Heterogeneity of circulating tumor cells (CTCs) in patients with recurrent small cell lung cancer (SCLC) treated with pazopanib.

OBJECTIVES: To investigate the effect of pazopanib on different CTCs subpopulations in patients with recurrent SCLC and evaluate their clinical relevance. METHODS: Peripheral blood was obtained before the administration of pazopanib (n=56 patients), after the first cycle (n=35 patients) and at disease progression (n=45 patients). CTCs were detected by CellSearch and double immunofluorescent staining using antibodies against the cytokeratins (CK), TTF-1, CD56 and VEGFR2. RESULTS: Before treatment, CTCs could be detected in 50% of patients by CellSearch; phenotypic characterization of CTCs demonstrated that 50%, 46.6% and 27.6% of patients had CD45-/TTF1+, CD45-/CD56+ and TTF-1+/CD56+ CTCs, respectively. Additionally, 59% of CTCs were TTF-1+/VEGFR2+ and 53% CK+/VEGFR2+. One pazopanib cycle resulted to a significant decrease of the number of CTCs (CellSearch: p=0.043) and CK+/VEGFR2+ cells (p=0.027). At the time of PD, both the total number of CTCs (p=0.027) and the number of the different subpopulations were significantly increased compared to post-1st cycle values; this increased CTCs number was associated with a significant increase of TTF-1+/VEGFR2+ (p=0.028) and CK+/VEGFR2+ CTCs (p=0.018). In multivariate analysis, only the number of CTCs as assessed by CellSearch after one treatment cycle was significantly associated with OS (HR: 0.21; p=0.005). CONCLUSIONS: Pazopanib has a significant effect on different subpopulations of CTCs in patients with relapsed SCLC; the detection of VEGFR2+ CTCs during treatment could be a surrogate marker associated with resistance to pazopanib.

Effect of front-line chemotherapy on circulating CK-19 mRNA-positive cells in patients with metastatic breast cancer.

PURPOSE: To evaluate the effect of front-line chemotherapy on CK-19mRNA+ circulating tumor cells (CTCs) and their relevance in patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: The presence of CK-19mRNA+ CTCs was assessed using a real-time RT-PCR assay in 298 previously untreated patients with MBC before and after the administration of front-line chemotherapy. RESULTS: CK-19mRNA+ CTCs were detected in the blood of 199 (66.8 %) and 148 (49.7 %) patients before and after chemotherapy, respectively. There was no correlation between the detection of CK-19mRNA+ CTCs after chemotherapy and the various known clinicopathologic parameters except with HER2 status. The incidence of detection of CK-19mRNA+ CTCs was significantly decreased after the administration of 3 (47.8 %; p < 0.001) or 6 (44.3 %; p = 0.001) chemotherapy cycles. The persistent detection of >2.25 CK-19mRNA+ CTCs both before and after chemotherapy (persistently high group) was associated with a significantly (p = 0.003) decreased overall survival. In addition, chemotherapy-induced decrease of CK-19mRNA+ CTCs (≤2.25 CTCs) was associated with a better survival (47 vs 34 months; p < 0.001). Failure of chemotherapy to decrease the CK-19mRNA+ CTCs ≤2.25 was associated with decreased overall survival (HR 1.405, 95 % CI 1.044-1.891; p = 0.025) whereas in multivariate analysis the persistence of >2.25 CTCs both before and after chemotherapy was emerged as an independent prognostic factor (HR 1.661, 95 % CI 1.070-2.579; p = 0.024). CONCLUSION: Detection of CK-19mRNA+ CTCs after the completion of front-line chemotherapy in patients with MBC is associated with poor survival and may be a useful tool for the evaluation of front-line chemotherapy.

A multicenter phase I-II study of docetaxel plus epirubicin plus bevacizumab as first-line treatment in women with HER2-negative metastatic breast cancer.

PURPOSE: To assess the efficacy and toxicity of docetaxel (D) plus epirubicin (E) in combination with bevacizumab (B) [DEB regimen] as front-line treatment in patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: Women with previously untreated HER2-negative MBC received B (15 mg/kg), E (75 mg/m2) and D (75 mg/m2) with prophylactic G-CSF support every 3 weeks (q3w) for up to 9 cycles followed by B (15 mg/kg q3w) until disease progression. Primary endpoint was the overall response rate (ORR). Circulating tumor cells (CTCs) were evaluated using the CellSearch system at different time points during therapy. RESULTS: Eighty-three women were enrolled with median age 62 years, performance status 0-1 in 93%, triple negative disease in 12% and liver metastases in 47%. In an intention to treat analysis, complete response was achieved in 13 (15.7%) and partial response in 42 (50.6%) (overall response rate 66.3%; 95% CI 56.09-76.44%). The median time to progression was 20.1 months and the 1-year overall survival rate 82.3%. Grade 3-4 neutropenia occurred in 37%, febrile neutropenia in 10%, anemia in 4%, thrombocytopenia in 2% and diarrhea in 2% of patients. There were two deaths possibly related to study treatment (sigmoid perforation n = 1; sudden death n = 1). Moreover, one patient developed pulmonary embolism and another one myocardial infarction while on treatment. Although DEB administration significantly reduced the proportion of patients presenting CTCs, the detection of ≥5 or ≥1 CTCs before treatment initiation was significantly associated with worse progression-free survival (p = 0.001 and p = 0.004) and overall survival (p = 0.001 and p = 0.027), respectively. CONCLUSIONS: The DEB regimen is a very active but also potentially toxic combination in MBC. Detection of CTCs before treatment is associated with worse outcome. CLINICALTRIALSGOV: NCT00705315.

Circulating HER2 mRNA-positive cells in the peripheral blood of patients with stage I and II breast cancer after the administration of adjuvant chemotherapy: evaluation of their clinical relevance.

BACKGROUND: The purpose of this study was to evaluate the prognostic value of circulating tumor cells (CTCs) expressing HER2 messenger RNA (mRNA) after the administration of adjuvant chemotherapy in women with operable breast cancer. PATIENTS AND METHODS: HER2 mRNA-positive CTCs were detected by nested RT-PCR in the peripheral blood of 214 patients with stage I and II breast cancer after the completion of adjuvant chemotherapy. RESULTS: HER2 mRNA-positive CTCs were detected in 45 (21%) patients. Adjuvant chemotherapy could eliminate HER2 mRNA-positive CTCs in 16 (30.2%) prechemotherapy-positive patients. Moreover, HER2 mRNA-positive CTCs were detected in eight (5%) of 161 prechemotherapy-negative patients. The detection of HER2 mRNA-positive CTCs after chemotherapy was associated with reduced disease-free interval (DFI) (P = 0.006) but not with overall survival (P = 0.2); this effect was mainly observed in node-negative patients (P = 0.04) and to a lesser extent in node-positive (P = 0.06). Multivariate analysis revealed that the detection of HER2 mRNA-positive CTCs was an independent predictive factor for DFI (hazard ratio 3.238, P < 0.0005). CONCLUSIONS: The detection of HER2 mRNA-positive CTCs after the completion of adjuvant chemotherapy may provide clinically useful information concerning the efficacy of treatment and the prognosis of patients with operable breast cancer.