Treatment of Peritoneal Metastasis with Pressurized Intraperitoneal Aerosol Chemotherapy: Results from the Prospective PIPAC-OPC2 Study.

BACKGROUND: Pressurized Intraperitoneal Aerosol chemotherapy (PIPAC) is a local treatment for peritoneal metastasis (PM). Prospective data are scarce and evaluation of treatment response remains difficult. This study evaluated the use of the Peritoneal Regression Grading score (PRGS) and its prognostic value. PATIENTS AND METHODS: This was a prospective, controlled phase II trial in patients with PM from gastrointestinal, gynaecological, hepatopancreatobiliary, primary peritoneal, or unknown primary cancer. Patients in performance status 0-1, with a non-obstructed gastrointestinal tract, and a maximum of one extraperitoneal metastasis were eligible. Colorectal or appendiceal PM had PIPAC with oxaliplatin, other primaries had PIPAC with cisplatin and doxorubicin. Biopsies were taken at each PIPAC and evaluated using the PRGS. Quality-of-life questionnaires were reported at baseline and after three PIPACs. RESULTS: One hundred ten patients were treated with 336 PIPACs (median 3, range 1-12). One hundred patients had prior palliative chemotherapy and 45 patients received bidirectional treatment. Complete or major histological response to treatment (PRGS 1-2) was observed in 38 patients (61%) who had three PIPACs, which was the only independent prognostic factor in a multivariate analysis. The median overall survival (mOS) from PIPAC 1 was 10 months, while patients with PM from gastric, colorectal, and pancreatic cancer had a mOS of 7.4, 16.7, and 8.2 months, respectively. Global health scores were significantly reduced, but patients were less fatigued, nauseated, constipated, and had better appetite after three PIPACs. CONCLUSIONS: PIPAC with oxaliplatin or cisplatin and doxorubicin was able to induce a major or complete histological response during three PIPACs, which may provide significant prognostic information, both at baseline and after treatment.

Feasibility and Safety of Laparoscopic D2 Gastrectomy in Combination with Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) in Patients with Gastric Cancer at High Risk of Recurrence-The PIPAC-OPC4 Study.

BACKGROUND: Patients with gastric adenocarcinoma (GAC) are at high risk of peritoneal recurrence despite perioperative chemotherapy and radical resection. This study evaluated feasibility and safety of laparoscopic D2 gastrectomy in combination with pressurized intraperitoneal aerosol chemotherapy (PIPAC). METHODS: This was a prospective, controlled bi-institutional study in patients with GAC at high risk of recurrence treated with PIPAC with cisplatin and doxorubicin (PIPAC C/D) after laparoscopic D2 gastrectomy. High risk was defined as a poorly cohesive subtype with predominance of signet-ring cells, clinical stage ≥ T3 and/or ≥ N2, or positive peritoneal cytology. Peritoneal lavage fluid was collected before and after resection. Cisplatin (10.5 mg/m2) and doxorubicin (2.1 mg/m2) were aerosolized after anastomosis (flow 0.5-0.8 ml/s, maximum pressure 300 PSI). Treatment was feasible and safe if ≤ 20% had Dindo-Clavien ≥ 3b surgical complications or CTCAE ≥ 4 medical adverse events within 30 days. Secondary outcomes were length of stay (LOS), peritoneal lavage cytology, and completion of postoperative systemic chemotherapy. RESULTS: Twenty-one patients were treated with a D2 gastrectomy and PIPAC C/D. The median age was 61 years (range 24-76), there were eleven female patients, and 20 patients had preoperative chemotherapy. There was no mortality. Two patients had grade 3b complications that were potentially related to PIPAC C/D (one anastomotic leakage, and one late duodenal blow-out). One patient had severe neutropenia, and nine patients had moderate pain. The LOS was 6 days (4-26). One patient had positive peritoneal lavage cytology before resection, and none were positive after. Fifteen patients had postoperative chemotherapy. CONCLUSIONS: Laparoscopic D2 gastrectomy in combination with PIPAC C/D is feasible and safe.

First-line trifluridine/tipiracil + bevacizumab in patients with unresectable metastatic colorectal cancer: final survival analysis in the TASCO1 study.

