a subsidiary of Merck & Co, Inc, Rahway, NJ, USA.

Skin toxicity and efficacy of sunitinib and sorafenib in metastatic renal cell carcinoma: a national registry-based study

BACKGROUND

A retrospective, registry-based analysis to assess the outcomes of metastatic renal cell cancer (mRCC) patients treated with sunitinib and sorafenib who developed dermatologic adverse events was performed.

PATIENTS AND METHODS

Data on mRCC patients treated with sunitinib or sorafenib were obtained from the Czech Clinical Registry of Renal Cell Cancer Patients. Outcomes of patients who developed hand-foot syndrome (HFS) of any grade and/or grade 3/4 rash during the treatment were compared with patients without HFS and no, mild, or moderate rash.

RESULTS

The cohort included 705 patients treated with sunitinib and 365 patients treated with sorafenib. For sunitinib, the median overall survival (OS) was 43.0 months versus 31.0 months (P = 0.027) and median progression-free survival (PFS) 20.8 months versus 11.1 months (P = 0.007) for patients with versus without dermatologic toxicity, respectively. For sorafenib, the median OS and PFS were 27.9 and 24.6 months (P = 0.244), and 12.2 and 8.8 months (P = 0.050), respectively. In multivariable Cox regression, the skin toxicity was significantly associated with longer OS in the sunitinib cohort.

CONCLUSION

The presence of skin toxicity is associated with improved OS and PFS in patients with mRCC treated with sunitinib.

Lenvatinib plus pembrolizumab versus sunitinib as first-line treatment of patients with advanced renal cell carcinoma (CLEAR): extended follow-up from the phase 3, randomised, open-label study

BACKGROUND

In the primary analysis of the CLEAR study, lenvatinib plus pembrolizumab significantly improved progression-free survival and overall survival versus sunitinib in patients with advanced renal cell carcinoma (data cutoff Aug 28, 2020). We aimed to assess overall survival based on 7 months of additional follow-up.

METHODS

This is a protocol-prespecified updated overall survival analysis (data cutoff March 31, 2021) of the open-label, phase 3, randomised CLEAR trial. Patients with clear-cell advanced renal cell carcinoma who had not received any systemic anticancer therapy for renal cell carcinoma, including anti-vascular endothelial growth factor therapy, or any systemic investigational anticancer drug, were eligible for inclusion from 200 sites (hospitals and cancer centres) across 20 countries. Patients were randomly assigned (1:1:1) to receive lenvatinib (20 mg per day orally in 21-day cycles) plus pembrolizumab (200 mg intravenously every 21 days; lenvatinib plus pembrolizumab group), lenvatinib (18 mg per day orally) plus everolimus (5 mg per day orally; lenvatinib plus everolimus group [not reported in this updated analysis]) in 21-day cycles, or sunitinib (50 mg per day orally, 4 weeks on and 2 weeks off; sunitinib group). Eligible patients were at least 18 years old with a Karnofsky performance status of 70 or higher. A computer-generated randomisation scheme was used, and stratification factors were geographical region and Memorial Sloan Kettering Cancer Center prognostic groups. The primary endpoint was progression-free survival assessed by independent imaging review according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1). In this Article, extended follow-up analyses for progression-free survival and protocol-specified updated overall survival data are reported for the intention-to-treat population. No safety analyses were done at this follow-up. This study is closed to new participants and is registered with ClinicalTrials.gov, NCT02811861.

FINDINGS

Between Oct 13, 2016, and July 24, 2019, 1417 patients were screened for inclusion in the CLEAR trial, of whom 1069 (75%; 273 [26%] female, 796 [74%] male; median age 62 years [IQR 55-69]) were randomly assigned: 355 (33%) patients (255 [72%] male and 100 [28%] female) to the lenvatinib plus pembrolizumab group, 357 (33%) patients (275 [77%] male and 82 [23%] female) to the sunitinib group, and 357 (33%) patients to the lenvatinib plus everolimus group (not reported in this updated analysis). Median follow-up for progression-free survival was 27·8 months (IQR 20·3-33·8) in the lenvatinib plus pembrolizumab group and 19·4 months (5·5-32·5) in the sunitinib group. Median progression-free survival was 23·3 months (95% CI 20·8-27·7) in the lenvatinib plus pembrolizumab group and 9·2 months (6·0-11·0) in the sunitinib group (stratified hazard ratio [HR] 0·42 [95% CI 0·34-0·52]). Median overall survival follow-up was 33·7 months (IQR 27·4-36·9) in the lenvatinib plus pembrolizumab group and 33·4 months (26·7-36·8) in the sunitinib group. Overall survival was improved with lenvatinib plus pembrolizumab (median not reached [95% CI 41·5-not estimable]) versus sunitinib (median not reached [38·4-not estimable]; HR 0·72 [95% CI 0·55-0·93]).

