Comparison of 3'-deoxy-3'-[¹⁸F]fluorothymidine positron emission tomography (FLT PET) and FDG PET/CT for the detection and characterization of pancreatic tumours

PURPOSE

Despite recent advances in clinical imaging modalities, differentiation of pancreatic masses remains difficult. Here, we tested the diagnostic accuracy of molecular-based imaging including 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) positron emission tomography (PET) and [(18)F]fluorodeoxyglucose (FDG) PET/CT in patients with suspected pancreatic masses scheduled to undergo surgery.

METHODS

A total of 46 patients with pancreatic tumours suspicious for malignancy and scheduled for resective surgery were recruited prospectively. In 41 patients, FLT PET and FDG PET/CT scans were performed. A diagnostic CT performed on a routine basis was available in 31 patients. FLT PET and FDG PET/CT emission images were acquired according to standard protocols. Tracer uptake in the tumour [FDG and FLT standardized uptake value (SUV)] was quantified by the region of interest (ROI) technique. For FDG PET/CT analysis, correct ROI placement was ensured via side-by-side reading of corresponding CT images.

RESULTS

Of 41 patients, 33 had malignancy, whereas 8 patients had benign disease. Visual analysis of FDG and FLT PET resulted in sensitivity values of 91% (30/33) and 70% (23/33), respectively. Corresponding specificities were 50% (4/8) for FDG PET and 75% (6/8) for FLT PET. In the subgroup of patients with contrast-enhanced CT (n = 31), sensitivities were 96% (PET/CT), 88% (CT alone), 92% (FDG PET) and 72% (FLT PET), respectively. Mean FLT uptake in all malignant tumours was 3.0 (range SUV(max) 1.1-6.5; mean FDG SUV(max) 7.9, range 3.3-17.8; p < 0.001).

CONCLUSION

For differentiation of pancreatic tumours, FDG PET and FDG PET/CT showed a higher sensitivity but lower specificity than FLT PET. Interestingly, visual analysis of FLT PET led to two false-positive findings by misinterpreting physiological bowel uptake as pathological FLT uptake in the pancreas. Due to the limited number of patients, the clinical value of adding FLT PET to the diagnostic workup of pancreatic tumours remains to be determined.

Salvage radiotherapy in patients with recurrent esophageal carcinoma

PURPOSE

The feasibility and effectiveness of radiotherapy in the management of recurrent esophageal carcinoma (REC) is reported.

PATIENTS AND METHODS

A consecutive cohort of 54 patients with rcT1-4, rcN0-1, or cM0 recurrent esophageal carcinoma (69% squamous cell carcinoma, 31% adenocarcinoma) was treated between 1988 and 2010. The initial treatment for these patients was definitive radiochemotherapy, surgery alone, or neoadjuvant radiochemotherapy + surgical resection in 8 (15%), 33 (61%), and 13 (24%) patients, respectively. The median time to recurrence from initial treatment was 19 months (range 4-79 months). The site of the recurrence was anastomotic or local, nodal, or both in 63%, 30%, and 7% of patients, respectively. Salvage radio(chemo)therapy was carried out with a median dose of 45 Gy (range 30-68 Gy).

RESULTS

Median follow-up time for surviving patients from the start of R(C)T was 38 months (range 10-105 months). Relief of symptoms was achieved in 19 of 28 symptomatic patients (68%). The median survival time was 12 months (95% confidence interval (CI) 7-17 months) and the median recurrence-free interval was 8 months (95% CI 4-12 months). The survival rates at 1, 2, and 3 years were 55 ± 7%, 29 ± 6%, and 19 ± 5%, respectively. The recurrence-free survival rates at 1, 2, and 3 years were 44 ± 7%, 22 ± 6%, and 15 ± 5%, respectively. A radiation dose ≥ 45 Gy and conformal RT were associated with a better prognosis.

