Lifestyle habits as a contributor to anti-cancer treatment failure

Oxidative Stress in the Pathogenesis of Oral Cancer

Oxidative stress, arising from an imbalance between reactive oxygen species (ROS) and antioxidants, contributes significantly to oral cancer such as oral squamous cell carcinoma (OSCC) initiation, promotion, and progression. ROS, generated both internally and externally, induce cellular damage including DNA mutations and lipid peroxidation, fostering oncogene activation and carcinogenesis. The objective of this review was to cover and analyze the interplay between ROS and antioxidants, influencing the key processes such as cell proliferation, apoptosis, and angiogenesis, shaping the trajectory of OSCC development. Despite the promise of antioxidants to halt cancer progression and mitigate oxidative damage, their therapeutic efficacy remains debated. The conducted literature search highlighted potential biomarkers that indicate levels of oxidative stress, showing promise for the early detection and monitoring of OSCC. Furthermore, melatonin has emerged as a promising adjunct therapy for OSCC, exerting antioxidant and oncostatic effects by modulating tumor-associated neutrophils and inhibiting cancer cell survival and migration. In addition, this review aims to shed light on developing personalized therapeutic strategies for patients with OSCC such as melatonin therapy, which will be discussed. Research is needed to elucidate the underlying mechanisms and clinical implications of oxidative stress modulation in the context of oral cancer.

Patient Perspectives and Side-Effects Experience on Chemotherapy of Non-Small Cell Lung Cancer: A Qualitative Study

Purpose

This study aimed to explore patients' experiences of palliative chemotherapy for non-small cell lung cancer (NSCLC), how patients adapt to their new and challenging life after chemotherapy, their beliefs, and their quality of life.

Patients and Methods

The study used an exploratory descriptive qualitative approach that was designed to explore the experiences and side effects of NSCLC patients on chemotherapy in Pakistan. The study was designed to obtain a deeper understanding of 22 NSCLC patients' experiences, using a face-to-face approach and interviews were conducted. Patients who have completed chemotherapy agreed to participate in semi-structured interviews.

Results

The data were arranged into five themes: hospital facilities and environment, patient's beliefs in alternative treatments, presenting a positive/negative face, life is for living, and health insurance coverage. The major complaints related to bad experiences of chemotherapy-induced side effects, but these patients still managed to complete the full course of their respective chemotherapy. Additionally, the current study revealed the real experience of patients with NSCLC which had been less studied. The patient's experience was summarized into four themes and several subthemes.

Conclusion

This study aid healthcare providers when deciding on treatment options that will improve shared decision-making between clinicians and treatment outcomes.

Synthesis and Properties of Magnetic Fe3O4/PCL Porous Biocomposite Scaffolds with Different Sizes and Quantities of Fe3O4 Particles

In clinical practice, to treat diseases such as osteosarcoma or chondrosarcoma with broad surgical ostectomy, it would be ideal to have scaffolds that not only fill up the bone void but also possess the ability to regulate the subsequent regimes for targeted chemotherapy and/or bone regeneration. Magnetic targeting of therapeutic agents to specific sites in the body provides certain advantages such as minimal side-effects of anti-cancer drugs. The objective of this study was to characterize novel magnetic scaffolds that can be used as a central station to regulate the drug delivery of a magnetic nanoparticle system. Different sizes and quantities of Fe3O4 particles were mixed with poly-ε-caprolactone (PCL) to construct the magnetic scaffolds, and their mechanical properties, degradation performance, and cell biocompatibility were evaluated. It appeared that the presence of Fe3O4 particles influenced the magnetic, mechanical, and biological performances of the scaffolds. The prepared bio-nanocomposite scaffolds provided predominantly magnetic/superparamagnetic properties. Scaffolds with a micron-sized Fe3O4 to PCL weight (wt) ratio of 0.1:0.9 exhibited higher mechanical performances among samples, with Young’s modulus reaching 1 MPa and stiffness, 13 N/mm. Although an increased Fe3O4 particle proportion mildly influenced cell growth during the biocompatibility test, none of the Fe3O4/PCL scaffolds showed a cytotoxic effect.