INTERPRETATION

Efficacy benefits of lenvatinib plus pembrolizumab over sunitinib were durable and clinically meaningful with extended follow-up. These results support the use of lenvatinib plus pembrolizumab as a first-line therapy for patients with advanced renal cell carcinoma.

FUNDING

Eisai and Merck Sharp & Dohme.

Mycophenolate mofetil for the treatment of acute and chronic steroid-refractory graft-versus-host disease

Corticosteroid-resistant graft-versus-host disease (GvHD) is difficult to manage and is associated with high morbidity and mortality. The purpose of our study was to evaluate the safety and efficacy of mycophenolate mofetil (MMF) as the salvage therapy for steroid-refractory GvHD. Twenty one patients (10 with acute GvHD and 11 with chronic GvHD) were studied retrospectively. Steroid-resistant GvHD was defined as acute or chronic GvHD not responding to a first-line regimen of cyclosporine A and corticosteroids in a dose equivalent to 2 mg/kg methylprednisolone for at least 7 days. MMF was added at a dose of 2 g daily, and corticosteroids were tapered. Thirteen (62%) of 21 patients responded to the treatment with MMF, including 6 (60%) of 10 patients with acute refractory GvHD and 7 (64%) of 11 patients with chronic refractory GvHD. The most common adverse effects were infectious complications (67%, 14 of 21 patients) and hematological toxicity (29%, 6 of 21 patients). Median duration of MMF administration was 6 months (range 1-27 months). Sixteen of 21 patients were alive after the median follow-up of 27 months (range 1-72 months) after the initiation of MMF therapy. All 16 surviving patients were in good clinical condition and in remission of their hematological malignancy. Five patients died--two of relapses of leukemia and three of refractory intestinal GvHD. These results suggest that MMF can be an effective treatment for some cases of steroid-refractory GvHD.

Sunitinib followed by sorafenib or vice versa for metastatic renal cell carcinoma--data from the Czech registry

BACKGROUND

Sequential therapy with tyrosine kinase inhibitors (TKIs), sunitinib and sorafenib, is a common treatment choice for patients with advanced/metastatic renal cell carcinoma (mRCC) despite lack of randomised trials. The aim of this retrospective registry-based study was to analyse the outcomes of RCC patients treated with sunitinib-sorafenib or sorafenib-sunitinib sequence.

PATIENTS AND METHODS

The Czech database containing information on patients treated for mRCC using targeted agents was used as a source of data for retrospective analysis. There were 138 patients treated with sunitinib-sorafenib sequence and 122 patients treated with sorafenib-sunitinib sequence.

RESULTS

Progression-free survival (PFS) was 17.7 months for patients treated with sunitinib-sorafenib sequence and 18.8 months for those receiving sorafenib followed by sunitinib (P = 0.47). Overall survival (OS) at 1 year was 83% [95% confidence interval (CI) 77% to 90%] for patients treated with sunitinib-sorafenib and 84% (95% CI 77% to 91%) for sorafenib-sunitinib patients (P = 0.99). Treatment toxic effects were predictable but a significant proportion of patients (up to 14%-25% for different lines of therapy and used TKI) switched between TKIs or discontinued TKI therapy because of toxicity.

CONCLUSIONS

In contrast to most of the previously published reports, we have not observed improved PFS or OS for mRCC patients treated with the sorafenib-sunitinib sequence as compared to the sunitinib-sorafenib sequence.

Variation within 3'-UTRs of base excision repair genes and response to therapy in colorectal cancer patients: A potential modulation of microRNAs binding

PURPOSE

Colorectal cancer is routinely treated with a 5-fluorouracil (5-FU)-based chemotherapy. 5-FU incorporates into DNA, and the base excision repair (BER) pathway specifically recognizes such damage. We investigated the association of single-nucleotide polymorphisms (SNP) in the 3'-untranslated regions (UTR) of BER genes, and potentially affecting the microRNA (miRNA) binding, on the risk of colorectal cancer, its progression, and prognosis. SNPs in miRNA-binding sites may modulate the posttranscriptional regulation of gene expression operated by miRNAs and explain interindividual variability in BER capacity and response to 5-FU.