CONCLUSION

RT is feasible and effective in the management of recurrent esophageal carcinoma, especially for relief of symptoms. Toxicity is in an acceptable range. The outcome of REC is poor; however, long-term survival of patients with recurrent esophageal carcinoma after radiochemotherapy might be possible, even with a previous history of radiotherapy in the initial treatment. If re-irradiation of esophageal carcinoma is contemplated, three-dimensional conformal techniques and a minimum total dose of 45 Gy are recommended.

Specific activity of cyclin-dependent kinase I is a new potential predictor of tumour recurrence in stage II colon cancer

Background:

There are no established biomarkers to identify tumour recurrence in stage II colon cancer. As shown previously, the enzymatic activity of the cyclin-dependent kinases 1 and 2 (CDK1 and CDK2) predicts outcome in breast cancer. Therefore, we investigated whether CDK activity identifies tumour recurrence in colon cancer.

Methods:

In all, 254 patients with completely resected (R0) UICC stage II colon cancer were analysed retrospectively from two independent cohorts from Munich (Germany) and Leiden (Netherlands). None of the patients received adjuvant treatment. Development of distant metastasis was observed in 27 patients (median follow-up: 86 months). Protein expression and activity of CDKs were measured on fresh-frozen tumour samples.

Results:

Specific activity (SA) of CDK1 (CDK1SA), but not CDK2, significantly predicted distant metastasis (concordance index=0.69, 95% confidence interval (CI): 0.55–0.79, P=0.036). Cutoff derivation by maximum log-rank statistics yielded a threshold of CDK1SA at 11 (SA units, P=0.029). Accordingly, 59% of patients were classified as high-risk (CDK1SA ⩾11). Cox proportional hazard analysis revealed CDK1SA as independent prognostic variable (hazard ratio=6.2, 95% CI: 1.44–26.9, P=0.012). Moreover, CKD1SA was significantly elevated in microsatellite-stable tumours.

Conclusion:

Specific activity of CDK1 is a promising biomarker for metastasis risk in stage II colon cancer.

Natural-orifice transluminal endoscopic surgery: low-pressure pneumoperitoneum is sufficient and is associated with an improved cardiopulmonary response (PressurePig Study)

BACKGROUND AND AIMS

The aim of this randomized trial in the acute porcine model was to compare the quality of transgastric peritoneoscopy with the use of low-pressure versus standard-pressure pneumoperitoneum and to evaluate the respective associated cardiopulmonary changes.

METHODS

For transgastric peritoneoscopy, carbon dioxide was insufflated via the endoscope for a constant intraperitoneal pressure of 6 mmHg or 12 mmHg in 9 pigs each. The quality of transgastric peritoneoscopy was rated on a visual analog scale (0 mm, min.; 100 mm, max.) by the endoscopist, who was blinded to the intraperitoneal pressure. The cardiac index and global end-diastolic volume index (GEDVI, reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. The following were also recorded: heart rate, mean arterial pressure (MAP), systemic vascular resistance index (SVRI, reflecting afterload), peak inspiratory pressure (PIP), pH, PCO (2), and PO (2).

RESULTS

The quality of transgastric peritoneoscopy with the use of low-pressure pneumoperitoneum was not inferior to that obtained using standard-pressure pneumoperitoneum (87.0 mm vs. 87.3 mm; P<0.05). In both groups we observed a statistically significant rise in MAP and SVRI. The increase in SVRI was less pronounced during low-pressure peritoneum ( P=0.042), indicating a reduced stress response in comparison to standard-pressure peritoneum. There were no relevant differences between the groups in relation to cardiac index, GEDVI, and heart rate. An intra-abdominal pressure of 6 mmHg also led to better oxygenation ( P=0.031 for difference in PO (2) between the two groups) due to lower peak inspiratory pressure ( P<0.001 for difference). There were only slight differences between the groups with regard to pH and PCO (2).

CONCLUSIONS

Pneumoperitoneum of 12-16 mmHg is used for standard laparoscopy. For NOTES, low-pressure pneumoperitoneum is sufficient and is associated with an improved cardiopulmonary response compared to standard-pressure pneumoperitoneum.

