Circulating tumor cells and survival in abiraterone- and enzalutamide-treated patients with castration-resistant prostate cancer.

BACKGROUND: The outcome to treatment administered to patients with metastatic castration-resistant prostate cancer (mCRPC) greatly differs between individuals, underlining the need for biomarkers guiding treatment decision making. OBJECTIVE: To investigate the prognostic value of circulating tumor cell (CTC) enumeration and dynamics, in the context of second-line endocrine therapies (ie, abiraterone acetate or enzalutamide), irrespective of prior systemic therapies. DESIGN, SETTINGS, AND PARTICIPANTS: In a prospective, multicentre study blood samples for CTC enumeration were collected from patients with mCRPC at baseline (n = 174). In patients who responded for minimally 10-12 weeks a follow-up sample was collected. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: For baseline analysis, patients were stratified in <5 or ≥5 CTCs/7.5 mL, whereas for the analysis of CTC dynamics at 10-12 weeks, in patients with stable, increasing or decreasing CTC counts. Progression-free survival (PFS), overall survival (OS), and PSA changes at 10-12 weeks were compared between groups. RESULTS: Patients demonstrating increasing CTCs on therapy had a shorter median PFS (4.03 vs 12.98 vs 13.67 months, HR 3.6, 95%CI 1.9-6.8; P < 0.0001) and OS (11.2 months vs not reached, HR 9.5, 95%CI 3.7-24; P < 0.0001), compared to patients with decreasing or stable CTCs. Multivariable Cox regression showed that prior chemotherapy (HR 4.1, 95%CI 1.9-8.9; P = 0.0003), a high baseline CTC count (HR 1.5, 95%CI 1.2-1.9; P = 0.002) and increasing CTCs at follow-up (HR 3.3, 95%CI 1.4-7.6; P = 0.005) were independent predictors of worse PFS. Previous chemotherapy (HR 7, 95%CI 1.9-25; P = 0.003), high baseline CTC counts (HR 2.2, 95%CI 1.4-3.7; P = 0.002) and increasing CTCs during therapy (HR 4.6, 95%CI 1.4-15; P = 0.01) were independently associated with shorter OS. ≥30% and ≥50% PSA responses less frequently occurred in patients with CTC inclines at 10-12 weeks on therapy (χ2 test: P < 0.01). CONCLUSIONS: CTC dynamics during therapy are associated with PSA response and provide independent clinical prognostication over PSA declines. Hence the study demonstrates the pharmacodynamic properties of CTCs.

Comprehensive Profiling of the Androgen Receptor in Liquid Biopsies from Castration-resistant Prostate Cancer Reveals Novel Intra-AR Structural Variation and Splice Variant Expression Patterns.

BACKGROUND: Expression of the androgen receptor splice variant 7 (AR-V7) is associated with poor response to second-line endocrine therapy in castration-resistant prostate cancer (CRPC). However, a large fraction of nonresponding patients are AR-V7-negative. OBJECTIVE: To investigate if a comprehensive liquid biopsy-based AR profile may improve patient stratification in the context of second-line endocrine therapy. DESIGN, SETTING, AND PARTICIPANTS: Peripheral blood was collected from patients with CRPC (n=30) before initiation of a new line of systemic therapy. We performed profiling of circulating tumour DNA via low-pass whole-genome sequencing and targeted sequencing of the entire AR gene, including introns. Targeted RNA sequencing was performed on enriched circulating tumour cell fractions to assess the expression levels of seven AR splice variants (ARVs). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Somatic AR variations, including copy-number alterations, structural variations, and point mutations, were combined with ARV expression patterns and correlated to clinicopathologic parameters. RESULTS AND LIMITATIONS: Collectively, any AR perturbation, including ARV, was detected in 25/30 patients. Surprisingly, intra-AR structural variation was present in 15/30 patients, of whom 14 expressed ARVs. The majority of ARV-positive patients expressed multiple ARVs, with AR-V3 the most abundantly expressed. The presence of any ARV was associated with progression-free survival after second-line endocrine treatment (hazard ratio 4.53, 95% confidence interval 1.424-14.41; p=0.0105). Six out of 17 poor responders were AR-V7-negative, but four carried other AR perturbations. CONCLUSIONS: Comprehensive AR profiling, which is feasible using liquid biopsies, is necessary to increase our understanding of the mechanisms underpinning resistance to endocrine treatment. PATIENT SUMMARY: Alterations in the androgen receptor are associated with endocrine treatment outcomes. This study demonstrates that it is possible to identify different types of alterations via simple blood draws. Follow-up studies are needed to determine the effect of such alterations on hormonal therapy.

Influence of cisplatin-use, age, performance status and duration of chemotherapy on symptom control in advanced non-small cell lung cancer: detailed symptom analysis of a randomised study comparing cisplatin-vindesine to gemcitabine.

BACKGROUND: We previously reported that treatment of patients with symptomatic advanced non-small cell lung cancer with single agent Gemcitabine (GEM) resulted in a superior clinical-benefit response rate (RR) compared to cisplatin-based combination chemotherapy. We now report the detailed individual symptom control analysis, and the influence of cisplatin-use, age, performance status (PS) and duration of treatment. PATIENTS AND METHODS: Patients received either GEM (1000 mg/m(2), days 1, 8 and 15) or cisplatin (100 mg/m(2), day 1) plus Vindesine (3 mg/m(2), days 1 and 15) (PV), both every 4 weeks. Scores of 9 symptoms were listed weekly by the patient on visual analogue scales. Improvement of a symptom was defined as 2 consecutive cycles of improvement over baseline. RESULTS: Baseline symptoms in the 169 patients were well balanced between the 2 arms (84 GEM, 85 PV). Both patients with objective response and disease stabilisation had clearly better symptom control than those with disease progression. Symptom control in both arms was similar for 'disease-specific' symptoms such as cough, dyspnea, pain or haemoptysis. Compared to PV, a significantly larger number of GEM-patients had better scores for 'constitutional' items such as anorexia (P=0.007), ability to carry on with daily activities (P=0.04) and overall impression of quality-of-life (P=0.008). Symptom control was very similar in younger (<65 years) versus older (>/=65 years) patients, and only slightly better in those with a Karnofsky PS >/=80% compared to those <80%. Most of the symptom improvement occurred in the first 3 cycles, with some further symptom improvement in the following cycles in the GEM-arm only. CONCLUSIONS: Both GEM and PV yield a symptom control rate much higher than expected by the objective tumour RR. GEM is equally effective in controlling 'disease-specific' symptoms, but superior in controlling 'constitutional' symptoms. Most of the symptom control was achieved during the first 3 cycles of treatment, with some further improvement thereafter in the GEM-arm only.