Efficacy of open dialogue about complementary and alternative medicine compared with standard care in improving quality of life in patients undergoing conventional oncology treatment (CAMONCO 2): protocol for a randomised controlled trial

INTRODUCTION

Complementary and alternative medicine (CAM) has been shown to reduce symptoms and adverse effects and improve quality of life of patients undergoing conventional oncology treatment, but CAM might also cause symptoms and adverse effects such as headache and fatigue. Thus, patients need guidance towards safe and healthy use of CAM. According to published results, open dialogue about CAM (OD-CAM) between health professionals and patients as an integral part of anticancer treatment may improve patients' quality of life and well-being. Since the literature on the issue is sparse, the aim of this study is to assess the efficacy of OD-CAM integrated early in conventional oncology treatment versus standard care (SC) in patients undergoing standard anticancer treatment.

METHODS AND ANALYSIS

The study is a randomised controlled trial, being conducted at an oncology outpatient clinic in Denmark. 207 patients undergoing curative or palliative oncology treatment for breast, gynaecological, prostate, pulmonary, colorectal, anal or pancreatic cancer will be randomly assigned to SC with or without OD-CAM. A nurse specialist will facilitate the OD-CAM in one or two sessions. The primary endpoint is patient reported quality of life in relation to psychological well-being 8 weeks after enrollment. Secondary endpoints are patient reported level of depression and anxiety, top concerns, and decision regret 8, 12 and 24 weeks after enrolment, and overall survival.

ETHICS AND DISSEMINATION

According to the Committee on Health Research Ethics for Southern Denmark, ethics approval of this study is not required (S-20202000-5, 20/1019). The Region of Southern Denmark (Journal no. 20/11100) approved the storing and handling of data. Participants' informed consent will be obtained before inclusion and randomisation. The results of the study, whether positive, negative or inconclusive, will be disseminated through open-access, peer-reviewed publications, stake-holder-reporting and presentations at relevant conferences.

TRIAL REGISTRATION NUMBER

NCT04299451.

Impact of Open Dialogue about Complementary Alternative Medicine-A Phase II Randomized Controlled Trial

Simple Summary

A large number of patients with cancer use complementary alternative medicine (CAM), such as diet supplements, massage and acupuncture, as an adjunct to conventional cancer treatment and care. Some types of CAM reduce nausea and vomiting, pain, fear, fatigue and depression, but CAM may also cause new symptoms and side effects. Therefore, it is crucial that cancer patients receive professional guidance on how to use CAM in a safe and healthy manner. Open dialogue about CAM between patients and health professionals is, however, not an integrated part of cancer treatment and care. Therefore, the aim of our study was to assess how open dialogue, including guidance about CAM, affected patients’ safety and health when it was an integrated part of the cancer treatment and care. We found that open dialogue about CAM does not compromise patient safety and that it may improve patients’ quality of life, self-care and survival.

Abstract

Complementary alternative medicine (CAM) may reduce the symptom burden of side effects to antineoplastic treatment but also cause new side effects and non-adherence to conventional treatment. The aim of this RCT was to investigate the impact of open dialogue about complementary alternative medicine (OD-CAM) on cancer patients’ safety, health and quality of life (QoL). Patients undergoing antineoplastic treatment were randomly assigned to standard care (SC) plus OD-CAM or SC alone. The primary endpoint was frequency of grade 3–4 adverse events (AE) eight weeks after enrollment. Secondary endpoints were frequency of grade 1–4 AE, QoL, psychological distress, perceived information, attitude towards and use of CAM 12 and 24 weeks after enrollment. Survival was analyzed post hoc. Fifty-seven patients were randomized to the OD-CAM group and fifty-five to the SC group. No significant difference in frequency of grade 3–4 AEs was shown. The same applied to grade 1–4 AEs and QoL, psychological distress and perceived information. A tendency towards better QoL, improved survival and a lower level of anxiety was found in the OD-CAM group. OD-CAM is not superior to SC in reducing the frequency of AEs in patients undergoing antineoplastic treatment. OD-CAM does not compromise patient safety; it may reduce psychological stress and improve QoL and overall survival.

