Alternative treatment options in colorectal cancer patients with 5-fluorouracil- or capecitabine-induced cardiotoxicity. Clin Colorectal Cancer. 2013;12:8-14. [PMID: 23102544 DOI: 10.1016/j.clcc.2012.09.003]

Investigation of 5-fluorouracil cardiotoxicity in combinational therapy: Influence of risk factors and demographics in a Pakistani population

INTRODUCTION

5-Fluorouracil (5-FU) is a chemotherapeutic agent used to treat various types of cancers. Although widely used, it has consistently been attributed to cardiotoxicities after administration. The purpose of this study was to assess the parameters and predictors of cardiotoxicities associated with various 5-FU-based chemotherapeutic protocols in patients with GI/colorectal cancer, as well as the correlation of these cardiotoxic events with age, sex, cumulative dose, and risk factors such as obesity, hypertension, and family history of cardiac diseases.

METHODS

A prospective study consisting of 396 patients of both sexes was conducted in the oncology ward of Nishtar Hospital in Multan, Pakistan. Patients were grouped according to the therapeutic protocol they received (5-FU monotherapy or in combination, with different dosing regimens). Electrocardiography and serum troponin levels were used to assess 5-FU-induced cardiotoxicity. In cases where cardiotoxicity was detected, 5-FU treatment was interrupted; nitroglycerin, nitrates, and calcium channel blockers were administered; and cardiac monitoring was initiated. 5-FU was discontinued in all cases of acute myocardial infarction.

RESULTS

Of the 396 patients, 28.5% reported different cardiotoxic symptoms after receiving various 5-FU-containing protocols. 35% had anginal pain, 13% suffered a myocardial infarction, 11% developed hypertension, and 10% presented heart failure. Patients receiving 5-FU combination therapy showed cardiotoxic events that were significantly different from those on 5-FU monotherapy. Based on the ECG results, only the QTc-d interval increased significantly (p < 0.001) after therapy. 68% of the patients had troponin levels > 2 ng/mL at the end of treatment.

CONCLUSIONS

Pre-existing cardiac diseases, treatment duration, smoking, and obesity were found to be influential components in the development of cardiotoxicity, and patients with cancer should be closely monitored during 5-FU chemotherapy.

Predicting cardiovascular events with fluoropyrimidine chemotherapy using a standard cardiovascular risk calculator

AIMS

Fluoropyrimidine chemotherapy is important for treatment of many solid tumours but is associated with cardiotoxicity. The relationship of fluoropyrimidine-associated cardiotoxicity (FAC) with conventional cardiovascular (CV) risk factors is poorly understood, and standard cardiovascular risk scores are not validated in this context.

METHODS AND RESULTS

Single-centre retrospective study of patients treated with fluoropyrimidine chemotherapy using electronic health records for cardiovascular risk factors (and calculation of QRISK3 score), cancer treatment, and clinical outcomes. FAC was defined by cardiovascular events during or within 3 months of fluoropyrimidine treatment, and Cox regression was used to assess associations of CV risk and cancer treatment with FAC. One thousand eight hundred ninety-eight patients were included (45% male; median age 64 years), with median follow up 24.5 (11.5-48.3 months); 52.7% of patients were at moderate or high baseline CV risk (QRISK3 score >10%) Cardiovascular events occurred in 3.1% (59/1898)-most commonly angina (64.4%, 38/59) and atrial fibrillation (13.6%, 8/59), with 39% events during cycle one of treatment. In univariable analysis, QRISK3 score >20% was significantly associated with incident FAC (HR 2.25, 95% CI 1.11-4.93, P = 0.03). On multivariable analysis, beta-blocker use (HR 1.04, 95% CI 1.00-1.08, P = 0.04) and higher BMI (HR 2.33, 95% CI 1.04-5.19, P = 0.04) were independently associated with incident CV events. Thirty-two of the 59 patients with FAC were subsequently rechallenged with fluoropyrimidine chemotherapy, with repeat CV events in 6% (2/32). Incident FAC did not affect overall survival (P = 0.50).

CONCLUSIONS

High BMI and use of beta-blockers are associated with risk of CV events during fluoropyrimidine chemotherapy. QRISK3 score may also play a role in identifying patients at high risk of CV events during fluoropyrimidine chemotherapy. Re-challenge with further fluoropyrimidine chemotherapy can be considered in patients following CV events during prior treatment.

The function and mechanism of circRNAs in 5-fluorouracil resistance in tumors: Biological mechanisms and future potential

5-Fluorouracil (5-FU) is a well-known chemotherapy drug extensively used in the treatment of breast cancer. It works by inhibiting cancer cell proliferation and inducing cell death through direct incorporation into DNA and RNA via thymidylate synthase (TS). Circular RNAs (circRNAs), a novel family of endogenous non-coding RNAs (ncRNAs) with limited protein-coding potential, contribute to 5-FU resistance. Their identification and targeting are crucial for enhancing chemosensitivity. CircRNAs can regulate tumor formation and invasion by adhering to microRNAs (miRNAs) and interacting with RNA-binding proteins, regulating transcription and translation. MiRNAs can influence enzymes responsible for 5-FU metabolism in cancer cells, affecting their sensitivity or resistance to the drug. In the context of 5-FU resistance, circRNAs can target miRNAs and regulate biological processes such as cell proliferation, cell death, glucose metabolism, hypoxia, epithelial-to-mesenchymal transition (EMT), and drug efflux. This review focuses on the function of circRNAs in 5-FU resistance, discussing the underlying molecular pathways and biological mechanisms. It also presents recent circRNA/miRNA-targeted cancer therapeutic strategies for future clinical application.

Detailed analysis of metastatic colorectal cancer patients who developed cardiotoxicity on another fluoropyrimidine and switched to S-1 treatment (subgroup analysis of the CardioSwitch-study)

BACKGROUND AND PURPOSE

The CardioSwitch-study demonstrated that patients with solid tumors who develop cardiotoxicity on capecitabine or 5-fluorouracil (5-FU) treatment can be safely switched to S-1, an alternative fluoropyrimidine (FP). In light of the European Medicines Agency approval of S-1 in metastatic colorectal cancer (mCRC), this analysis provides more detailed safety and efficacy information, and data regarding metastasectomy and/or local ablative therapy (LAT), on the mCRC patients from the original study.

MATERIALS AND METHODS

This retrospective cohort study was conducted at 12 European centers. The primary endpoint was recurrence of cardiotoxicity after switch. For this analysis, safety data are reported for 78 mCRC patients from the CardioSwitch cohort (N = 200). Detailed efficacy and outcomes data were available for 66 mCRC patients.