The role of the transverse acetabular ligament for acetabular component orientation in total hip replacement

Orientation of the native acetabular plane as defined by the transverse acetabular ligament (TAL) and the posterior labrum was measured intra-operatively using computer-assisted navigation in 39 hips. In order to assess the influence of alignment on impingement, the range of movement was calculated for that defined by the TAL and the posterior labrum and compared with a standard acetabular component position (abduction 45°/anteversion 15°).

With respect to the registration of the plane defined by the TAL and the posterior labrum, there was moderate interobserver agreement (r = 0.64, p < 0.001) and intra-observer reproducibility (r = 0.73, p < 0.001). The mean acetabular component orientation achieved was abduction of 41° (32° to 51°) and anteversion of 18° (−1° to 36°). With respect to the Lewinnek safe zone (abduction 40° ±10°, anteversion 15° ±10°), 35 of the 39 acetabular components were within this zone. However, there was no improvement in the range of movement (p = 0.94) and no significant difference in impingement (p = 0.085).

Alignment of the acetabular component with the TAL and the posterior labrum might reduce the variability of acetabular component placement in total hip replacement. However, there is only a moderate interobserver agreement and intra-observer reliability in the alignment of the acetabular component using the TAL and the posterior labrum. No reduction in impingement was found when the acetabular component was aligned with the TAL and the posterior labrum, compared with a standard acetabular component position.

Breast cancer after hormone replacement therapy--does prognosis differ in perimenopausal and postmenopausal women?

Hormone replacement therapy (HRT) has been associated with higher incidence of breast cancer in postmenopausal women, but it is unclear if breast cancers developing after HRT use have different prognosis. 1053 women with hormone receptor positive non-metastasized breast cancer were analyzed in a retrospective trial, stratifying by HRT use before diagnosis. Postmenopausal HRT users had significantly more early tumor stages (p<0.001). HRT in postmenopausal patients was associated with longer time to progression (TTP) (HR 0.81, 95%CI 0.55-1.19, p=0.28) and overall survival (OS) (HR 0.68, 95%CI 0.45-1.02, p=0.059). Perimenopausal HRT users showed shorter TTP and OS (HR 1.99, 95%CI 0.57-6.91, p=0.28 and HR 4.59, 95%CI 0.91-23.25, p=0.06 respectively). Higher BMI was significantly associated with poorer prognosis in perimenopausal women only (TTP: HR=1.16; OS: HR=1.31). In this retrospective analysis postmenopausal HRT users seemed to have a better breast cancer prognosis. For perimenopausal HRT users however, a trend towards worse prognosis was found.

ARFI-based tissue elasticity quantification in comparison to histology for the diagnosis of renal transplant fibrosis

BACKGROUND AND PURPOSE

Until recently clinical diagnosis of chronic renal allograft dysfunction could only be established invasively by renal biopsy. Given the risks of that procedure, a non-invasive, diagnostic test would be very advantageous. Novel ultrasound-based elasticity tools, using "Acoustic Radiation Force Impulse (ARFI)" technology are now available. Previously this technique has been utilised to quantify liver fibrosis. First results of these studies are promising. The purpose of our study was to investigate correlation between stiffness values obtained by ARFI-quantification and histological fibrosis score in renal transplants.

METHODS

We employed "Virtual Touch™ tissue quantification" (Siemens Acuson, S2000) to quantitatively measure tissue stiffness in the cortex of transplant kidneys. Eighteen patients were included in this prospective study, recording close temporal ARFI-quantification and fibrosis measurements. All patients undergoing renal transplant biopsy were examined with ARFI-quantification (15 measurements per transplant kidney). Resistive indices were also calculated from pulsed-wave Doppler ultrasound. Transplant biopsies were histologically evaluated by a reference nephropathologist and graded according to the percentage of fibrosis and to the BANFF-score. Due to the non-normal distribution of the data the Spearman-correlation-coefficient (rho) was used to assess the bivariate relationship of ARFI and fibrosis in the transplant kidney.

