Magnesium Depletion in Patients Receiving Cisplatin-based Chemotherapy

Dietary Magnesium Replacement for Prevention of Hypomagnesemia in Patients With Ovarian Cancer Receiving Carboplatin-Based Chemotherapy

PURPOSE

Hypomagnesemia is a common side effect of platinum-based chemotherapy and predicts poor overall survival in some cancers. Standard magnesium replacement strategies are often inadequate for maintaining magnesium levels. We hypothesized that a daily dietary magnesium replacement approach through magnesium-rich foods would help maintain adequate magnesium levels during platinum-based treatment.

MATERIALS AND METHODS

We conducted a prospective feasibility study of magnesium-rich diets in patients 18 years and older with previously untreated ovarian cancer scheduled to receive carboplatin-containing chemotherapy of at least six consecutive cycles. Education about magnesium-rich diets was provided at enrollment and then weekly during chemotherapy. Feasibility was defined as ≥60% completion of dietary recalls and ≥280 mg average daily dietary magnesium intake across all patients.

RESULTS

Twenty-one of 26 patients enrolled completed at least five chemotherapy cycles and were included in the analysis. Adherence to the study diet was 76%. Daily dietary magnesium intake was 100.5 mg at baseline and increased throughout each cycle: 6% of patients at baseline, 24% after the first cycle, and 67% after the fifth cycle reached ≥280-mg/day magnesium intake. Seven (33%) of 21 had at least one incident of hypomagnesemia. Patients who were adherent had significantly lower incidence of hypomagnesemia (19% v 80%, P = .03) and less need for intravenous magnesium (6% v 60%, P = .03) than those who were nonadherent.

CONCLUSION

The study achieved primary feasibility objectives of retention and adherence to the study intervention. Weekly education about magnesium-rich diets was effective in increasing dietary magnesium intake. Adequate dietary magnesium appeared to be protective against hypomagnesemia.

Pre-treatment risk factors to predict early cisplatin-related nephrotoxicity in locally advanced head and neck cancer patients treated with chemoradiation: A single Institution experience

OBJECTIVES

Cisplatin is essential in the curative treatment of locally advanced head and neck squamous cell carcinoma (LA-HNSCC) patients. The assessment of risk factors to predict an early cisplatin-induced nephrotoxicity could help in better managing one of the most relevant cisplatin-related dose-limiting factors.

MATERIAL AND METHODS

We retrospectively collected data of LA-HNSCC patients treated at our Institution from 2008 to 2019. Patients received cisplatin in a curative setting concurrently with radiation. Acute Kidney Injury (AKI) was assessed as a dichotomous variable (CreaIncr) based on pre-treatment values, and values recorded at days 6-20 post-first cycle of cisplatin. Univariable logistic regression models were performed to investigate associations between CreaIncr and clinical characteristics. A multivariable logistic model on a priori selected putative covariates was performed.

RESULTS

Of the 350 LA-HNSCC treated patients, 204 were analyzed. Ninety (44 %) suffered from any grade AKI (grade I 51.1 %): out of them, 84.4 % received high-dose cisplatin (100 mg/m2 q21). On the univariable logistic regression model, male sex, age, serum uric acid, creatinine, concomitant drugs, and cisplatin schedule were significantly associated with a higher rate of AKI. At multivariable model, age (p = 0.034), baseline creatinine (p = 0.027), concomitant drugs (p = 0.043), and cisplatin schedule (one-day bolus or fractionated high-dose vs. weekly; p = 0.001) maintained their significant association.

CONCLUSIONS

Identifying pre-treatment risk factors in LA-HNSCC patients may improve decision-making in a setting where cisplatin has a curative significance. A strict monitoring of AKI could avoid cisplatin dose adjustments, interruptions, and treatment delays, thus limiting a negative impact on outcomes.

Magnesium Homeostasis: Lessons from Human Genetics

Mg 2+ , the fourth most abundant cation in the body, serves as a cofactor for about 600 cellular enzymes. One third of ingested Mg 2+ is absorbed from the gut through a saturable transcellular process and a concentration-dependent paracellular process. Absorbed Mg 2+ is excreted by the kidney and maintains serum Mg 2+ within a narrow range of 0.7-1.25 mmol/L. The reabsorption of Mg 2+ by the nephron is characterized by paracellular transport in the proximal tubule and thick ascending limb. The nature of the transport pathways in the gut epithelia and thick ascending limb has emerged from an understanding of the molecular mechanisms responsible for rare monogenetic disorders presenting with clinical hypomagnesemia. These human disorders due to loss-of-function mutations, in concert with mouse models, have led to a deeper understanding of Mg 2+ transport in the gut and renal tubule. This review focuses on the nature of the transporters and channels revealed by human and mouse genetics and how they are integrated into an understanding of human Mg 2+ physiology.

Will the Interactions of Some Platinum (II)-Based Drugs with B-Vitamins Reduce Their Therapeutic Effect in Cancer Patients? Comparison of Chemotherapeutic Agents such as Cisplatin, Carboplatin and Oxaliplatin-A Review

Pt (II) derivatives show anti-cancer activity by interacting with nucleobases of DNA, thus causing some spontaneous and non-spontaneous reactions. As a result, mono- and diaqua products are formed which further undergo complexation with guanine or adenine. Consequently, many processes are triggered, which lead to the death of the cancer cell. The theoretical and experimental studies confirm that such types of interactions can also occur with other chemical compounds. The vitamins from B group have a similar structure to the nucleobases of DNA and have aromatic rings with single-pair orbitals. Theoretical and experimental studies were performed to describe the interactions of B vitamins with Pt (II) derivatives such as cisplatin, oxaliplatin and carboplatin. The obtained results were compared with the values for guanine. Two levels of simulations were implemented at the theoretical level, namely, B3LYP/6-31G(d,p) with LANL2DZ bases set for platinum atoms and MN15/def2-TZVP. The polarizable continuum model (IEF-PCM preparation) and water as a solvent were used. UV-Vis spectroscopy was used to describe the drug-nucleobase and drug-B vitamin interactions. Values of the free energy (ΔG_r) show spontaneous reactions with mono- and diaqua derivatives of cisplatin and oxaliplatin; however, interactions with diaqua derivatives are more preferable. The strength of these interactions was also compared. Carboplatin products have the weakest interaction with the studied structures. The presence of non-covalent interactions was demonstrated in the tested complexes. A good agreement between theory and experiment was also demonstrated.

