DPYD genotype-guided dose individualisation of fluoropyrimidine therapy in patients with cancer: a prospective safety analysis.

BACKGROUND: Fluoropyrimidine treatment can result in severe toxicity in up to 30% of patients and is often the result of reduced activity of the key metabolic enzyme dihydropyrimidine dehydrogenase (DPD), mostly caused by genetic variants in the gene encoding DPD (DPYD). We assessed the effect of prospective screening for the four most relevant DPYD variants (DPYD*2A [rs3918290, c.1905+1G>A, IVS14+1G>A], c.2846A>T [rs67376798, D949V], c.1679T>G [rs55886062, DPYD*13, I560S], and c.1236G>A [rs56038477, E412E, in haplotype B3]) on patient safety and subsequent DPYD genotype-guided dose individualisation in daily clinical care. METHODS: In this prospective, multicentre, safety analysis in 17 hospitals in the Netherlands, the study population consisted of adult patients (≥18 years) with cancer who were intended to start on a fluoropyrimidine-based anticancer therapy (capecitabine or fluorouracil as single agent or in combination with other chemotherapeutic agents or radiotherapy). Patients with all tumour types for which fluoropyrimidine-based therapy was considered in their best interest were eligible. We did prospective genotyping for DPYD*2A, c.2846A>T, c.1679T>G, and c.1236G>A. Heterozygous DPYD variant allele carriers received an initial dose reduction of 25% (c.2846A>T and c.1236G>A) or 50% (DPYD*2A and c.1679T>G), and DPYD wild-type patients were treated according to the current standard of care. The primary endpoint of the study was the frequency of severe (National Cancer Institute Common Terminology Criteria for Adverse Events version 4.03 grade ≥3) overall fluoropyrimidine-related toxicity across the entire treatment duration. We compared toxicity incidence between DPYD variant allele carriers and DPYD wild-type patients on an intention-to-treat basis, and relative risks (RRs) for severe toxicity were compared between the current study and a historical cohort of DPYD variant allele carriers treated with full dose fluoropyrimidine-based therapy (derived from a previously published meta-analysis). This trial is registered with ClinicalTrials.gov, number NCT02324452, and is complete. FINDINGS: Between April 30, 2015, and Dec 21, 2017, we enrolled 1181 patients. 78 patients were considered non-evaluable, because they were retrospectively identified as not meeting inclusion criteria, did not start fluoropyrimidine-based treatment, or were homozygous or compound heterozygous DPYD variant allele carriers. Of 1103 evaluable patients, 85 (8%) were heterozygous DPYD variant allele carriers, and 1018 (92%) were DPYD wild-type patients. Overall, fluoropyrimidine-related severe toxicity was higher in DPYD variant carriers (33 [39%] of 85 patients) than in wild-type patients (231 [23%] of 1018 patients; p=0·0013). The RR for severe fluoropyrimidine-related toxicity was 1·31 (95% CI 0·63-2·73) for genotype-guided dosing compared with 2·87 (2·14-3·86) in the historical cohort for DPYD*2A carriers, no toxicity compared with 4·30 (2·10-8·80) in c.1679T>G carriers, 2·00 (1·19-3·34) compared with 3·11 (2·25-4·28) for c.2846A>T carriers, and 1·69 (1·18-2·42) compared with 1·72 (1·22-2·42) for c.1236G>A carriers. INTERPRETATION: Prospective DPYD genotyping was feasible in routine clinical practice, and DPYD genotype-based dose reductions improved patient safety of fluoropyrimidine treatment. For DPYD*2A and c.1679T>G carriers, a 50% initial dose reduction was adequate. For c.1236G>A and c.2846A>T carriers, a larger dose reduction of 50% (instead of 25%) requires investigation. Since fluoropyrimidines are among the most commonly used anticancer agents, these findings suggest that implementation of DPYD genotype-guided individualised dosing should be a new standard of care. FUNDING: Dutch Cancer Society.

