Pseudoprogression and Mixed Responses in Metastatic Renal Cell Carcinoma Patients Treated With Nivolumab: A Retrospective Analysis.

INTRODUCTION: Immune checkpoint inhibitors (ICI) are part of the current standard of care for metastatic clear-cell renal cell carcinoma (m-ccRCC). ICI can elicit diverse tumor response, including atypical responses such as pseudoprogression (psPD), mixed responses (MR) and late responses. We aimed to analyze the occurrence and prognostic impact of atypical responses in m-ccRCC patients treated with nivolumab. MATERIALS AND METHODS: A retrospective analysis of m-ccRCC patients treated with nivolumab in first or subsequent therapy line between November 2012 and July 2022 was performed. All radiographic evaluations of eligible patients were analyzed using the iRECIST consensus guideline. RESULTS: We assessed 247 baseline target lesions in 94 eligible patients. MR occurred in 11 (11.7%) patients: in 7 at first CT (computed tomography) evaluation (CT1) and in 4 at second CT evaluation (CT2). In 8 patients (73%), MR evolved to confirmed PD. In 3 patients (27%), MR evolved towards a partial response (PR) and was thus a psPD. psPD occurred in 8 (8.5%) patients: with psPD features at CT1 in 3 patients, with psPD features at CT2 in 2 patients, and with MR features at CT1 in 3 patients. psPD patients had similar progression-free survival and overall survival compared to patients displaying PR as best response without a phase of psPD. 76 patients were treated beyond immune unconfirmed progressive disease (iUPD) at any moment: 12 (16%) of them evolved towards PR or stable disease (SD). Treatment beyond immune confirmed PD (iCPD) in 20 patients did not lead to PR or SD. CONCLUSION: Atypical responses such as psPD and MR occurred in 8.5% and 11.7% of m-ccRCC patients treated with nivolumab at CT1 and CT2. Patients with psPD had favorable outcomes, while MR most often evolved to progression. Treatment with nivolumab beyond iCPD did not lead to tumor stabilization or regression.

Overall survival improvement in patients with metastatic clear-cell renal cell carcinoma between 2000 and 2020: a retrospective cohort study.

BACKGROUND: Only a few recent phase III trials with targeted therapies or immune checkpoint inhibitors (ICIs) in metastatic clear-cell renal cell carcinoma (m-ccRCC) demonstrated an overall survival (OS) benefit compared to standard of care. We aimed to study the evolution of OS since the start of systemic therapy from 2000 to 2020. PATIENTS AND METHODS: Retrospective study on all consecutively treated m-ccRCC patients in three Belgian hospitals starting with systemic therapy. The study outcome was OS since the start of systemic therapy. We used a univariable Cox model for OS with year of the start of therapy as a predictor, and a multivariable analysis including known prognostic factors. Linear and non-linear trends of time were tested. RESULTS: Five hundred patients were included. In a linear model, the HR for OS depending on the year of the start of therapy was 0.95 (95%CI 0.93-0.97; p < 0.0001), estimated for an increase with 1 year in time. In a non-linear model, OS started to improve from 2006 on, when vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) replaced interferon alfa (IFNa) as a standard of care and continued to increase steadily during the following years. On multivariable analysis, the year of the start of therapy remained an independent prognostic factor for OS. Two-year OS after the start of systemic therapy was 23%, 34%, 50% and 59% for patients who started treatment in 2000-2005, 2006-2011, 2012-2017, and 2018-2020, respectively. The five-year OS of the first three groups was 7%, 14% and 24%. The mean number of administered lines of therapy increased over time, with an incidence rate ratio of 1.07 (95%CI 1.05-1.08; p < 0.0001) per year increase for the period 2000-2016. CONCLUSION: OS of m-ccRCC patients has been improving significantly over the last 15 years since the introduction of VEGFR-TKIs and ICIs.

Bone metastasis is associated with poor prognosis in metastatic papillary renal cell carcinoma patients treated with first agent angiogenesis inhibitors.