Assessment of Renal Function in Head and Neck Cancer Patients Treated with Cisplatin: Different Biomarkers and Acute Kidney Injury Classifications

Cisplatin is associated with dose-limiting nephrotoxicity, and the timely detection of acute kidney injury (AKI) can affect morbimortality. Therefore, this study aimed to investigate the tools for monitoring renal function in AKI. This was a retrospective, cohort study. Cisplatin-treated patients with head and neck cancer were included. Nephrotoxicity was assessed using serum creatinine, estimated creatinine clearance, serum electrolytic alterations, and plasma kidney injury molecule-1 (KIM-1). The toxicity severity was classified according to Common Terminology Criteria for Adverse Events (CTCAE), and AKI was classified by Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) and Acute Kidney Injury Network (AKIN). A total of 81 participants were included, of whom only 32 did not have AKI. Almost 90% of participants had a decreased estimated glomerular filtration rate five (D5) days after chemotherapy. The AKI estimate differs between AKIN and RIFLE; more participants were diagnosed by the RIFLE at D5, 19.5% versus 2.4% by AKIN, and fifteen had a discordance between these classifications. All laboratory markers showed significant changes on D5. KIM-1 appeared a possible biomarker when considering CTCAE or AKIN classifications (p < 0.05 on D5), but not when RIFLE classification was used (p = 0.0780). Further studies may seek to understand the profiles of different biomarkers together.

Affinities to Oxaliplatin: Vitamins from B Group vs. Nucleobases

Oxaliplatin, similar to Cisplatin, exhibits anticancer activity by interacting with DNA and inducing programmed cell death. It is biotransformed through a number of spontaneous and non-enzymatic processes. In this way, several transient reactive species are formed, including dichloro-, monochloro-, and diaqua-DACH platin, which can complex with DNA and other macromolecules. The molecular level suggests that such interactions can also take place with vitamins containing aromatic rings with lone pair orbitals. Theoretical and experimental studies were performed to investigate interactions of vitamins from the B group with Oxaliplatin, and the results were compared with values characterizing native purines. Quantum-chemical simulations were carried out at the B3LYP/6-31G(d,p) level, with the LANL2DZ basis set representing atomic orbitals of platinum atom, and at the MN15/def2-TZVP levels of theory with the use of Polarizable Continuum Model (IEF-PCM formulation) and water as a solvent. Additionally, time-dependent density functional theory (TD-DFT) was employed to study molecular properties in the electronic excited state. Interactions of vitamins and Oxaliplatin were investigated using UV-Vis spectroscopy. Values of the free energy (ΔG_r) indicate spontaneous reactions with monoaqua [PtH₂OClDACH]⁺ and diaqua [Pt(H₂O)₂DACH]²⁺ derivatives of Oxaliplatin. However, diaqua derivatives were found to be preferable. The free energy (ΔG_r) values obtained for vitamins from the B group indicate lower affinity of Oxaliplatin compared with values characterizing complexes formed by guanine, adenine, and cytosine. The exception is the monoaqua form of vitamin B1 (thiamine) at the MN15/def2-TZVP levels of calculations. An application of atoms in molecules (AIM) theory revealed non-covalent interactions present in the complexes studied. The comparison of computed and experimental spectroscopic properties showed a good agreement.

Evaluation of the Concentration of Selected Elements in Patients with Cancer of the Reproductive Organs with Respect to Treatment Stage-Preliminary Study

(1) Background: The aim of this study was to assess the concentrations of selected elements in female patients with cancer of the reproductive organs, taking into account the stage of treatment. (2) Methods: The study sample consisted of 51 patients with advanced endometrial cancer and ovarian cancer, undergoing chemotherapy. The median age of the studied patients with endometrial cancer was 66.0 years (IQR: from 60.75 to 70.25), and with ovarian cancer―60.0 years (IQR: from 49.0 to 64.0). Each of the qualified women, after consent to participate in the study, had her blood drawn several times (before surgery, the first course of chemotherapy, the third course of chemotherapy, and the sixth course of chemotherapy) in order to determine serum levels of macro- and micronutrients (Na, Mg, Ca, Zn, P, Cu, Fe, Cd, Ni, and Sr). (3) Results: In the study group of patients with cancer of the reproductive tract, the concentrations of iron (<0.001), magnesium (0.038), sodium (0.014), and nickel (0.037) varied significantly over the course of the study. The analysis showed that the interaction between the stage of chemotherapy and the type of cancer had an effect on the concentrations of magnesium and cadmium (p < 0.05). (4) Conclusions: In the studied group of patients with ovarian and endometrial cancer, the applied chemotherapy significantly changed the concentrations of Fe, Na, and Ni, regardless of the type of tumor. Changes in Mg and Cd concentrations resulted from the interaction between the stage of chemotherapy and the type of cancer. The results of serum concentrations of selected elements in women with cancer of the reproductive organs may help understand the physiological changes resulting from the applied chemotherapy.