EXPERIMENTAL DESIGN

We tested 12 SNPs in the 3'-UTRs of five BER genes for colorectal cancer susceptibility in a case-control study (1,098 cases and 1,459 healthy controls). Subsequently, we analyzed the role of these SNPs on clinical outcomes of patients (866 in the Training set and 232 in the Replication set).

RESULTS

SNPs in the SMUG1 and NEIL2 genes were associated with overall survival. In particular, SMUG1 rs2233921 TT carriers showed increased survival compared with those with GT/GG genotypes [HR, 0.54; 95% confidence interval (CI), 0.36-0.81; P = 0.003] in the Training set and after pooling results from the Replication set. The association was more significant following stratification for 5-FU-based chemotherapy (P = 5.6 × 10(-5)). A reduced expression of the reporter gene for the T allele of rs2233921 was observed when compared with the common G allele by in vitro assay. None of the genotyped BER polymorphisms were associated with colorectal cancer risk.

CONCLUSIONS

We provide the first evidence that variations in miRNA-binding sites in BER genes 3'-UTR may modulate colorectal cancer prognosis and therapy response.

Polymorphisms in microRNA genes as predictors of clinical outcomes in colorectal cancer patients

Colorectal cancer (CRC) is one of the most frequently diagnosed malignancies worldwide. It is routinely cured by a 5-fluorouracil (5-FU)-based chemotherapy which improves outcomes in patients. We investigated the effect of single nucleotide polymorphisms (SNPs) in two microRNA (miRNA)-encoding genes that have been previously reported as important in prognosis in patients with stage III CRC and treated with 5-FU-based chemotherapy. Two SNPs (rs4919510 in miR-608 and rs213210 in miR-219-1) were genotyped in 1083 CRC patients recruited in the Czech Republic to evaluate their effect on clinical outcomes. Carriers of the variant T allele in rs213210 and receiving 5-FU chemotherapy were associated with a significantly worse survival [hazard ratio (HR) = 2.18; 95% confidence interval (CI): 1.20-3.98; adjusted P = 0.01] and an increased risk of relapse (HR = 1.94; 95% CI: 1.16-3.25; adjusted P = 0.01). After further stratification for tumor grading, stage III patients carrying the G allele of rs4919510 and undergoing adjuvant chemotherapy were at decreased risk of relapse (HR = 0.44; 95% CI: 0.20-0.94; adjusted P = 0.03). The present study confirms that variations in miRNA-encoding genes may be an important factor for modulating CRC prognosis and predicting therapy response.

Fusobacterium nucleatum tumor DNA levels are associated with survival in colorectal cancer patients

There is increasing evidence indicating a role for Fusobacterium nucleatum (F. nucleatum) in colorectal cancer (CRC) development and prognosis. This study evaluated F. nucleatum as a prognostic biomarker, by assessing its association with post-diagnosis survival from CRC. From September 2008 to April 2012 CRC patients (n = 190) were recruited from three hospitals within the Czech Republic. F. nucleatum DNA copies were measured in adjacent non-malignant and colorectal tumor tissues using quantitative real-time PCR. Cox Proportional Hazards (HR) models were applied to evaluate the association between F. nucleatum DNA and overall survival, adjusting for key confounders. Risk prediction modeling was conducted to evaluate the ability to predict survival based on F. nucleatum status. High, compared with low, levels of F. nucleatum in colorectal tumor tissues were associated with poorer overall survival (adjusted HR 1.68, 95% CI 1.02–2.77), which was slightly attenuated after additional adjustment for microsatellite instability status. However, inclusion of F. nucleatum in risk prediction models did not improve the ability to identify patients who died beyond known prognostic factors such as disease pathology staging. Although the increased presence of F. nucleatum was associated with poorer prognosis in CRC patients, this may have limited clinical relevance as a prognostic biomarker.

