New ARCHITECT plasma pro-gastrin-releasing peptide assay for diagnosing and monitoring small-cell lung cancer.

BACKGROUND: Progastrin-releasing peptide (ProGRP) is a potential marker for small-cell lung cancer (SCLC) in serum; however, it may be more stable in plasma. We investigated a new plasma assay (ProGRPp) and its usefulness in diagnosing and monitoring SCLC. METHODS: The marker concentrations were determined on the ARCHITECT i system. RESULTS: The assay could distinguish SCLC from non-small-cell lung cancer (NSCLC: area under the curve 0.931, 95% CI 0.893-0.969; cross-validated accuracy 0.813; sensitivity 84.0%, specificity 96.3%; at 140 pg ml(-1) cutoff). The probability of SCLC when ProGRPp was >140 pg ml(-1) was 91.8%, after adjusting for age, gender, and renal dysfunction. The NSCLC patients with ProGRPp >140 pg ml(-1) were at high risk (odds ratio=37.0, P<0.001) for tumours with neuroendocrine features. False negatives in SCLC were associated with a lack of thyroid transcription factor-1 (P<0.001). A decrease of ProGRPp to <140 pg ml(-1) during chemotherapy was significantly associated with the image-based response (P<0.001), and independently affected progression-free survival (PFS, relative risk=2.51, P=0.04) and overall survival (OS, relative risk=4.38, P=0.003), after adjustment for imaging response, performance status, and stage. CONCLUSIONS: The ProGRPp assay is specific and sensitive for diagnosing SCLC. Changes in ProGRPp during chemotherapy are significantly associated with image-based response, PFS, and OS.

Comparison of diagnostic and prognostic performance of two assays measuring thymidine kinase 1 activity in serum of breast cancer patients.

BACKGROUND: We compared two recently developed immunoassays for serum thymidine kinase 1 (TK1) activity: one manual assay (DiviTum, Biovica(®)) and one fully automated assay (Liaison, Diasorin(®)). METHODS: The study included 368 women: 149 healthy blood donors (control), 59 patients with benign breast disease (BBD) and 160 patients with primary breast cancer (BC). RESULTS: A regression analysis of the Liaison (y) and DiviTum (x) assays for all three groups yielded the equation y=3.93+0.03x (r=0.85, n=368). The r-value in BC was higher than in control and BBD (0.90 vs. 0.81 and 0.64). The correlation between the two assays for TK1 values above the cut-off was higher compared to that below (0.88 and 0.59). Breakdown of the BBD group into subgroups with proliferative and non-proliferative lesions was effective only with the measurement of TK1 with DiviTum assay (p=0.03). The TK1 activity determined preoperatively in BC patients with DiviTum and Liaison assays was significantly associated with T-stage (for both p=0.01), presence of vascular invasion (p=0.002 and p=0.02), lack of estrogen receptor (ER) (p=0.001 and p=0.01) and progesterone receptor (PR) (p=0.01 and p=0.03) expression. Only TK1 analyzed with the DiviTum assay was associated with tumor grade and molecular subtype of BC (p=0.02 and p=0.003). Multivariate Cox proportional hazards analyses demonstrated that T-stage, PR status and TK1 activity measured by both methods (DiviTum, RR=3.0, p=0.02 and Liaison, RR=3.1, p=0.01) were independent predictors of disease recurrence. CONCLUSIONS: In spite of differences observed between TK1 activity measured by the DiviTum and Liaison assays, both of them may be used for recurrence prediction in preoperative evaluation of BC patients.

Plasma Progastrin-Releasing Peptide and Chromogranin A Assays for Diagnosing and Monitoring Lung Well-Differentiated Neuroendocrine Tumors: A Brief Report.

