Hypomagnesemia is a reliable predictor for efficacy of anti-EGFR monoclonal antibody used in combination with first-line chemotherapy for metastatic colorectal cancer

Evaluation of the usefulness of protocol-based magnesium supplementation for hypomagnesemia in patients with advanced or recurrent colorectal cancer treated with panitumumab

PURPOSE

Panitumumab (Pmab) is associated with a higher incidence and severity of hypomagnesemia compared to cetuximab, necessitating appropriate monitoring and management strategies. This study aimed to evaluate the efficacy of protocol-based magnesium (Mg) supplementation for treating hypomagnesemia in patients with advanced or recurrent colorectal cancer receiving Pmab.

METHODS

In this retrospective study, patients with colorectal cancer treated with Pmab between October 2010 and September 2023 were divided into two groups: the pre-protocol group (n = 30) and the post-protocol group (n = 30). The incidence of hypomagnesemia was compared between the groups. The hypomagnesemia management protocol included Mg supplementation at grade 1 (< LLN-1.2 mg/dL), initially with 20 mL (1 mEq/mL) of Mg sulfate injection. If Mg levels continued to decrease despite supplementation, the dose was increased to 40 mL (1 mEq/mL).

RESULTS

No significant difference was observed in the frequency of hypomagnesemia between the pre-protocol (56.7%, 17/30) and post-protocol (53.3%, 16/30) groups (P = 1.000). However, the incidence of grade 3 or higher hypomagnesemia was significantly lower in the post-protocol group than in the pre-protocol group (3.3%, 1/30 vs. 30.0%, 9/30; P = 0.012). The rate of deterioration from grade 1 to grade 3 or higher in patients who received Mg supplementation was significantly lower in the post-protocol group than in the pre-protocol group (6.3%, 1/16 vs. 60.0%, 9/15; P = 0.002).

CONCLUSION

Early Mg supplementation effectively reduced the incidence of severe hypomagnesemia, highlighting the utility of this protocol in managing hypomagnesemia in Pmab-treated patients.

Pharmacist intervention and identification of adverse events related to treatment efficacy in cancer chemotherapy to improve clinical outcomes

Adverse events (AEs) induced by cancer chemotherapy reduce not only patient quality of life (QOL) but also the efficacy of treatment. Management of AEs can therefore improve both the efficacy and safety of cancer chemotherapy. This review describes the contribution of pharmacists to the management of adverse events aimed at improving the treatment efficacy of cancer chemotherapy. Efforts to improve the evidence-practice gap are a useful approach to countermeasures against AEs. Pharmacists can intervene in these efforts in the course of their daily practice. Here, we made undertook to improve the evidence-practice gap in prophylaxis pharmacotherapy for chemotherapy-induced nausea and vomiting (CINV) and anti-EGFR antibody-induced acneiform rash. After intervention by pharmacists, the rate of adherence to prophylaxis pharmacotherapy for these AEs was significantly improved, and the incidence of CINV and acneiform rash was significantly decreased. Notably, time to treatment failure (TTF) with anti-EGFR antibody therapy tended to be increased, and may have contributed to an improvement in therapeutic effect. Next, we examined adverse events associated with anti-cancer drugs related to the therapeutic effect of cancer chemotherapy. Incidence of hypomagnesemia in patients receiving anti-EGFR antibodies and neutropenia in patients receiving TAS-102 was significantly associated with the therapeutic effect of cancer chemotherapy. Moreover, we examined the impact of cancer cachexia, a cancer-associated AE, on the therapeutic effect of immune checkpoint inhibitors. In patients receiving nivolumab, the presence of cancer cachexia prior to treatment initiation was associated with shorter OS and TTF. In summary, pharmacist management of AEs was shown to improve treatment response. Further, AEs which are predictive of treatment response in cancer chemotherapy were identified. Management of these AEs is an important role for pharmacists aiming to improve patient QOL and treatment efficacy.