Case Report and Supporting Documentation: Acute Kidney Injury Manifested as Oliguria Is Reduced by Intravenous Magnesium Before Cisplatin

After more than four decades of post-approval, cisplatin is still an important treatment for numerous cancers. However, acute kidney injury (AKI), defined as significant impairment of renal filtration as discussed below, is the major limiting side effect of cisplatin, occurring in approximately 30% of patients (25–33% after the first course). Cisplatin also damages the kidneys’ ability to reabsorb magnesium in 40–100% of patients, with collateral health risks due to subsequent hypomagnesemia. Multiple methods and drugs have been proposed for preventing cisplatin-induced AKI, including saline infusion with or without mannitol, which has not always prevented AKI and has been found to activate a cellular stress response in renal tubular cells. While numerous reports and trials, as well as the National Comprehensive Cancer Network (NCCN), support premedication with magnesium and hydration, this practice has not been universally accepted. Many clinics administer intravenous magnesium (IV) only after identification of hypomagnesemia post-cisplatin treatment, thus placing patients at risk for AKI and chronic renal loss of magnesium. We present the following case report and additional supporting evidence identifying the immediate effect of IV magnesium prior to intraperitoneal cisplatin for cycle 4 because of documented hypomagnesemia resulting in normalization of oliguria, which had been experienced for the first three cycles. The patient subsequently requested and received IV magnesium before cisplatin for the next two cycles with continuation of normal urinary output. The effect of pretreatment with IV magnesium on urine output following cisplatin has not been previously reported and further supports pre-cisplatin administration. In addition, two recent meta-analyses of clinical trials and pre-clinical research are reviewed that demonstrate effectiveness of magnesium pretreatment to preventing AKI without reducing its chemotherapeutic efficacy. This case report with additional evidence supports the adoption of administration of 1–3 g IV magnesium before cisplatin as best practice to prevent cisplatin induced AKI and hypomagnesemia regardless of patient baseline serum magnesium levels.

Hypomagnesemia and survival in patients with head and neck cancers who received primary concurrent chemoradiation

BACKGROUND

Prior research has confirmed that persistent hypomagnesemia was predictive of shorter survival among patients with ovarian cancer who received carboplatin-based chemotherapy. In the current retrospective study, the authors examined the association between hypomagnesemia and survival in patients with head and neck cancer who received concurrent chemoradiation with weekly infusions of cisplatin and/or carboplatin.

METHODS

Patients with head and neck cancers who had undergone chemoradiation with cisplatin and/or carboplatin between January 1, 2010, and December 31, 2014, were included. Patients were aged ≥18 years with pathology of squamous cell carcinoma of the larynx, oral cavity, or oropharynx who had received at least 30 fractions of radiotherapy with concurrent weekly cisplatin and/or carboplatin. Pathology features, laboratory results, Eastern Cooperative Oncology Group performance status, social histories, and survival were recorded. The association between hypomagnesemia and survival was analyzed controlling for known prognostic factors.

RESULTS

The final cohort consisted of 439 patients with a median age of 59 years. A greater frequency of hypomagnesemia during the treatment course was found to be significantly associated with shorter survival (hazard ratio [HR], 1.13; P = .033) independent of age (HR, 1.65; P = .042), cancer site (nonoropharynx vs oropharynx: HR, 2.15 [P = .003]), Eastern Cooperative Oncology Group performance status (>1 vs ≤1: HR, 2.64 [P < .001]), and smoking history (smoker vs nonsmoker: HR, 1.88 [P = .012]). In addition, more severe hypomagnesemia was associated with shorter survival compared with the milder form.

CONCLUSIONS

The frequency and severity of hypomagnesemia during treatment are prognostic of survival for patients with head and neck cancers who are receiving concurrent chemoradiation with cisplatin and/or carboplatin. A prospective study is needed to investigate the impact of the prevention of hypomagnesemia on survival in this patient population.

Chronic Oral Administration of Magnesium-L-Threonate Prevents Oxaliplatin-Induced Memory and Emotional Deficits by Normalization of TNF-α/NF-κB Signaling in Rats

Antineoplastic drugs such as oxaliplatin (OXA) often induce memory and emotional deficits. At present, the mechanisms underlying these side-effects are not fully understood, and no effective treatment is available. Here, we show that the short-term memory deficits and anxiety-like and depression-like behaviors induced by intraperitoneal injections of OXA (4 mg/kg per day for 5 consecutive days) were accompanied by synaptic dysfunction and downregulation of the NR2B subunit of N-methyl-D-aspartate receptors in the hippocampus, which is critically involved in memory and emotion. The OXA-induced behavioral and synaptic changes were prevented by chronic oral administration of magnesium-L-threonate (L-TAMS, 604 mg/kg per day, from 2 days before until the end of experiments). We found that OXA injections significantly reduced the free Mg²⁺ in serum and cerebrospinal fluid (from ~ 0.8 mmol/L to ~ 0.6 mmol/L). The Mg²⁺ deficiency (0.6 mmol/L) upregulated tumor necrosis factor (TNF-α) and phospho-p65 (p-p65), an active form of nuclear factor-kappaB (NF-κB), and downregulated the NR2B subunit in cultured hippocampal slices. Oral L-TAMS prevented the OXA-induced upregulation of TNF-α and p-p65, as well as microglial activation in the hippocampus and the medial prefrontal cortex. Finally, similar to oral L-TAMS, intracerebroventricular injection of PDTC, an NF-κB inhibitor, also prevented the OXA-induced memory/emotional deficits and the changes in TNF-α, p-p65, and microglia. Taken together, the activation of TNF-α/NF-κB signaling resulting from reduced brain Mg²⁺ is responsible for the memory/emotional deficits induced by OXA. Chronic oral L-TAMS may be a novel approach to treating chemotherapy-induced memory/emotional deficits.

Cisplatin given at three divided doses for three consecutive days in metastatic breast cancer: an alternative schedule for one full dose with comparable efficacy but less CINV and hypomagnesaemia

PURPOSE

Cisplatin, an effective medication for metastatic breast cancer (MBC), is recommended to be applied at the dose of 75 mg/m² on day 1 every 3 weeks. However, the 75 mg/m² schedule is often associated with a variety of side effects (such as vomiting and kidney toxicity), and time-consuming hydration treatment is usually needed. Divided dose (25 mg/m² on day 1-3) without hydration is an alternative. This study aimed to compare the efficacy and toxicity profiles between these two dosage regimens.

METHODS

Patients with MBC treated with cisplatin-based regimens in Fudan University Shanghai Cancer Center between December 2008 and June 2019 were retrospectively analyzed. Objective response rate (ORR), progression-free survival (PFS), and toxicity profiles were analyzed.