RESULTS

There was a significant positive moderate correlation between mean ARFI-values and the grade of fibrosis (rho = +0.465; p = 0.026). This correlation was also valid for the mean ARFI-values and the BANFF-category (rho = +0.468; p = 0.025). There was no significant correlation between the mean ARFI-values and the resistive indices in the transplant kidney (rho = +0.034; p = 0.904). Nevertheless, a positive correlation between the mean RI-values of the kidney and the grade of fibrosis was established (rho = +0.563; p = 0.015).

CONCLUSION

The mean values of ARFI measurements and the resistive indices are potentially independent explanation variables for evaluating the grade of fibrosis in transplant kidneys.

Meta-analysis of neoadjuvant treatment modalities and definitive non-surgical therapy for oesophageal squamous cell cancer

BACKGROUND

The standard treatment for resectable oesophageal squamous cell carcinoma (OSCC) is surgical resection with adequate lymphadenectomy. Most Western patients receive neoadjuvant chemotherapy or chemoradiotherapy (CRT). In recent years some patients have received CRT alone (definitive CRT, dCRT). This meta-analysis sought to clarify the benefits of neoadjuvant and definitive treatment for OSCC.

METHODS

Eligible randomized controlled trials (RCTs) were identified using the Cochrane database, MEDLINE and Embase. Only RCTs with intention-to-treat analysis, and published hazard ratios (HRs) or estimates from survival data, were included.

RESULTS

Nine RCTs involving neoadjuvant CRT versus surgery, eight involving neoadjuvant chemotherapy versus surgery, and three involving neoadjuvant treatment followed by surgery or surgery alone versus dCRT were identified. The HR for overall survival was 0·81 (95 per cent confidence interval 0·70 to 0·95; P = 0·008) after neoadjuvant CRT and 0·93 (0·81 to 1·08; P = 0·368) after neoadjuvant chemotherapy. The likelihood of R0 resection was significantly higher after neoadjuvant treatment (CRT: HR 1·15, P = 0·043; chemotherapy: HR 1·16, P = 0·006). Morbidity rates were not increased after neoadjuvant CRT (HR 0·94, P = 0·363) but 30-day mortality was non-significantly higher with combined treatment. Morbidity (HR 1·03, P = 0·638) and mortality (HR 1·04, P = 0·810) rates after neoadjuvant chemotherapy and surgery did not differ from those after surgery alone. None of the RCTs reporting outcome after dCRT demonstrated a significant survival benefit, but treatment-related mortality rates were lower (HR 7·60, P = 0·007) than with neoadjuvant treatment followed by surgery or surgery alone.

CONCLUSION

For patients with resectable OSCC, a significant survival benefit for neoadjuvant CRT was evident, with no increase in morbidity rate. dCRT did not demonstrate any survival benefit over other curative strategies. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Exercise-induced alterations of retinal vessel diameters and cardiovascular risk reduction in obesity

BACKGROUND

The retinal microcirculation is affected early in the process of atherosclerosis and retinal vessel caliber is an emerging cardiovascular risk factor. Obesity is associated with vascular dysfunction. Here, we investigate the effect of regular exercise on retinal vessel diameters in lean and obese runners. We analyze a possible link to alterations of the nitric oxide (NO)-asymmetric dimethylarginine (ADMA) pathway.

METHODS

Retinal vessel diameters were assessed by means of a static vessel analyzer (SVA-T) in 15 obese athletes (OA), 14 lean amateur athletes (AA) and 17 lean elite athletes (EA) following a 10 week training program. ADMA serum levels were detected by ELISA and dimethylarginine dimethylaminohydrolase (DDAH) -1/-2 mRNA-expression in peripheral mononuclear cells (PBMC) was analyzed by real time PCR.

RESULTS

At baseline, the mean (±SD) arteriolar to venular diameter ratio (AVR) was impaired in obese (OA: 0.81±0.05) compared to lean subjects (AA: 0.87±0.07; EA: 0.94±0.05). The individual fitness levels correlated with AVR (rho=+0.66; P<0.001) and the training program improved AVR in all groups (P<0.001), normalising AVR in the obese (OA: 0.86±0.1). A training-induced arteriolar dilatation was found in OA (P=0.01), which was accompanied by a significant decrease of ADMA levels (0.56±0.12-0.46±0.12 μmoll(-1); P<0.028). DDAH-1 mRNA levels in PBMC increased in all groups (P<0.01).