Long intergenic non-protein-coding RNA 467 promotes tumor progression and angiogenesis via the microRNA-128-3p/vascular endothelial growth factor C axis in colorectal cancer

Long non-coding RNAs (lncRNAs) are important regulators and biomarkers of tumorigenesis and tumor metastasis. Long intergenic non-protein-coding RNA 467 (LINC00467) is associated with various cancers. However, the role and mechanism of LINC00467 in colorectal cancer (CRC) promotion are poorly understood. This study aimed to present new details of LINC00467 in the progression of CRC. Reverse transcription–polymerase chain reaction demonstrated that the expression level of LINC00467 in CRC tissues and cell lines was significantly upregulated, which was closely related to the clinical features of CRC. Cell and animal studies showed that the downregulation of LINC00467 expression in CRC cells significantly inhibited cell proliferation, metastasis, and angiogenesis. Moreover, the overexpression of LINC00467 accelerated CRC promotion. Bioinformatics analysis and luciferase reporter assay confirmed that LINC00467 binds to miR-128-3p. Rescue experiments manifested that decreased miR-128-3p level reversed CRC cell inhibition by silencing LINC00467. Furthermore, vascular endothelial growth factor C (VEGFC) was identified as a target of miR-128-3p that could reverse the inhibition of cell growth that is mediated by miR-128-3p. Altogether, our results showed that LINC00467 contributes to CRC progression and angiogenesis via the miR-128-3p/VEGFC axis. Our findings expand the understanding of the mechanisms underlying CRC and suggest potential targets for clinical strategies against CRC.

Forkhead Box q1 promotes invasion and metastasis in colorectal cancer by activating the epidermal growth factor receptor pathway

BACKGROUND

Colorectal cancer (CRC) is an extremely malignant tumor with a high mortality rate. Little is known about the mechanism by which forkhead Box q1 (FOXQ1) causes CRC invasion and metastasis through the epidermal growth factor receptor (EGFR) pathway.

AIM

To illuminate the mechanism by which FOXQ1 promotes the invasion and metastasis of CRC by activating the heparin binding epidermal growth factor (HB-EGF)/EGFR pathway.

METHODS

We investigated the differential expression and prognosis of FOXQ1 and HB-EGF in CRC using the Gene Expression Profiling Interactive Analysis (GEPIA) website (http://gepia.cancer-pku.cn/index.html). Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to detect the expression of FOXQ1 and HB-EGF in cell lines and tissues, and we constructed a stable low-expressing FOXQ1 cell line and verified it with the above method. The expression changes of membrane-bound HB-EGF (proHB-EGF) and soluble HB-EGF (sHB-EGF) in the low-expressing FOXQ1 cell line were detected by flow cytometry and ELISA. Western blotting was used to detect changes in the expression levels of HB-EGF and EGFR pathway-related downstream genes when exogenous recombinant human HB-EGF was added to FOXQ1 knockdown cells. Proliferation experiments, transwell migration experiments, and scratch experiments were carried out to determine the mechanism by which FOXQ1 activates the EGFR signaling pathway through HB-EGF, and then to evaluate the clinical relevance of FOXQ1 and HB-EGF.

RESULTS

GEPIA showed that the expression of FOXQ1 in CRC tissues was relatively high and was related to a lower overall survival rate. PCR array results showed that FOXQ1 is related to the HB-EGF and EGFR pathways. Knockdown of FOXQ1 suppressed the expression of HB-EGF, and led to a decrease in EGFR and its downstream genes AKT, RAF, KRAS expression levels. After knockdown of FOXQ1 in CRC cell lines, cell proliferation, migration and invasion were attenuated. Adding HB-EGF restored the migration and invasion ability of CRC, but not the cell proliferation ability. Kaplan–Meier survival analysis results showed that the combination of FOXQ1 and HB-EGF may serve to predict CRC survival.

CONCLUSION

Based on these collective data, we propose that FOXQ1 promotes the invasion and metastasis of CRC via the HB-EGF/EGFR pathway.