INTRODUCTION: The use of chromogranin A (CGA) as a circulating biomarker in lung carcinoids (LCs) is limited by low specificity and sensitivity. This study aimed to evaluate plasma progastrin-releasing peptide (ProGRPp) as an alternative to plasma CGA (CGAp), for the diagnosis and follow-up of LC. METHODS: ProGRPp and CGAp concentrations were measured in 107 patients with LC and 105 patients with benign lung disease (BLD). RESULTS: ProGRPp distinguished patients with LC with active disease in the pretreatment (n = 43) and post-treatment (n = 43) groups from those with BLD: area under the curve for both 0.864 (p < 0.0001); sensitivity 67.4% and 58.1%, respectively; specificity 96.2%; at 64 pg/mL cutoff. CGAp failed to differentiate both LC groups from those with BLD: area under the curve 0.579 and 0.526 (for both p > 0.1); sensitivity 34.9% and 25.6%, respectively; specificity 73.3%; at 104 ng/mL cutoff. Only ProGRPp correlated with the Ki67 proliferation index (r = 0.40, p < 0.001) and was associated with mitotic count (p = 0.025), stage (p = 0.018), grade (p = 0.019), and the expression of thyroid transcription factor-1 (p = 0.005). ProGRPp had a high sensitivity (92.3%) in LC with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. Abnormal postoperative ProGRPp level was associated with residual disease (p = 0.029). The changes in ProGRPp level during treatment, a decrease greater than 30% and an increase greater than 8%, were associated with image-based outcomes, partial response and disease progression, respectively (p < 0.0001). CGAp did not reflect the disease course. CONCLUSIONS: ProGRPp was superior to CGAp in diagnosing LC with correlations concerning proliferation, grading, staging, diffuse idiopathic pulmonary neuroendocrine cell hyperplasia co-occurrence, and response to treatment. ProGRPp is an optimal emerging biomarker to be further evaluated.

A Comparison of Outcomes in Medullary Thyroid Carcinoma Patients With and Without a Preoperative Diagnosis: A Multicenter Retrospective Cohort Study.

Background: Cytological limitations pose a challenge to preoperative diagnosis of medullary thyroid carcinoma (MTC) and therefore, a significant subset of patients is only diagnosed postoperatively. The objective of this study was to investigate the impact of knowledge of a preoperative MTC diagnosis on disease management and outcomes. Methods: Multicenter, retrospective, cohort study of MTC patients treated in Israel from January 2000 to June 2021. We compared cohorts of patients according to the presence or absence of a preoperative MTC diagnosis. Results: Ninety-four patients with histologically confirmed MTC were included (mean age 56.2 ± 14.3 years, 43% males). Fifty-three patients (56%) had a preoperative MTC diagnosis (preop-Dx group), and 41 (44%) were confirmed only postoperatively (no-Dx group). The extent of surgical resection, including completion procedures, was as follows: total thyroidectomy in 83% versus 100% (p = 0.002), central lymph node dissection (LND) in 46% versus 98% (p < 0.001), ipsilateral lateral LND in 36% versus 79% (p < 0.001), and contralateral lateral LND in 17% versus 28% (NS), in the no-Dx versus the preop-Dx group, respectively. Pathology confirmed a smaller median tumor size of 16 ± 17.4 mm versus 23 ± 14.0 mm (p = 0.09), a higher proportion of micro-MTC (size ≤10 mm) 32% versus 15% (p = 0.03), and a higher rate of co-occurrence of follicular cell-derived carcinoma 24% versus 4% (p = 0.003), in the no-Dx compared to the preop-Dx group, respectively. The rates of extrathyroidal and extranodal tumor extension were not significantly different between the groups. At the last follow-up, the biochemical cure was attained in 55% [CI 0.38-0.71] compared to 64% [CI 0.50-0.77] of the no-Dx and the preop-Dx group, respectively (p = 0.41). After the exclusion of patients with micro-MTC, biochemical cure was more commonly achieved in the preop-Dx group (33% [CI 0.14-0.52] vs. 62% [CI 0.46-0.77], p = 0.04). Preop-Dx patients had improved overall survival compared to the no-Dx group (log-rank p = 0.04) over a median follow-up of 82 months (interquartile range [IQR] 30-153). Conclusions: Preoperatively, the diagnosis of MTC is often missed. An accurate preoperative diagnosis of MTC may enable guideline-concordant surgical treatment and ultimately contribute to an overall survival benefit in MTC patients.

Valproic acid reprograms the metabolic aberration of cisplatin treatment via ALDH modulation in triple-negative breast cancer cells.