RESULTS

227 patients receiving a 1-day schedule and 256 patients receiving a 3-day schedule were included. Median PFS was 6.68 (5.66-7.70) months for patients in the 1-day schedule group and 6.70 (5.89-7.52) months for patients in the 3-day schedule group. There was no statistically significant difference in PFS between the two treatment groups (hazard ratio, 0.942; 95% CI 0.759 to 1.170; P = 0.589). The ORRs were comparable between the two groups. ORRs were 44.9% in 1-day schedule group and 44.5% in 3-day schedule group, respectively (P = 0.929). Compared with patients in the 3-day schedule group, patients in the 1-day schedule group experienced higher rates of chemotherapy-induced nausea and vomiting (CINV) (139 [61.2%] vs. 132 [51.6%], P = 0.033). The risk of hypomagnesaemia was also significantly higher (43.2% vs. 28.3%, P = 0.016) among patients receiving 1-day schedule (without magnesium supplementation). No other differences in adverse events were observed between the two groups.

CONCLUSIONS

Cisplatin given at three divided doses with no hydration in MBC is a less toxic (less CINV and hypomagnesaemia) schedule with comparable efficacy. Thus, it may be a good alternative for one full-dose (75 mg/m²) schedule.

Hypomagnesemia and Survival in Patients with Ovarian Cancer Who Received Chemotherapy with Carboplatin

BACKGROUND

Hypomagnesemia is a known side effect of several antineoplastic agents, but its impact on outcomes of patients with cancer is not well understood. We examined whether magnesium abnormalities affect survival in patients with ovarian cancer who receive chemotherapy containing carboplatin.

MATERIALS AND METHODS

We included patients with advanced ovarian cancer who had undergone surgery and chemotherapy between January 1, 2004, and December 31, 2014, at our institution. Inclusion criteria were age 18 years or older, pathology of high-grade serous carcinoma, first treatment (surgery or chemotherapy) within 60 days of diagnosis, and chemotherapy containing carboplatin. The final cohort consisted of 229 patients. Vital signs and laboratory tests were recorded at baseline and during the treatment course. The associations between magnesium abnormalities (and other clinical characteristics) and survival were analyzed.

RESULTS

The median patient age was 64 years. Higher baseline heart rate (beats per minute; hazard ratio [HR] = 1.02, p = .002) and greater frequency of hypomagnesemia during the treatment course (HR = 1.05, p = .002) were significantly associated with shorter survival independent of completeness of tumor reduction (HR = 1.60, p = .02), and International Federation of Gynecology and Obstetrics stage (HR = 1.63, p = .01).

CONCLUSION

Baseline heart rate and the frequency of hypomagnesemia episodes during treatment are prognostic of survival for patients with advanced ovarian cancer receiving carboplatin-containing chemotherapy and tumor reductive surgery. Future research is needed for strategies to detect and prevent hypomagnesemia in this patient population.

IMPLICATIONS FOR PRACTICE

Despite standard laboratory tests and intravenous magnesium replacement prior to each cycle of chemotherapy, hypomagnesemia remains a common side effect of platinum-based chemotherapy. This study revealed that frequent occurrence of hypomagnesemia during the course of treatment including carboplatin-containing chemotherapy and tumor reductive surgery was strongly predictive of shorter survival in patients with advanced ovarian cancer. Strategies to effectively mitigate hypomagnesemia, such as more frequent detection, dietary recommendations, and timely replacement, should be considered in the overall cancer treatment plan for these patients.

Effects of furosemide administration on the concentration of essential and toxic elements in Wistar rats by inductively coupled plasma optical emission spectrometry

Furosemide can interfere with the metabolism of chemical elements, changing their levels in several tissues, thus causing imbalance. In this study, inductively coupled plasma optical emission spectrometry (ICP OES) was used for multi-element analysis (Cd, Cu, Fe, Mg, Pb, Se and Zn) after microwave-assisted digestion, to evaluate the effect of furosemide (loop diuretic) on the composition of these essential and toxic elements in biological samples (liver, kidney, heart, lung and serum) of Wistar rats. Male and female Wistar rats (n = 40, 180-350 g) were randomly divided into 2 groups (n = 20/group). The results were expressed as μg/g dry weight. The mean tissue concentrations (minimum-maximum in μg/g) of Cu, Fe, Mg and Zn in the biological samples ranged between 5.2 and 1023.5. The levels of Cd, Pb and Se were below the detection limit of the ICP OES. Accuracy was assessed by microwave-assisted digestion and recovery values of 83-116% were obtained. Liver had significantly higher trace element concentrations in most of the analyzed samples. Mg showed a significant reduction (for males and females) in its levels in the heart. In both genders, there was similarity in the Cu concentration reduction (around 16%) for all tissues. The highest iron losses were found for serum (52% and 12%) for male and female rats, respectively. Reductions in Zn occurred between 0.3 and 18.0%, mainly for kidneys and heart, respectively. This study demonstrated that furosemide altered the concentration of some elements in rats.

Oral rehydration solution (OS-1) as a substitute of intravenous hydration after cisplatin administration in patients with lung cancer: a prospective multicenter trial

Background

The aim of this trial was to evaluate the safety and efficacy of oral hydration as a substitute for intravenous hydration after cisplatin (CDDP) administration.

Methods

The major eligibility criteria included patients with lung cancer, indications for a CDDP-based regimen at a dose of 60 mg/m² or higher, an age of between 20 and 74 years and adequate renal function. Antiemetic prophylaxis consisted of an appropriate dose of palonosetron, aprepitant, dexamethasone and magnesium sulfate (8 mEq). Five hundred millilitres of commercially available oral hydration solution (OS-1: Otsuka Pharmaceutical Factory, Tokushima, Japan) was used as a substitute for intravenous posthydration. The planned sample size was 46 to reject a proportion of 70% under an expectation of 88% with a power of 90% and an alpha error of 5%.

Results

Between May and November 2013, 31 men and 15 women with a median (range) age of 65 (33–74) years were enrolled from three institutions. Of these, five received adjuvant chemotherapy, 17 received definitive chemoradiotherapy and 24 received chemotherapy for advanced diseases. The median (range) number of chemotherapy cycles was 4 (1–5). After the first cycle of CDDP administration, none of the patients experienced a creatinine elevation of grade 2 or higher, thereby meeting the primary endpoint. Of the 46 patients, 45 (97.8%, 95% CI 88.2 to 99.9) completed the CDDP-based chemotherapy without grade 2 or higher renal dysfunction.