Epidermal Growth Factor Receptor Inhibitor-Induced Hypomagnesaemia: Is There a Best Replacement Strategy?

Monoclonal antibodies targeting the epidermal growth factor receptor (EGFRI), such as cetuximab and panitumumab, are commonly used systemic therapies for advanced colorectal and head and neck cancers. Hypomagnesaemia is a common side effect of these therapies and occurs in up to 30% of patients. Interruption of EGFR signalling in the distal convoluted tubule leads to inactivation of the transcellular transporter transient receptor potential channel melastatin member 6 and increased renal magnesium excretion. This paper describes the incidence, risk factors, and the emerging management options for EGFRI-induced hypomagnesaemia.

Predictive and prognostic value of magnesium serum level in FOLFIRI plus cetuximab or bevacizumab treated patients with stage IV colorectal cancer: results from the FIRE-3 (AIO KRK-0306) study

Magnesium wasting is a frequent side effect of epidermal growth factor receptor (EGFR)-antibody treatment as magnesium-absorption mechanisms are dependent on EGFR signaling. EGFR-inhibition results in decreased renal reabsorption. There is evidence that hypomagnesemia during cetuximab treatment correlates with response. The prognostic role of hypomagnesemia during bevacizumab treatment has not been studied yet. Here, we evaluate the prognostic value of hypomagnesemia in patients with metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab as first-line therapy. A total of 391 of 752 patients of the firstline irinotecan study population had magnesium levels measured at baseline and for the first three cycles (6 weeks) of treatment. Of those, 240 had Rat Sarkoma wildtype tumors. Overall hypomagnesemia was more common in the cetuximab compared to the bevacizumab arm (80 vs. 43%, P < 0.005). During therapy, magnesium showed a time-dependent decrease to 80% of baseline in the cetuximab and to 89% in the bevacizumab arm. Whereas magnesium continued to decrease over time in the cetuximab-treated patients, it remained stable in the bevacizumab-treated. Overall response rate (ORR) was associated with higher magnesium at week 6 (20.9 vs. 79.1%, P = 0.041). Bevacizumab-treated patients with magnesium levels below the median value at week 6 had a significantly longer progression-free survival (PFS; 11.7 vs. 9.9 months, P = 0.034; hazard ratio 0.73) and a trend towards longer overall survival (OS) (29.6 vs. 23.2 months, P = 0.089; hazard ratio 0.77). Hypomagnesemia at predefined time points and magnesium nadir had no significant effect on ORR, OS and PFS in the cetuximab arm. Our data show different magnesium kinetics in patients with metastatic colorectal cancer treated with cetuximab or bevacizumab. For patients treated with cetuximab, hypomagnesemia did not have an impact on response and survival. Hypomagnesemia might have a prognostic value in bevacizumab treatment.

A novel lncRNA SOX2OT promotes the malignancy of human colorectal cancer by interacting with miR-194-5p/SOX5 axis

Long noncoding RNAs (lncRNAs) show emerging roles in colorectal cancer (CRC) development and are considered to be involved in the potential mechanism of tumor malignancy. While Sox2 overlapping transcript (SOX2OT) has been implicated in the progression of multiple cancers, its role in CRC remains to be explored. In this study, in situ hybridization (ISH) and qRT-PCR were performed to establish the functional relationships between SOX2OT and CRC deranged in CRC tissue and cells. Subsequently, SOX2OT shRNAs vectors were transfected into CRC cells to performed loss-of-function assays to detect the potential role of SOX2OT on proliferation and metastasis in vitro and vivo. The results showed SOX2OT was an oncogene that was up-regulated in human CRC tissues and cell lines. SOX2OT silencing suppressed cell proliferation, migration, and invasion in CRC cells in vitro, and inhibited tumorigenesis in the mouse xenografts. Bioinformatic predictive analysis coupled with the dual-luciferase reporter, RNA immunoprecipitation (RIP), and functional rescue assay elucidated the mechanistic network of the SOX2OT-miR-194-5p-SOX5 axis in CRC. Mechanistically, SOX2OT acted as a competing endogenous RNA (ceRNA) to upregulate SOX5 by sponging miR-194-5p. Downregulated SOX2OT boosted miR-194-5p expression, thus decreased the protein level of SOX5, which suppresses tumorgenesis of CRC.

