Association between event-free survival and overall survival after neoadjuvant treatment for non-small cell lung cancer: a systematic review and meta-analysis.

BACKGROUND: We wanted to evaluate if event-free survival (EFS) is a reliable surrogate for overall survival (OS) in patients with resectable non-small cell lung cancer (r-NSCLC) receiving neoadjuvant therapy. We conducted a systematic literature review and meta-analysis to investigate the statistical association between EFS and OS. RESEARCH DESIGN AND METHODS: Electronic databases were searched on 30 July 2021 to identify sources reporting both EFS and OS data in patients with stage I-IIIB r-NSCLC receiving neoadjuvant therapy. Correlation and regression analyses evaluated the association between the effect of treatment on EFS and OS using log-hazard ratios (HRs). Sources in which the entire population had epidermal growth factor receptor mutations were excluded from the analyses. RESULTS: We identified 74 sources, of which 8 reported EFS and OS HRs from randomized controlled trials. Based on these, we found a positive linear correlation and a strong association between EFS and OS log-HRs (weighted Pearson's correlation coefficient r = 0.864; 95% confidence interval 0.809-0.992; P = 0.006; random-effects meta-regression, R2 = 0.777). CONCLUSIONS: We found a strong association between treatment effects for EFS and OS, indicating that improvements in EFS are likely to be predictive of improvements in OS. EFS may therefore be a reliable surrogate for OS after neoadjuvant therapy in r-NSCLC.

Dynamic changes of CTCs in patients with metastatic HR(+)/HER2(-) breast cancer receiving salvage treatment with everolimus/exemestane.

PURPOSE: Detection of CTCs represents a poor prognostic factor in patients with early and metastatic breast cancer (mBC) and treatment with everolimus-exemestane (E/E) is an established effective treatment in hormone receptor-positive/HER2-negative mBC patients. The effect of E/E on CTCs in mBC patients was prospectively investigated. METHODS: CTCs from 50 pre-treated patients with mBC receiving E/E were analyzed using the CellSearch (CS) platform and triple immunofluorescence (IF) staining for cytokeratin, M30 and Ki67 expression to assess their proliferative and apoptotic status. RESULTS: CTCs (by CS) were detected in 64% of patients before treatment and E/E administration resulted in their decreased prevalence [(n = 18; 36%, p = 0.004) and (n = 7; 19.4%, p = 0.019) post-1st and post-3rd treatment cycle, respectively] whereas it was significantly increased at disease progression (PD: 61%) compared to post-1st and post-3rd cycle (p = 0.049 and p = 0.021, respectively). Ki67-positive CTCs were detected in 60%, 60%, 17% and 50% of patients before treatment, post-1st, post-3rd cycle and at PD, respectively, while the opposite was observed for M30-positive CTCs (0% at baseline, 10% after the 1st cycle, 50% after the 3rd cycle and 0% at PD). The detection of even ≥ 1 CTC/5 ml after one cycle was associated with decreased PFS (3.3 vs 9.0 months, p = 0.025) whereas the detection of even ≥ 2 CTCs at PD was associated with decreased OS (32.4 vs 19.5 months; p = 0.009). CONCLUSIONS: The combination of E/E resulted in early elimination of proliferating CTCs in mBC patients and this effect was associated with a favorable clinical outcome.

Bcl-2 expression in circulating tumor cells (CTCs) of patients with small cell lung cancer (SCLC) receiving front-line treatment.

INTRODUCTION: To investigate the presence of Bcl-2+CTCs in chemotherapy-naïve SCLC patients and their clinical relevance during front-line treatment. METHODS: Peripheral blood was obtained from 66 consecutive-patients before chemotherapy administration, after one-cycle and at relapse. CTCs were detected by CellSearch and immunofluorescence using anti-Bcl-2, anti-M30, anti-cytokeratins(CK), anti-CD45 and anti-vimentin(Vim) antibodies. RESULTS: Before treatment, CTCs were detected in 62.1% and 72.7% of patients using the CellSearch and immunofluorescence (Bcl-2+/CD45-), respectively. One-treatment cycle significantly decreased both CTCs' detection rate(p < 0.001) and their absolute number (p < 0.001). On relapse, both the number of positive-patients and the absolute number of CTC subpopulations were significantly increased, compared to post-1st cycle (CellSearch: p = 0.002 and immunofluorescence: p < 0.001). Immunofluorescence revealed an important CTC heterogeneity (Bcl2+/Vim+, Bcl2+/Vim-, Bcl2+/CK+, Bcl2+/CK- and Bcl2+/M30- CTCs). Moreover, 50.0% of patients without detectable CTCs by CellSearch had detectable Bcl-2+/CD45- cells. Multivariate analysis revealed a significant association between Bcl-2+/CD45-cells at baseline and PFS (HR = 4.5;p = 0.005) and OS (HR: 4.3; p = 0.001). Bcl-2+/CD45-cells after one-treatment cycle were significantly associated with shorter OS (HR: 13.9; p = 0.007). CONCLUSIONS: These results demonstrate an important phenotypic CTCs heterogeneity based on the co-expression of Bcl-2, CK, Vim and M30 in SCLC patients. The changes of Bcl-2+/CD45- CTCs during treatment seem to be a dynamic biomarker associated with treatment efficacy and patients' clinical outcome.