BACKGROUND: Therapeutic options are limited in patients with unresectable metastatic colorectal cancer (mCRC) ineligible for intensive chemotherapy. The use of trifluridine/tipiracil plus bevacizumab (TT-B) in this setting was evaluated in the TASCO1 trial; here, we present the final overall survival (OS) results. METHODS: TASCO1 was an open-label, non-comparative phase II trial. Patients (n = 153) were randomised 1:1 to TT-B (trifluridine/tipiracil 35 mg/m2 orally twice daily on days 1-5 and 8-12, and bevacizumab intravenously 5 mg/kg on days 1 and 15 of each 28-day cycle) or capecitabine plus bevacizumab (C-B; capecitabine, 1250 mg/m2 orally twice daily on days 1-14 and bevacizumab 7.5 mg/kg intravenously on day 1 of each 21-day cycle). Final OS was analysed when all patients had either died or withdrawn from the study. Adjusted multivariate regression was used to investigate the effects of pre-specified variables on OS. RESULTS: At 1 September 2020, median OS was 22.3 months (95% CI: 18.0-23.7) with TT-B and 17.7 months (95% CI: 12.6-19.8) with C-B (adjusted HR 0.78; 95% CI: 0.55-1.10). No variables negatively affected OS with TT-B. Safety results were consistent with prior findings. CONCLUSIONS: TT-B is a promising therapeutic regimen in mCRC patients ineligible for intensive chemotherapy. CLINICAL TRIAL INFORMATION: NCT02743221 (clinicaltrials.gov).

Trifluridine/tipiracil plus bevacizumab in patients with untreated metastatic colorectal cancer ineligible for intensive therapy: the randomized TASCO1 study.

BACKGROUND: We designed an open-label, noncomparative phase II study to assess the safety and efficacy of first-line treatment with trifluridine/tipiracil plus bevacizumab (TT-B) and capecitabine plus bevacizumab (C-B) in untreated patients with unresectable metastatic colorectal cancer (mCRC) who were not candidates for combination with cytotoxic chemotherapies. PATIENTS AND METHODS: From 29 April 2016 to 29 March 2017, 153 patients were randomly assigned (1:1) to either TT-B (N = 77) or C-B (N = 76). The primary end point was progression-free survival (PFS). The primary PFS analysis was performed after 100 events (radiological progression or death) were observed. Secondary end points included overall survival (OS), quality of life (QoL; QLQ-C30 and QLQ-CR29 questionnaires), and safety. RESULTS: Median (range) duration of treatment was 7.8 (6.0-9.7) months and 6.2 (4.1-9.1) months in the TT-B and C-B groups, respectively. Median (range) PFS was 9.2 (7.6-11.6) and 7.8 (5.5-10.1) months, respectively. Median (range) OS was 18 (15.2 to NA) and 16.2 (12.5 to NA) months, respectively. QoL questionnaires showed no relevant changes over time for either treatment. Therapies were well tolerated. Patients receiving TT-B had more grade ≥3 neutropenia (47% versus 5% with C-B). Patients receiving C-B had more grade ≥3 hand-foot syndrome (12% versus 0% with TT-B) and grade ≥3 diarrhea (8% versus 1% with TT-B), consistent with the known safety profiles of these agents. CONCLUSION: TT-B treatment showed promising clinical activity in untreated patients with unresectable mCRC ineligible for intensive therapy, with an acceptable safety profile and no clinically relevant changes in QoL. CLINICAL TRIAL INFORMATION: NCT02743221 (ClinicalTrials.gov).

Early changes in tests of peripheral nerve function during oxaliplatin treatment and their correlation with chemotherapy-induced polyneuropathy symptoms and signs.

BACKGROUND AND PURPOSE: Assessment of the severity of chronic peripheral neuropathy during oxaliplatin treatment is based on symptoms. Efforts to adjust the total dose of oxaliplatin to prevent severe neuropathy can be complicated by the worsening of neuropathy symptoms following treatment. Objective measures of the structure and function of peripheral nerves during early phases of treatment may aid in determining the optimal oxaliplatin dose in individual patients. Intraepidermal nerve fibre density (IENFD) has been suggested as an early marker of peripheral neuropathy. METHODS: Sixty patients were examined before treatment and following 25% and 50% of the total planned oxaliplatin dose. Fifty-five of them were also examined at completion of chemotherapy and 6 months later. IENFD in skin biopsies from the distal leg, nerve conduction studies and quantitative sensory testing at the dorsum of the foot were performed. Forty-six healthy subjects were examined at baseline and after 6 and 52 weeks for comparison. RESULTS: Intraepidermal nerve fibre density was not reduced during treatment. Sural nerve amplitude and conduction velocity, vibration detection thresholds, mechanical detection threshold and cold detection threshold were significantly reduced during treatment. Compared to reference values and spontaneous changes in healthy subjects, the largest proportions of patients with deterioration were found for vibration detection thresholds followed by nerve conduction studies, mechanical detection threshold, cold detection threshold and IENFD. CONCLUSIONS: Significant changes were most pronounced for measures of large nerve fibre function, especially vibration sensation. Skin biopsies do not seem to provide a clinically relevant objective measure of peripheral nerve deterioration during oxaliplatin treatment.