Women are predisposed to early dose-limiting toxicities during adjuvant CAPOX for colorectal cancer

AIM

Oxaliplatin-based adjuvant chemotherapy was demonstrated to be beneficial for stage III or high-risk stage II colorectal cancer (CRC). Moreover, a recent international collaborative trial suggested 3-months CAPOX as an alternative regimen for low-risk stage III colorectal cancer (CRC) patients. Thus, it is important to clarify the frequency and predictive markers of dose-limiting toxicities (DLTs) developed within the short-course CAPOX cycles.

METHODS

We investigated CRC patients who underwent radical surgery and adjuvant CAPOX therapy at our hospital between December 2010 and February 2021. Patients who received initially reduced doses of CAPOX and those who had early recurrence were excluded. We reviewed the age, sex, comorbidities, physical, laboratory and oncological data and other perioperative factors. The associations between these variables and early DLTs within four cycles of CAPOX were examined by multivariate analyses using logistic regression models.

RESULTS

Among 168 patients (96 men, mean age: 58.3 years), 120 (71%) developed early DLTs. Patients with early DLTs were predominantly women and sarcopenic and habitual alcohol consumers. On multivariate analyses, only the female sex was an independent predictive factor for early DLTs (odds ratio: 2.61, P = .027).

CONCLUSION

Women were prone to early DLTs during adjuvant CAPOX in the current study. Doctors should be aware of the sex difference in the incidence of early DLTs, adjust the CAPOX dosage and provide supportive care for female CRC patients.

Therapeutic Drug Monitoring of Targeted Anticancer Protein Kinase Inhibitors in Routine Clinical Use: A Critical Review

BACKGROUND

Therapeutic response to oral targeted anticancer protein kinase inhibitors (PKIs) varies widely between patients, with insufficient efficacy of some of them and unacceptable adverse reactions of others. There are several possible causes for this heterogeneity, such as pharmacokinetic (PK) variability affecting blood concentrations, fluctuating medication adherence, and constitutional or acquired drug resistance of cancer cells. The appropriate management of oncology patients with PKI treatments thus requires concerted efforts to optimize the utilization of these drug agents, which have probably not yet revealed their full potential.

METHODS

An extensive literature review was performed on MEDLINE on the PK, pharmacodynamics, and therapeutic drug monitoring (TDM) of PKIs (up to April 2019).

RESULTS

This review provides the criteria for determining PKIs suitable candidates for TDM (eg, availability of analytical methods, observational PK studies, PK-pharmacodynamics relationship analysis, and randomized controlled studies). It reviews the major characteristics and limitations of PKIs, the expected benefits of TDM for cancer patients receiving them, and the prerequisites for the appropriate utilization of TDM. Finally, it discusses various important practical aspects and pitfalls of TDM for supporting better implementation in the field of cancer treatment.

CONCLUSIONS

Adaptation of PKIs dosage regimens at the individual patient level, through a rational TDM approach, could prevent oncology patients from being exposed to ineffective or unnecessarily toxic drug concentrations in the era of personalized medicine.

Open dialogue about complementary and alternative medicine (CAM) integrated in conventional oncology care, characteristics and impact. A systematic review

OBJECTIVE

To systematically review evidence on the characteristics, experiences and impact of an open dialogue about complementary and alternative medicine (CAM) integrated in oncology care.

METHODS

We searched MEDLINE, EMBASE, AMED, Scopus, ProQuest Dissertations and Thesis, Cochrane Central Register, clinicaltrials.gov, forskningsdatabase.dk and PROSPERO. Two reviewers screened title, abstract and full-text articles. Each study was appraised using the Critical Appraisal Skills Programme (CASP) and synthesized narratively. PROSPERO registration CRD42019112242.

RESULTS

We retrieved 4736 articles and included 5; 3 received 9 ½, 1 received 9, and 1 received 5 points on the CASP score. Predominately, the open dialogue was one or two individual, patient-centered, face-to-face consultations led by oncology physicians. In one study, it was a tele-phone consultation and in another it was structured counseling led by pharmacists. Integrated information and recommendations about CAM contributed to high level of satisfaction and improvement in concerns, quality of life and well-being.

CONCLUSION

Integration of open dialogue about CAM in oncology care including acknowledging patients' preferences, values, wishes and knowledge, and providing information about CAM expands the opportunities for improving patients' health, quality of life and well-being.

PRACTICE IMPLICATIONS

Open dialogue about CAM has potentials, but research on how it specifically helps patients, is needed.