RESULTS

Data for the safety of S-1 in mCRC patients were similar to the original CardioSwitch cohort and that expected for FP-based treatment, with no new concerns. Recurrent cardiotoxicity (all grade 1) with S-1-based treatment occurred in 4/78 (5%) mCRC patients; all were able to complete FP treatment. Median progression-free survival from initiation of S-1-based treatment was 9.0 months and median overall survival 26.7 months. Metastasectomy and/or LAT was performed in 33/66 (50%) patients, and S-1 was successfully used in recommended neoadjuvant/conversion or adjuvant-like combination regimens and schedules as for standard FPs.

INTERPRETATION

S-1 is a safe and effective FP alternative when mCRC patients are forced to discontinue 5-FU or capecitabine due to cardiotoxicity and can be safely used in the standard recommended regimens, settings, and schedules.

Raltitrexed induces apoptosis through activating ROS-mediated ER stress by impeding HSPA8 expression in prostate cancer cells

Prostate cancer is the most common malignant tumor in males, which frequently develops into castration-resistant prostate cancer (CRPC). CRPC metastasis is the main reason for its high mortality rate. At present, it lacks effective treatment for patients with CRPC. Raltitrexed (RTX) has been shown to be effective in the treatment of colorectal cancer. However, the effect of RTX on prostate cancer and the underlying mechanism remain unknown. In the current study, we found that RTX could dose-dependently inhibit proliferation, migration, colony formation and induce apoptosis in DU145 and PC-3 cells. RTX also increased ROS generation in prostate cancer cells. Pretreatment with N-acetyl-L-cysteine (NAC) significantly prevented RTX-induced cell apoptosis and endoplasmic reticulum (ER) stress signaling activation in prostate cancer cells. Additionally, we found RTX-induced ROS generation and ER stress activation depended on the expression of heat shock protein family A member 8 (HSPA8). Over-expression of HSPA8 could alleviate RTX-induced cell apoptosis, ROS generation and ER stress signaling activation. Finally, our study also showed that RTX attenuated the tumor growth of prostate cancer in the DU145 xenograft model and significantly downregulated HSPA8 expression and activated ER stress signaling pathway in tumor tissues. Our study is the first to reveal that RTX induces prostate cancer cells apoptosis through inhibiting the expression of HSPA8 and further inducing ROS-mediated ER stress pathway action. This study suggests that RTX may be a novel promising candidate drug for prostate cancer therapy.

Fluoropyrimidine-induced hand-foot syndrome and cardiotoxicity: recommendations for the use of the oral fluoropyrimidine S-1 in metastatic colorectal cancer

BACKGROUND

Fluoropyrimidines (FPs) are an essential part of the majority of systemic regimens in the treatment of metastatic colorectal cancer (CRC). The use of the oral FP S-1 has been approved by the European Medicines Agency as monotherapy or in combination with oxaliplatin or irinotecan, with or without bevacizumab, for the treatment of patients with metastatic CRC in whom it is not possible to continue treatment with another FP due to hand-foot syndrome (HFS) or cardiovascular toxicity (CVT). Subsequently, this indication has been included in the 2022 ESMO guidelines for metastatic CRC. Recommendations for use in daily practice are not available.

PATIENTS AND METHODS

Based on peer-reviewed published data on the use of S-1 in Western patients with metastatic CRC who switched from infusional 5-fluorouracil (5-FU) or capecitabine to S-1 for reasons of HFS or CVT, recommendations for its use were formulated by an international group of medical oncologists with expertise in the treatment of metastatic CRC and a cardio-oncologist.

RESULTS

In patients who experience pain and/or functional impairment due to HFS during treatment with capecitabine or infusional 5-FU, a switch to S-1 is recommended without prior dose reduction of capecitabine/5-FU. S-1 should preferably be initiated at full dose when HFS has decreased to grade ≤1. In patients with cardiac complaints, in whom an association with capecitabine or infusional 5-FU treatment cannot be excluded, capecitabine/5-FU should be discontinued and a switch to S-1 is recommended.

CONCLUSIONS

These recommendations should guide clinicians in daily practice in the treatment of patients with metastatic CRC with FP-containing regimens.

Fluoropyrimidine‑induced cardiotoxicity in colorectal cancer patients: a prospective observational trial (CHECKPOINT)

Fluoropyrimidines (FP) are the backbone chemotherapy in colorectal cancer (CRC) treatment; however, their use is associated with cardiotoxicity, which is underreported. In the present study, it was aimed to prospectively determine the incidence rates and related risk factors of FP‑induced cardiotoxicity (FIC) in CRC patients and at identifying predictive biomarkers. A total of 129 consecutive previously untreated CRC patients underwent active cardiological monitoring, including 5‑items simplified questionnaire on symptoms, electrocardiogram (ECG) and plasma sample collection during FP chemotherapy. FIC was defined as the presence of ECG alterations and/or the arising of at least one symptom of chest pain, dyspnoea, palpitations or syncope. The primary objective was the evaluation of FIC incidence. Secondary objectives were the correlation of FIC with well‑known cardiological risk factors and the identification of circulating biomarkers (serum levels of troponin I, pro hormone BNP; miRNA analysis) as predictors of FIC. A total of 20 out of 129 (15.5%) patients experienced FIC. The most common symptoms were dyspnoea (60%) and chest pain (40%), while only 15% of patients presented ECG alterations, including one acute myocardial infarction. Retreatment with FP was attempted in 90% of patients with a favourable outcome. Despite 48% of patients having cardiological comorbidities, an increased FIC was not observed in this subgroup. Only the subgroup of females with the habit of alcohol consumption showed an increased risk of FIC. None of the circulating biomarkers evaluated demonstrated a clinical utility as FIC predictors. FIC can be an unexpected, life‑threatening adverse event that can limit the subsequent treatment choices in patients with CRC. In this prospective study, well‑known cardiological comorbidities were not related to higher FIC risk and circulating biomarkers predictive of toxicity could not be found. With careful monitoring, mainly based on symptoms, almost all patients completed the FP treatment.