Discovering novel germline genetic variants linked to severe fluoropyrimidine-related toxicity in- and outside DPYD.

BACKGROUND: The Alpe-DPD study (NCT02324452) demonstrated that prospective genotyping and dose-individualization using four alleles in DPYD (DPYD*2A/rs3918290, c.1236G > A/rs75017182, c.2846A > T/rs67376798 and c.1679 T > G/rs56038477) can mitigate the risk of severe fluoropyrimidine toxicity. However, this could not prevent all toxicities. The goal of this study was to identify additional genetic variants, both inside and outside DPYD, that may contribute to fluoropyrimidine toxicity. METHODS: Biospecimens and data from the Alpe-DPD study were used. Exon sequencing was performed to identify risk variants inside DPYD. In silico and in vitro analyses were used to classify DPYD variants. A genome-wide association study (GWAS) with severe fluoropyrimidine-related toxicity was performed to identify variants outside DPYD. Association with severe toxicity was assessed using matched-pair analyses for the exon sequencing and logistic, Cox, and ordinal regression analyses for GWAS. RESULTS: Twenty-four non-synonymous, frameshift, and splice site DPYD variants were detected in ten of 986 patients. Seven of these variants (c.1670C > T, c.1913 T > C, c.1925 T > C, c.506delC, c.731A > C, c.1740 + 1G > T, c.763 - 2A > G) were predicted to be deleterious. The carriers of either of these variants showed a trend towards a 2.14-fold (95% CI, 0.41-11.3, P = 0.388) increased risk of severe toxicity compared to matched controls (N = 30). After GWAS of 942 patients, no individual single nucleotide polymorphisms achieved genome-wide significance (P ≤ 5 × 10-8), however, five variants were suggestive of association (P < 5 × 10-6) with severe toxicity. CONCLUSIONS: Results from DPYD exon sequencing and GWAS analysis did not identify additional genetic variants associated with severe toxicity, which suggests that testing for single markers at a population level currently has limited clinical value. Identifying additional variants on an individual level is still promising to explain fluoropyrimidine-related severe toxicity. In addition, studies with larger samples sizes, in more diverse cohorts are needed to identify potential clinically relevant genetic variants related to severe fluoropyrimidine toxicity.

Methotrexate plus or minus cetuximab as first-line treatment in a recurrent or metastatic (R/M) squamous cell carcinoma population of the head and neck (SCCHN), unfit for cisplatin combination treatment, a phase Ib-randomized phase II study Commence.

BACKGROUND: Methotrexate in recurrent or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN) has limited progression-free survival (PFS) benefit. We hypothesized that adding cetuximab to methotrexate improves PFS. METHODS: In the phase-Ib-study, patients with R/M SCCHN received methotrexate and cetuximab as first-line treatment. The primary objective was feasibility. In the phase-II-study patients were randomized to this combination or methotrexate alone (2:1). The primary endpoint was PFS. Secondary endpoints were overall survival (OS), toxicity, and quality of life (QoL). RESULTS: In six patients in the phase-Ib-study, no dose limiting toxicities were observed. In the phase II study, 30 patients received the combination and 15 patients methotrexate. In the phase-II-study median PFS was 4.5 months in the combination group vs 2.0 months in the methotrexate group (HR 0.37; P = .002). OS, toxicity, and QoL were not significantly different. CONCLUSION: Cetuximab with methotrexate improved PFS without increased toxicity in R/M SCCHN-patients.

A cost analysis of upfront DPYD genotype-guided dose individualisation in fluoropyrimidine-based anticancer therapy.