Prognostic factors for survival after autologous transplantation: a single centre experience in 133 multiple myeloma patients

Autologous stem cell transplantation (ASCT) has an established role in the treatment of symptomatic multiple myeloma (MM). Our aim was to analyse the impact of selected prognostic parameters on the survival of patients with MM after ASCT. The new International Staging System (ISS) was also evaluated. A total of 133 MM patients were transplanted in our centre between 1995 and 2002. Following ASCT, 35% of patients were in complete remission (CR) and 60% were in partial remission (PR). The median progression-free (PFS) and overall (OS) survival from transplantation were 29.5 and 68.8 months, respectively. Transplant-related mortality (TRM) was 3%. On multivariate analysis, factors associated with significantly shorter OS were lack of CR after transplant (P = 0.002, hazard ratio (HR): 3.1), stage 3 according to ISS (P = 0.001, HR: 3.0) and age at transplant over 60 years (P = 0.035, HR: 2.0). The status of disease before ASCT did not significantly affect PFS and OS after transplantation. We conclude that ASCT is a safe and effective procedure in MM patients, associated with low TRM. The survival after ASCT was dependent on response after ASCT, stage according to ISS and age.

Detection of let-7 miRNAs in urine supernatant as potential diagnostic approach in non-metastatic clear-cell renal cell carcinoma

Introduction

Urinary microRNAs (miRNAs) are emerging as a clinically useful tool for early and non-invasive detection of various types of cancer. The aim of this study was to evaluate whether let-7 family miRNAs differ in their urinary concentrations between renal cell carcinoma (RCC) cases and healthy controls.

Materials and methods

In the case-control study, 69 non-metastatic clear-cell RCC patients and 36 gender/age-matched healthy controls were prospectively enrolled. Total RNA was purified from cell-free supernatant of the 105 first morning urine specimens. Let-7 family miRNAs were determined in cell-free supernatant using quantitative miRNA real-time reverse-transcription PCR and absolute quantification approach.

Results

Concentrations of all let-7 miRNAs (let-7a, let-7b, let-7c, let-7d, let-7e and let-7g) were significantly higher in urine samples obtained from RCC patients compared to healthy controls (P < 0.001; P < 0.001; P = 0.005; P = 0.006; P = 0.015 and P = 0.002, respectively). Subsequent ROC analysis has shown that let-7a concentration possesses good ability to differentiate between cases and controls with area under curve being 0.8307 (sensitivity 71%, specificity 81%).

Conclusions

We have shown that let-7 miRNAs are abundant in the urine samples of patients with clear-cell RCC, and out of six let-7 family members, let-7a outperforms the others and presents promising non-invasive biomarker for the detection of RCC.

Double-strand break repair and colorectal cancer: gene variants within 3' UTRs and microRNAs binding as modulators of cancer risk and clinical outcome

Genetic variations in 3' untranslated regions of target genes may affect microRNA binding, resulting in differential protein expression. microRNAs regulate DNA repair, and single-nucleotide polymorphisms in miRNA binding sites (miRSNPs) may account for interindividual differences in the DNA repair capacity. Our hypothesis is that miRSNPs in relevant DNA repair genes may ultimately affect cancer susceptibility and impact prognosis.In the present study, we analysed the association of polymorphisms in predicted microRNA target sites of double-strand breaks (DSBs) repair genes with colorectal cancer (CRC) risk and clinical outcome. Twenty-one miRSNPs in non-homologous end-joining and homologous recombination pathways were assessed in 1111 cases and 1469 controls. The variant CC genotype of rs2155209 in MRE11A was strongly associated with decreased cancer risk when compared with the other genotypes (OR 0.54, 95% CI 0.38-0.76, p = 0.0004). A reduced expression of the reporter gene was observed for the C allele of this polymorphism by in vitro assay, suggesting a more efficient interaction with potentially binding miRNAs. In colon cancer patients, the rs2155209 CC genotype was associated with shorter survival while the TT genotype of RAD52 rs11226 with longer survival when both compared with their respective more frequent genotypes (HR 1.63, 95% CI 1.06-2.51, p = 0.03 HR 0.60, 95% CI 0.41-0.89, p = 0.01, respectively).miRSNPs in DSB repair genes involved in the maintenance of genomic stability may have a role on CRC susceptibility and clinical outcome.

Varicella-zoster virus prophylaxis with low-dose acyclovir in patients with multiple myeloma treated with bortezomib

BACKGROUND

Varicella-zoster virus (VZV) reactivation is a common complication in patients with multiple myeloma (MM) treated with bortezomib, with an incidence rate of 10%-60%. The aim of our study was to analyze the effect of acyclovir prophylaxis in this patient population.