The puzzling clinical presentation of fluoropyrimidines cardiotoxicity

The cardiotoxicity of fluoropyrimidines (FP) [5-Fluorouracil and Capecitabine] is often reported as acute cardiac ischemia with rest typical angina, signs of ischemia at electrocardiogram (ECG), and ventricular kinetics abnormalities. However, silent ischemia, effort-related toxicity, and ventricular arrhythmias (VA) have been also described. The aim of this study is to report a consecutive series of 115 patients with FP cardiotoxicity observed in a single center both within clinical prospective studies and during the clinical routine. The clinical presentation widely varied as regards symptoms, ECG abnormalities, and clinical outcomes. We report also the strategies used to prevent cardiotoxicity in a subgroup of 35 patients who continued o rechallenged FP therapy after cardiotoxicity. In nearly half of the patients, the cardiotoxicity was triggered by physical effort. Typical angina was rare: the symptoms were absent in 51% of cases and were atypical in half of the other cases. ST-segment elevation and VA were the most frequent ECG abnormality; however, ST segment depression or negative T waves were the only abnormalities in 1/3 of the cases. Troponins essays were often within the normal limits, even in presence of extensive signs of ischemia. The most effective strategy to prevent cardiotoxicity at rechallenge was reducing FP dosage and avoiding physical effort. Anti-ischemic therapies were not always effective. Raltitrexed was a safe alternative to FP. Fluoropyrimidine cardiotoxicity shows a wide variety of clinical presentations in real life, from silent ischemia to atypical symptoms, acute coronary syndrome, left ventricular dysfunction (LVD), VA, or complete atrio-ventricular block. Physical effort is the trigger of cardiotoxicity in nearly half of the cases. The recognition of cardiotoxicity cannot rely on symptoms only but requires an active screening with ECG and stress test in selected cases.

First-line chemotherapy with raltitrexed in metastatic colorectal cancer: an Association des Gastro-entérologues Oncologues (AGEO) multicentre study

BACKGROUND

In case of contraindication or intolerance to fluoropyrimidines, raltitrexed is a validated alternative in metastatic colorectal cancer (mCRC), associated or not with oxaliplatin. Little is known about the outcomes of raltitrexed combined with irinotecan or targeted therapies.

METHODS

This retrospective multicentre study enroled mCRC patients treated with first-line raltitrexed-based chemotherapy. Treatment-related toxicities were recorded. Progression-free survival (PFS) and overall survival (OS) were calculated from treatment start.

RESULTS

75 patients were treated with raltitrexed alone, TOMOX, or TOMIRI with or without bevacizumab. Grade 3-4 adverse events were seen in 31% of patients, without significant difference between the different treatment schedules. amongst the 36 patients with a history of fluoropyrimidine-induced cardiac toxicity, none developed cardiovascular events on raltitrexed. Median PFS and OS were 10.6 (95% CI 8.2 - 13.1) and 27.4 months (95% CI 24.1-38.1), respectively. Considering the chemotherapy regimen, TOMOX was significantly associated with better PFS and OS compared to TOMIRI and raltitrexed alone.

CONCLUSIONS

In patients with mCRC not eligible for fluoropyrimidines, first-line raltitrexed-based chemotherapy had an acceptable safety profile. PFS and OS were consistent with usual survival data in mCRC, and significantly better in patients treated with TOMOX, independently of associated targeted therapies.

Estimating Risk of Cardiovascular Disease Among Long-Term Colorectal Cancer Survivors: A Nationwide Cohort Study

Background

Concerns about a growing number of colorectal cancer survivors have emerged regarding cardiovascular disease (CVD) risks. However, there is not yet a predictive tool that can estimate CVD risk and support the management of healthcare as well as disease prevention in terms of CVD risk among long-term colorectal cancer survivors.

Aim

To develop predictive tools to estimate individualized overall and each subtype of CVD risk using a nationwide cohort in South Korea.

Methods and Results

A total of 4,709 newly diagnosed patients with colorectal cancer who survived at least 5 years in the National Health Insurance System were analyzed. Cox proportional hazard regression was used for the identification of independent risk factors for the derivation of predictive nomograms, which were validated in an independent cohort (n = 3,957). Age, fasting serum glucose, γ-glutamyl transpeptidase, Charlson comorbidity index, household income, body mass index, history of chemotherapy, cigarette smoking, and alcohol consumption were identified as independent risk factors for either overall CVD or each subtype of CVD subtype. Based on the identified independent risk factors, six independent nomograms for each CVD category were developed. Validation by an independent cohort demonstrated a good calibration with a median C-index of 0.687. According to the nomogram-derived median score, relative risks of 2.643, 1.821, 4.656, 2.629, 4.248, and 5.994 were found for overall CVD, ischemic heart disease, myocardial infarction, total stroke, ischemic stroke, and hemorrhage stroke in the validation cohort.

Conclusions

The predictive tools were developed with satisfactory accuracy. The derived nomograms may support the estimation of overall and individual CVD risk for long-term colorectal cancer survivors.

Managing 5FU Cardiotoxicity in Colorectal Cancer Treatment

Fluorouracil (5FU) is the backbone chemotherapy agent in the treatment of colorectal cancer (CRC). Cardiotoxicity represents an uncommon but serious side effect of treatment with 5FU. Here, we review the current literature on 5FU-cardiotoxicity in the setting of CRC specifically, with a focus on data from the modern era of combination chemotherapy. Despite decades of study, there is little consensus on risk factors and biomarkers for 5FU-cardiotoxicity, nor how patients with CRC should be managed following a cardiotoxicity event. Given the elevated risk of recurrent cardiotoxicity on rechallenge, the use of alternative regimens that do not contain 5FU is a critical aspect of management. Data on the cardiotoxicity risk and efficacy of non-5FU regimens in CRC are therefore reviewed in detail.

Risk for Myocardial Infarction Following 5-Fluorouracil Treatment in Patients With Gastrointestinal Cancer

Background

Myocardial infarction is a cardiac adverse event associated with 5-fluorouracil (5-FU). There are limited data on the incidence, risk, and prognosis of 5-FU-associated myocardial infarction.

Objectives

The aim of this study was to examine the risk for myocardial infarction in patients with gastrointestinal (GI) cancer treated with 5-FU compared with age- and sex-matched population control subjects without cancer (1:2 ratio).

Methods

Patients with GI cancer treated with 5-FU between 2004 and 2016 were identified within the Danish National Patient Registry. Prevalent ischemic heart disease in both groups was excluded. Cumulative incidences were calculated, and multivariable regression and competing risk analyses were performed.