CONCLUSIONS

Cardiovascular fitness and body composition affect retinal vessel diameters. Regular exercise reverses the subclinical impairment of the retinal microvasculature in obesity by inducing retinal arteriolar dilatation. The NO/ADMA pathway may play a key role in the training-induced improvement of microvascular function, which has the potential to counteract progression of small vessel disease.

Improvement of the Luminescing Behaviour of Simmplanted SiO2 Films

In previous work we reported on the observation of continuously tunable photoluminescence in Si+-implanted SiO2-films with moderate intensities. In this paper we demonstrate improved performance of such samples. The photoluminescence intensity increases abruptly up to two orders of magnitude when the anneal temperature is elevated to values higher than 1000…1100°C. This strong photoluminescence degrades less than that of porous silicon. Very fine tunability in the spectral range from 2.1 eV to 1.3 eV is achieved in samples implanted with a graded dose. In the analysis of the results we try to distinguish between the contributions of the Si-nanocrystals and of the oxide related defects.

[Hereditary vascular malformations: classification, symptoms, diagnostics and prognosis]

The understanding of hereditary vascular anomalies was hampered for a long time by unclear und unspecific terminology. Today, the classification of the International Society for the Study of Vascular Anomalies (ISSVA) differentiates between vascular tumours (mostly infantile haemangioma) with active endothelial proliferation and regression and vascular malformations (VM), which are defects of the vascular morphogenesis and are distinguished in predominantly venous, arterial, capillary, lymphatic, arteriovenous or combined VM. Symptoms are pain, swelling and restricted movement, accompanied by skin signs like dys-plastic veins and capillary VM (naevus flammeus). Thrombophlebitis and chronic venous insufficiency are related to venous VM. Arteriovenous VM are progressive and can cause ischaemic necroses, in rare cases even a high-output cardiac fail-ure. Lymphatic VM lead to localised swelling, in the long run often to recurrent erysipelas and lymphorroea. Primary imaging is provided by -ul-trasound including flow measurements. Mor-phol-ogy and organ involvement is best delineated by magnetic resonance imaging. Phlebography is used to image deep venous system anomalies and is always accompanied by varicography of the dysplastic parts of the venous VM. Digital subtraction angiography is performed to demon-strate the flow pattern in feeding arteries, the nidus and the drainage veins of arteriovenous VM. Besides size and localisation the prognosis of the patients is determined by the pressure (the high-er the pressure, the poorer the prognosis) and the flow rate (the higher the flow rate, the poorer the prognosis) in the VM. Diagnosis and treatment of these rare diseases are best performed in special-ised, interdisciplinary centres.

Long-term outcome of almost 3,000 patients with carcinoma of the esophagus: Evaluation of the new UICC/AJCC staging system

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Background: In the new 7th edition of the TNM classification for cancers of the esophagus, the UICC stage groups are still based on the anatomic extent of the tumor alone. In contrast, the AJCC prognostic groupings is the first staging system for esophageal cancer to add histologic tumor type, tumor site and grade.

Methods: Data of a single center cohort of 2,920 patients operated for cancers of the esophagus were analyzed. Statistical methods to evaluate survival of the patients and the prognostic performance of the new staging systems included Kaplan-Meier analyzes and time dependent ROC-analysis.

Results: UICC stage, R-status, histologic tumor type and age were identified as independent prognostic factors for cancers of the esophagus. Grade and tumor site, additional parameters in the new AJCC prognostic groupings, were not significantly correlated with survival. Patients with esophageal adenocarcinoma had a significantly better long-term prognosis after resection than patients with squamous cell carcinoma (p < 0.0001). The new number-dependent N- classification proved superior to the former site-dependent classification with significantly decreasing prognosis with increasing number of lymph node metastases (p < 0.001). The new subclassification of T1 tumors also revealed significant differences in prognosis between pT1a and pT1b patients (p < 0.001). However, the multiple new UICC and AJCC subgroupings did not prove distinctive for survival between stages IIA and IIB, IIIA and IIIB, and between IIIC and IV.