Conclusion

Oral hydration can be used as a safe and convenient substitute for intravenous posthydration for CDDP administration at the standard dose.

Trial registration number

UMIN000010201.

Oral Application of Magnesium-L-Threonate Attenuates Vincristine-induced Allodynia and Hyperalgesia by Normalization of Tumor Necrosis Factor-α/Nuclear Factor-κB Signaling

BACKGROUND

Antineoplastic agents, including vincristine, often induce neuropathic pain and magnesium deficiency clinically, but the causal link between them has not been determined. No drug is available for treating this form of neuropathic pain.

METHODS

Injection of vincristine (0.1 mg · kg · day, intraperitoneally, for 10 days) was used to induce nociceptive sensitization, which was accessed with von Frey hairs and the plantar tester in adult male Sprague-Dawley rats. Magnesium-L- threonate was administered through drinking water (604 mg · kg · day). Extracellular and intracellular free Mg were measured by Calmagite chromometry and flow cytometry. Molecular biologic and electrophysiologic experiments were performed to expose the underlying mechanisms.

RESULTS

Vincristine injection induced allodynia and hyperalgesia (n = 12), activated tumor necrosis factor-α/nuclear factor-κB signaling, and reduced free Mg in cerebrospinal fluid by 21.7 ± 6.3% (mean ± SD; n = 13) and in dorsal root ganglion neurons by 27 ± 6% (n = 11). Reducing Mg activated tumor necrosis factor-α/nuclear factor-κB signaling in cultured dorsal root ganglion neurons. Oral application of magnesium-L-threonate prevented magnesium deficiency and attenuated both activation of tumor necrosis factor-α/nuclear factor-κB signaling and nociceptive sensitization (n = 12). Mechanistically, vincristine induced long-term potentiation at C-fiber synapses, up-regulated N-methyl-D-aspartate receptor type 2B subunit of N-methyl-D-aspartate receptor, and led to peptidergic C-fiber sprouting in spinal dorsal horn (n = 6 each). The vincristine-induced pathologic plasticity was blocked by intrathecal injection of nuclear factor-κB inhibitor (n = 6), mimicked by tumor necrosis factor-α, and substantially prevented by oral magnesium-L-threonate (n = 5).

CONCLUSIONS

Vincristine may activate tumor necrosis factor-α/nuclear factor-κB pathway by reduction of intracellular magnesium, leading to spinal pathologic plasticity and nociceptive sensitization. Oral magnesium-L-threonate that prevents the magnesium deficiency is a novel approach to prevent neuropathic pain induced by chemotherapy.

The Incidence of Cisplatin-induced Hypomagnesemia in Cervical Cancer Patients Receiving Cisplatin Alone

Hypomagnesemia is one side effect in patients receiving cisplatin. However, there are few reports of cisplatin-induced hypomagnesemia in Japan. We retrospectively investigated the incidence of hypomagnesemia and nephrotoxicity in patients undergoing radiation therapy who were treated with cisplatin alone (dosage: 40 mg/m², administration interval: 1 week) for cervical cancer. Thirty-two patients undergoing radiation therapy who received cisplatin alone for cervical cancer between January 2012 and May 2016 at Aichi Medical University Hospital were included. We measured patients' serum magnesium and creatinine levels on the day before cisplatin was administered. We utilized the RIFLE criteria (categorized into "risk", "injury", "failure", "loss", and "end-stage kidney disease") to define levels of cisplatin-induced nephrotoxicity, and classified cisplatin-induced nephrotoxicity into "risk" or "injury". Eighteen patients (56.3%) had cisplatin-induced hypomagnesemia, the majority of which occurred after the 4th treatment cycle. The number of patients with moderate renal dysfunction classified as "risk" in the hypomagnesemia group was not significantly higher than in the non-hypomagnesemia group (hypomagnesemia group=27.8%, non-hypomagnesemia group=7.1%; p=0.20). This survey sheds light on the incidence rates of cisplatin-induced hypomagnesemia in patients receiving cisplatin alone. We recommend monitoring the serum magnesium levels during cisplatin administration to prevent hypomagnesemia.

Cisplatin-Induced Nephrotoxicity; Protective Supplements and Gender Differences

Cisplatin (CDDP) has been widely used as a chemotherapeutic agent for solid tumors. The most common side effect of CDDP is nephrotoxicity, and many efforts have been made in the laboratory and the clinic to employ candidate adjuvants to CDDP to minimize this adverse influence. Many synthetic and herbal antioxidants as well as trace elements have been investigated for this purpose in recent years and a variety of positive and negative results have been yielded. However, no definitive supplement has so far been proposed to prevent CDDP-induced nephrotoxicity; however, this condition is gender related and the sex hormone estrogen may protect the kidney against CDDP damage. In this review, the results of research related to the effect of different synthetic and herbal antioxidants supplements are presented and discussed with suggestions included for future work.

Changes in blood concentrations of trace metals in cancer patients receiving cisplatin-based chemotherapy

The administration of cisplatin (CDDP) may influence trace metal concentrations in body fluids. In order to test this hypothesis, the blood concentrations of trace metals were determined during the present study in eight Japanese esophageal and lung cancer patients receiving CDDP-based chemotherapy. The levels of manganese, iron (Fe), cobalt, copper, zinc (Zn), platinum and lead in the plasma were determined by inductively coupled plasma-mass spectrometry. In addition, the serum levels of Fe, transferrin and ferritin were evaluated. The baseline plasma concentration of Fe in patients with esophageal cancer was significantly lower than that in lung cancer patients (P=0.011), although there were no significant differences identified with respect to the plasma levels of other trace metals. The data obtained from six fasting patients without blood transfusion demonstrated that plasma concentrations of Fe increased 3.5-fold soon after CDDP treatment and returned to baseline levels ~10 days after therapy. The excessive Fe levels in the bloodstream induced changes in serum ferritin and transferrin levels. Furthermore, serum Zn levels increased 1.8-fold in the 1-3 days following CDDP treatment, and serum cystatin C levels transiently increased. These findings indicate that serum Fe and Zn levels may be useful to understanding the physiological responses in the early stages of CDDP-based chemotherapy, which may be associated with systemic inflammation and/or tissue distribution of CDDP.