Epidermal growth factor signaling through transient receptor potential melastatin 7 cation channel regulates vascular smooth muscle cell function

OBJECTIVE

Transient receptor potential (TRP) melastatin 7 (TRPM7) cation channel, a dual-function ion channel/protein kinase, regulates vascular smooth muscle cell (VSMC) Mg2+ homeostasis and mitogenic signaling. Mechanisms regulating vascular growth effects of TRPM7 are unclear, but epidermal growth factor (EGF) may be important because it is a magnesiotropic hormone involved in cellular Mg2+ regulation and VSMC proliferation. Here we sought to determine whether TRPM7 is a downstream target of EGF in VSMCs and if EGF receptor (EGFR) through TRPM7 influences VSMC function. Approach and results: Studies were performed in primary culture VSMCs from rats and humans and vascular tissue from mice deficient in TRPM7 (TRPM7+/Δkinase and TRPM7R/R). EGF increased expression and phosphorylation of TRPM7 and stimulated Mg2+ influx in VSMCs, responses that were attenuated by gefitinib (EGFR inhibitor) and NS8593 (TRPM7 inhibitor). Co-immunoprecipitation (IP) studies, proximity ligation assay (PLA) and live-cell imaging demonstrated interaction of EGFR and TRPM7, which was enhanced by EGF. PP2 (c-Src inhibitor) decreased EGF-induced TRPM7 activation and prevented EGFR-TRPM7 association. EGF-stimulated migration and proliferation of VSMCs were inhibited by gefitinib, PP2, NS8593 and PD98059 (ERK1/2 inhibitor). Phosphorylation of EGFR and ERK1/2 was reduced in VSMCs from TRPM7+/Δkinase mice, which exhibited reduced aortic wall thickness and decreased expression of PCNA and Notch 3, findings recapitulated in TRPM7R/R mice.

CONCLUSIONS

We show that EGFR directly interacts with TRPM7 through c-Src-dependent processes. Functionally these phenomena regulate [Mg2+]i homeostasis, ERK1/2 signaling and VSMC function. Our findings define a novel signaling cascade linking EGF/EGFR and TRPM7, important in vascular homeostasis.

Identifying optimal magnesium replenishment points based on risk of severe hypomagnesemia in colorectal cancer patients treated with cetuximab or panitumumab

PURPOSE

Cetuximab and panitumumab are monoclonal antibodies that target the epidermal growth factor receptor (EGFR). Treatment with cetuximab and panitumumab commonly causes hypomagnesemia, and optimal management of this adverse effect remains unclear. Here, we evaluated the optimal magnesium replacement points based on the risk of severe hypomagnesemia in colorectal cancer patients who received cetuximab or panitumumab.

METHODS

We retrospectively evaluated 184 patients who received cetuximab or panitumumab for colorectal cancer at Ogaki Municipal Hospital (Ogaki, Japan) between January 2010 and December 2019. Univariate analyses were conducted to evaluate the relationship between patient baseline characteristics and development of hypomagnesemia following cetuximab or panitumumab treatment. Variables that were significantly associated with hypomagnesemia in the univariate analyses as well as previously reported risk factors were entered into a multivariate logistic regression model.

RESULTS

The incidence of hypomagnesemia was associated with panitumumab treatment, pre-replenishment serum magnesium concentration, treatment duration, and treatment line. Severe hypomagnesemia post-cetuximab or panitumumab treatment was significantly associated with low baseline magnesium concentrations (< 1.8 mg/dL; odds ratio 18.100, 95% confidence interval 1.570-210.000; p = 0.020) and low serum magnesium concentrations during treatment (< 1.1 mg/dL; odds ratio 93.800, 95% confidence interval 3.510-2510.000; p = 0.007).