Conclusions: The new 7th edition of the TNM classification improved the predictive ability for cancers of the esophagus, however, stage groups could be condensed to a clinically relevant number. Differences in patient characteristics, pathogenesis and especially survival clearly identify adenocarcinomas and squamous cell carcinoma of the esophagus as two separate tumor entities requiring differentiated therapeutic concepts.

No significant financial relationships to disclose.

PET-guided treatment in locally advanced adenocarcinoma of the esophagogastric junction (AEG): The MUNICON-II study

3

Background: Previous studies demonstrated that fluorodeoxyglucose (FDG)-PET can help to detect response early during neoadjuvant chemotherapy. The prognosis of metabolic non-responders is poor. Therefore, we initiated the prospective MUNICON-II study to determine the value of salvage neoadjuvant chemoradiation in early PET nonresponders.

Methods: 56 patients (pts) with locally advanced AEG type I and II (cT3/4 Nx M0) were included. Tumor glucose uptake was assessed by FDG-PET before and 14 days after initiation of chemotherapy. PET nonresponse was defined as a decrease of the tumor FDG standard uptake value < 35%. Nonresponders received salvage preoperative chemoradiation consisting of external beam radiation 32 Gy (1.6 Gy/fr x 2/day) plus daily cisplatin 6mg/m2 and then proceeded to surgery. Metabolic responders continued with chemotherapy (platin/5-FU-based) for 3 months.

Results: 33 pts had a PET response, 23 had a PET nonresponse. Resection was performed on 54 pts. R0 was achieved in 27 (82%) PET responders versus 16 (70%) nonresponders (p = 0.51). Major histologic remissions (< 10% residual tumor) were observed in 12 PET responders (36%) and 6 PET non responders (26%). After a median follow-up time of 38.0 mon, the median event-free survival (EFS) and the median overall survival (OS) were not yet reached in the PET responders, while EFS was 15.4 mon and OS was 18.3 mon in nonresponders.

Conclusions: This study confirms the prognostic value of early metabolic response evaluation during neoadjuvant chemotherapy. Histopathologic responses were observed after salvage chemoradiation, but the clinical outcome of early PET non-responders to chemotherapy remains poor, indicating a dismal tumor biology in this group of pts.

No significant financial relationships to disclose.

Independent validation of a prognostic genomic profile (ColoPrint) for stage II colon cancer (CC) patients

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Background: Adjuvant therapy is not routinely recommended for stage II CC patients but may be considered for high-risk patients. In this study we aim to independently validate a genomic profile that was developed to identify high-risk patients and can assist in treatment decisions.

Methods: An 18-gene profile had been developed using gene expression data from whole genome Agilent 44K oligonucleotide arrays and was validated in samples from an independent cohort of 206 CC patients and in in-silico datasets (Salazar et al. JCO 2010 in press). The profile was translated into a robust diagnostic test (ColoPrint) using customized 8-pack arrays. For this study, 233 patients who underwent curative resection (R0) for colon cancer stages II or III at the Klinikum rechts der Isar from 1987 to 2003 were selected. Fresh frozen tissues, clinical parameters and follow-up data for all patients were available. The samples were hybridized and the ColoPrint index was determined for all samples blinded from the clinical data.

Results: Patients in this study had a median age of 64 years and median follow-up of 97 months. The median number of resected lymph nodes was 21, giving an indirect measure of the quality of surgery. In the 135 stage II patients, ColoPrint identified most patients (73%) as low risk. The 5-year distant-metastasis free survival was 95% for low-risk patients and 80% for high-risk patients. In the univariate analysis, ColoPrint was the only significant parameter to predict the development of distant metastasis with a HR of 4.1 (95% CI 1.31-13.01, p=0.009). Using clinical parameters from the ASCO recommendation (T4, perforation, less than 12 LN assessed and/ or high grade) for the identification of high-risk patients was not significant (HR 2.3; 95% CI 0.68-7.53, p=0.18) and did not add power to the ColoPrint classification. These results are in good agreement with results from the first independent validation.