Prognostic significance of CEACAM5mRNA-positive circulating tumor cells in patients with metastatic colorectal cancer.

PURPOSE: Τo evaluate the clinical relevance of CEACAM5mRNA-positive circulating tumor cells (CTCs) in patients with metastatic colorectal cancer (mCRC). METHODS: Peripheral blood was obtained from 436 patients with mCRC before the initiation of systemic therapy. A second sample was obtained on treatment assessment from 296 (67.9%) patients. The detection of CEACAM5mRNA-positive CTCs was performed using a real-time PCR assay. RESULTS: The patients' median age was 67 years and PS (EGOG 0-1) 92%; KRAS exon 2 and BRAFV600E mutated primary tumors were identified in 31.9% and 6.4% of the tested patients, respectively, whereas metastasectomy was performed in 17.7% of the patients. Circulating CEACAM5mRNA-positive CTCs were detected in 125 (28.7%) and 85 (28.7%) patients at baseline and on treatment assessment, respectively. The detection of CEACAM5mRNA-positive cells was revealed, in multivariate analysis, as an independent prognostic factor associated with decreased PFS (HR 1.6; 95% CI 1.1-2.5; p = 0.026) and OS (HR 2.2; 95% CI 1.3-3.2; p < 0.001). The detection of CEACAM5mRNA-positive CTCs in patients with KRAS and BRAFV600E mutations was correlated with shorter PFS (p = 0.041 and p = 0.022, respectively). Moreover, OS was significantly shorter in patients with CEACAM5+/KRAS mutations compared to those with CEACAM5+/KRAS wt tumors (p = 0.023). CONCLUSIONS: Detection of peripheral blood CEACAM5mRNA-positive CTCs is an adverse prognostic factor correlated with poor clinical outcome in patients with mCRC, especially in patients with KRAS and BRAF mutated tumors.

KRAS genotypic changes of circulating tumor cells during treatment of patients with metastatic colorectal cancer.

INTRODUCTION: Circulating tumor cells (CTCs) could represent a non-invasive source of cancer cells used for longitudinal monitoring of the tumoral mutation status throughout the course of the disease. The aims of the present study were to investigate the detection of KRAS mutations in CTCs from patients with metastatic colorectal cancer (mCRC) and to compare their mutation status during treatment or disease progression with that of the corresponding primary tumors. MATERIALS AND METHODS: Identification of the seven most common KRAS mutations on codons 12 and 13 was performed by Peptide Nucleic Acid (PNA)-based qPCR method. The sensitivity of the assay was determined after isolation of KRAS mutant cancer cells spiked into healthy donors' blood, using the CellSearch Epithelial Cell kit. Consistent detection of KRAS mutations was achieved in samples containing at least 10 tumor cells/7.5 ml of blood. RESULTS: The clinical utility of the assay was assessed in 48 blood samples drawn from 31 patients with mCRC. All patients had PIK3CA and BRAF wild type primary tumors and 14 KRAS mutant tumors. CTCs were detected in 65% of specimens obtained from 74% of patients. KRAS mutation analysis in CTC-enriched specimens showed that 45% and 16.7% of patients with mutant and wild type primary tumors, respectively, had detectable mutations in their CTCs. Assessing KRAS mutations in serial blood samples revealed that individual patient's CTCs exhibited different mutational status of KRAS during treatment. CONCLUSIONS: The current findings support the rationale for using the CTCs as a dynamic source of tumor cells which, by re-evaluating their KRAS mutation status, could predict, perhaps more accurately, the response of mCRC patients to targeted therapy.