Improving Smoking Cessation Outcomes Through Tailored-Risk Patient Messages at a University Hospital Tobacco Cessation Service

BACKGROUND

Postdischarge follow-up is a critical step for increasing effectiveness of hospital smoking cessation treatment. A quality improvement project was undertaken at an academic medical center tobacco cessation consult service to evaluate whether a tailored message (TM) linking immediate risks of continued smoking-particularly carbon monoxide exposure-to hospital recovery would stimulate more patient interest in the hospital's cessation treatment, including agreement to postdischarge follow-up, compared to patients receiving the usual treatment protocol with a standard message (SM) regarding more general health benefits of abstinence.

METHODS

Data from 697 smokers ordered/referred for smoking cessation treatment in 2013 who received either the SM (January-April; n = 323) or the TM (April-November; n =374) were analyzed.

RESULTS

Multivariate regression analysis showed that the TM was associated with significantly greater agreement for follow-up (odds ratio [OR] = 10.83, 95% confidence interval [CI] = 3.66-32.04, p < 0.0001) than the SM. Those patients who received the TM were more willing to try to remain abstinent postdischarge (willingness score = 10, p = 0.0052) and engaged in longer consults (consult time > 10 minutes, p = 0.0075) than SM patients. TM patients also self-reported a higher continuous abstinence rate (OR = 2.07, 95% CI = 1.17-3.66, p = 0.0130] at follow-up than SM.

CONCLUSION

Linking risks of continued smoking, particularly carbon monoxide exposure, to hospital patients' immediate recovery following discharge in a treatment protocol resulted in longer consult times and increased agreement to follow-up compared to the usual protocol message. The TM was integrated into the hospital tobacco cessation intervention as standard of care.

Smoking cessation treatment and outcomes in medium to heavy cigarette smokers being treated for cancer in Jordan

BACKGROUND

Studies evaluating smoking cessation treatment outcomes in cancer patients are scarce, despite smoking cessation importance in cancer care. We sought to add to the literature by evaluating smoking cessation in a challenging group of cancer patients (medium-to-heavy smokers) visiting an out-patient smoking cessation clinic (SCC) in a cancer center in Amman, Jordan.

MATERIALS AND METHODS

Patients smoking >9 cigarettes per day (CPD) and referred to the SCC between June 2009 and May 2012 were studied. Clinic records were reviewed to measure demographic and baseline clinical characteristics, and longitudinal (3-, 6- and 12- month) follow- up by phone/clinic visit was conducted. At each follow-up, patients were asked if they experienced medication side-effects, if they had returned to smoking, and reasons for failing to abstain. Descriptive and multivariable logistic regression analyses were performed.

RESULTS

A total of 201 smokers were included in the analysis. The 3-month abstinence was 23.4% and significantly associated with older age, being married, and presenting with lower (≤ 10 ppm) baseline carbon monoxide (CO) levels. On a multivariable level, lower CO levels, a higher income (relative to the lowest income group), being older, and reporting severe dependence (relative to dependence reported as 'somewhat' or 'not') were significant predictors of higher odds of abstinence at three months. Reasons for failing to quit included not being able to handle withdrawal and seeing no value in quitting. Long- term ARs did not reach 7%.

CONCLUSIONS

In a sample of Jordanian smokers (>9CPD) with cancer and receiving smoking cessation treatment, ARs were low and further declined with time. Results underscore the need for more aggressive patient management and rigorous follow-up during and after smoking cessation treatment, particularly when this takes place in challenging settings. Observed reasons for failure to abstain should be used to tailor counseling practices.

Use of complementary and alternative medicine (CAM) and changes in depressive symptoms from 3 to 15 months after surgery for primary breast cancer: results from a nationwide cohort study