PATIENTS AND METHODS

We studied 98 consecutive patients with relapsed MM treated with bortezomib. Bortezomib 1.3 mg/m2 was given on days 1, 4, 8, and 11 of a 21-day cycle. At first, patients did not receive any VZV prophylaxis, but because of the high incidence of VZV reactivation, VZV prophylaxis with acyclovir was implemented subsequently.

RESULTS

A total of 11 patients treated with bortezomib did not have any VZV prophylaxis, and 4 of these 11 patients (36%) developed VZV reactivation in the form of herpes zoster. No VZV reactivations were observed in the 32 patients who received acyclovir 400 mg 3 times daily or the 55 patients who received acyclovir in a dose reduced to 400 mg once daily during bortezomib treatment.

CONCLUSION

Varicellazoster virus reactivation is a common and serious adverse effect of bortezomib treatment. Acyclovir 400 mg once daily is sufficient to protect from VZV reactivation in patients with MM treated with bortezomib.

Methylation-Based Therapies for Colorectal Cancer

Colorectal carcinogenesis (CRC) is caused by the gradual long-term accumulation of both genetic and epigenetic changes. Recently, epigenetic alterations have been included in the classification of the CRC molecular subtype, and this points out their prognostic impact. As epigenetic modifications are reversible, they may represent relevant therapeutic targets. DNA methylation, catalyzed by DNA methyltransferases (DNMTs), regulates gene expression. For many years, the deregulation of DNA methylation has been considered to play a substantial part in CRC etiology and evolution. Despite considerable advances in CRC treatment, patient therapy response persists as limited, and their profit from systemic therapies are often hampered by the introduction of chemoresistance. In addition, inter-individual changes in therapy response in CRC patients can arise from their specific (epi)genetic compositions. In this review article, we summarize the options of CRC treatment based on DNA methylation status for their predictive value. This review also includes the therapy outcomes based on the patient's methylation status in CRC patients. In addition, the current challenge of research is to develop therapeutic inhibitors of DNMT. Based on the essential role of DNA methylation in CRC development, the application of DNMT inhibitors was recently proposed for the treatment of CRC patients, especially in patients with DNA hypermethylation.

G12V and G12A KRAS mutations are associated with poor outcome in patients with metastatic colorectal cancer treated with bevacizumab

The v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations are found in 35-45 % of colorectal cancer (CRC) cases. Although the association between the RAS signaling and angiogenesis is well known, the negative predictive value of KRAS mutation has not been established in patients treated with bevacizumab. The aim of this study was to evaluate the association between specific KRAS mutation types and outcome of patients with metastatic CRC treated with bevacizumab. The study included 404 patients with metastatic CRC (mCRC) treated with bevacizumab. Clinical data obtained from the clinical registry CORECT were retrospectively analyzed. The shortest survival was observed in patients with tumors harboring G12V or G12A KRAS mutation (G12V/A). The median progression-free survival (PFS) and overall survival (OS) for patients with tumors harboring G12V/A KRAS mutation was 6.6 and 16.8 compared to 11.6 and 26.3 months for patients with tumors harboring other KRAS mutation type (p < 0.001 and p < 0.001), while the survival of patients harboring other KRAS mutation types was comparable to those with tumors harboring wild-type KRAS gene. In the Cox multivariable analysis, KRAS G12V/A mutation type remains a significant factor predicting both PFS (HR = 2.18, p < 0.001) and OS (HR = 2.58, p < 0.001). In conclusion, the results of the present study indicate that there is a significant difference in biological behavior between tumors harboring G12V/A and other KRAS mutations. Moreover, comparison of the survival of patients with tumors harboring G12V/A KRAS mutations with those harboring wild-type KRAS gene revealed that G12V/A KRAS mutations are prognostic biomarker for inferior PFS and OS in patients with mCRC treated with bevacizumab in univariate as well as multivariable analyses.