BACKGROUND: Fluoropyrimidine therapy including capecitabine or 5-fluorouracil can result in severe treatment-related toxicity in up to 30% of patients. Toxicity is often related to reduced activity of dihydropyrimidine dehydrogenase, the main metabolic fluoropyrimidine enzyme, primarily caused by genetic DPYD polymorphisms. In a large prospective study, it was concluded that upfront DPYD-guided dose individualisation is able to improve safety of fluoropyrimidine-based therapy. In our current analysis, we evaluated whether this strategy is cost saving. METHODS: A cost-minimisation analysis from a health-care payer perspective was performed as part of the prospective clinical trial (NCT02324452) in which patients prior to start of fluoropyrimidine-based therapy were screened for the DPYD variants DPYD*2A, c.2846A>T, c.1679T>G and c.1236G>A and received an initial dose reduction of 25% (c.2846A>T, c.1236G>A) or 50% (DPYD*2A, c.1679T>G). Data on treatment, toxicity, hospitalisation and other toxicity-related interventions were collected. The model compared prospective screening for these DPYD variants with no DPYD screening. One-way and probabilistic sensitivity analyses were also performed. RESULTS: Expected total costs of the screening strategy were €2599 per patient compared with €2650 for non-screening, resulting in a net cost saving of €51 per patient. Results of the probabilistic sensitivity and one-way sensitivity analysis demonstrated that the screening strategy was very likely to be cost saving or worst case cost-neutral. CONCLUSIONS: Upfront DPYD-guided dose individualisation, improving patient safety, is cost saving or cost-neutral but is not expected to yield additional costs. These results endorse implementing DPYD screening before start of fluoropyrimidine treatment as standard of care.

Painful ophthalmoplegia from metastatic nonproducing parathyroid carcinoma: case study and review of the literature.

Parathyroid carcinoma is an uncommon malignancy. Of the fewer than 400 cases reported, most have been cases of producing parathyroid carcinoma with accompanying hypercalcemia. Only 13 patients with nonproducing parathyroid carcinoma have been described. Nine of these 13 patients had metastatic disease. We report a patient with i.c. metastasis. Distal metastases of producing parathyroid carcinoma are treated surgically to prolong survival and prevent complications of hyperparathyroidism and hypercalcemia. One half of the patients with producing parathyroid carcinoma die within 5 years, mostly because of the complications of hypercalcemia. Nonproducing parathyroid carcinoma compares unfavorably with producing parathyroid carcinoma in terms of tumor progression and prognosis. Few data on choice of therapy in nonproducing parathyroid carcinoma are available. We treated our patient with a combination of radiotherapy and chemotherapy. Treatment was followed by an unexpectedly prolonged survival of 31 months after diagnosis of metastatic disease.

Management of temozolomide toxicity by nurse practitioners in neuro-oncology.

PURPOSE/OBJECTIVES: To investigate the toxicity of temozolomide (TMZ) in patients with brain tumors and appropriate nursing interventions. DESIGN: Explorative analysis of prospective data. SETTING: A TMZ clinic led by a nurse practitioner (NP). SAMPLE: Group A (n = 71) received a standard dose of TMZ daily for five days 200 mg/m2 every four weeks; group B (n = 19) received a dose-intense schedule of TMZ daily for 21 days 75 mg/m2 every four weeks. METHODS: Toxicities were scored according to National Cancer Institute Common Terminology Criteria, and results in the two groups were compared. MAIN RESEARCH VARIABLES: Thrombopenia, neutropenia, and lymphopenia; nausea and vomiting; and NP interventions. FINDINGS: Of observed toxicities during six cycles, grade 3-4 thrombopenia was seen most frequently in group A. Neutropenia and subsequent interventions occurred more frequently in group A than in group B. Subsequent interventions consisted of dose delays and reductions. When patients were treated for a longer duration of time with TMZ, grade 3-4 lymphopenia occurred significantly more often in group B, necessitating Pneumocystis carinii pneumonia prophylaxis. CONCLUSIONS: Degree of toxicity using a 5-day 200 mg/m2 or 21-day 75 mg/m2 schedule every four weeks was similar to that found in other studies. IMPLICATIONS FOR NURSING: Through awareness of toxicity in relation to knowledge of brain tumors, NPs can become more effective in active management of TMZ toxicity.