CONCLUSION

To minimize the risk of severe hypomagnesemia during anti-EGFR treatment, magnesium replenishment should be initiated in patients with pre-replenishment concentrations of < 1.8 mg/dL, preferably before reaching intra-treatment concentrations of < 1.1 mg/dL.

HB-EGF Activates the EGFR/HIF-1α Pathway to Induce Proliferation of Arsenic-Transformed Cells and Tumor Growth

Arsenic was recently identified as a pollutant that is a major cause of lung cancer. Since heparin-binding EGF-like growth factor (HB-EGF) was reported to be a promising therapeutic target for lung cancer, we investigated the role and mechanism of HB-EGF during arsenic-induced carcinogenesis and development of lung cancer. HB-EGF expression were upregulated in As-T cells, lung cancer cell lines, and in most lung cancer tissue samples; and HB-EGF activated the EGFR/p-ERK/HIF-1α pathway and induced VEGF by regulating HIF-1α transcription. HIF-1α transcriptional stimulation by HB-EGF was facilitated by PKM2 and played an important role in HB-EGF's effect on cells. An HB-EGF inhibitor(CRM197, cross-reacting material 197) slowed cell proliferation and inhibited migration of As-T and A549 cells, and inhibited tumor growth. PKM2 also played an important role in the proliferation and migration in As-T cells. The positive staining ratios of EGFR phosphorylation (Y1068) and PKM2 were significantly higher in most cases of lung cancer than in paired normal tumor-adjacent lung tissues; and HB-EGF expression levels strongly correlated with p-EGFR expression levels. Thus, HB-EGF drives arsenic-induced carcinogenesis, tumor growth, and lung cancer development via the EGFR/PKM2/HIF-1α pathway.

Clinical Pharmacokinetics and Pharmacodynamics of the Epidermal Growth Factor Receptor Inhibitor Panitumumab in the Treatment of Colorectal Cancer

Despite progress in the treatment of metastatic colorectal cancer (mCRC) in the last 15 years, it is still a condition with a relatively low 5-year survival rate. Panitumumab, a fully human monoclonal antibody directed against the epidermal growth factor receptor (EGFR), is able to prolong survival in patients with mCRC. Panitumumab is used in different lines of therapy in combination with chemotherapy, and as monotherapy for the treatment of wild-type (WT) RAS mCRC. It is administered as an intravenous infusion of 6 mg/kg every 2 weeks and has a t_½ of approximately 7.5 days. Elimination takes place via two different mechanisms, and immunogenicity rates are low. Only RAS mutations have been confirmed as a negative predictor of efficacy with anti-EGFR antibodies. Panitumumab is generally well tolerated and has a manageable toxicity profile, despite a very high prevalence of dermatologic side effects. This article presents an overview of the clinical pharmacokinetics and pharmacodynamics of panitumumab, including a description of the studies that led to its approval in the different lines of therapy of mCRC.

Importance of magnesium sulfate supplementation in the prevention of hypomagnesemia and hypocalcemia during chemoradiation in head and neck cancer

In advanced squamous cell carcinoma of the head and neck, concomitant radiotherapy with cisplatin and/or cetuximab is frequently combined with cisplatin-based induction chemotherapy, which can cause severe hypomagnesemia, hypocalcemia, and hypokalemia. The aim of our study was to analyze the effects of magnesium sulfate supplementation on the incidence of hypomagnesemia, hypokalemia, and hypocalcemia during four cycles of TPF (docetaxel, cisplatin, and 5-fluorouracil) induction chemotherapy followed by concomitant radiotherapy (CRT) with cisplatin and cetuximab. Twenty-five patients included in a phase II prospective study received routine magnesium sulfate infusions before each cycle of cisplatin, and additional supplementation based on laboratory findings. During TPF, the incidence of grade 1/2 and grade 3/4 hypomagnesemia was 16% and 4%, respectively; and increased despite magnesium supplementation during CRT to 72% and 8%, respectively. During TPF, a grade 2 and grade 4 hypocalcemia occurred in 8% and 4%, respectively; and during CRT, it reached 36% (grade 1/2). Grade 1 hypokalemia only was observed during TPF (4%) and CRT (8%). The median amounts of supplemented magnesium sulfate during TPF and CRT were 20 mEq and 50 mEq, respectively. It appears that a low incidence of grade 3/4 hypomagnesemia and hypocalcemia in our patients resulted from intensive magnesium supplementation. Thorough measurements of magnesium and calcium during cisplatin-based chemoradiation protocols in patients with head and neck cancer are crucial in preventing the development of grade 3/4 hypomagnesemia and hypocalcemia.