Total circulating cell-free DNA as a prognostic biomarker in metastatic colorectal cancer before first-line oxaliplatin-based chemotherapy.

BACKGROUND: Metastatic colorectal cancer (mCRC) is a heterogeneous disease where prognosis is dependent both on tumor biology and host factors. Total circulating cell-free DNA (cfDNA) has shown to harbor prognostic information in mCRC, although less is known about the biological correlates of cfDNA levels in this patient group. The primary objective was to evaluate the prognostic value of pretreatment cfDNA in patients receiving the first-line oxaliplatin-based chemotherapy for mCRC, by using a predefined upper limit of normal (ULN) from a cohort of presumed healthy individuals. The secondary objective was to model cfDNA levels as a function of predefined tumor and host factors. PATIENTS AND METHODS: This was a retrospective post hoc study based on a prospective multicenter phase III trial, the NORDIC-VII study. DNA was purified from 547 plasma samples and cfDNA quantified by a droplet digital PCR assay (B2M, PPIA) with controls for lymphocyte contamination. Main clinical end point was overall survival (OS). RESULTS: cfDNA was quantified in 493 patients, 54 were excluded mainly due to lymphocyte contamination. Median cfDNA level was 7673 alleles/ml (1050-1 645 000) for B2M and 5959 alleles/ml (555-854 167) for PPIA. High cfDNA levels were associated with impaired outcome; median OS of 16.6 months for levels above ULN and 25.9 months for levels below ULN (hazard ratio = 1.83, 95% confidence interval 1.51-2.21, P < 0.001). The result was confirmed in multivariate OS analysis adjusting for established clinicopathological characteristics. A linear regression model predicted cfDNA levels from sum of longest tumor diameters by RECIST, the presence of liver metastases and systemic inflammatory response as measured by interleukin 6 (F(6, 357) = 62.7, P < 0.001). CONCLUSION: cfDNA holds promise as a minimally invasive and clinically relevant prognostic biomarker in mCRC before initiating first-line oxaliplatin-based chemotherapy and may be a complex entity associated with tumor burden, liver metastases and systemic inflammatory response. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00145314.

Phase II randomized clinical trial of endosonography and PET/CT versus clinical assessment only for follow-up after surgery for upper gastrointestinal cancer (EUFURO study).

BACKGROUND: Upper gastrointestinal malignancies have a poor prognosis. There is no consensus on how patients should be followed after surgery. The authors hypothesized that a structured follow-up programme including endoscopic ultrasonography (EUS) and [18 F]fluorodeoxyglucose (FDG) PET/CT would detect cancer recurrences, leading to more patients being eligible for therapy. METHODS: After surgery with curative intent for adenocarcinomas in the gastro-oesophageal junction, stomach or pancreas, patients were randomized 1 : 1 to standard clinical assessment in the outpatient clinic at 3, 6, 9, 12, 18 and 24 months after operation, or clinical assessment plus imaging including [18 F]FDG PET/CT and EUS. The primary endpoint was number of patients receiving oncological treatment for recurrence. Secondary endpoints were overall and progression-free survival, survival after recurrence detection of isolated locoregional recurrences and risk factors affecting survival. RESULTS: In total, 183 patients were enrolled, including 93 who underwent standard follow-up and 90 who had follow-up plus imaging. A recurrence was detected in 84 patients within 2 years after surgery (42 in each group), including 33 of 42 patients in the imaging group who were asymptomatic. Some 25 of 42 patients in the imaging group and 14 of 42 in the standard group received chemotherapy (P = 0·028). Although survival after detection of recurrence in asymptomatic patients was significantly longer than that for symptomatic patients (P < 0·001), overall survival from date of surgery in the two treatment groups was comparable. CONCLUSION: Follow-up after surgery for upper gastrointestinal cancer with EUS and PET/CT leads to detection of more asymptomatic cancer recurrences and patients referred for treatment without prolonging overall survival. Registration number: NCT02209415 ( http://www.clinicaltrials.gov).