Background This large population-based prospective study explored the associations between use of complementary and alternative medicine (CAM) and prevalence and changes in depressive symptoms from 3 to 15 months after surgery for primary breast cancer. Methods In an ongoing nationwide cohort study, depressive symptoms and the use of ten different types of CAM since time of diagnosis were assessed by questionnaire at 3 (N = 3233) and 15 months post-surgery (N = 2833). Clinical and socio-demopraphic variables were obtained from the Danish Breast Cancer Cooperative Group (DBCG) and national longitudinal registries. Results At 3 months post-surgery, 40.2 % reported having used CAM since the diagnosis, and in the time from 3 to 15 months after surgery, 49.9 % had used CAM. Compared with non-users, CAM users experienced more depressive symptoms at both 3 and 15 months follow-up when adjusting for several possible confounders. In a fully adjusted model, including all CAM variables and adjusting for depressive symptoms at 3 months, use of dietary/vitamin supplements was the only independent, statistically significant risk factor for experiencing more depressive symptoms at 15 months (RM = 1.10; 95 % CI 1.02-1.19, P = 0.014). Conclusion Cross-sectionally, CAM use was associated with higher levels of depressive symptoms at both time-points. Prospectively, users of dietary or vitamin supplements at 3 months after surgery reported higher levels of depressive symptoms than non-users 1 year later. Possible explanations could be an increased vulnerability for depressive symptoms among women using CAM or adverse effects of dietary or vitamin supplements.

Assessing stakeholder opinion on relations between cancer patient groups and pharmaceutical companies in Europe

BACKGROUND

The relationship between the pharmaceutical industry and cancer patient groups has been the subject of much scrutiny and skepticism, and some high-profile negative media coverage has focused attention on some of the problematic aspects of the relationship. Both the pharmaceutical industry and cancer patient groups have made an effort in recent years to improve the transparency and openness of their relations, specifically with regard to the financial support offered by pharmaceutical companies to patient groups.

OBJECTIVE

The objectives of this survey were to benchmark perceptions held by different stakeholder groups about current relationships between cancer patient groups and pharmaceutical companies in Europe, and to explore opinions about ways in which partnerships between patient groups and pharmaceutical companies could evolve to the benefit of cancer patients.

METHODS

The survey was conducted using a structured questionnaire that contained a combination of matrix, scaled, and open-ended questions. The questionnaire was developed based on a literature search and the findings from ten in-depth interviews conducted with policy makers and advocates working at an EU level. Telephone interviews were carried out using a structured questionnaire with a convenience sample of 161 policy makers, cancer healthcare group representatives, and cancer patient group leaders from France, Germany, Hungary, Italy, Latvia, the Netherlands, Poland, Portugal, Romania, Spain, Sweden, and the UK. The interviews took place in the relevant language of the country.

RESULTS

The current relationship between the pharmaceutical industry and cancer patient groups in Europe is generally viewed as positive, but it is also viewed as being unequal, not transparent enough, and not sufficiently patient-centric. There is broad agreement that cancer patient groups can help companies identify unmet needs and contribute to the development of innovative medicines; however, there is some concern about cancer patients' competence to take on this role. Also, pharmaceutical companies and patient groups have a common interest in working together on the development of non-promotional patient information and strategies to support medicines adherence. Respondents also indicated that the two sectors have a legitimate interest in ensuring that patients in need access appropriate treatments in a timely manner. Ongoing cooperation between health professionals, pharmaceutical companies, and cancer patient groups is also viewed as important. Efforts should continue to make relations between pharmaceutical companies and cancer patient groups as equal, open, and transparent as possible.

CONCLUSION

Despite ongoing concerns about the openness and transparency of relations between pharmaceutical companies and patient groups, there is scope for these two sectors to work together on issues of common interest.

The Peter Brojde lung cancer centre: a model of integrative practice

BACKGROUND

The generally poor prognosis and poor quality of life for lung cancer patients have highlighted the need for a conceptual model of integrative practice. Although the philosophy of integrative oncology is well described, conceptual models that could guide the implementation and scientific evaluation of integrative practice are lacking.

PURPOSE

The present paper describes a conceptual model of integrative practice in which the philosophical underpinnings derive mainly from integrative oncology, with important contributions from Traditional Chinese Medicine (TCM) and the discipline of nursing. The conceptual model is described in terms of its purpose, values, concepts, dynamic components, scientific evidence, clinical approach, and theoretical underpinnings. The model argues that these components delineate the initial scope and orientation of integrative practice. They serve as the needed context for evaluating and interpreting the effectiveness of clinical interventions in enhancing patient outcomes in lung cancer at various phases of the illness. Furthermore, the development of relevant and effective integrative clinical interventions requires new research methods based on whole-systems research. An initial focus would be the identification of interrelationship patterns among variables that influence clinical interventions and their targeted patient outcomes.