Prognostic role of epiregulin/amphiregulin expression in recurrent/metastatic head and neck cancer treated with cetuximab

BACKGROUND

Cetuximab combined with chemoradiotherapy chemotherapy is the standard therapy for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC). However, survival benefit is limited. The purpose of this study was to investigate the expression of epiregulin (EREG) and amphiregulin (AREG), as predictive prognostic markers for the efficacy of cetuximab combined with chemotherapy in R/M HNSCC.

METHODS

We conducted a retrospective analysis of 37 patients diagnosed with R/M HNSCC. Tumor samples were analyzed for EREG and AREG mRNA gene expression, and clinical outcomes evaluated.

RESULTS

Values of EREG and AREG were associated with significantly longer overall survival (OS) (P = .03 and P = .01, respectively), as well as progression-free survival (PFS) (P = .04 and P = .04, respectively). Multivariate analysis revealed that AREG expression was significantly associated with OS and PFS.

CONCLUSIONS

Patients with recurrent/metastatic HNSCC with higher EREG and AREG gene expression appear to benefit more from cetuximab combined with chemoradiotherapy chemotherapy than those with lower expression.

Oral mucositis associated with anti-EGFR therapy in colorectal cancer: single institutional retrospective cohort study

Background

Chemotherapy-induced oral mucositis impairs the quality of life. The difference in severity of oral mucositis between different anti-epidermal growth factor receptor (EGFR) antibodies combined with cytotoxic drugs in colorectal cancer is unclear. The aim of this study was to investigate the differences in oral mucositis between panitumumab (Pmab) and cetuximab (Cmab) combined with 5-fluorouracil (5-FU).

Methods

We conducted a retrospective cohort study. A total of 75 colorectal cancer outpatients treated with an anti-EGFR antibody combined with FOLFOX, FOLFIRI, or 5-FU/leucovorin as the first- to third-line treatment were included. The primary endpoint was the incidence of grade 2–3 oral mucositis. The secondary endpoint was the time to onset of oral mucositis. We also compared the incidence of toxicities of interest, skin toxicity, hypomagnesaemia and neutropenia, and time to treatment failure (TTF) between the two groups.

Results

Thirty-two patients treated with Pmab and 43 patients treated with Cmab were evaluated. Patient characteristics were similar between the two groups. The incidence of grade 2–3 oral mucositis was significantly higher with Pmab than with Cmab (31.3% vs 9.3%, P < 0.05). Moreover, the incidence of grade 3 oral mucositis was significantly higher in patients treated with Pmab (18.8% vs 0%, P < 0.01). The mean (SD) cycles to onset of the worst oral mucositis was 3.0 (2.9) in the Pmab group and 2.3 (1.7) in the Cmab group (P = 0.29). Oral mucositis was characterized by glossitis and cheilitis. The incidences of other toxicities were the following (Pmab vs Cmab): grade 2–3 skin toxicity: 68.8% vs 74.4% (P = 0.61), grade 2–3 hypomagnesaemia: 9.3% vs 7.0% (P = 1.00), grade 3–4 neutropenia: 28.1% vs 37.2% (P = 0.46). The median TTF was not significantly different, i.e., 223 days vs 200 days (P = 0.39) for Pmab vs Cmab.

