BackgroundRecently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs) is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection.Methods and FindingsPlasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC)–electrospray ionization (ESI)–mass spectrometry (MS). Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer), regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling.ConclusionsThese findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a relatively simple plasma assay and imposes a lower physical burden on subjects when compared to existing screening methods.

The VHL alteration status may provide useful prognostic information, as a biomolecular marker, for patients with stage I-III clear-cell RCC who have undergone nephrectomy.

To delineate more precisely the somatic von Hippel-Lindau disease (VHL) gene alteration as well as to elucidate its etiologic role in renal tumorigenesis, we examined a total of 240 sporadic renal cell carcinomas (RCCs) for somatic VHL gene alterations by DNA-SSCP followed by sequencing, methylation-specific PCR assay, microsatellite LOH study, and Southern blot analysis. Intragenic mutation of the VHL gene was found exclusively in clear-cell or variant-type RCCs at a frequency of 51% (104/202). Hypermethylation of the VHL promoter region was detected in an additional 11 clear-cell RCCs. Microsatellite analysis demonstrated that LOH of the VHL locus was found in 140/155 (90%) informative clear-cell RCCs. The VHL gene therefore seems to be inactivated in a two-hit manner by intragenic mutation or hypermethylation plus allelic loss in clear-cell RCC. Genomic rearrangement of the VHL gene detected by Southern analysis was not found (0/216 cases); this is in contrast to germ lines in which Southern aberrations consisted of 7-19% of the mutations. Clinicopathologic data demonstrated that VHL mutation/LOH did not vary according to tumor progression in clear-cell RCC, including tumor diameter, stage, grading, distant metastasis, and lymph node metastasis. Interestingly, VHL mutation was significantly less frequent in RCCs occurring in younger (< or = 55 years) than that in older (> or = 56 years) patients. These data suggested that the inactivation of the VHL tumor-suppressor gene is a specific genetic change in clear-cell RCC, and that it may occur at an early or first step in the clear-cell tumorigenic pathway rather than as a late event.

Although accumulating preclinical evidence indicates the involvement of androgen receptor signals in bladder cancer (BC) development, its clinical relevance remains unclear. We aimed to evaluate the predictive role of androgen deprivation therapy (ADT) in BC recurrence in prostate cancer (PC) patients.We retrospectively reviewed 20,328 patients with PC diagnosed during 1991–2013 and identified 239 (1.2%) men having primary BC. After excluding ineligible patients, 162 patients made up a final cohort.With a median follow-up of 62 months, 38 (50%) of 76 control patients without ADT experienced BC recurrence, while 19 (22%) of 86 did in ADT group. Thus, patients having received ADT for their PC showed a significantly lower risk of BC recurrence (5-year actuarial recurrence-free survival: 76% v 40%; P < 0.001) and also had a significantly smaller number of recurrence episodes (5-year cumulative recurrence: 0.44 v 1.54; P < 0.001), compared to the control patients. A multivariable analysis revealed ADT as an independent prognosticator (hazard ratio, 0.29; 95% confidence interval, 0.17–0.49) for BC recurrence.This is the first clinical study showing that ADT significantly reduces the risk of BC recurrence.

Our recent retrospective study revealed a significantly reduced risk of bladder cancer (BC) recurrence in men who received androgen deprivation therapy (ADT) for their prostate cancer. However, whether androgen receptor (AR) signals contributed to the preventive effect of ADT remained unclear because ADT could reduce serum estrogens as well. The purpose of this study is to investigate the associations between the expression of AR/estrogen receptors (ERs) and BC recurrence in patients treated with ADT. We immunohistochemically stained 72 BCs and 42 corresponding normal urothelial tissues. AR/ERα/ERβ were positive in 44(61%)/22(31%)/39(54%) tumors and 35(83%)/24(57%)/34(81%) corresponding normal urothelial tissues, respectively. There were no statistically significant correlations between AR/ERα/ERβ expression and clinicopathological features of BC. With a median follow-up of 31.3 months, 12 (43%) of 28 patients with AR-negative tumor versus 11 (23%) of 44 patients with AR-positive tumor experienced BC recurrence. Thus, patients with AR-positive tumor had a significantly lower risk of BC recurrence (P=0.031), compared with those with AR-negative tumor. Meanwhile, the expression of ERα/ERβ in tumors and that of AR/ERα/ERβ in normal urothelial tissues were not significantly correlated with BC recurrence. A multivariate analysis revealed AR positivity in tumors as an independent prognosticator (hazard ratio: 0.27; 95% confidence interval: 0.11-0.67) for BC recurrence. These results indicate that ADT prevents BC recurrence via the AR pathway, but not via the ERα/ERβ pathways.