Adherence to adjuvant therapy in post-menopausal breast cancer patients: a review

This review aimed to address the concept of adherence to adjuvant therapy in post-menopausal women. Thirteen studies were included in the review. Study quality was assessed using Critical Appraisal Skills Programme and CONSORT tools. Adherence to adjuvant medication was assessed using a variety of methods. Estimates of adherence rates to adjuvant therapies indicated that of the post-menopausal women prescribed adjuvant therapy, between 15% and 55% were adherent to tamoxifen from 1 to 5 years of follow-up, albeit two studies proposed adherence rates greater than 85%; these data may be flawed due to the methods of data collection. Between 31% and 73% of women were adherent to anastrozole, letrozole or exemestane from 1 year of treatment. These estimates of adherence are based on a variety of reported records including self-report. Current evidence on the assessment of adherence to adjuvant therapies in post-menopausal women indicate that the adherence rates of medication maybe suboptimal and therefore therapeutic efficacy is questionable and may increase the risk of cancer recurrence and reduce disease survival rates. Concerted research is needed to investigate adherence rates, examine patient health beliefs in the medication management of post-menopausal breast cancer patients and also develop new measures to assess adherence with medication.

The influence of traffic-related pollution on individuals' life-style: results from the BRFSS

This paper employs the Behavioral Risk Factor Surveillance System (2001) data in conjunction with the Environmental Protection Agency's Air Quality System data to investigate how air pollution caused by motor vehicle emissions affects the likelihood of good health and the amount of health investments. Models are estimated using three different measures of overall health: a measure of self-assessed health and two health outcome indicators (asthma and blood pressure). A multivariate probit approach is used to estimate recursive systems of equations for self-assessed health, health outcomes and life-styles. The most interesting result concerns the influence of pollution on health-improving life-style choices: only if traffic pollution is in the 'satisfactory range' (AQI level at or below 100), individuals will have incentive to invest in health.

Effects of methimazole on the elimination of irinotecan

PURPOSE

To study the possible pharmacokinetic and pharmacodynamic interactions between irinotecan and methimazole.

METHODS

A patient treated for colorectal cancer with single agent irinotecan received methimazole co-medication for Graves' disease. Irinotecan pharmacokinetics and side effects were followed during a total of four courses (two courses with and two courses without methimazole).

RESULTS

Plasma concentrations of the active irinotecan metabolite SN-38 and its inactive metabolite SN-38-Glucuronide were both higher (a mean increase of 14 and 67%, respectively) with methimazole co-medication, compared to irinotecan monotherapy. As a result, the mean SN-38 glucuronidation rate increased with 47% during concurrent treatment. Other possible confounding factors did not change over time. Specific adverse events due to methimazole co-treatment were not seen.

CONCLUSIONS

Additional in vitro experiments suggest that these results can be explained by induction of UGT1A1 by methimazole, leading to higher SN-38G concentrations. The prescribed combination of these drugs may lead to highly toxic intestinal SN-38 levels. We therefore advise physicians to be very careful in combining methimazole with regular irinotecan doses, especially in patients who are prone to irinotecan toxicity.

A CYP3A4 phenotype-based dosing algorithm for individualized treatment of irinotecan

PURPOSE

Irinotecan, the prodrug of SN-38, is extensively metabolized by cytochrome P450-3A4 (CYP3A4). A randomized trial was done to assess the utility of an algorithm for individualized irinotecan dose calculation based on a priori CYP3A4 activity measurements by the midazolam clearance test.

EXPERIMENTAL DESIGN

Patients were randomized to receive irinotecan at a conventional dose level of 350 mg/m(2) (group A) or doses based on an equation consisting of midazolam clearance, gamma-glutamyl-transferase, and height (group B). Pharmacokinetics and toxicities were obtained during the first treatment course.