Results

A total of 30,870 patients were included in the final analysis, of whom 10,290 had GI cancer and were treated with 5-FU and 20,580 were population control subjects without cancer. Differences in comorbid conditions and select antianginal medications were nonsignificant (P > 0.05 for all). The 6-month cumulative incidence of myocardial infarction was significantly higher for 5-FU patients at 0.7% (95% CI: 0.5%-0.9%) versus 0.3% (95% CI: 0.3%-0.4%) in population control subjects, with a competing risk for death of 12.1% versus 0.6%. The 1-year cumulative incidence of myocardial infarction for 5-FU patients was 0.9% (95% CI: 0.7%-1.0%) versus 0.6% (95% CI: 0.5%-0.7%) among population control subjects, with a competing risk for death of 26.5% versus 1.4%. When accounting for competing risks, the corresponding subdistribution hazard ratios suggested an increased risk for myocardial infarction in 5-FU patients, compared with control subjects, at both 6 months (hazard ratio: 2.10; 95% CI: 1.50-2.95; P < 0.001) and 12 months (hazard ratio: 1.39; 95% CI: 1.05-1.84; P = 0.022).

Conclusions

Despite a statistically significantly higher 6- and 12-month risk for myocardial infarction among 5-FU patients compared with population control subjects, the absolute risk for myocardial infarction was low, and the clinical significance of these differences appears to be limited in the context of the significant competing risk for death in this population.

Abnormal Dihydropyrimidine Dehydrogenase Activity as an Indicator of Potential 5-Fluorouracil Linked Cardiotoxicity in Colorectal Cancer Patients: Are Toxic Events Inevitable?

Colorectal cancer (CRC) treatment can be limited to surgical resection for low stages of the disease while subsequent chemotherapy is the preferred treatment for the higher-stage disease. This chemotherapy relies heavily on fluoropyrimidine: 5-fluorouracil (5-FU) and capecitabine, a role played for decades. Fluoropyrimidine-linked treatment can present important and even lethal toxic events at the cardiac level like acute coronary syndrome, arrhythmias, and death.

The production of these toxic events depends on the capacity of a subject to metabolize the fluoropyrimidines adequately, and this depends on the activity of the enzyme dihydropyrimidine dehydrogenase (DPD). Any change that affects the quantity or quality of this enzyme will compromise its capacity to metabolize the fluoropyrimidines. The resultant abnormal enzyme activity exposes the patient to continuously high levels of the chemotherapeutic agent or its catabolites. Consequently, the patient becomes more susceptible to pyrimidine-linked toxic adverse events.

Genetic testing of patients for potential decreased DPD activity before subjecting them to fluoropyrimidine-based chemotherapy will help identify subjects at greater risk of increased cardiotoxicities, the possibility of prompt intervention, should these appear, and a multidisciplinary strategy aimed at managing these cases. Potential cases of cardiotoxicity in CRC patients, candidates to fluoropyrimidine toxicities, can be anticipated by pretreatment screening of DPD activity. Pretreatment screening will reduce many hospitalizations with a consequent decrease in costs both to the patients and the healthcare system.

This review article will examine the 5-FU linked cardiotoxicity, known correlated risk factors, clinical manifestations, management strategy, and the role of genetic testing in identifying high-risk patients.

Adjuvant Therapies in Colon Cancer

Most of the patients with localized colon cancer undergo curative resection. However, significant number of patients will recur with metastatic disease, especially those with node positive cancer. Adjuvant chemotherapy has shown to improve cure rate and survival by eradicating micrometastases. The benefit of adjuvant therapy is well established in node-positive cancers, while their role in stage II cancer is not well defined. A number of molecular markers have been identified that are prognostic and/or predictive in colon cancer. Such molecular markers, and other clinicopathological features play an important role in selection of appropriate therapy and duration of treatment. Emerging evidence for the utility of genomic profiling or detection of circulating tumor DNA (ctDNA) are promising which may further facilitate decision making in the future. This chapter reviews the evolution of adjuvant therapy for resected colon cancer, the current evidence and the factors influence the choice of therapy.

What the Cardiologist Needs to Consider in the Management of Oncologic Patients with STEMI-Like Syndrome: A Case Report and Literature Review

In pre-hospital care, an accurate and quick diagnosis of ST-segment elevation myocardial infarction (STEMI) is imperative to promptly kick-off the STEMI network with a direct transfer to the cardiac catheterization laboratory (cath lab) in order to reduce myocardial infarction size and mortality. Aa atherosclerotic plaque rupture is the main mechanism responsible for STEMI. However, in a small percentage of patients, emergency coronarography does not reveal any significant coronary stenosis. The fluoropyrimidine agents such as 5-Fluorouracil (5-FU) and capecitabine, widely used to treat gastrointestinal, breast, head and neck cancers, either as a single agent or in combination with other chemotherapies, can cause potentially lethal cardiac side effects. Here, we present the case of a patient with 5-FU cardiotoxicity resulting in an acute coronary syndrome (ACS) with recurrent episodes of chest pain and ST-segment elevation.. Our case report highlights the importance of widening the knowledge among cardiologists of the side effects of chemotherapeutic drugs, especially considering the rising number of cancer patients around the world and that fluoropyrimidines are the main treatment for many types of cancer, both in adjuvant and advanced settings.

Metastatic colorectal cancer: Advances in the folate-fluoropyrimidine chemotherapy backbone

Notwithstanding recent treatment advances in metastatic colorectal cancer (mCRC), chemotherapy with a combination of a fluoropyrimidine and a folate agent, often 5-fluorouracil (5-FU) and leucovorin, remains the backbone of treatment regimens for the majority of patients with mCRC. This is despite a recent focus on molecular-targeted treatments and patient stratification according to mutational status or expression levels of specific genes. Intracellular folate concentration was discovered to be pivotal in the cytotoxic efficacy of 5-FU, paving the way to the current standard combination therapy approach. Subsequent discovery that systemic chemotherapy agents, such as irinotecan and oxaliplatin, can further increase the efficacy of 5-FU-based treatments led to the development of several combination chemotherapy regimens, including FOLFOX, FOLFIRI and FOLFOXIRI. Subsequent efforts to optimise 5-FU-based treatments have focused on 5-FU analogues, initially capecitabine and the combination drug tegafur/gimeracil/oteracil (S-1) and then TAS-102, which has recently been evaluated in phase 3 clinical trials for refractory colorectal cancer. Further approaches taken to improve the efficacy of 5-FU chemotherapy regimens have focused on optimising the route and dosing schedules and regulating folate metabolism. Pharmacokinetic variability caused by the requirement for metabolic conversion of leucovorin has been central to recent research, and the development of agents such as arfolitixorin which bypass the need for metabolic conversion remains promising for future therapeutic candidates. In this review, we summarise the evidence leading to the current treatment regimens employing 5-FU and leucovorin, focusing on recent approaches taken to optimise and refine treatments to improve clinical outcomes in patients with mCRC.