Conclusions

Pmab-based chemotherapy resulted in significantly higher grades of oral mucositis compared with Cmab-based chemotherapy. The oral condition should be monitored carefully and early supportive care should be provided for patients treated with Pmab-based chemotherapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4862-z) contains supplementary material, which is available to authorized users.

Efficacy and safety of anti-EGFR agents administered concurrently with standard therapies for patients with head and neck squamous cell carcinoma: a systematic review and meta-analysis of randomized controlled trials

Agents targeting epidermal growth factor receptor (EGFR) are used to treat head and neck squamous cell carcinoma (HNSCC); however, their efficacy and safety is poorly understood. Here we evaluated the efficacy and safety of anti-EGFR agents administered concurrently with standard therapies for HNSCC. Randomized controlled trials that evaluated addition of EGFR targeted therapy versus standard therapy alone were included. The primary outcome was overall survival (OS). Secondary outcomes were progression-free survival (PFS), overall response rate (ORR), locoregional control, and severe adverse events (SAEs, grade ≥ 3). Sixteen eligible trials with 4031 patients were included. Addition of anti-EGFR regimens to standard therapy significantly improved OS of patients with HNSCC (HR = 0.89; 95% CI, 0.82-0.96), with a moderately elevated rate of SAEs (RR = 1.08; 95% CI, 1.03-1.13). Subgroup analysis indicated that the survival benefit was observed when cetuximab was administered concurrently with radiotherapy (RT) for stage III/IV patients (HR = 0.76; 95% CI, 0.61-0.94; p = 0.01), or with chemotherapy for recurrent or metastatic (R/M) HNSCC (HR = 0.86; 95% CI, 0.78-0.95; p = 0.005). Significantly increased ORR (RR = 1.51; 95% CI 1.05-2.18) and PFS (HR = 0.72; 95% CI, 0.59-0.88) were found in R/M HNSCC patients treated with anti-EGFR plus chemotherapy, while no significant improvements were found in stage III/IV patients treated with anti-EGFR plus standard therapy. In conclusion, addition of cetuximab to standard therapy may improve outcomes for R/M HNSCC patients, while causing a moderate increase in SAEs. For stage III/IV patients, anti-EGFR mAb plus RT can improve OS compared with RT alone, while replacement of chemotherapy with EGFR mAb or adding EGFR mAb to combined chemotherapy and RT did not improve outcomes.

Cutaneous toxicity as a predictive biomarker for clinical outcome in patients receiving anticancer therapy

The relationship between treatment outcome and cutaneous toxicity induced by anticancer therapy has gained attention in the past decade. In this article, we have provided an overview of the 3 main classes of anticancer agents-specifically, molecularly targeted kinase inhibitors, immune checkpoint inhibitors, and cytotoxic chemotherapeutics-and described the data evaluating the association between cutaneous toxicity induced by these agents and survival benefit. Although preliminary studies are promising with regard to the potential role of cutaneous toxicities as a surrogate biomarker of efficacy of treatment, larger prospective studies are needed to confirm this relationship. Dermatologists have a unique opportunity to collaborate with oncologists in the multidisciplinary treatment paradigm by helping to identify and manage these dermatologic events in patients with cancer. A heightened awareness of these toxicities is critical, as it can potentially allow recognition of the efficacy of anticancer therapy and may influence treatment decisions and patient outcomes.

Hypomagnesemia and clinical benefits of anti-EGFR monoclonal antibodies in wild-type KRAS metastatic colorectal cancer: a systematic review and meta-analysis