OBJECTIVE: Papillary renal cell carcinoma (papRCC) is a rare (10%-15%) subtype of renal cancer. Few prognostic biomarkers have been described in metastatic papRCC (m-papRCC) patients treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs). We aimed to study the prognostic impact of bone metastases (BM) on response rate, progression-free and overall survival (PFS and OS) in patients with m-papRCC treated with first agent VEGFR-TKIs. PATIENTS AND METHODS: A multicentric, retrospective analysis of patient records was conducted. BM were detected by computed tomography and/or bone scintigraphy. The International Metastatic RCC Database Consortium (IMDC) score was calculated at start of first agent VEGFR-TKI treatment. RESULTS: Forty-nine patients were included. Best objective response was partial response in 20%, stable disease in 60% and early progressive disease in 20% of patients. Median PFS (mPFS) was 6.0 months and median OS (mOS) 14.0 months after start of first agent VEGFR-TKI. The IMDC score correlated with mOS: 77.5 months in good, 17.0 months in intermediate and 8.0 months in poor risk patients (P = 0.002). Patients with BM had a poorer outcome compared to patients without BM: mPFS was 4.0 vs. 7.0 months (P = 0.006) and mOS 7.5 vs. 19.0 months (P = 0.002). On bivariate analysis, the presence of BM was independently associated with PFS (P = 0.02) and OS (P = 0.049), independent of the IMDC risk groups. CONCLUSION: In m-papRCC patients treated with first agent VEGFR-TKIs, the presence of BM is an unfavorable prognostic factor, associated with shorter PFS and OS.

Real-world use of granulocyte colony-stimulating factor in ambulatory breast cancer patients: a cross-sectional study.

PURPOSE: To prevent febrile neutropenia (FN), European Organisation for Research and Treatment of Cancer (EORTC) guidelines recommend primary prophylaxis with granulocyte colony-stimulating factors (PPG) for patients at high risk (≥ 20%) of FN. In Belgium, the use of PPG is restricted by specific reimbursement criteria. The impact of these criteria on PPG use and adherence to guidelines is unknown. METHODS: This multicentre, cross-sectional, observational study aimed to describe PPG use by FN risk category in breast cancer patients who were scheduled to receive myelosuppressive chemotherapy in outpatient clinics in Belgium during a 2-week period between 13 October and 12 December 2014. RESULTS: In total, 490 patients were enrolled. Median age was 57.0 years. Based on their chemotherapy regimen, 53.9, 5.1 and 41.0% of patients were at a low, intermediate and high risk of FN, respectively. Overall, 39.8% of patients received PPG (17.0, 12.0 and 73.1% of those receiving low-, intermediate- and high-risk regimens, respectively). In the high-risk category, PPG was used in 89.9% of dose-dense and in 25.0% of classical chemotherapy regimens. PPG use was adherent to EORTC guidelines in 75.3% of patients (30.6% appropriate use, 44.7% appropriate non-use). EORTC guidelines would recommend PPG use in 46.1% of this study population (n = 226), and its use was reimbursable in Belgium in 76.1% of these patients (n = 172), but only 66.4% of them received PPG (n = 150). CONCLUSIONS: Both Belgian reimbursement criteria and physician decision-making led to a proportion of patients for whom PPG treatment was recommended but finally not receiving it.

Tamoxifen Metabolism and Efficacy in Breast Cancer: A Prospective Multicenter Trial.

Purpose: Levels of endoxifen, the most active metabolite of tamoxifen, vary by the highly polymorphic cytochrome P450 (CYP) 2D6 enzyme. We prospectively investigated tamoxifen efficacy by serum endoxifen levels and the tamoxifen activity score (TAS).Experimental Design: A prospective observational multicenter study included postmenopausal women with an estrogen receptor-positive breast cancer receiving first-line tamoxifen, 20 mg daily in the neoadjuvant or metastatic setting, recruited between February 2009 and May 2014. The primary endpoint was the objective response rate (ORR) using RECIST criteria 1.0. Secondary endpoints were clinical benefit (CB), progression-free survival (PFS), and tolerability of tamoxifen. The main analysis used logistic regression to relate ORR to serum endoxifen levels after 3 months. Endpoints were also related to other tamoxifen metabolites and to TAS.Results: Endoxifen levels were available for 247 of all 297 patients (83%), of which 209 with target lesions (85%). Median follow-up time for PFS was 32.5 months, and 62% progressed. ORR and CB were 45% and 84%, respectively. ORR was not related to endoxifen, and the OR of ORR was 1.008 per µg/L increase in endoxifen (95% confidence interval, 0.971-1.046; P = 0.56). In general, none of the endpoints was associated with endoxifen levels, tamoxifen metabolites, or TAS.Conclusions: Under the prespecified assumptions, the results from this prospective clinical trial do not suggest therapeutic drug monitoring of endoxifen to be of clinical value in postmenopausal women treated with tamoxifen for breast cancer in the neoadjuvant or metastatic setting. Clin Cancer Res; 24(10); 2312-8. ©2018 AACR.

Which Factors Predict Overall Survival in Patients With Metastatic Castration-Resistant Prostate Cancer Treated With Abiraterone Acetate Post-Docetaxel?