Clinical efficacy of irinotecan plus raltitrexed chemotherapy in refractory esophageal squamous cell cancer

Our retrospective study assessed the efficacy and safety of irinotecan plus raltitrexed in esophageal squamous cell cancer (ESCC) patients who were previously treated with multiple systemic therapies. Between January 2016 and December 2018, records of 38 ESCC patients who underwent irinotecan plus raltitrexed chemotherapy after at least one line of chemotherapy were reviewed. Efficacy assessment was performed every two cycles according to the RECIST version 1.1. A total of 95 cycles of chemotherapy were administered, and the median course was 3 (range 2-6). There was no treatment-related death. Nine patients had partial response, 21 had stable disease and eight had progressive disease. The overall objective response rate was 23.68% (9/38) and the disease control rate was78.94% (30/38). After a median follow-up of 18.5 months, the median progression-free survival and overall survival were 105 and 221 days, respectively. There were five patients (13.15%) with grade 3/4 leukopenia, three patients (7.89%) with grade 3/4 neutropenia and one patient (2.63%) with grade 3/4 diarrhea. The combination of irinotecan plus raltitrexed was effective for pretreated ESCC patients. Further studies are needed to determine the optimal dose of the two drugs.

A comparison between raltitrexed plus cisplatin and docetaxel plus cisplatin in concurrent chemoradiation for non-surgical esophageal squamous cell carcinoma

PURPOSE

Chemoradiotherapy (CRT) is considered as a standard treatment for unresectable and inoperable esophageal cancer (EC) patients. However, no consensus has been reached regarding the optimal synchronous chemotherapy regimen and the best combination of radiotherapy and chemotherapy. The aim of this study was to evaluate the efficacy and toxicity of raltitrexed plus cisplatin and docetaxel plus cisplatin to find a safe and effective concurrent chemotherapy schedule.

PATIENTS AND METHODS

Our retrospective study included 151 EC patients treated with raltitrexed and cisplatin (RP) (n=90) or docetaxel and cisplatin (DP) (n=61) from 2011 till 2018. Survival outcomes and treatment related toxicity were analyzed between the two groups.

RESULTS

PFS and OS were 18 and 34 months in the RP group, while 13 and 20 months in the DP group (P=0.118 and P=0.270). The 1-, 2-, 3-year survival rates of the RP group were 71.1, 55.4 and 46.4%. For the DP group, these were 63.9, 44.3 and 37.6%, respectively. Compared with DP group, RP group received a superior CR rate (68.9% versus 52.5%, P=0.041). There was a trend that the total number of toxic reactions in RP group was lower than that in DP group (P=0.058).

CONCLUSIONS

Even RP and DP groups have the similar survival outcomes and toxicity, raltitrexed/cisplatin get a higher complete response rate. Our study suggests that raltitrexed combined with cisplatin is a safe and effective concurrent chemotherapy regimen and it might be used as an alternative for cisplatin/5-FU and cisplatin/docetaxel in CCRT for EC patients.

Fluoropyrimidine-induced cardiotoxicity

Cardio-oncology is a discipline based on early screening, monitoring, and treating chemotherapy-induced cardiotoxicity. There are many chemotherapeutics known for their cardiac toxic effects, including fluoropyrimidines. Fluoropyrimidine represents the cornerstone of many types of cancer and each year almost two million cancer patients undergo this treatment. Fluoropyrimidine-induced cardiotoxicity can be manifested in several forms, from angina pectoris to sudden death. This paper is a review of how the cardiotoxicity of fluoropyrimidines is presented, the mechanisms of its occurrence, its diagnosis, and management.

Inhibition of EZH2 enhances the therapeutic effect of 5-FU via PUMA upregulation in colorectal cancer

Although the survival rate of patients with cancer have increased due to the use of current chemotherapeutic agents, adverse effects of cancer therapy remain a concern. The reversal of drug resistance, reduction in harmful side effects and accelerated increase in efficiency have often been addressed in the development of combination therapeutics. Tazemetostat (EPZ-6438), a histone methyltransferase EZH2 selective inhibitor, was approved by the FDA for the treatment of advanced epithelioid sarcoma. However, the effect of tazemetostat on colorectal cancer (CRC) and 5-FU sensitivity remains unclear. In this study, the enhancement of tazemetostat on 5-FU sensitivity was examined in CRC cells. Our findings demonstrated that tazemetostat combined with 5-FU exhibits synergistic antitumor function in vitro and in vivo in CRC cells. In addition, tazemetostat promotes PUMA induction through the ROS/ER stress/CHOP axis. PUMA depletion attenuates the antitumor effect of the combination therapy. Therefore, tazemetostat may be a novel treatment to improve the sensitivity of tumors to 5-FU in CRC therapy. In conclusion, the combination of 5-FU and tazemetostat shows high therapeutic possibility with reduced unfavorable effects.

Protective Effect of Calcitriol on Organ Damage Induced by 5-Fluorouracil Treatment

Chemotherapy is a major therapeutic strategy for patients with cancer. Owing to the severe inflammatory response of chemotherapy, patients experience extreme discomfort during treatment, and this may interrupt treatment completion. The vitamin D3 has a role in anti-inflammation, but no study has explored whether vitamin D3 has beneficial effects on patients undergoing chemotherapy. In this study, we investigated the effect of calcitriol (Vit-D) on inflammatory responses during 5-fluorouracil (5-FU) treatment. Rats were divided into five groups and treated with 1:1 dilution of 5-FU with equal amount of 0.9% saline, 1:3 dilution of 5-FU with 0.9% saline threefold dilution, 5-FU, Vit-D, or 5-FU + Vit-D. A single dose of 15 mg/kg of 5-FU was intravenously administered for 4 h, and the blood biochemical substances and inflammatory cytokines were assessed after the intervention. The 5-FU group had higher AST, ALT, LDH, and CPK levels than those in the 5-FU + Vit-D group. The 5-FU + Vit-D group had a lower TNF-α value than the 5-FU. The IL-6 levels in the 5-FU + Vit-D group were also significantly lower than those in 5-FU. Calcitriol administration during 5-FU therapy can alleviate the production of inflammatory cytokines and liver damage.