We recently demonstrated that the histone deacetylase inhibitor valproic acid (VPA) reprograms the cisplatin-induced metabolome of triple-negative breast cancer (TNBC) cells, including a shift in hexose levels. Accordingly, here, we tested the hypothesis that VPA alters glucose metabolism in correlation with cisplatin sensitivity. Two TNBC cell lines, MDA-MB-231 (a cisplatin-resistant line) and MDA-MB-436 (a cisplatin-sensitive line), were analyzed. The glycolysis and oxidative metabolism were measured using the Glycolysis Stress Test kit. The expression of aldehyde dehydrogenases (ALDHs), enzymes linked to drug resistance, was investigated by Western blot and real-time PCR analyses. We additionally studied the influence of ALDH inhibition by disulfiram on the viability of MDA-MB-231 cells and on a TNBC patient-derived organoid system. Cisplatin treatment reduced the extracellular acidification rate in MDA-MB-436 cells but not MDA-MB-231 cells, whereas VPA addition increased the extracellular acidification rate in both cell lines. VPA further reduced the oxygen consumption rate of cisplatin-treated MDA-MB-436 cells, which correlated with cell cycle alterations. However, in MDA-MB-231 cells, the cell cycle distribution did not change between cisplatin/VPA-cisplatin treatments. In both cell lines, VPA increased the expression of ALDH isoform and ALDH1A1 expression. However, only in MDA-MB-231 cells, VPA synergized with cisplatin to augment this effect. Disulfiram sensitized the cells to the cytotoxic effects of the VPA-cisplatin combination. Furthermore, the disulfiram-VPA-chemotherapy combination was most effective in TNBC organoids. Our results show that ALDH overexpression may act as one mechanism of cellular resistance to VPA in TNBC and that its inhibition may enhance the therapeutic efficacy of VPA-chemotherapeutic drug combinations.

Thyroid Hormones and Morphological Features of Primary Breast Cancer.

BACKGROUND/AIM: Many experimental studies have suggested the importance of thyroid hormones in breast cancer (BC) morphogenesis. The aim of this study was to evaluate the association of thyroid hormone levels in serum of patients with primary BC with morphological presentations of the disease in pathological specimens and prognosis. PATIENTS AND METHODS: We measured the serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), along with serum thymidine kinase 1 activity and examined their relation to pathological features and prognosis of 158 patients with primary BC. RESULTS: We found a significant positive association of serum FT3 level with the presence of carcinoma in situ component (CIS) (p=0.032) and its size (p=0.047), with the presence (p=0.022) and the number of multifocal/multicentric tumors (MMTs) (p=0.002), as well as with increased proliferative activity in terms of serum thymidine kinase 1 (p=0.002). Moreover, we report that each 1.0 unit rise of FT3/FT4 ratio×10 was associated with an odds ratio of 1.77 (95% confidence interval=1.17-3.30, p=0.007), 1.97 (95% confidence interval=1.17-2.67, p=0.010) and 1.56 (95% confidence interval=1.02-2.37, p=0.039) for the detection of patients with CIS, MMTs and lymphovascular invasion, respectively, after adjusting for age. We did not find statistically significant associations of serum TSH level with breast cancer`s parameters. A Cox regression survival analysis identified serum FT3 level >5.95 pmol/l as a risk factor for BC recurrence (relative risk=2.65, p=0.017), a finding that retained significance in a multivariate model (relative risk=2.52, p=0.027). CONCLUSION: The FT3/FT4 ratio is a valuable parameter predicting the presence of CIS, MMTs and lymphovascular invasion in pathological specimens. An elevated serum FT3 level is associated with the presence of CIS, MMTs, increased proliferative activity and poor prognosis.

Potential Refinement of Recurrence Score by pSTAT3 Status.

The likelihood of recurrence in breast cancer patients with hormone receptor-positive (HR-positive) tumors is influenced by clinical, histopathological, and molecular features. Recent studies suggested that activated STAT3 (pSTAT3) might serve as a biomarker of outcome in breast cancer patients. In the present work, we have analyzed the added value of pSTAT3 to OncotypeDx Recurrence Score (RS) in patient prognostication. We have found that patients with low RS (<26) and low pSTAT3 might represent a population at a higher risk for cancer recurrence. Furthermore, we have observed that a positive pSTAT3 score alone can be a favorable marker for patients with HR-positive breast cancer under the age of 50. In an era of personalized medicine, these findings warrant further appraisal of chemotherapy benefit in this population.