BACKGROUND: Abiraterone acetate (AA) increases overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel. However, survival time varies substantially between individuals. Our goal was to identify prognostic factors that better estimate OS. MATERIALS AND METHODS: This is a retrospective multicentric analysis of 368 patients with mCRPC starting AA with prednisone after docetaxel. Cox proportional hazards statistics were applied. A multivariate model was constructed based on significant univariate predictors by using a manual stepwise forward and backward selection strategy. Model performance was determined by using receiver operating characteristic (ROC) curves. RESULTS: Univariate analysis identified 20 significant OS predictors. A multivariate model was constructed, based on 220 patients, incorporating 5 independent risk factors for decreased OS at the time of AA initiation: hemoglobin < 12 g/dL (hazard ratio [HR] 2.02), > 10 metastases (HR 1.80), ECOG performance status ≥ 2 (HR 1.88), radiographic progression (HR 1.50), and time since diagnosis < 90 months (HR 1.66, all P < .05). Patients were stratified into 3 groups: good (0-2 risk factors, median OS 22.6 months), intermediate (3 risk factors, median OS 13.9 months), and poor prognosis (4-5 risk factors, median OS 6.2 months). The area under the ROC curve based on the event "death by the time of median OS (13.3 months)" was 0.736 (95% confidence interval 0.670-0.803). CONCLUSION: We identified 5 readily available risk factors independently associated with decreased OS. The resulting model may be used for patient counseling in daily clinical practice, as well as patient stratification in clinical trials.

Abiraterone acetate post-docetaxel for metastatic castration-resistant prostate cancer in the Belgian compassionate use program.

BACKGROUND: Abiraterone acetate (AA) is licensed for treating metastatic castration-resistant prostate cancer (mCRPC). Real-world data on oncological outcome after AA are scarce. The current study assesses efficacy and safety of AA in mCRPC patients previously treated with docetaxel who started treatment during the Belgian compassionate use program (January 2011-July 2012). PATIENTS AND METHODS: Records from 368 patients with mCRPC from 23 different Belgian hospitals who started AA 1000mg per day with 10mg prednisone or equivalent were retrospectively reviewed (September 2013-December 2014). Prostate-specific antigen (PSA) response (decrease≥50%), time to PSA progression (increase>50% over PSA nadir in case of PSA response/>25% in absence of PSA response), time to radiographic progression (on bone scans or for soft tissue lesions using Response Evaluation Criteria In Solid Tumors 1.1), overall survival and adverse event rate (Common Terminology Criteria for Adverse Events v4.03) were analyzed. Kaplan-Meier statistics were applied. RESULTS: Overall, 92 patients (25%) had an Eastern Cooperative Oncology Group performance status≥2. Median age was 73 years, median PSA was 103ng/dl. PSA response was observed in 131 patients (37.4%). Median time to PSA and radiographic progression was 4.1 months (95% CI: 3.6-4.6) and 5.8 months (5.3-6.4), respectively. Median overall survival was 15.1 months (13.6-16.6). Most common grade 3 to 4 adverse events were anemia (13.9%), hypokalemia (7.3%), fatigue (6.8%), and pain (6.3%). Median duration of AA treatment was 5.3 months (interquartile range: 2.8-10.3). The main study limitation is its retrospective design. CONCLUSIONS: These real-world data on post-docetaxel AA efficacy are in line with the COU-AA-301 trial. Importantly, incidence of severe anemia and hypokalemia is up to 50% higher than reported in previous studies.

Adequate iron chelation therapy for at least six months improves survival in transfusion-dependent patients with lower risk myelodysplastic syndromes.

BACKGROUND: Most patients with myelodysplastic syndromes (MDS) require transfusions at the risk of iron overload and associated organ damage, and death. Emerging evidence indicates that iron chelation therapy (ICT) could reduce mortality and improve survival in transfusion-dependent MDS patients, especially those classified as International Prognostic Scoring System (IPSS) Low or Intermediate-1 (Low/Int-1). METHODS: Follow-up of a retrospective study. Sample included 127 Low/Int-1 MDS patients from 28 centers in Belgium. Statistical analysis stratified by duration (≥6 versus <6 months) and quality of chelation (adequate versus weak). RESULTS: Crude chelation rate was 63% but 88% among patients with serum ferritin ≥1000 µg/L. Of the 80 chelated patients, 70% were chelated adequately mainly with deferasirox (26%) or deferasirox following deferoxamine (39%). Mortality was 70% among non-chelated, 40% among chelated, 32% among patients chelated ≥6 m, and 30% among patients chelated adequately; with a trend toward reduced cardiac mortality in chelated patients. Overall, median overall survival (OS) was 10.2 years for chelated and 3.1 years for non-chelated patients (p<0.001). For patients chelated ≥6 m or patients classified as adequately chelated, median OS was 10.5 years. Mortality increased as a function of average monthly transfusion intensity (HR=1.08, p=0.04) but was lower in patients receiving adequate chelation or chelation ≥6 m (HR=0.24, p<0.001). CONCLUSION: Six or more months of adequate ICT is associated with markedly better overall survival. This suggests a possible survival benefit of ICT in transfusion-dependent patients with lower-risk MDS.