Incidence and risk markers of 5-fluorouracil and capecitabine cardiotoxicity in patients with colorectal cancer

Background: Fluoropyrimidines are mainstay chemotherapeutics in the treatment of gastrointestinal cancers and are also used to treat breast cancer and head and neck cancers. However, 5-flourouracil (5-FU) and capecitabine may induce cardiotoxicity that mostly presents as acute coronary syndromes. We compared the incidence of cardiotoxicity induced by 5-FU and capecitabine in patients with colorectal cancer and sought to identify risk markers for cardiotoxicity.Methods: We reviewed all consecutive patients with colorectal cancer who received 5-FU or capecitabine at one institution in the neoadjuvant (2007-2016), adjuvant (2000-2016) or metastatic setting (2007-2016).Results: Totally, 995 patients received 5-FU and 1241 received capecitabine. The incidence of cardiotoxicity induced by 5-FU was 5.2% [95% confidence interval (CI): 3.8-6.6%] and 4.1% (95% CI: 3.0-5.2%) induced by capecitabine (p = .21). The most common events were angina without ischemia (5-FU: 1.6%, capecitabine: 1.3%, p = .53), angina with ischemia on ECG (5-FU: 0.9%, capecitabine: 0.8%, p = .53), unspecified chest pain (5-FU: 0.9%, capecitabine: 0.6%, p = .34), ST-elevation myocardial infarction (5-FU: 0.5%; capecitabine: 0.4%, p = .76) and non-ST-elevation myocardial infarction (5-FU: 0.7%, capecitabine: 0.5%, p = .50). Cardiac arrest or sudden death occurred in 0.5 and 0.4%, respectively (p = 1). No risk markers for cardiotoxicity induced by 5-FU were identified. In the capecitabine group, ischemic heart disease was a risk marker (odds ratio: 2.9, 95% CI: 1.2-7.0, p = .016).Conclusions: Five percent of patients treated with 5-FU developed cardiotoxicity and 4% treated with capecitabine. Ischemic heart disease was a risk marker for cardiotoxicity induced by capecitabine.

Efficacy and Cardiotoxic Safety Profile of Raltitrexed in Fluoropyrimidines-Pretreated or High-Risk Cardiac Patients With GI Malignancies: Large Single-Center Experience

BACKGROUND

Gastrointestinal (GI) cancer patients may not be considered for therapy with fluoropyrimidines (FPs) because of previous cardiovascular (CV) toxicity or preexisting risk factors; such patients may benefit from raltitrexed-based therapy.

PATIENTS AND METHODS

Patient, tumor, and treatment characteristics, as well as clinical outcomes of all consecutively treated patients with raltitrexed at the Royal Marsden Hospital between October 1998 and July 2011 were examined. GI cancer patients who developed CV toxicity as a result of FPs and those with significant CV risk factors receiving raltitrexed were included in this analysis.

RESULTS

A total of 247 patients (155 and 92 with CV FP-related CV toxicities and significant CV risk factors, respectively) treated with raltitrexed alone or in combination were examined after a median follow-up of 47.1 months. CV toxicity profiles of patients receiving capecitabine (n = 110) and 5-fluorouracil (n = 45) were largely similar. Of raltitrexed-treated patients, 13 (5%) experienced CV toxicities and 1 (< 0.1%) died as a result of myocardial infarction. The median progression-free survival (PFS) and overall survival (OS) were 36.0 months (95% confidence interval [CI], 26.5-48.6) and 44.3 months (95% CI, 33.1-56.8), respectively. The 5-year survival for early stage GI malignancies (n = 140) was 62.0% (95% CI, 50.1-71.9). Median PFS and OS were not reached in this group (interquartile range = 38.4 months to NR); median PFS and OS for advanced GI malignancies (n = 107) were 18.8 (95% CI, 11.9-25.7) and 23.7 months (95% CI, 17.0-26.9), respectively.

CONCLUSION

A raltitrexed-based regimen is well-tolerated therapy with comparable efficacy to FPs in patients with GI malignancies with significant CV toxicities or risk factors.

Tegafur deteriorates established cardiovascular atherosclerosis in colon cancer: A case report and review of the literature

BACKGROUND

Cardiac toxic effect of tegafur (S-1) is extremely rare, and there has been no report on this issue so far.

CASE SUMMARY

We herein report a typical case of single S-1 administration after radical operation for colon cancer. The patient had no background or medical history of acute coronary syndrome (ACS), and only aortic and coronary atherosclerosis was revealed by computed tomography (CT) before surgery. He complained of sternum pain during the fifth cycle of S-1 treatment. Electrocardiogram (ECG) and serum cardiac marker cardiac troponin T (cTnT) strongly suggested ACS, which was possibly caused by S-1 cardiotoxicity.

CONCLUSION

Monitoring protocols based on ECG, CT, and cTnT should be performed in real time to evaluate cardiac function during S-1 administration.

Acute coronary syndrome in the oncology patient: An avoidable event?

5-Fluorouracil is a first-line agent in several cancer-therapy regimens. Cardiotoxicity is common, with coronary artery disease being an important risk factor. We report the case of an acute coronary syndrome presumably induced by 5-FU, in a patient with previously unknown and asymptomatic coronary artery disease, with an estimated intermediate risk for cardiovascular events. Pre-chemotherapy risk evaluation and optimal patient care are still not standardized in this clinical scenario.

Cardiotoxicity of 5-fluorouracil and capecitabine in Chinese patients: a prospective study

Background

5-Fluorouracil (5-FU) and capecitabine-associated cardiotoxicity ranging from asymptomatic electrocardiography (ECG) abnormalities to severe myocardial infarction has been reported in a number of studies, but such cardiotoxicity in Chinese patients with malignant diseases has not been investigated to date. In the present study, we aimed to prospectively evaluate the incidence rates and clinical manifestations of 5-FU- and capecitabine-associated cardiotoxicity in cancer patients recruited from multiple centers in China.

Methods

Among the 527 patients who completed the study, 196 received 5-FU-based chemotherapy and 331 received capecitabine-based chemotherapy as either first-line or adjuvant therapy. Adverse events were reported during the treatment and up to 28 days of follow-up. Outcome measures included ECG, myocardial enzymes, cardiac troponin, brain natriuretic peptide and echocardiography. Univariate analysis and logistic regression were performed for subgroup analysis and identification of significant independent variables that are associated with cardiotoxicity of both agents.