ANTECEDENTES: Las neoplasias del tracto digestivo superior tienen un mal pronóstico. No existe consenso sobre en qué pacientes debe indicarse un seguimiento tras la cirugía. Se estableció la hipótesis de que un programa de seguimiento estructurado en el que se incluía ecoendoscopia (endosonography, EUS) y 18F-FDG-PET/CT detecta recidivas del cáncer logrando que más pacientes sean elegibles para tratamiento. MÉTODOS: Después de cirugía con intención curativa para adenocarcinomas de la unión gastroesofágica, estómago o páncreas, los pacientes fueron aleatorizados 1:1 a evaluación clínica estándar en consultas externas a los 3, 6, 9, 12, 18, y 24 meses postoperatorios o evaluación clínica más pruebas de diagnóstico por la imagen en las que se incluían 18F-FDG-PET/CT y EUS. La variable principal fue el número de pacientes que recibieron tratamiento oncológico para la recidiva. Las variables secundarias fueron la supervivencia global y libre de progresión, supervivencia tras la recidiva, la detección de recidivas locorregionales aisladas (isolated loco-regional recurrences, ILR) y factores de riesgo que afectan a la supervivencia. RESULTADOS: En total se reclutaron 183 pacientes, incluyendo 93 pacientes sometidos a un seguimiento estándar (controles) y 90 pacientes con seguimiento y pruebas de imagen. Se detectó recidiva en 84 pacientes dentro de los primeros dos años tras la cirugía (42 pacientes en cada grupo), incluyendo 33 de 42 pacientes (78%) en el grupo con pruebas de imagen que estaban asintomáticos. Veinticinco de 42 pacientes (60%) del grupo con pruebas de imagen y 14 de 42 pacientes (33%) del grupo control recibieron quimioterapia (P = 0,03). Aunque la supervivencia tras la detección de la recidiva en pacientes asintomáticos fue significativamente más larga en comparación con los pacientes sintomáticos (P < 0,001), la supervivencia global desde la fecha de la cirugía en las dos ramas del tratamiento fue comparable. CONCLUSIÓN: El seguimiento tras la cirugía del cáncer gastrointestinal del tracto superior con EUS y PET-CT permite detectar más recidivas asintomáticas de la enfermedad y derivar a los pacientes para tratamiento sin que ello prolongue la supervivencia global.

ESMO consensus guidelines for the management of patients with metastatic colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies in Western countries. Over the last 20 years, and the last decade in particular, the clinical outcome for patients with metastatic CRC (mCRC) has improved greatly due not only to an increase in the number of patients being referred for and undergoing surgical resection of their localised metastatic disease but also to a more strategic approach to the delivery of systemic therapy and an expansion in the use of ablative techniques. This reflects the increase in the number of patients that are being managed within a multidisciplinary team environment and specialist cancer centres, and the emergence over the same time period not only of improved imaging techniques but also prognostic and predictive molecular markers. Treatment decisions for patients with mCRC must be evidence-based. Thus, these ESMO consensus guidelines have been developed based on the current available evidence to provide a series of evidence-based recommendations to assist in the treatment and management of patients with mCRC in this rapidly evolving treatment setting.

AGXT and ERCC2 polymorphisms are associated with clinical outcome in metastatic colorectal cancer patients treated with 5-FU/oxaliplatin.

The objective of the study was to investigate whether specific single nucleotide polymorphisms (SNPs) with influence on drug transport, biotransformation and repair mechanisms are associated with treatment outcome and toxicity in metastatic colorectal cancer (mCRC). We genotyped blood samples from 519 mCRC patients treated with first-line 5-fluorouracil and oxaliplatin +/- cetuximab for 17 SNPs in 10 genes involved in membrane transport (ABCC1 and ABCC2), drug biotransformation (GSTP1 and AGXT) and DNA repair (ERCC1, ERCC2, XRCC1, XRCC3, XPG and MSH6). The AGXT-rs34116584 and the ERCC2-rs238406 polymorphisms were significantly associated with progression-free survival (P=0.002 and P=0.001, respectively). Associations between 18 toxicity variables and SNPs were identified, although none were significant after Bonferroni correction for multiple comparisons. The study identified SNPs of potential use as markers of clinical outcome in oxaliplatin-treated mCRC patients. If validated in other studies, they could improve the selection of therapy in mCRC.

Characterization and diagnostic evaluation of chronic polyneuropathies induced by oxaliplatin and docetaxel comparing skin biopsy to quantitative sensory testing and nerve conduction studies.