Conclusions: ColoPrint is able to predict the development of distant metastasis of stage II colon cancer patients and facilitates the identification of patients who may be safely managed without chemotherapy.

[Table: see text]

Specific activity of cyclin dependent kinase 1 as a novel predictor of recurrence risk in stage II colon cancer

402

Background: Altered cell cycle dynamics and check points are typical features of solid tumors, and cyclin dependent kinases (CDKs) play pivotal roles in these processes. Previously we have demonstrated that CDK-based analysis, composed of CDK1 and CDK2, is useful in the prediction of outcomes in early breast cancer patients (Ann Oncol. 19(1):68-72, 2008, Br J Cancer. 100(3):494-500, 2009). Clinically, there is a need for risk stratification in patients with stage II colon cancer who have a recurrence risk of 20 to 30%. Therefore we investigated the use of CDK-based analysis for recurrence prediction of stage II colon cancer patients.

Methods: Fresh frozen tissue samples of 254 patients with histologically confirmed adenocarcinoma of the colon, UICC stage II, who received primary tumor resection in Munich (217 cases), and Leiden (37 cases) were used. Protein expression and activity of CDK1 and CDK2 were determined by in vitro assays as previously described. Specific activity (SA) of CDKs was calculated as kinase activity in relation to its corresponding mass concentration.

Results: Development of distant metastasis was observed in 27 patients (10.6%) after a median follow up of 86 months. We found that predictive performance of CDK1SA, but not CDK2SA, for the metastasis was substantial and almost constant for long-term event prediction (average area under the curve (AUC) = 0.69). Tumor recurrence risk analysis in association with CDK1SA identified a low- (41% of population) and high- risk group (59%). Cox proportional hazard model analysis retained the CDK-based patient classification as an independent prognostic factor for distant metastases-free survival (low vs. high-risk group: Hazard ratio = 6.2, 95% CI: 1.45 to 26.9, p=0.0049). Clinical parameters such as grading, T-categories, age, and sex were excluded as confounding factors for CDK1SA-risk.

Conclusions: CDK1SA allows stratification of different risk subgroups of stage II colon cancer patients. CDK1SA-based analysis is useful for predicting patients with high risk of distant recurrence, who should be treated with chemotherapy.

No significant financial relationships to disclose.

Circulating biomarker tissue kallikrein-related peptidase KLK5 impacts ovarian cancer patients' survival

BACKGROUND

Effective cancer biomarkers for early detection, prognosis, or therapy response prediction are urgently needed in ovarian cancer. Kallikrein-related peptidases, including KLK5, have been reported to play an important role in the course of the disease.

PATIENTS AND METHODS

KLK5 antigen content was determined by enzyme-linked immunosorbent assay in ovarian cancer patients' [FIGO (International Federation of Gynecology and Obstetrics) stages I-IV, n = 52] serum as well as ascitic fluid and compared with KLK5 content in serum of patients with benign ovarian tumors (n = 45).

RESULTS

KLK5 antigen content was significantly elevated in the serum of ovarian cancer patients compared with the serum of patients with benign ovarian tumors. Forty-two of 52 ovarian cancer serum samples, 42 of 43 benign ovarian tumor serum samples, and all 41 ascitic fluid samples were KLK5 positive. Elevated KLK5 antigen in serum and ascitic fluid of ovarian cancer patients was a prognostic factor for progression-free survival.

CONCLUSIONS

Our data support the finding that ovarian cancer patients release significant amounts of KLK5 into serum and ascitic fluid but KLK5 antigen is low in serum of patients with benign ovarian tumors. Increased serum and ascitic fluid KLK5 levels are associated with poor patient outcome, thus underlining the importance of KLK5 as a biomarker for early detection as well as for disease management in ovarian cancer.