Results

In total, 161 of 527 patients (30.6%) experienced cardiotoxicity. The incidence rate of cardiotoxicity was 33.8% (112/331) in the capecitabine group, which was significantly higher than the rate of 25% (49/196) in the 5-FU group (P = 0.0042). 110/527 patients (20.9%) suffered arrhythmia, 105/527 (19.9%) developed ischemic changes, while only 20/527 patients (3.8%) presented heart failure and 6/527 patients (1.1%) had myocardial infarction. Pre-existing cardiac disease, hypertension, capecitabine-based chemotherapy and duration of treatment were identified as significant risk factors associated with cardiotoxicity. The odds ratio were 15.7 (prior history of cardiac disease versus no history), 1.86 (capecitabine versus 5-FU), 1.06 (5–8 versus 1–4 chemotherapy cycles) and 1.58 (hypertension versus no hypertension), respectively.

Conclusions

Cardiotoxicity induced by fluoropyrimidines in the Chinese population may be underestimated in clinical practice. Close monitoring of patients is recommended, especially for those patients at high risk for cardiotoxicity. Possible risk factors are duration of treatment, capecitabine-based chemotherapy, pre-existing cardiac diseases and hypertension.

Trial registration This study was initiated on January 22, 2014 and has been retrospectively registered with the registration number ChiCTR1800015434

Fluoropyrimidine-induced cardiotoxicity

Fluoropyrimidines (5-fluorouracil and capecitabine) are antimetabolite drugs, widely used for the treatment of a variety of cancers, both in adjuvant and in metastatic setting. Although the most common toxicities of these drugs have been extensively studied, robust data and comprehensive characterization still lack concerning fluoropyrimidine-induced cardiotoxicity (FIC), an infrequent but potentially life-threatening toxicity. This review summarizes the current state of knowledge of FIC with special regard to proposed pathogenetic models (coronary vasospasm, endothelium and cardiomyocytes damage, toxic metabolites, dihydropyrimidine dehydrogenase deficiency); risk and predictive factors; efficacy and usefulness in detection of laboratory markers, electrocardiographic changes and cardiac imaging; and specific treatment, including a novel agent, uridine triacetate. The role of alternative chemotherapeutic options, namely raltitrexed and TAS-102, is discussed, and, lastly, we overview the most promising future directions in the research on FIC and development of diagnostic tools, including microRNA technology.

Fluoropyrimidine-induced cardiac toxicity: challenging the current paradigm

BACKGROUND

Fluoropyrimidine chemotherapy [5-fluorouracil (5-FU) and capecitabine] are commonly used agents in the treatment of various solid malignancies. However, their use has been limited by cardiac toxicity, presenting as a wide spectrum of asymptomatic (e.g., EKG changes) and symptomatic (e.g., chest pain) manifestations related to coronary vasospasm leading to myocardial ischemia. Historically, patients with suspected coronary vasospasm have been treated with traditional acute ischemic workup and various combinations of anti-anginal therapies. In addition, most patients typically are not rechallenged with fluoropyrimidine after experiencing initial cardiovascular side-effects with resulting interruption of planned chemotherapy regimens.

METHODS

We report a case series of 11 consecutive patients in a single-center with suspected fluoropyrimidine-induced coronary vasospasm who were successfully rechallenged with the culprit drug to allow for planned chemotherapy completion. Our protocol utilized rechallenge with bolus infusional regimen of intravenous fluoropyrimidine chemotherapy and oral capecitabine with cardioprotective pretreatment with two calcium blockers and long-acting oral nitrate therapy.

RESULTS

We were successfully able to continue and complete the previously planned first-line chemotherapy regimen for all 11 patients with minimal therapeutic interruption. There have been no cardiac events or evidence of recurrent coronary spasm after completion of therapy with discontinuation of prophylactic medications upon therapy completion.

CONCLUSIONS

We report a single-institution experience of successful rechallenge with fluoropyrimidines with careful cardiac monitoring and the combined use of calcium channel blockers and long-acting nitrates. With further study, this algorithm can be used to safely continue fluoropyrimidines, a potentially curative regimen in the treatment of many solid tumors.

Thymidine phosphorylase expression and prognosis in colorectal cancer treated with 5-fluorouracil-based chemotherapy: A meta-analysis

In the past decades, various studies have suggested a possible link between thymidine phosphorylase (TP) level and colorectal cancer (CRC) treated with 5-fluorouracil (5-FU)-based chemotherapy; however, they have arrived at inconsistent results. Therefore, the present meta-analysis aimed to disclose a more comprehensive evaluation of this relationship. PubMed, the Cochrane Library, Ovid MEDLINE, Embase and China National Knowledge Infrastructure were systematically searched for studies that evaluated the prognostic value of TP in CRC. Stata 12.0 software was used to test the heterogeneity and evaluate the overall test performance. A total of 15 studies, including 1,225 patients, were included. The summary estimates of TP for CRC treated with 5-FU-based chemotherapy indicated a moderately positive prognosis with a hazard ratio (HR) of 0.76 (P=0.031) for overall survival and a HR of 0.711 (P=0.022) for relapse-free survival. On the basis of the present meta-analysis, TP could be promising and meaningful in the prognosis of CRC treated with 5-FU-based chemotherapy.

Safe administration of S-1 after 5-fluorouracil-induced cardiotoxicity in a patient with colorectal cancer

Cardiotoxicity is a rare but challenging complication of 5-fluorouracil (5-FU) therapy. Compared with 5-FU, after application of S-1 lower plasma levels of the cardiotoxic metabolite alpha-fluoro-beta-alanine have been reported. Evidence for safe administration of S-1 following 5-FU cardiotoxicity is limited to a case report in an Asian patient. Herein we report the first case of S-1 application after 5-FU cardiotoxicity in a Caucasian patient.A 67-year-old man with right-sided metastatic colorectal cancer and history of 5-FU cardiotoxicity had a progressive disease after 8-month therapy with irinotecan and bevacizumab. In consideration of known 5-FU cardiotoxicity, he was referred to our department for therapy counselling. We started a combination therapy with S-1, oxaliplatin and bevacizumab. The treatment was well tolerated without any cardiac problems.Our report confirms the safety of S-1 in cases of 5-FU cardiotoxicity also in a Caucasian patient.

