Trastuzumab plus pertuzumab for HER2-amplified advanced colorectal cancer: Results from the drug rediscovery protocol (DRUP).

BACKGROUND: In 2-5% of patients with colorectal cancer (CRC), human epidermal growth factor 2 (HER2) is amplified or overexpressed. Despite prior evidence that anti-HER2 therapy confers clinical benefit (CB) in one-third of these patients, it is not approved for this indication in Europe. In the Drug Rediscovery Protocol (DRUP), patients are treated with off-label drugs based on their molecular profile. Here, we present the results of the cohort 'trastuzumab/pertuzumab for treatment-refractory patients with RAS/BRAF-wild-type HER2amplified metastatic CRC (HER2+mCRC)'. METHODS: Patients with progressive treatment-refractory RAS/BRAF-wild-type HER2+mCRC with measurable disease were included for trastuzumab plus pertuzumab treatment. Primary endpoints of DRUP are CB (defined as confirmed objective response (OR) or stable disease (SD) ≥ 16 weeks) and safety. Patients were enrolled using a Simon-like 2-stage model, with 8 patients in stage 1 and 24 patients in stage 2 if at least 1/8 patients had CB. To identify biomarkers for response, whole genome sequencing (WGS) was performed on pre-treatment biopsies. RESULTS: CB was observed in 11/24 evaluable patients (46%) with HER2+mCRC, seven patients achieved an OR (29%). Median duration of response was 8.4 months. Patients had undergone a median of 3 prior treatment lines. Median progression-free survival and overall survival were 4.3 months (95% CI 1.9-10.3) and 8.2 months (95% CI 7.2-14.7), respectively. No unexpected toxicities were observed. WGS provided potential explanations for resistance in 3/10 patients without CB, for whom WGS was available. CONCLUSIONS: The results of this study confirm a clinically significant benefit of trastuzumab plus pertuzumab treatment in patients with HER2+mCRC.

Population-based impact of COVID-19 on incidence, treatment, and survival of patients with pancreatic cancer.

BACKGROUND: The COVID-19 pandemic has put substantial strain on the healthcare system of which the effects are only partly elucidated. This study aimed to investigate the impact on pancreatic cancer care. METHODS: All patients diagnosed with pancreatic cancer between 2017 and 2020 were selected from the Netherlands Cancer Registry. Patients diagnosed and/or treated in 2020 were compared to 2017-2019. Monthly incidence was calculated. Patient, tumor and treatment characteristics were analyzed and compared using Chi-squared tests. Survival data was analyzed using Kaplan-Meier and Log-rank tests. RESULTS: In total, 11019 patients were assessed. The incidence in quarter (Q)2 of 2020 was comparable with that in Q2 of 2017-2019 (p = 0.804). However, the incidence increased in Q4 of 2020 (p = 0.031), mainly due to a higher incidence of metastatic disease (p = 0.010). Baseline characteristics, surgical resection (15% vs 16%; p = 0.466) and palliative systemic therapy rates (23% vs 24%; p = 0.183) were comparable. In 2020, more surgically treated patients received (neo)adjuvant treatment compared to 2017-2019 (73% vs 67%; p = 0.041). Median overall survival was comparable (3.8 vs 3.8 months; p = 0.065). CONCLUSION: This nationwide study found a minor impact of the COVID-19 pandemic on pancreatic cancer care and outcome. The Dutch health care system was apparently able to maintain essential care for patients with pancreatic cancer.

Treatment and overall survival of four types of non-metastatic periampullary cancer: nationwide population-based cohort study.

BACKGROUND: Periampullary adenocarcinoma consists of pancreatic adenocarcinoma (PDAC), distal cholangiocarcinoma (DC), ampullary cancer (AC), and duodenal adenocarcinoma (DA). The aim of this study was to assess treatment modalities and overall survival by tumor origin. METHODS: Patients diagnosed with non-metastatic periampullary cancer in 2012-2018 were identified from the Netherlands Cancer Registry. OS was studied with Kaplan-Meier analysis and multivariable Cox regression analyses, stratified by origin. RESULTS: Among the 8758 patients included, 68% had PDAC, 13% DC, 12% AC, and 7% DA. Resection was performed in 35% of PDAC, 56% of DC, 70% of AC, and 59% of DA. Neoadjuvant and/or adjuvant therapy was administered in 22% of PDAC, 7% of DC, 7% of AC, and 12% of DA. Three-year OS was highest for AC (37%) and DA (34%), followed by DC (21%) and PDAC (11%). Adjuvant therapy was associated with improved OS among PDAC (HR = 0.62; 95% CI 0.55-0.69) and DC (HR = 0.69; 95% CI 0.48-0.98), but not AC (HR = 0.87; 95% CI 0.62-1.22) and DA (HR = 0.85; 95% CI 0.48-1.50). CONCLUSION: This retrospective study identified considerable differences in treatment modalities and OS between the four periampullary cancer origins in daily clinical practice. An improved OS after adjuvant chemotherapy could not be demonstrated in patients with AC and DA.