Pretreatment hepatocyte growth factor and thrombospondin-1 levels predict response to high-dose chemotherapy for multiple myeloma

Our aim was to establish whether the pretreatment levels of angiogenesis activators and inhibitors can be used to predict clinical responses to treatment that included high-dose chemotherapy with peripheral stem cell support.<br />We analyzed samples and treatment outcomes of 96 patients with MM enrolled in the CMG 2002 randomized clinical trial and treated with induction chemotherapy and high-dose chemotherapy with stem cell support. Concentrations of vascular endothelial growth factor (VEGF), hepatocytar growth factor (HGF), basic fibroblastic growth factor (bFGF), thrombospondin-1 (TSP-1), endostatin, and angiostatin were measured in the peripheral blood plasma and in the bone marrow plasma at diagnosis. <br />Pretreatment HGF concentrations in the peripheral blood plasma as well as in the bone marrow plasma of patients who achieved complete or very good partial response were significantly lower than those in patients who had partial or worse response. Patients with complete or very good partial response had higher TSP-1 levels in the bone marrow plasma than the partial or insufficient response subgroups. There were no correlations between the pretreatment levels of VEGF, bFGF, endostatin, or angiostatin and the treatment response. <br />Pretreatment concentrations of HGF and TSP-1 were predictive factors for treatment response. Patients with low angiogenesis rate as determined by the relative HGF and TSP-1 concentrations were more likely to achieve complete or very good partial response after high-dose chemotherapy.

KEYWORDS

Angiogenesis, cytokines, high-dose chemotherapy, multiple myeloma, therapeutic response.

Base excision repair capacity as a determinant of prognosis and therapy response in colon cancer patients

The DNA-damaging agent 5-fluorouracil represents the most commonly used chemotherapeutic drug for colorectal cancer patients. DNA lesions associated with 5-fluorouracil therapy are primarily repaired by base excision repair (BER) and mismatch repair (MMR) pathways. Published evidence suggests that the individual DNA repair capacity (DRC) may affect a patient's prognosis and response to chemotherapy. With this in mind, we designed a prospective study of which the main aim was to investigate BER-DRC in relation to 5-fluorouracil response as potential predictive and/or prognostic biomarker. BER-DRC was supplemented by a microsatellite instability (MSI) analysis which represents an indirect marker of MMR activity in the tumor. All parameters were measured in paired samples of tumor tissue and non-malignant adjacent mucosa of 123 incident colon cancer patients. Our results indicate that BER-DRC in non-malignant adjacent mucosa was positively associated with overall survival (P = 0.007) and relapse-free survival (P = 0.04). Additionally, in multivariate analysis, good therapy responders in TNM stage II and III with an elevated BER-DRC in mucosa exhibited better overall survival. Moreover, the overall survival of these patients was even better in the presence of a decreased BER-DRC in tumor tissue. The ratio of BER-DRC in tumor tissue over BER-DRC in mucosa positively correlated with advanced tumor stage (P = 0.003). With respect to MSI, we observed that MSI-high tumors were mostly localized in proximal colon; however, in our cohort, the MSI status affected neither patients' prognosis nor survival. In summary, the results of the present study suggest that the level of BER-DRC is associated with patients' survival. BER-DRC represents a potential prognostic biomarker, applicable for prediction of therapy response and useful for individual approach to patients.

The association of miR-126-3p, miR-126-5p and miR-664-3p expression profiles with outcomes of patients with metastatic colorectal cancer treated with bevacizumab

MicroRNAs regulate the expression of genes involved in several important cancer-related processes including cell adhesion, proliferation, and tumour angiogenesis. Bevacizumab is routinely used in the treatment of patients with metastatic colorectal cancer, but, so far, no reliable biomarker predicting response to bevacizumab has been established. The aim of our retrospective study was to evaluate the association of miR-126-3p, miR-126-5p and miR-664-3p tumour expression levels with outcomes of patients with metastatic colorectal cancer treated with bevacizumab. The study included 63 patients. For the assessment of microRNA expression, gene-specific TaqMan assays were used. The median progression-free survival and overall survival for patients with low tumour expression of miR-126-3p were 8.8 and 20.6 months versus 13.5 months and median overall survival was not reached for patients with high expression ( p = 0.0064 and p = 0.0027), respectively. The median progression-free survival and overall survival for patients with low tumour expression of miR-126-5p were 9.0 and 22.2 months versus 12.0 and 23.4 months for patients with high expression ( p = 0.2113 and 0.6858), respectively. The median progression-free survival and overall survival for patients with low tumour expression of miR-664-3p were 9.1 and 22.5 months versus 8.8 and 23.4 months for patients with high expression ( p = 0.2542 and p = 0.1922), respectively. The multivariable Cox proportional hazards model revealed that miR-126-3p expression was significantly associated with progression-free survival (hazard ratio = 0.28, p = 0.0053) and also with overall survival (hazard ratio = 0.18, p = 0.0046). In conclusion, the results of this study suggest that the expression of miR-126-3p in the tumour tissue was associated with outcome of metastatic colorectal cancer patients treated with bevacizumab.