Safety of a short hydration method for cisplatin administration in comparison with a conventional method-a retrospective study

OBJECTIVE

Cisplatin is administered in combination with massive hydration to avoid renal toxicity, making its administration difficult in an outpatient setting. Although a short hydration protocol for cisplatin has been recently developed, its safety is not fully understood.

METHODS

Consecutive patients with lung or other cancer and an Eastern Cooperative Oncology Group performance status of 0-2 who were receiving chemotherapy containing cisplatin at a dose of ≥60 mg/m(2) in a single administration were evaluated. Seventy-four patients were treated with a short hydration protocol consisting of 1750-2250 ml of hydration with mannitol and magnesium supplementation over a period of 3.75-4.75 h on Day 1. Sixty-nine patients were treated with a conventional hydration protocol consisting of 2100-2600 ml of hydration over 6.5-7.5 h on Day 1 with pre- and post-hydration on Days 0, 2 and 3. Toxicity was then compared between the two groups.

RESULTS

An elevated serum creatinine level ≥grade 1 was significantly less frequent in the group receiving the short hydration protocol than in the group receiving conventional hydration. Other toxicities were similar between the two groups. Consequently, the completion rate for the planned treatment in the short hydration group (73.0%, 54/74) was significantly higher than that in the conventional hydration group (53.6%, 37/69).

CONCLUSIONS

Short hydration is safe, making cisplatin-containing chemotherapy easier to perform.

Expression of magnesium transporter genes in head and neck cancer patients underwent neoadjuvant cisplatin-based chemotherapy

We aimed to investigate expression of magnesium transporter genes in patients with head and neck cancer who underwent cisplatin-based neoadjuvant chemotherapy and their association with serum magnesium level. Head and neck cancer patients scheduled to undergo neoadjuvant cisplatin-based chemotherapy were eligible for enrollment. Blood samples were obtained at three time points: prior to, during, and after completion of chemotherapy. Expression levels of magnesium transporter genes were determined by quantitative real-time PCR. A total of 23 patients were included in the final analysis. The average serum magnesium levels dropped 6.98 and 5.20% during and after completion of chemotherapy. There were neither significant associations between serum magnesium level and demographic variables nor tumor-related variables. SLC41A1 expression level was positively correlated with serum magnesium whereas TRPM6 expression level was negatively correlated with serum magnesium. Serum magnesium level decreased during cisplatin-based chemotherapy in head and neck cancer patients. Further studies are warranted to investigate optimal magnesium measurement and substitution protocol.

Pathophysiology of cisplatin-induced acute kidney injury

Cisplatin and other platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors. A known complication of cisplatin administration is acute kidney injury (AKI). The nephrotoxic effect of cisplatin is cumulative and dose-dependent and often necessitates dose reduction or withdrawal. Recurrent episodes of AKI may result in chronic kidney disease. The pathophysiology of cisplatin-induced AKI involves proximal tubular injury, oxidative stress, inflammation, and vascular injury in the kidney. There is predominantly acute tubular necrosis and also apoptosis in the proximal tubules. There is activation of multiple proinflammatory cytokines and infiltration of inflammatory cells in the kidney. Inhibition of the proinflammatory cytokines TNF-α or IL-33 or depletion of CD4+ T cells or mast cells protects against cisplatin-induced AKI. Cisplatin also causes endothelial cell injury. An understanding of the pathogenesis of cisplatin-induced AKI is important for the development of adjunctive therapies to prevent AKI, to lessen the need for dose decrease or drug withdrawal, and to lessen patient morbidity and mortality.

TRPM6

TRPM6 is a bifunctional protein comprising a TRP cation channel segment covalently linked to an α-type serine/threonine protein kinase. TRPM6 is expressed in the intestinal and renal epithelial cells. Loss-of-function mutations in the human TRPM6 gene give rise to hypomagnesemia with secondary hypocalcemia (HSH), suggesting that the TRPM6 channel kinase plays a central role in systemic Mg(2+) homeostasis. In contrast, Trpm6 null mice show a delay in prenatal development, neural tube defects, and prenatal death. Possible functions of TRPM6 in prenatal and adult organisms will be discussed in this chapter.

Short hydration in chemotherapy containing cisplatin (≥75 mg/m2) for patients with lung cancer: a prospective study

OBJECTIVE

We previously reported that 22% of lung cancer patients experienced a Grade 2 or 3 elevation in creatinine after chemotherapy containing cisplatin. We conducted a Phase II trial to evaluate the safety and efficacy of short hydration.

METHODS

The major eligibility criteria included patients with lung cancer for whom a ≥75 mg/m(2) cisplatin-based regimen was indicated and adequate organ function. Cisplatin was administered with pre- and post-hydration containing 10 mEq of potassium chloride in 500 ml of fluid over a 60-min period. Immediately before the administration of cisplatin, mannitol (20%, 200 ml) was administered as forced diuresis over 30 min. And magnesium sulfate (8 mEq) was added to pre-hydration.

RESULTS

Forty-four patients were enrolled between April and December 2011. The patients included 29 men and 15 women with a median (range) age of 64 (42-74) years. Twenty patients received cisplatin and pemetrexed as their most frequent regimen and 38 patients received three to four cycles of chemotherapy. The median (range) duration and volume of the chemotherapies were 4.0 (3.3-6.8) h and 1600 (1550-2050) ml, respectively. Of the 44 patients, 43 (97.8%) completed the cisplatin-based chemotherapy without Grade 2 or higher renal dysfunction. The only patient who had Grade 2 elevation in creatinine (maximum value 1.7 mg/dl) had prompt improvement in creatinine levels and completed four cycles of chemotherapy.

CONCLUSIONS

The short hydration is safe without severe renal toxicities in regimens containing cisplatin (≥75 mg/m(2)) for patients with lung cancer.