Hypomagnesemia is a recognized side-effect of cetuximab- or panitumumab-based chemotherapy for metastatic colorectal cancer (mCRC). The clinical relevance of hypomagnesemia is under debate. Thus, a systematic review and meta-analysis of retrospective studies and randomized clinical trials (RCTs) comparing hypomagnesemia with normal magnesium levels in wild-type KRAS mCRC was performed. One RCT, two retrospective studies, and two American Society of Clinical Oncology (ASCO) and European Society for Medical Oncology (ESMO) conference presentations from phase III RCTs involving 1723 patients were included in this study. Patients with hypomagnesemia demonstrated better progression-free survival (PFS) (Hazard ratio [HR]: 0.64; 95% confidence interval [CI]: 0.47–0.88), overall survival (OS) (HR: 0.72; 95% CI: 0.53–0.92), and objective response rate (ORR) (Risk ratio [RR]: 1.81; 95% confidence interval [CI]: 1.30–2.52). By subgroup analysis, frontline, later lines or combination therapy with hypomagnesemia were associated with PFS benefits (HR: 0.78; 95% CI: 0.62–0.98; HR: 0.60; 95% CI: 0.40–0.90; HR: 0.62; 95% CI: 0.41–0.94, respectively). In patients with wild-type KRAS mCRC, hypomagnesemia is associated with better clinical benefits of PFS, OS and ORR when treated with cetuximab- or panitumumab-based chemotherapy. Future clinical trials should corroborate its predictive role.

Anti-Angiogenic Tyrosine Kinase Inhibitors and Reversible Posterior Leukoencephalopathy Syndrome: Could Hypomagnesaemia Be the Trigger?

Reversible posterior leukoencephalopathy syndrome (RPLS), also known frequently as posterior reversible encephalopathy syndrome (PRES), is a characteristic acute neuro-radiology syndrome with clinical presentation that typically includes acute hypertension, seizures and other neurological symptoms and signs. Many patients with RPLS have (a history of) pre-existing hypertension and in receipt of diuretics. It is being diagnosed more frequently and in association with an increasing number of morbidities and medications. Drugs most frequently implicated are immunosuppressant drugs and anticancer agents, including a number of anti-angiogenic tyrosine kinase inhibitors (TKIs). Hypomagnesaemia is a frequent finding at presentation in RPLS patients, which is known to lead to or aggravate hypertension. Pre-eclampsia, a variant of RPLS, responds effectively to intravenous magnesium. Cyclosporin, tacrolimus and some TKIs that induce RPLS are also known to give rise to both hypertension and hypomagnesaemia. This raises an interesting hypothesis that hypomagnesaemia may play a contributory role in triggering RPLS in some patients by acutely raising the blood pressure further. Additional systematic studies are required to test this hypothesis. If the hypothesis is confirmed, hypomagnesaemia offers an effective target for risk mitigation and prevention of RPLS in patients identified at risk.

Durable complete remission following anti-EGFR antibodies in recurrent metastatic colorectal cancer

In this case report, we describe a patient who remains in complete remission two years after the discontinuation of anti-EGFR monotherapy as a third-line treatment, accompanied by persistent severe hypomagnesemia. A 45-year-old Caucasian woman with mCRC started chemotherapy with weekly cetuximab. After ten months of treatment, the therapy was stopped because the patient had persistent grade III hypomagnesemia despite amiloride, oral, and intravenous magnesium. A month later, the patient was switched to panitumumab 6 mg/kg every two weeks for four additional months to avoid weekly visits to the clinic. Following discontinuation of panitumumab, PET scans remain negative to this day, two years after anti-EGFR therapy discontinuation. No factor has been identified to explain the complete and sustained response experienced by this patient. Hypomagnesemia is a common adverse effect of anti-EGFR therapy that can lead to treatment interruption and discontinuation if severe. This case highlights the importance of pursuing anti-EGFR therapy when a response is observed in spite of severe hypomagnesemia. It also provides preliminary information that anti-EGFR therapy could be stopped after a complete response is obtained.

Kidney Toxicities Associated With Novel Cancer Therapies

Targeted therapies that act via unique molecular pathways and interfere with cancer cell growth and tumor progression have dramatically changed the cancer treatment paradigm. However, although, ideally, these therapies intend to target only cancer cells, they do often affect nonmalignant tissue. Numerous renal side effects have been reported to date. This article will review clinical presentation, presumed pathophysiology, and treatment of kidney side effects of targeted therapies. Feasibility of the continuation of cancer therapy despite renal toxicity will also be addressed.