RESULTS

Demographics of 40 evaluable cancer patients were balanced between both groups, including UGT1A1*28 genotype and smoking status. The absolute dose of irinotecan ranged from 480 to 800 mg in group A and 380 to 1,060 mg in group B. The mean absolute dose and area under the curve of irinotecan and SN-38 were not significantly different in either group (P > 0.18). In group B, the interindividual variability in the area under the curve of irinotecan and SN-38 was reduced by 19% and 25%, respectively (P > 0.22). Compared with group A, the incidence of grades 3 to 4 neutropenia was >4-fold lower in group B (45 versus 10%; P = 0.013). The incidence of grades 3 to 4 diarrhea was equal in both groups (10%).

CONCLUSIONS

Incorporation of CYP3A4 phenotyping in dose calculation resulted in an improved predictability of the pharmacokinetic and toxicity profile of irinotecan, thereby lowering the incidence of severe neutropenia. In combination with UGT1A1*28 genotyping, CYP3A4 phenotype determination should be explored further as a strategy for the individualization of irinotecan treatment.

A field synopsis on low-penetrance variants in DNA repair genes and cancer susceptibility

BACKGROUND

Several genes encoding for DNA repair molecules implicated in maintaining genomic integrity have been proposed as cancer-susceptibility genes. Although efforts have been made to create synopses for specific fields that summarize the data from genetic association studies, such an overview is not available for genes involved in DNA repair.

METHODS

We have created a regularly updated database of studies addressing associations between DNA repair gene variants (excluding highly penetrant mutations) and different types of cancer. Using 1087 datasets and publicly available data from genome-wide association platforms, meta-analyses using dominant and recessive models were performed on 241 associations between individual variants and specific cancer types that had been tested in two or more independent studies. The epidemiological strength of each association was graded with Venice criteria that assess amount of evidence, replication, and protection from bias. All statistical tests were two-sided.

RESULTS

Thirty-one nominally statistically significant (ie, P < .05 without adjustment for multiple comparisons) associations were recorded for 16 genes in dominant and/or recessive model analyses (BRCA2, CCND1, ERCC1, ERCC2, ERCC4, ERCC5, MGMT, NBN, PARP1, POLI, TP53, XPA, XRCC1, XRCC2, XRCC3, and XRCC4). XRCC1, XRCC2, TP53, and ERCC2 variants were each nominally associated with several types of cancer. Three associations were graded as having "strong" credibility, another four had modest credibility, and 24 had weak credibility based on Venice criteria. Requiring more stringent P values to account for multiplicity of comparisons, only the associations of ERCC2 codon 751 (recessive model) and of XRCC1 -77 T>C (dominant model) with lung cancer had P <or= .0001 and retained P <or= .001 even when the first published studies on the respective associations were excluded.

CONCLUSIONS

We have conducted meta-analyses of 241 associations between variants in DNA repair genes and cancer and have found sparse association signals with strong epidemiological credibility. This synopsis offers a model to survey the current status and gaps in evidence in the field of DNA repair genes and cancer susceptibility, may indicate potential pleiotropic activity of genes and gene pathways, and may offer mechanistic insights in carcinogenesis.

Dose calculation of anticancer drugs

BACKGROUND

Anticancer drugs are characterized by a narrow therapeutic window and significant inter-patient variability in therapeutic and toxic effects. Current body surface area (BSA)-based dosing fails to standardize systemic anticancer drug exposure and other alternative dosing strategies also have their limitations. Just as important as the initial dose selection is the subsequent dose revision to ensure the dose is correct.

OBJECTIVE

To provide an insight into the different dose individualization and dose adjustment methods, their feasibility and applicability in daily oncology practice and to suggest a practical framework for dose calculation and a basis for future research.

METHODS

Review of relevant literature related to dose calculation of anticancer drugs.

RESULTS

Strategies using clinical parameters, genotype and phenotype markers, and therapeutic drug monitoring all have potential and each has a role for specific drugs. However, no one method is a practical dose calculation strategy for many or all drugs.

CONCLUSION

Given that BSA-dosing leads to significant underdosing it is not reasonable to use this as the sole method of dose calculation. Because of wide disparity in individual patient characteristics and elimination mechanisms, we are unlikely to find the 'Holy Grail' of a single individualized dosing strategy for every patient and anticancer drug in the near future. We propose a pragmatic, although invalidated system for initial dose calculation using dose clusters and structured subsequent dose revision based on treatment-related toxicities and therapeutic drug monitoring. These models need to be tested in clinical trials.