Loss of Heterozygosity of BRCA1/2 as a Predictive Marker for Talazoparib Response.

BACKGROUND/AIM: Tumor cell lines are essential tools in understanding the molecular mechanisms underlying cancer biology and therapeutic responses. Poly (ADP-ribose) polymerase inhibitors (PARPi) kill tumor cells harboring pathogenic mutations of BRCA DNA repair-associated genes 1/2 (BRCA1/2) and are approved to treat ovarian and metastatic breast cancer. Loss of heterozygosity (LOH) of the wild-type BRCA1/2 locus is suspected to increase cellular response to PARPi. To better elucidate the molecular mechanisms underlying PARPi sensitivity and resistance, this study assessed the responses of various pathogenic BRCA1/2-mutant cell lines to the PARPi talazoparib. MATERIALS AND METHODS: Mutant cell lines were extracted and cultured from four surgically resected, human breast cancer specimens with different pathogenic BRCA1/2, one normal breast specimen and one ovarian cancer specimen. Mutation analysis was performed on all cell lines using genomic DNA extraction and polymerase chain reaction. Following treatment with talazoparib, cell growth was assessed using tetrazolium salt and half-maximal inhibitory concentration values were determined. RESULTS: A partial correlation between different variants of pathogenic BRCA1/2 mutation and talazoparib susceptibility was found, with five of the cell lines exhibiting sensitivity to talazoparib. The most sensitive cell-line to talazoparib had LOH for BRCA1, while the breast cancer cell line harboring BRCA2 LOH was resistant to talazoparib. CONCLUSION: This study suggests that LOH does not necessarily correlate with PARPi efficacy. These results lay a foundation for future studies to utilize these novel cell lines to further elucidate the underlying molecular mechanisms of PARPi resistance and reveal new potential drug targets.

Elevated Free Triiodothyronine Is Associated With Increased Proliferative Activity in Triple-negative Breast Cancer.

BACKGROUND/AIM: Thyroid hormones (THs) stimulate breast cancer (BC) cell proliferation. We hypothesized that these hormones and the proliferative marker thymidine kinase 1 (TK1) represent the initial and final steps of the proliferative pathway, respectively. PATIENTS AND METHODS: We measured the serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), along with serum TK1 activity, in 144 newly diagnosed BC patients, and examined the associations between THs and proliferation in different BC receptor profiles. RESULTS: TK1 activity did not correlate with TSH (r=0.06, p=0.473) or FT4 levels (r=0.04, p=0.665), but did correlate with FT3 levels (r=0.28, p=0.001). Elevated FT3 (>6.0 pmol/l) predicted increased TK1 activity (>140 Du/l) after adjusting for age (odds ratio 4.1, p=0.014). We also found a significant association of the combined elevation of FT3 and TK1, assumed as a surrogate marker of accomplished proliferative signal, with triple-negative (TN) profile (p=0.003). The rates of combined FT3 and TK1 elevation in TN and ER-positive profiles were 20.0% and 1.8%, respectively (p=0.005). CONCLUSION: FT3 may be involved in proliferative signaling, as measured by TK1 activity, predominately in TN breast cancer.

Thyroid Hormones, Silencing Mediator for Retinoid and Thyroid Receptors and Prognosis in Primary Breast Cancer.

BACKGROUND/AIM: Silencing mediator of retinoid and thyroid receptors (SMRT) is a nuclear corepressor in thyroid and estrogen hormones pathways. The aim was to evaluate SMRT expression in relation to thyroid hormone levels and prognostic markers in breast cancer (BC). PATIENTS AND METHODS: Serum and tumor tissues were obtained from 36 patients with benign breast disease (BBD) and 79 BC patients. SMRT expression was determined by immunohistochemistry. Free-triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured in serum. RESULTS: Higher FT4, lower FT3/FT4 ratio and higher expression of SMRT were found in BC compared to BBD (for all p<0.001). In BC, increased SMRT expression was associated with lower FT3 (p=0.028), higher tumor grade (p=0.031), increased KI67 proliferation index (p=0.015), higher risk of recurrence (p=0.014) and shorter disease-free survival (p=0.006). In multivariate analysis, SMRT overexpression and below-median levels of TSH were independent prognostic factors in BC. CONCLUSION: Elevated FT4 and decreased FT3/FT4 in BC patients suggest a role for thyroid hormones in malignant transformation. SMRT tumor overexpression is associated with lower FT3 levels, tumor proliferative activity and an aggressive clinical course.