Real-world evidence of adjuvant gemcitabine plus capecitabine vs gemcitabine monotherapy for pancreatic ductal adenocarcinoma.

The added value of capecitabine to adjuvant gemcitabine monotherapy (GEM) in pancreatic ductal adenocarcinoma (PDAC) was shown by the ESPAC-4 trial. Real-world data on the effectiveness of gemcitabine plus capecitabine (GEMCAP), in patients ineligible for mFOLFIRINOX, are lacking. Our study assessed whether adjuvant GEMCAP is superior to GEM in a nationwide cohort. Patients treated with adjuvant GEMCAP or GEM after resection of PDAC without preoperative treatment were identified from The Netherlands Cancer Registry (2015-2019). The primary outcome was overall survival (OS), measured from start of chemotherapy. The treatment effect of GEMCAP vs GEM was adjusted for sex, age, performance status, tumor size, lymph node involvement, resection margin and tumor differentiation in a multivariable Cox regression analysis. Secondary outcome was the percentage of patients who completed the planned six adjuvant treatment cycles. Overall, 778 patients were included, of whom 21.1% received GEMCAP and 78.9% received GEM. The median OS was 31.4 months (95% CI 26.8-40.7) for GEMCAP and 22.1 months (95% CI 20.6-25.0) for GEM (HR: 0.71, 95% CI 0.56-0.90; logrank P = .004). After adjustment for prognostic factors, survival remained superior for patients treated with GEMCAP (HR: 0.73, 95% CI 0.57-0.92, logrank P = .009). Survival with GEMCAP was superior to GEM in most subgroups of prognostic factors. Adjuvant chemotherapy was completed in 69.5% of the patients treated with GEMCAP and 62.7% with GEM (P = .11). In this nationwide cohort of patients with PDAC, adjuvant GEMCAP was associated with superior survival as compared to GEM monotherapy and number of cycles was similar.

A population-based study on incidence, treatment, and survival in ampullary cancer in the Netherlands.

INTRODUCTION: Ampullary cancer is rare and as a result epidemiological data are scarce. The aim of this population-based study was to determine the trends in incidence, treatment and overall survival (OS) in patients with ampullary adenocarcinoma in the Netherlands between 1989 and 2016. METHODS: Patients diagnosed with ampullary adenocarcinoma were identified from the Netherlands Cancer Registry. Incidence rates were age-adjusted to the European standard population. Trends in treatment and OS were studied over (7 years) period of diagnosis, using Kaplan-Meier and Cox regression analyses for OS and stratified by the presence of metastatic disease. RESULTS: In total, 3840 patients with ampullary adenocarcinoma were diagnosed of whom, 55.0% were male and 87.1% had non-metastatic disease. The incidence increased from 0.59 per 100,000 in 1989-1995 to 0.68 per 100,000in 2010-2016. In non-metastatic disease, the resection rate increased from 49.5% in 1989-1995 to 63.9% in 2010-2016 (p < 0.001). The rate of adjuvant therapy increased from 3.1% to 7.9%. In non-metastatic disease, five-year OS (95% CI) increased from 19.8% (16.9-22.8) in 1989-1995 to 29.1% (26.0-31.2) in 2010-2016 (logrank p < 0.001). In patients with metastatic disease, median OS did not significantly improve (from 4.4 months (3.6-5.0) to 5.9 months (4.7-7.1); logrank p = 0.06). Cancer treatment was an independent prognostic factor for OS among all patients. CONCLUSION: Both incidence and OS of ampullary cancer increased from 1989 to 2016 which is most likely related to the observed increased resection rates and use of adjuvant therapy.

Liquid chromatography-tandem mass spectrometric assay for the PARP-1 inhibitor olaparib in combination with the nitrogen mustard melphalan in human plasma.

A bioanalytical assay for the new poly(ADP-ribose) polymerase-1 inhibitor olaparib in combination with melphalan was developed and validated. For the quantitative assay, human plasma samples were pre-treated on ice using protein precipitation with 2% (v/v) acetic acid in acetonitrile containing erlotinib and melphalan-d8 as internal standards. The extract was diluted with water and injected into the chromatographic system. This system consisted of a sub-2 µm particle, trifunctional bonded octadecyl silica column with an isocratic elution using 0.01% (v/v) of formic acid in a mixture of water and methanol. The eluate was transferred into the electrospray interface with positive ionization and the analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. The assay was validated in a 10-5000 ng/ml calibration range for both drugs. The lowest level of this range corresponded to the lower limit of quantification. Within day precisions were 3.0-9.3%, between day precisions 6.0-9.8% and accuracies were between 101 and 110% for the whole calibration range. After validation the assay was used to assess the pharmacokinetics of olaparib in a patient with metastatic breast carcinoma. In addition, systemic exposure of melphalan was monitored in patients subjected to isolated hepatic perfusion with this drug. Both applications show that the new assay can be applied for human pharmacokinetic studies for both drugs.