BACKGROUND AND PURPOSE: Chemotherapy-induced peripheral neuropathy negatively affects the quality of life for many patients treated with oxaliplatin or docetaxel for gastrointestinal cancer or breast cancer. Symptoms can persist long after treatment and often include neuropathic pain. Our objective was to characterize the neuropathies with regard to symptoms, neurological signs and objective evidence of damage to the structure and function of the peripheral nerves. Furthermore, the diagnostic values of skin biopsy, quantitative sensory testing (QST) and nerve conduction studies (NCS) were compared. METHODS: Patients complaining of neuropathy symptoms at least 3 months after completion of treatment with oxaliplatin (n = 20) or docetaxel (n = 20) were recruited from the Department of Oncology or using hospital records. Neuropathy scores were determined along with the intraepidermal nerve fibre density in skin biopsies from the proximal and distal parts of the leg, QST and NCS. RESULTS: Clinically only sensory functions were affected. In general, neuropathy scores were higher in the oxaliplatin-treated group. Both sensory and motor fibres were affected in the NCS, showing predominantly signs of axonal damage. Mechanical detection threshold was most often affected in the QST. NCS, QTS and skin biopsy were abnormal in 11, 13 and 17 and 7, 11 and 15 of the oxaliplatin-treated patients and docetaxel-treated patients, respectively. CONCLUSIONS: Chemotherapy-induced peripheral neuropathy after oxaliplatin or docetaxel treatment is a clinically sensory, axonal neuropathy affecting only small nerve fibres in some patients. NCS are often normal, whereas QST and skin biopsy have a higher diagnostic sensitivity.

Generalized anxiety disorder screening scores are associated with greater treatment need among Veterans with depression.

Comorbid anxiety and depression predict a poorer prognosis than either disorder occurring alone. It is unclear whether self-reported anxiety symptom scores identify patients with depression in need of more intensive mental health services. This study evaluated how anxiety symptoms predicted treatment receipt and outcomes among patients with new depression diagnoses in the Veterans Health Administration (VHA). Electronic medical record data from 128,917 VHA patients (71.6% assessed for anxiety, n = 92,237) with new diagnoses of depression were analyzed to examine how Generalized Anxiety Disorder-7 (GAD-7) scores predicted psychotropic medication prescriptions, psychotherapy receipt, acute care service utilization, and follow-up depression symptoms. Patients who reported severe symptoms of anxiety were significantly more likely to receive adequate acute phase and continuation phase antidepressant treatment, daytime anxiolytics/sedatives, nighttime sedative/hypnotics, and endorse more severe depression symptoms and suicidal ideation at follow-up. Patients who reported severe symptoms of anxiety at baseline were less likely to initiate psychotherapy. The GAD-7 may help identify depressed patients who have more severe disease burden and require additional mental health services.

Do measures of social support and social distress share general factors associated with suicidal ideation and attempts?

INTRODUCTION: Aspects of social relationships have variably been associated with suicidal ideation (SI) and suicide attempts (SAs). This study assessed whether social support and social distress measures have general factors versus measure-specific factors that are associated with suicide risk. METHODS: Adults (N = 455, 60.0% female), admitted to psychiatric inpatient units following a recent suicide attempt or active SI, completed assessments of social support (emotional support, instrumental support, friendship, perceived support from significant others, friends, family) and social distress (loneliness, perceived rejection, perceived burdensomeness, thwarted belongingness). Bifactor modeling examined general and specific factors of social support and distress in relation to SI (week prior to hospitalization, via the Beck Scale for SI) and SAs (past 30 days, via the Columbia Suicide Severity Rating Scale). RESULTS: SI was significantly associated with the general social support (B = -1.51), the general social distress (B = 1.67), and the specific perceived burdensomeness (B = 1.57) factors. SAs were significantly associated with the specific Perceived Rejection (OR = 1.05) and Thwarted Belongingness (OR = 0.91) factors. CONCLUSION: General social support and social distress were associated with SI but not recent SAs. Specific social distress factors were also related to SI and SAs controlling for general social distress, suggesting areas for future interventions.

Age-dependent improvement in median and long-term survival in unselected population-based Nordic registries of patients with synchronous metastatic colorectal cancer.