Serum Thymidine Kinase 1 Activity Following Nephrectomy for Renal Cell Carcinoma and Radiofrequency Ablation of Metastases to Lung and Liver.

BACKGROUND/AIM: Thymidine kinase 1 (TK1) is involved in DNA synthesis and is considered a reliable and sensitive marker of cell proliferation. The aim of this study was to investigate the prognostic value of measurements of serum TK1 activity following tumor ablation. PATIENTS AND METHODS: This study was performed on 32 patients with renal cell carcinoma (RCC) who had undergone nephrectomy and 35 patients with cancer of different histology with metastases to the liver (n=28) and lung (n=7) treated with radiofrequency ablation (RFA). The TK1 activity was measured with DiviTum (Biovica) immunoassay. RESULTS: In patients with RCC with no evidence of disease during their observation, a significant decrease of the TK1 activity was observed on the day following nephrectomy (p<0.0001). The mean calculated half-life ±SEM was 10.8±1.2 h. Taking into account the short half-life, measurements of TK1 were performed 24 h after nephrectomy or RFA of metastases. It was found that elevated TK1 activity (>60 Du/l) on the day after nephrectomy independently predicted poor recurrence-free survival (hazard ratio=5.0, p=0.040), after adjustment for T-stage, age and pretreatment TK1. Patients scheduled for RFA averaged 1.4 lesions and an average lesion diameter of 2.2 cm. Multivariate Cox's regression model demonstrated the significant association of any increase of TK1 activity or decrease not reaching ≤60 Du/l on the day after ablation with poor progression-free survival (hazard ratio=4.6, p=0.001), after adjustment for the type of primary tumor, the number and size of metastases. CONCLUSION: The half-life for serum TK1 activity is 10.8±1.2 h. The measurements of TK1 activity following nephrectomy or RFA of metastases could be an important tool in prognostic evaluation.

Prognostic factors for survival in metastatic breast cancer during first-line paclitaxel chemotherapy.

The prognostic value of various demographic, clinical and laboratory characteristics was investigated in 54 patients with metastatic breast cancer during first-line paclitaxel chemotherapy. As a single-agent treatment, paclitaxel (175 mg/m2) was given by 3-hour infusion every three weeks. The overall response rate was 30%. The follow-up ranged from 3 to 65 months (median 17 months). The most important pretreatment prognostic factors for survival were found to be hemoglobin (Relative Risk-2.26; p = 0.02) and serum lactic dehydrogenase (RR-1.81; p = 0.04) levels. The survival showed a strong association to the type of response. The median survival for responders was 5-fold greater than for patients with progressive disease (30.2 months and 5.7 months, respectively). Following the first-line paclitaxel treatment the estimates of tumor response became the major predictor of survival (RR-12.3; p < 0.0001).

Serum thymidine kinase 1 activity in the prognosis and monitoring of chemotherapy in lung cancer patients: a brief report.

INTRODUCTION: Thymidine kinase 1 (TK1) is a metabolic enzyme involved in DNA synthesis. Most standard treatment protocols for lung cancer (LC) include cytotoxic agents, which are potential modulators of TK1. We aimed to assess the prognostic significance of serum TK1 activity and its role in monitoring chemotherapy in LC patients. METHODS: TK1 activity was measured using the DiviTum (Biovica) assay in sera from 233 patients with non-small-cell lung cancer (NSCLC), 91 with small-cell lung cancer (SCLC), and 90 with benign lung disease. RESULTS: TK1 activity was significantly associated with age, performance status, and stage in NSCLC and with stage and weight loss in SCLC. In multivariate analysis, pretreatment TK1 activity, adjusted for performance status, stage, and weight loss, independently affected survival in NSCLC (relative risk =1.45, p = 0.031) and SCLC (relative risk = 2.49, p = 0.001). In NSCLC patients, adjusted elevated TK1 activity (>100 Du/L) at pretreatment was a significant predictor of treatment failure (odds ratio = 2.55, p = 0.01). A small (less than twofold) increase in TK1 activity after the first and second cycle of chemotherapy was significantly associated with treatment failure and poor overall survival. CONCLUSIONS: Elevated pretreatment serum TK1 activity was an independent, adverse prognostic factor, based on survival, in the two main histological types of LC. A small (less than twofold) increase in TK1 activity after the first and second cycle of chemotherapy was associated with treatment failure and poor overall survival.