In vitro schedule-dependent interaction between melphalan and oxaliplatin in human colorectal cancer cell lines.

OBJECTIVE: In order to determine the applicability of oxaliplatin in isolated liver perfusion, we identified the interaction between combinations of oxaliplatin and melphalan in 13 human colorectal cancer cell lines. METHODS: Cytotoxic activity was determined by the MTT-assay. Three different administration schedules of the two drugs were compared and median effect isobologram analysis was applied to the results, to determine the presence of synergism, additive effects, or antagonism as described by Chou and Talalay. RESULTS: Resistance to melphalan did not correspond to resistance to oxaliplatin. All combinations of melphalan and oxaliplatin showed synergistic or additive interaction in the majority of the cell lines. One hour of oxaliplatin followed by 1h of melphalan showed the lowest percentage of cell viability, with synergy in 10 out of 13 cell lines at 50% cell viability. Simultaneous treatment showed the highest cell viability, with antagonism in six cell lines, additivity in two cell lines, synergism in five cell lines at 50% cell viability. One hour of melphalan followed by 1h of oxaliplatin showed synergy in six cell lines, antagonism in another six, and additivity in one cell line. CONCLUSIONS: Our findings suggest a schedule-dependent synergistic interaction between melphalan and oxaliplatin. Therefore, oxaliplatin should be considered as a new, potentially valuable additional agent to the currently commonly used melphalan in isolated hepatic perfusion in colorectal cancer patients.

Isolated hepatic perfusion with 200 mg melphalan for advanced noncolorectal liver metastases.

PURPOSE: The liver is one of the most common sites for metastatic solid tumors. If the liver is the only site of metastatic disease, regional treatment options can offer the benefit of high local exposure with limited systemic toxicity, especially for patients without (further) systemic treatment options. We report the results of our experience with isolated hepatic perfusion (IHP) in patients with isolated liver metastases from a variety of primary tumors. PATIENTS AND METHODS: Nineteen patients with isolated unresectable liver metastases from a variety of tumors (13 uveal melanomas, 2 neuroendocrine carcinomas, 2 gastrointestinal stromal tumors, 1 hepatocellular carcinoma, and 1 high-grade sarcoma) were treated with a 60-min IHP using 200 mg melphalan. Patients were monitored for toxicity, response according to response evaluation criteria in solid tumors (RECIST) criteria, and survival. RESULTS: One melanoma patient was not perfused due to insufficient isolation of the liver. There was no treatment-related mortality. Reversible grade 3 or 4 hepatoxicity occurred in 10 (56%) patients, while veno-occlusive disease occurred in 4 (22%) patients. Of the 12 uveal melanoma patients who were perfused, 4 (33%) patients had a partial hepatic response, 6 (50%) patients had stable hepatic disease, and 2 (17%) patients were immediately progressive. Median disease-free survival was 6.6 months with a median overall survival of 10.0 months. Fifty percent of other primary tumors showed at least partial remission, including one complete remission in a high-grade sarcoma patient. CONCLUSION: IHP with melphalan shows activity in patients with liver metastases from a variety of primary tumors, but other or additional drugs may improve therapeutic outcome.

Four-color staining combining fluorescence and brightfield microscopy for simultaneous immune cell phenotyping and localization in tumor tissue sections.

Immune-cell infiltration is frequently seen within human solid tumors. A detailed phenotypic analysis of these cells may aid in the understanding of an antitumor immune response. Standard hematoxylin/eosin and conventional immunohistochemical stainings are helpful, but have major limitations in the number of markers that can be identified and localized per tissue section. Therefore, we developed a combined fluorescence and brightfield microscopic technique by using both immunofluorescence and immunogold-silver methods, thereby discriminating three different leukocyte markers plus one tumor marker simultaneously in a single section. This enabled us to study both phenotype and location of infiltrating immune cells in colorectal tumors. We used a two-step staining in which primary and secondary antibodies were selected for minimal cross-reactivity. Furthermore, the secondary fluorescent antibody conjugates were selected for minimal spectral overlap. For computer-assisted analysis the brightfield microscopy image was combined with the fluorescence microscopy images. This combination of techniques provides a powerful tool for detailed multiparameter microscopic analysis of formalin-fixed, paraffin-embedded tissue sections in general and for tumor-immune cell infiltration in particular.