Microsatellite Instability and Metastatic Colorectal Cancer - A Clinical Perspective

Approximately 4-5% of patients with metastatic colorectal cancer (mCRC) have mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) tumours. These tumours present challenges in the clinical practice due to variant response to fluoropyrimidine-based chemotherapy and, perhaps, also non-immunologic targeted therapies. Recently, a breakthrough in the treatment of dMMR/MSI-H mCRC has been achieved with several clinical trials showing dramatic long-term benefit of immunotherapy using checkpoint inhibitors. Nevertheless, several questions remain regarding the optimisation of immunotherapy regimens and the use of biomarkers to identify populations set to derive the greatest benefit from immunotherapy. Combination regimens and/or the use of immunotherapy as a maintenance after induction non-immunologic systemic therapy may be the way forward to improve outcomes.

Polymorphisms in microRNA binding sites of mucin genes as predictors of clinical outcome in colorectal cancer patients

Polymorphisms in microRNA (miRNA) binding sites may affect miRNA/target gene interaction, resulting in differential mRNA/protein expression and susceptibility to common diseases. Mucins have been identified as markers of adverse prognosis. We hypothesized that genetic variations in miRNA binding sites located in mucin genes may modulate signaling response and the maintenance of genomic stability ultimately affecting cancer susceptibility, efficacy of chemotherapy and survival. In this study, we analyzed the association of single nucleotide polymorphisms in predicted miRNA target sites (miRSNPs) of mucin genes with colorectal cancer (CRC) risk and clinical outcome. Thirteen miRSNPs in 9 genes were assessed in 1111 cases and 1469 controls. No strongly significant associations were observed in the case-control study. Patients carrying the CC genotype of rs886403 in MUC21 displayed a shorter survival and higher recurrence risk when compared with TT carriers [overall survival (OS): hazard ratios (HR) 1.69; 95% confidence intervals (CI) 1.13-2.46; P = 0.01 and event-free survival (EFS): HR 1.99; 95% CI 1.38-2.84; P = 0.0002, respectively]. The observed associations were more striking after stratification for tumor site (in patients with colon cancer, OS: HR 2.63; 95% CI 1.69-4.10; P < 0.0001 and EFS: HR 2.65; 95% CI 1.72-4.07; P < 0.0001). In contrast, rectal cancer cases carrying the CC genotype of rs4729655 in MUC17 displayed a longer survival (OS: HR 0.27; 95% CI 0.14-0.54; P = 0.0002) than those with the most common genotype. To our knowledge, this is the first study investigating miRSNPs potentially affecting miRNA binding to mucin genes and revealing their impact on CRC susceptibility or patient's survival.

Variations in mismatch repair genes and colorectal cancer risk and clinical outcome

DNA mismatch repair (MMR) deficiency is one of the best understood forms of genetic instability in colorectal cancer (CRC). CRC is routinely cured by 5-fluorouracil (5-FU)-based chemotherapy, with a prognostic effect and resistance to such therapy conferred by MMR status. In this study, we aimed to analyse the effect of genetic variants in classical coding regions or in less-explored predicted microRNA (miRNA)-binding sites in the 3' untranslated region (3'UTR) of MMR genes on the risk of CRC, prognosis and the efficacy of 5-FU therapy. Four single nucleotide polymorphisms (SNPs) in MMR genes were initially tested for susceptibility to CRC in a case-control study (1095 cases and 1469 healthy controls). Subsequently, the same SNPs were analysed for their role in survival on a subset of patients with complete follow-up. Two SNPs in MLH3 and MSH6 were associated with clinical outcome. Among cases with colon and sigmoideum cancer, carriers of the CC genotype of rs108621 in the 3'UTR of MLH3 showed a significantly increased survival compared to those with the CT + TT genotype (log-rank test, P = 0.05). Moreover, this polymorphism was also associated with an increased risk of relapse or metastasis in patients with heterozygous genotype (log-rank test, P = 0.03). Patients carrying the CC genotype for MSH6 rs1800935 (D180D) and not undergoing 5-FU-based chemotherapy showed a decreased number of recurrences (log-rank test, P = 0.03). No association with CRC risk was observed. We provide the first evidence that variations in potential miRNA target-binding sites in the 3'UTR of MMR genes may contribute to modulate CRC prognosis and predictivity of therapy.