The prognostic significance of LIAISON(R) CA15-3 assay in primary breast cancer.

AIM: To investigate the prognostic significance of cancer antigen 15-3 (CA15-3) in primary breast cancer (BC). PATIENTS AND METHODS: This prospective study included 368 women: 62 patients with benign breast disease (BBD), 159 patients with invasive BC and 88 healthy blood donors (control). The median follow-up was 76 months (range, 43-99 months). Serum CA15-3 was measured with LIAISON® CA15-3® chemilluminescence immunoassay. RESULTS: Significantly high levels of CA15-3 were found in patients with BC compared to controls (p=0.029), but not to the BBD group (p=0.16). Preoperative CA15-3 in patients with BC was significantly associated with tumor size (p=0.003), TNM stage (p=0.005), vascular invasion (p=0.018) and tumor necrosis (p<0.05). Increased CA15-3 (>30 U/ml) concentrations were more often found in patients with larger tumors (p<0.05), advanced stage (p=0.004) and node-positive disease (p=0.007). Patients with normal levels of CA15-3 had better recurrence-free survival (RFS) than those with elevated levels (p<0.001). After adjustment for T-stage, grade, tumor necrosis, estrogen receptor (ER) and progesterone receptor (PR) status, CA15-3 remained an important preoperative characteristic with independent impact on RFS (hazard ratio=4.4, 95% confidence interval=1.5-13.1, p=0.007). The independent prognostic contribution of CA15-3, considered on a continuous scale was significant among subgroups of the BC patients with ER/PR-positive (p=0.002), node-positive (p=0.028), node-negative (p=0.003), T1-stage node-negative (p=0.017), luminal-A (p=0.003), luminal-B (p=0.028) and human epidermal growth factor receptor-2 (HER2)/non-luminal disease (p=0.045). CONCLUSION: Preoperative measurement of CA15-3 allowed identifying high-risk of recurrence for patients with primary BC and might be combined with existing prognostic factors in planning adjuvant treatment.

Increased proliferative background in healthy women with BRCA1/2 haploinsufficiency is associated with high risk for breast cancer.

Previous studies indicated that BRCA haploinsufficiency was associated with activation of the EGF receptor (EGFR) signaling pathway and increased proliferative activity in mammary epithelial cells of healthy women. We hypothesized that these processes might be reflected in the expression of serologic soluble EGFR (sEGFR) and thymidine kinase 1 (TK1) activity, which signal the initial and final steps of the proliferative pathway, respectively. We found that healthy carriers of BRCA1/2 mutations (n = 80) showed a significantly higher TK1 activity than age-matched controls (P = 0.0003), and TK1 activity was similar in women with BRCA1 and BRCA2 mutations (P = 0.74). The sEGFR concentration was significantly higher in women with BRCA1 than in controls and BRCA2 mutation (P = 0.013 and 0.002, respectively). During follow-up, four of 80 BRCA1/2 mutation carriers developed breast cancer. These women showed a significantly higher TK1 activity and somewhat higher sEGFR concentrations than the other 76 BRCA1/2 carriers (P = 0.04 and 0.09, respectively). All tumors were negative for ovarian hormone receptors, but showed a high EGFR expression. This study was limited by the short-term follow-up (mean, 27 months; range, 5-45), which resulted in a small sample size. Women with BRCA1 and BRCA2 mutations that had undergone risk-reducing bilateral salpingo-oophorectomy (BSO) showed significantly lower sEGFR compared with those without surgery (P = 0.007 and 0.038, respectively). Larger, prospective studies are warranted to investigate whether TK1 and sEGFR measurements may be useful for identifying healthy BRCA1/2 carriers with high risk of developing breast cancer; moreover, sEGFR measurements may serve as effective tools for assessing risk before and after BSO.

Relevance of circulating biomarkers for the therapy monitoring and follow-up investigations in patients with non-small cell lung cancer.