Weekly paclitaxel versus weekly docetaxel in elderly or frail patients with metastatic breast carcinoma: a randomized phase-II study of the Belgian Society of Medical Oncology.

This randomized phase-II trial investigated the efficacy and tolerability of weekly docetaxel or paclitaxel in metastatic breast cancer (MBC) patients considered unfit for a 3-weekly therapy. The primary study endpoint was antitumor activity, the second endpoint was tolerability, time to progression (TTP) and overall survival (OS). In intent-to-treat analysis, we observed for paclitaxel and docetaxel respectively partial response (PR) in 48% versus 38%, stable disease (SD) in 24% versus 16%, PD in 15% versus 30%. Median TTP was 21.1 weeks versus 12.7 weeks and median OS 55.7 weeks versus 32 weeks. Toxicity profiles were acceptable with more anemia and neurotoxicity for paclitaxel and more edema and fatigue for docetaxel. In patients with MBC unfit for 3-weekly docetaxel or paclitaxel, weekly administration of either compound may certainly be considered. They display different, but acceptable toxicity profiles, with levels of antitumoral efficacy comparable to those previously reported for 3-weekly regimens.

Transfusion-induced serum sickness.

BACKGROUND: Transfusion-induced serum sickness reactions are rarely reported in the literature. The Type III hypersensitivity reaction to heterologous proteins involves deposition of complement and immune complexes in small vessel walls resulting in a leukocytoclastic vasculitis. A case of a multiply transfused patient with several episodes of serum sickness reactions is presented. CASE REPORT: A 61-year-old man with myelodysplastic syndrome type refractory anemia presented with fever, rash, and polyarthralgia 5 days after transfusion of red blood cells (RBCs). By transfusing plasma-free "washed" RBCs, similar serum sickness reactions were avoided. RESULTS: Laboratory investigation showed an increase of serum creatinine, hematuria, and proteinuria. Levels of circulating immune complexes immunoglobulin G and immunoglobulin M were increased. Hypocomplementemia could not be demonstrated. Histopathologic examination of the skin showed leukocytoclastic vasculitis, compatible with serum sickness. CONCLUSION: The importance of early recognition of transfusion-induced serum sickness reactions is emphasized, because this can reduce unnecessary morbidity from this unusual complication of transfusion. To prevent this type of transfusion reaction, patients who experienced serum sickness-like reactions after transfusion should only receive plasma-free washed RBCs.

Detection of micrometastatic disease and monitoring of perioperative tumor cell dissemination in primary operable breast cancer patients using real-time quantitative reverse transcription-PCR.

PURPOSE: We previously found a statistically significant number of cytokeratin 19 (CK19)+ cells in peripheral blood (PB) of stage IV breast cancer (BC) patients compared with those of healthy volunteers, using a quantitative real-time reverse transcription-PCR. We aimed to apply the technique on bone marrow (BM) of primary operable BC patients. Pre- and postoperative PB samples of these patients were further analyzed to investigate possible shedding of CK19+ cells during the operation. EXPERIMENTAL DESIGN: In 54 primary operable BC patients, we analyzed 50 BM samples taken preoperatively and 297 PB samples. PB samples were collected before surgery; immediately after surgery; on the first, second, and fifth day postoperatively; and one month postoperatively. RESULTS: In BM of controls and BC patients, we detected a median of 28 and 568 CK19+ cells/5 x 10(6) leukocytes, respectively (P < 0.001). In preoperative blood (B-1) samples, we measured a median of 109 CK19+ cells. Using the upper limit of 95% confidence interval of controls as cutoff, 74% and 52% of BM and (B-1), respectively were considered CK19+. There was no significant correlation between CK19+ cells in BM and (B-1) and classical prognostic factors. We found no significant difference between blood samples at different time points with respect to the average CK19+ cells. CONCLUSIONS: In primary BC patients, we detected high numbers of CK19+ cells in BM and PB (B-1) samples compared with controls. However, no significant correlation between the presence of CK19+ cells in BM and PB and classical prognostic factors was found. We detected no statistically significant influence of surgical manipulation on CK19+ cells.