The TRPM6/EGF pathway is downregulated in a rat model of cisplatin nephrotoxicity

Cisplatin-induced hypomagnesemia is described in humans and rats, but the underlying mechanisms are still unclear. Recent studies have shown that epidermal growth factor (EGF) stimulates Mg²⁺ re-absorption in the distal convoluted tubule via the Mg²⁺ channel TRPM6. This study investigates the role of TRPM Mg²⁺ channels, claudines, and EGF in the Mg²⁺ homeostasis in a rat model of cisplatin-induced nephrotoxicity. Wistar rats were given 2.5 mg/kg cisplatin per week for 3 weeks and were euthanized 4 or 9 weeks after the first administration. The cisplatin treatment significantly increased the fractional excretion of Mg²⁺. Real-time RT-PCR and/or Western blots were performed to assess the renal expression TRPM6, TRPM7, claudin-16, claudin-19, EGF, EGF receptor (EGFR) and EGFR-pathway components. The renal mRNA expression of TRPM6 and EGF showed a significant decrease after cisplatin treatment, while the TRPM7, claudin-16 and EGFR expressions remained stable. The claudin-19 mRNA expression was significantly upregulated after cisplatin treatment. Western blotting confirmed the mRNA expression data for the claudins, but an showed upregulation of EGFR only at week 9. The role of the EGFR pathway, involving Pi3-AKT-Rac1, in cisplatin-induced nephropathy, could not be substantiated in further detail. This study shows that cisplatin treatment results in EGF and TRPM6 downregulation in the rat kidney, causing renal Mg²⁺ loss. Our results are in line with the hypothesis that EGF influences the renal expression or activation of TRPM6 and plays a significant role in Mg²⁺ loss in medication-induced nephropathy.

Risk factors for chronic kidney disease after chemotherapy for testicular cancer

OBJECTIVE

To elucidate the patterns of and risk factors for deterioration of renal function after chemotherapy in metastatic testicular cancer survivors using the estimated glomerular filtration rate.

METHODS

A total of 96 patients who were treated with cisplatin-based chemotherapy for metastatic testicular cancer between January 1981 and December 2010 were enrolled in this study. The estimated glomerular filtration rate was based on the serum creatinine concentration using the formula of the Japanese Society of Nephrology. Risk factors for chronic kidney disease were examined by multivariate logistic-regression analysis.

RESULTS

The median follow-up period was 70 months (range 15-342). The median pretreatment estimated glomerular filtration rate was 98 mL/min/1.73 m(2) (range 44-216), and it gradually decreased for 1 year after the end of chemotherapy, although there was no significant change in estimated glomerular filtration rate beyond 1 year. One year after chemotherapy, 22 of 96 patients (23%) showed chronic kidney disease (less than 60 mL/min/1.73 m(2) estimated glomerular filtration rate). The multivariate analysis showed that the patients with mild renal damage (estimated glomerular filtration rate 60-89 mL/min/1.73 m(2) ) and elevated blood pressure (higher than 130/80 mmHg) before treatment had a significant risk with odds ratios of 2.63 (95% confidence interval 1.09-6.73) and 4.22 (95% confidence interval 1.45-12.6), respectively.

CONCLUSIONS

Close monitoring of renal function is important for at least 1 year after chemotherapy for testicular cancer, especially in patients having elevated blood pressure and/or mild renal damage before chemotherapy.

Vitamin E, Vitamin C, or Losartan Is Not Nephroprotectant against Cisplatin-Induced Nephrotoxicity in Presence of Estrogen in Ovariectomized Rat Model

Background. The nephroprotective effect of vitamins E and C or losartan against cisplatin (CP)- induced nephrotoxicity when they are accompanied by estrogen was investigated. Methods. The ovariectomized rats received estradiol valerate for two weeks. At the end of the first week, a single dose of CP (7 mg/kg, IP) was also administered, and they received placebo (group 1), vitamin E (group 2), vitamin C (group 3), or losartan (group 4) every day during the second week, and they were compared with another three control groups. Results. CP alone increased the serum levels of blood urea nitrogen (BUN), creatinine (Cr), and kidney tissue damage score (KTDS), significantly (P < 0.05), however at the presence of estradiol and CP, vitamin C, vitamin E, or losartan not only did not decrease these parameters, but also increased them significantly (P < 0.05). The serum level of superoxidase dismutase (SOD) was reduced by CP (P < 0.05), but it was increased when estradiol or estradiol plus vitamin C or losartan were added (P < 0.05). Conclusion. The particular pharmacological dose of estrogen used in this study abolish the nephroprotective effects vitamins C and E or losartan against CP-induced nephrotoxicity.

Long-term and late effects of germ cell testicular cancer treatment and implications for follow-up

Germ cell testicular cancer (TC) represents a malignancy with high cure rates. Since the introduction of cisplatin-based chemotherapy in the late 1970s, the 5-year survival rate has increased considerably, and it is currently above 95%. Because TC is usually diagnosed before the age of 40 years, these men can expect to live for another 40 to 50 years after being successfully treated. This success, however, is hampered by an increased risk of long-term and late effects of treatment. Secondary malignant neoplasms and cardiovascular disease represent the most common potentially life-threatening late effects, typically occurring more than 10 years after treatment. Other long-term effects include pulmonary toxicity, nephrotoxicity, neurotoxicity, decreased fertility, hypogonadism, and psychosocial problems. The incidence and time to onset of these various adverse effects vary according to treatment type and intensity. There is still little knowledge about underlying mechanisms and genetic susceptibility of the various adverse effects. Apart from treatment burden, it is not yet possible to identify patients who are at high risk for certain late effects after TC treatment. In this clinical review, we present the current status regarding different somatic and psychosocial long-term late effects after treatment for TC, based on Medline searches and our own research. Moreover, we postulate recommendations for general medical evaluations that should begin after treatment is completed and continue during follow-up.