As the release and amount of circulating biomarkers show considerable variations between individuals, single value determinations are often difficult to be interpreted on their diagnostic or prognostic significance on the individual level. However, changes of the biomarker levels in a specific person during the disease course are quite informative for the estimation of the efficacy of therapy or the early detection of recurrent disease because they consider only intraindividual variations. If methods for marker determination are maintained, preanalytical and analytical standard prerequistits are respected, thresholds for each marker have to be defined which exceeds the normal, intraindividual biological variation. Then continuous biomarker increases may be indicative for disease activity in terms of inefficient therapy response or tumor recurrence while decreasing values often are associated with activity reduction of cancer disease. Here, we review the current knowledge on biomarker kinetics in patients with non-small cell lung cancer (NSCLC) and discuss the conditions and pitfalls of their relevance for the estimation efficacy of therapy and the early detection of recurrent disease. Further, we suggest a scenario to reveal the power of the defined biomarker use in future and to include those markers into the individual management of NSCLC patients.

Serum thymidine kinase 1 activity in breast cancer.

AIMS: Thymidine kinase 1 (TK1) is an enzyme involved in DNA synthesis and an important proliferation marker. We explored the association of preoperative serum TK1 activity with clinicopathological parameters and prognosis in terms of recurrence-free survival (RFS) in breast cancer (BC) patients. PATIENTS AND METHODS: TK1 activity in serum of 120 healthy women and 161 BC patients was measured by quantitative ELISA. RESULTS: Serum TK1 activity in BC patients was significantly higher than in healthy women (P < 0.0001). In BC patients elevated TK1 activity was significantly associated with advanced T stage (P = 0.015), higher grade (P = 0.013), presence of tumor necrosis (P = 0.006), vascular invasion (P = 0.002), and lack of estrogen receptor (ER) and progesterone receptor (PR) expression (P = 0.0004 and P = 0.003). Higher TK1 activity was found in patients with BRCA1/2 mutations compared to those without the mutation (P = 0.004). Multivariate Cox proportional hazards analyses demonstrated that TK1, adjusted for stage, grade, necrosis, ER and PR negativity was retained as an independent predictor of disease recurrence (Hazard Ratio = 3.9, 95%CI 1.3-11.6, P = 0.013). CONCLUSION: Elevated serum TK1 is an important risk factor indicating a high proliferation potential of tumors at the time of excision. In multivariate analysis TK1 activity was found to be an independent prognostic factor for RFS.

Circulating tumor M2 pyruvate kinase and thymidine kinase 1 are potential predictors for disease recurrence in renal cell carcinoma after nephrectomy.

OBJECTIVES: Pyruvate kinase type M2 (TuM2-PK) and thymidine kinase 1 (TK1) are the key enzymes involved in tumor cells metabolism and proliferation. We explored the association of their preoperative circulating levels with disease recurrence in patients with renal cell carcinoma (RCC). METHODS: We measured the plasma levels of TuM2-PK levels and serum TK1 activity preoperatively in patients with RCC, using a quantitative ELISA, and correlated the results with clinicopathological parameters. RESULTS: Significantly higher levels of TuM2-PK and TK1 were found in 116 patients with RCC compared with 20 healthy participants (P < .001 and P = .03), but not compared with 27 patients with benign kidney tumors (P = .13 and P = .72). There was a significant association between the level of TuM2-PK and of TK1 activity with T stage (P = .01 and P = .04). Of 2 markers only TuM2-PK was significantly associated with tumor grade (P = .001). The presence of extensive tumor necrosis (> 50%) was associated with high TuM2-PK (P = .001) and low TK1 (P = .03). The 5-year recurrence-free survival for patients with elevated TuM2-PK or TK1 was significantly lower compared with those for patients with normal marker levels (55% vs 94%, P < .001 and 21% vs 90%, P = .002). Multivariate Cox Proportional Hazard analysis demonstrated that TuM2-PK and TK1, adjusted for stage, grade and tumor necrosis were retained as independent predictors of disease recurrence (HR = 7.3, P = .04 and HR = 3.8, P = .03). CONCLUSIONS: The measurements of 2 circulating biomarkers, TuM2-PK and TK1, in RCC patients before nephrectomy can be useful for predicting recurrence and stratifying the patients into risk groups for possible adjuvant treatment.