New Perspectives in the Treatment of Advanced Gastric Cancer: S-1 as a Novel Oral 5-FU Therapy in Combination with Cisplatin

Oral fluoropyrimidines have been available for more than 10 years. Capecitabine is well established in treating solid tumors in Europe. S-1 (Teysuno®), an oral formulation containing the 5-fluorouracil (5-FU) prodrug tegafur and the two enzyme modulators gimeracil and oteracil, has not been available in non-Asia countries until recently. In Japan, S-1 in combination with cisplatin is the recommended first-line treatment in patients with gastric cancer. In Europe, the first trials with S-1 were disappointing due to high unacceptable incidences of adverse events. Pharmacokinetic studies showed differences in Asian and Caucasian patients; therefore, a new non-Asian study program was initiated, which led to the pivotal phase 3 trial First-Line Advanced Gastric Cancer Study (FLAGS). In FLAGS, 1,053 patients with advanced gastric cancer from 24 non-Asian countries were enrolled. S-1 plus cisplatin showed no overall survival (OS) benefit when compared to 5-FU plus cisplatin. The primary endpoint superior OS was not met but better tolerability was shown. A post hoc noninferiority OS and safety analysis showed that S-1 plus cisplatin has the same efficacy as 5-FU plus cisplatin but a more favorable safety profile. This led to the approval of S-1 in combination with cisplatin in gastric cancer in Europe in 2011. This article reviews the mode of action of S-1, pivotal study results from an EU point of view, and future perspectives.

Optimizing adjuvant therapy and survivorship care of stage III colon cancer

The MOSAIC trial demonstrated nearly a decade ago that the addition of oxaliplatin to 5-fluorouracil improves outcomes in the adjuvant treatment of colon cancer, but no new agents have been shown to be superior to standard FOLFOX therapy. Oncologists have refined the use of oxaliplatin containing regimens to optimize outcomes, improved patient selection for multi-agent chemotherapy and expanded survivorship care to meet the needs of the growing number of survivors. In this article, we review the historical contexts of current therapy, appropriate staging investigations, the importance of timely initiation of therapy and key survivorship issues. We also discuss exciting opportunities for change, including reduced duration of adjuvant chemotherapy and the use of circulating tumor cells and DNA in surveillance.

TAS-102, the first "cardio-gentle" fluoropyrimidine in the colorectal cancer landscape?

Background

Cardiotoxicity in the form of cardiac arrhythmia, myocardial infarction, and angina-like symptoms are not rare complications of fluoropyrimidines as 5-Fluorouracil (5FU) and capecitabine.

Discussion

Tas-102, a novel oral fluoropyrimidine, was recently approved by FDA for the treatment of advanced and refractory colorectal cancer. Its unique mechanism of action doesn’t seem linked with cardiotoxicity in clinical trials reported so far.

Summary

TAS 102 may represent one of the drugs of choice for patients with advanced colorectal cancer with cardiac disease. This intriguing and clinically relevant issue is briefly examined.

Degradation of 5-FU by means of advanced (photo)oxidation processes: UV/H2O2, UV/Fe2+/H2O2 and UV/TiO2--Comparison of transformation products, ready biodegradability and toxicity

The present study investigates the degradation of the antimetabolite 5-fluorouracil (5-FU) by three different advanced photo oxidation processes: UV/H2O2, UV/Fe(2+)/H2O2 and UV/TiO2. Prescreening experiments varying the H2O2 and TiO2 concentrations were performed in order to set the best catalyst concentrations in the UV/H2O2 and UV/TiO2 experiments, whereas the UV/Fe(2+)/H2O2 process was optimized varying the pH, Fe(2+) and H2O2 concentrations by means of the Box-Behnken design (BBD). 5-FU was quickly removed in all the irradiation experiments. The UV/Fe(2+)/H2O2 and UV/TiO2 processes achieved the highest degree of mineralization, whereas the lowest one resulted from the UV/H2O2 treatment. Six transformation products were formed during the advanced (photo)oxidation processes and identified using low and high resolution mass spectrometry. Most of them were formed and further eliminated during the reactions. The parent compound of 5-FU was not biodegraded, whereas the photolytic mixture formed in the UV/H2O2 treatment after 256 min showed a noticeable improvement of the biodegradability in the closed bottle test (CBT) and was nontoxic towards Vibrio fischeri. In silico predictions showed positive alerts for mutagenic and genotoxic effects of 5-FU. In contrast, several of the transformation products (TPs) generated along the processes did not provide indications for mutagenic or genotoxic activity. One exception was TP with m/z 146 with positive alerts in several models of bacterial mutagenicity which could demand further experimental testing. Results demonstrate that advanced treatment can eliminate parent compounds and its toxicity. However, transformation products formed can still be toxic. Therefore toxicity screening after advanced treatment is recommendable.

The need for routine monitoring of cardiac function in patients receiving 5-fluorouracil infusion

Fluorouracil (5-FU) is an antimetabolite that has become the cornerstone chemotherapeutic agent used to treat tumors of the gastrointestinal tract. Although proven to be effective, 5-FU can cause cardiotoxicity, which can be life-threatening. Adverse cardiac-related events induced by 5-FU include angina pectoris, myocardial infarction, supraventricular tachycardia, and atrial fibrillation. Nurses play a crucial role in the routine monitoring of cardiac function by identifying patients at high risk of developing 5-FU-related cardiotoxicity, monitoring patients during treatment, and then implementing specific interventions if 5-FU-related cardiotoxicity is identified or suspected. This article discusses the relevance of 5-FU-related cardiotoxicity, highlights the need for routine monitoring of cardiac function, and discusses methods of early detection and management.

Germline oncopharmacogenetics, a promising field in cancer therapy

Pharmacogenetics (PGx) is the study of the relationship between inter-individual genetic variation and drug responses. Germline variants of genes involved in drug metabolism, drug transport, and drug targets can affect individual response to medications. Cancer therapies are characterized by an intrinsically high toxicity; therefore, the application of pharmacogenetics to cancer patients is a particularly promising method for avoiding the use of inefficacious drugs and preventing the associated adverse effects. However, despite continuing efforts in this field, very few labels include information about germline genetic variants associated with drug responses. DPYD, TPMT, UGT1A1, G6PD, CYP2D6, and HLA are the sole loci for which the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) report specific information. This review highlights the germline PGx variants that have been approved to date for anticancer treatments, and also provides some insights about other germline variants with potential clinical applications. The continuous and rapid evolution of next-generation sequencing applications, together with the development of computational methods, should help to refine the implementation of personalized medicine. One day, clinicians may be able to prescribe the best treatment and the correct drug dosage based on each patient's genotype. This approach would improve treatment efficacy, reduce toxicity, and predict non-responders, thereby decreasing chemotherapy-associated morbidity and improving health benefits.