B vitamin supplementation reduces excretion of urinary dicarboxylic acids in autistic children

Urinary dicarboxylic acids are an important source of information about metabolism and potential problems especially connected with energy production, intestinal dysbiosis, and nutritional individuality in autistic children. A diet rich in vitamins and macroelements is a new idea of intervention in autism. The objective of the present study was to test the hypothesis that vitamin B2, vitamin B6, and magnesium supplementation is effective in reducing the level of dicarboxylic acids in the urine of autistic children. We examined the levels of succinic, adipic, and suberic acids in the urine of autistic children before and after vitamin supplementation. Thirty children with autism received magnesium (daily dose, 200 mg), vitamin B6 (pyridoxine; daily dose, 500 mg), and vitamin B2 (riboflavin; daily dose, 20 mg). The treatment was provided for a period of 3 months. Organic acids were determined using gas chromatography/mass spectrometry. Before supplementation, the levels of succinic, adipic, and suberic acids in the urine of autistic children were 41.47 ± 50.40 μmol/mmol creatinine, 15.61 ± 15.31 μmol/mmol creatinine, 8.02 ± 6.08 μmol/mmol creatinine; and after supplementation, the levels were 9.90 ± 8.26 μmol/mmol creatinine, 2.92 ± 2.41 μmol/mmol creatinine, and 2.57 ± 3.53 μmol/mmol creatinine, respectively. The results suggest that the supplementation reduces the level of dicarboxylic acid in the urine of autistic children.

Risk of anti-EGFR monoclonal antibody-related hypomagnesemia: systematic review and pooled analysis of randomized studies

INTRODUCTION

The typical class side effect of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (panitumumab and cetuximab) is a cutaneous maculopapular rash, although hypomagnesemia is also described to be a frequent adverse event. The purpose of our meta-analysis is to evaluate the frequency and the relative risk of hypomagnesemia in patients treated with cetuximab or panitumumab in randomized trials.

AREA COVERED

Eligible studies included prospective randomized Phase III controlled trials in which cetuximab or panitumumab were compared with standard anti-neoplastic therapy or best supportive care. Summary incidence rates and relative risks with 95% confidence intervals were calculated.

EXPERT OPINION

The overall incidence of hypomagnesemia was 17% among the patients who received the treatment, whose risk of developing hypomagnesemia turned out to be significantly increased compared with the patients treated with control medication, with an overall relative risk of 5.83 (p < 0.00001), where 3.87 refers to cetuximab and 12.55 to panitumumab. The addition of anti-EGFR monoclonal antibodies to standard anticancer therapy showed a significantly increased risk of hypomagnesemia compared with controls. The risk seems to be even higher for panitumumab, probably correlated with the increased risk of other adverse events (e.g., diarrhea and dehydration). Hypomagnesemia does not seem to be linked with any serious complications.

Impaired fasting glycaemia vs impaired glucose tolerance: similar impairment of pancreatic alpha and beta cell function but differential roles of incretin hormones and insulin action

AIMS/HYPOTHESIS

The impact of strategies for prevention of type 2 diabetes in isolated impaired fasting glycaemia (i-IFG) vs isolated impaired glucose tolerance (i-IGT) may differ depending on the underlying pathophysiology. We examined insulin secretion during OGTTs and IVGTTs, hepatic and peripheral insulin action, and glucagon and incretin hormone secretion in individuals with i-IFG (n = 18), i-IGT (n = 28) and normal glucose tolerance (NGT, n = 20).

METHODS

Glucose tolerance status was confirmed by a repeated OGTT, during which circulating insulin, glucagon, glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) levels were measured. A euglycaemic-hyperinsulinaemic clamp with [3-3H]glucose preceded by an IVGTT was performed.

RESULTS

Absolute first-phase insulin secretion during IVGTT was decreased in i-IFG (p = 0.026), but not in i-IGT (p = 0.892) compared with NGT. Hepatic insulin sensitivity was normal in i-IFG and i-IGT individuals (p > or = 0.179). Individuals with i-IGT had peripheral insulin resistance (p = 0.003 vs NGT), and consequently the disposition index (DI; insulin secretion x insulin sensitivity) during IVGTT (DI(IVGTT))) was reduced in both i-IFG and i-IGT (p < 0.005 vs NGT). In contrast, the DI during OGTT (DI(OGTT)) was decreased only in i-IGT (p < 0.001), but not in i-IFG (p = 0.143) compared with NGT. Decreased levels of GIP in i-IGT (p = 0.045 vs NGT) vs increased levels of GLP-1 in i-IFG (p = 0.013 vs NGT) during the OGTT may partially explain these discrepancies. Basal and post-load glucagon levels were significantly increased in both i-IFG and i-IGT individuals (p < or = 0.001 vs NGT).

CONCLUSIONS/INTERPRETATION

We propose that differentiated preventive initiatives in prediabetic individuals should be tested, targeting the specific underlying metabolic defects.

Detection of metabolic syndrome features among childhood cancer survivors: a target to prevent disease

Along with the growing epidemic of obesity, the risk of atherosclerosis, cardiovascular disease morbidity, and mortality are increasing markedly. Several risk factors for cardiovascular disease, such as visceral obesity, glucose intolerance, arterial hypertension, and dyslipidemia commonly cluster together as a condition currently known as metabolic syndrome. Thus far, insulin resistance, and endothelial dysfunction are the primary events of the metabolic syndrome. Several groups have recommended clinical criteria for the diagnosis of metabolic syndrome in adults. Nonetheless, in what concerns children and adolescents, there are no unified definitions, and modified adult criteria have been suggested by many authors, despite major problems. Some pediatric disease states are at risk for premature cardiovascular disease, with clinical coronary events occurring very early in adult life. Survivors of specific pediatric cancer groups, particularly acute lymphocytic leukemia, central nervous system tumors, sarcomas, lymphomas, testicular cancer, and following bone marrow transplantation, may develop metabolic syndrome traits due to: hormonal deficiencies (growth hormone deficiency, thyroid dysfunction, and gonadal failure), drug or radiotherapy damage, endothelial impairment, physical inactivity, adipose tissue dysfunction, and/or drug-induced magnesium deficiency. In conclusion, some primary and secondary prevention remarks are proposed in order to reduce premature cardiovascular disease risk in this particular group of patients.