BACKGROUND: In metastatic colorectal cancer (mCRC) trials, median survival has increased from 6 months to above 20 months during the previous decades. Uncertainty exists in how this survival improvement has translated to the general mCRC population. PATIENTS AND METHODS: Survival data from patients with synchronous mCRC were collected from the Norwegian (1980-2008), Swedish (1996-2008) and Danish (2001-09) cancer registries. RESULTS: A total of 29 628 patients were identified. From 1980-1985 to 2006-2008, median survival increased from 5 to 10 months for Norwegian patients. Three-year survival increased from 7% to 21% and 5-year survival from 4% to 9%. For patients <60 years, median survival was doubled to 16 months, 3-year survival increased fourfold up to 28% and 5-year survival threefold up to 14%. Similar improvements were seen in Sweden and Denmark. In all countries, the improved outcome was seen especially for younger patients and much less for patients >75 years of age. CONCLUSION: An increase in median and long-term survival over time was found in unselected population-based registries of patients with synchronous mCRC. The improved outcome in survival was especially seen in younger patients, raising concerns over our ability to adapt available treatment options for elderly patients.

Primary tumor location and bevacizumab effectiveness in patients with metastatic colorectal cancer.

BACKGROUND: There is an unmet need for predictive markers for the antiangiogenic agent bevacizumab in metastatic colorectal cancer (mCRC). We aimed to assess whether the location of the primary tumor is associated with bevacizumab effectiveness when combined with capecitabine and oxaliplatin (CAPEOX) in the first-line treatment of patients with mCRC. PATIENTS AND METHODS: A cohort of 667 consecutive patients with mCRC from the general community treated from 2006 to 2011 with CAPEOX and bevacizumab as standard first-line therapy was compared with a cohort of 213 patients treated with CAPEOX from 2003 to 2006, before bevacizumab was approved. Main outcome measures were progression-free survival (PFS) and overall survival (OS). Differences in outcome were tested using Kaplan-Meier curves and log-rank tests, and multivariate analyses were carried out using Cox Proportional Hazards models. RESULTS: Patients treated with CAPEOX and bevacizumab with primary tumors originating in the sigmoid colon and rectum had a significantly better outcome than patients with primary tumors originating from the cecum to the descending colon, both for PFS (median PFS 9.3 versus 7.2 months; hazard ratio (HR) 0.68, 95% confidence interval (CI) 0.56-0.82) and for OS (median OS 23.5 versus 13.0 months; HR 0.47, 95% CI 0.38-0.57). This difference was confirmed in multivariate analyses after adjustment for other potentially prognostic factors. For patients treated with CAPEOX, there was no association between primary tumor location and outcome, neither in unadjusted nor adjusted analyses. CONCLUSIONS: The addition of bevacizumab to CAPEOX in first-line treatment of patients with mCRC may primarily benefit patients with primary tumors originating in the rectum and sigmoid colon. This hypothesis needs to be validated in data from completed randomized trials. CLINICALTRIALSGOV IDENTIFICATION NUMBER: NCT00212615.

Implementation and clinical benefit of DPYD genotyping in a Danish cancer population.

BACKGROUND: In 2020, the European Medicines Agency recommended testing patients for dihydropyrimidine dehydrogenase (DPD) deficiency before systemic treatment with fluoropyrimidines (FP). DPD activity testing identifies patients at elevated risk of severe FP-related toxicity (FP-TOX). The two most used methods for DPD testing are DPYD genotyping and DPD phenotyping (plasma uracil concentration). The primary objective of this study was to compare the overall frequency of overall grade ≥3 FP-TOX before and after the implementation of DPYD genotyping. PATIENTS AND METHODS: Two hundred thirty Danish, primarily gastrointestinal cancer patients, were DPYD-genotyped before their first dose of FP, and blood was sampled for post hoc assessment of P-uracil. The initial dose was reduced for variant carriers. Grade ≥3 FP-TOX was registered after the first three treatment cycles of FP. The frequency of toxicity was compared to a historical cohort of 492 patients with post hoc determined DPYD genotype from a biobank. RESULTS: The frequency of overall grade ≥3 FP-TOX was 27% in the DPYD genotype-guided group compared to 24% in the historical cohort. In DPYD variant carriers, DPYD genotyping reduced the frequency of FP-related hospitalization from 19% to 0%. In the control group, 4.8% of DPYD variant carriers died due to FP-TOX compared to 0% in the group receiving DPYD genotype-guided dosing of FP. In the intervention group, wild-type patients with uracil ≥16 ng/ml had a higher frequency of FP-TOX than wild-type patients with uracil <16 ng/ml (55% versus 28%). CONCLUSIONS: We found no population-level benefit of DPYD genotyping when comparing the risk of grade ≥3 FP-TOX before and after clinical implementation. We observed no deaths or FP-related hospitalizations in patients whose FP treatment was guided by a variant DPYD genotype. The use of DPD phenotyping may add valuable information in DPYD wild-type patients.