Lymph node assessment and lymphadenectomy in prostate cancer

Increased Paxillin expression in prostate cancer is associated with advanced pathological features, lymph node metastases and biochemical recurrence

Purpose Paxillin regulates cell-cell adhesion, and altered Paxillin expression has been associated with human carcinogenesis. This study analyzed the association between Paxillin expression in prostate cancer (PCa) tissues with clinicopathological features, lymph node metastasis and biochemical PCa recurrence.

Methods A total of 386 tissue specimens from PCa patients who received radical prostatectomy and 60 tissue specimens from benign prostatic hyperplasia (BPH) cases were collected to construct tissue microarrays, which were subsequently immunostained for Paxillin expression. Thirty positive lymph node tissue specimens and 10 healthy prostate tissue specimens were randomly selected for Paxillin immunostaining.

Results The association between Paxillin expression, lymph node metastasis and biochemical PCa recurrence was analyzed. Paxillin expression was significantly higher in PCa than both normal and BPH tissues (P<0.001) and was correlated with preoperative prostate-specific antigen level, Gleason score, clinical tumor stage, lymph node metastasis, positive surgical margin, extracapsular extension and seminal vesicle invasion (P<0.05 for all). Logistic regression analysis showed that Paxillin and Gleason score were independent risk factors for PCa lymph node metastasis (P<0.05). The receiver operating characteristic (ROC) curve indicated that Paxillin expression (AUC=0.723) more accurately predicted PCa lymph node metastasis than Gleason score (AUC=0.692). Kaplan-Meier curve analysis showed that increased Paxillin expression was associated with shortened biochemical-free survival (BFS) after radical prostatectomy (P<0.001).

Conclusion Paxillin was significantly upregulated in PCa compared with BPH and normal tissues and associated with lymph node metastasis and shortened BFS of PCa. Further study will investigate the underlying molecular mechanism and the role of Paxillin in PCa.

Upregulation of Talin-1 expression associates with advanced pathological features and predicts lymph node metastases and biochemical recurrence of prostate cancer

Talin-1 functions to regulate cell-cell adhesion, and its altered expression was reported to be associated with human carcinogenesis.A total of 280 tissue specimens from prostate cancer (PCa) patients who underwent radical prostatectomy, 75 cases of benign prostatic hyperplasia (BPH) tissue, and 6 cases of normal prostate tissue specimens were collected for construction of tissue microarray and subsequently subjected to immunohistochemical staining of Talin-1 expression.Talin-1 expression was significantly higher in PCa than both normal and BPH tissues (P <0.001). Talin-1 expression in PCa tissues was associated with preoperative prostate-specific antigen (PSA) level, Gleason score, tumor stage, lymph node metastasis, positive surgical margin, extracapsular extension and seminal vesicle invasion (all P <0.05). Logistic regression analysis showed that Talin-1 and Gleason score were independent risk factors for lymph node metastasis of PCa (P <0.001). Receiver operating characteristic (ROC) curve indicated that Talin-1 expression (AUC = 0.766) had a better accuracy to predict PCa lymph node metastasis than Gleason score (AUC = 0.697), whereas their combination could further enhance the prediction accuracy (AUC = 0.803). Kaplan-Meier curve analysis showed that increased Talin-1 expression was associated with shortened biochemical-free survival of PCa patients after radical prostatectomy (P <0.001).These findings suggested that Talin-1 protein was significantly upregulated in PCa tissues compared with that of BPH tissue and Talin-1 expression was an independent predictor for lymph node metastasis and biochemical recurrence of PCa. Further study will investigate the underlying molecular mechanism and the role of Talin-1 in PCa.

Is there a relationship between the number of lymph nodes and disease parameters in patients who underwent retropubic prostatectomy

PURPOSE

We aimed to establish the relationship between lymph nodes (LNs) counts that were removed with standard pelvic lymph node dissection (sPLND) and different disease parameters in patients who underwent radical prostatectomy (RP).

MATERIALS AND METHODS

A total of 70 patients who underwent sPLND during RP were scanned retrospectively. The scanned parameters were levels of serum PSA, the total weight of the removed prostate, the amount as a percentage of the tumor in the prostate tissue, the stage of the tumor, the total Gleason score (GS) and the number of standard pelvic lymph nodes that were removed from both right and left sides.

RESULTS

The average age of the patients was 59 years. A positive correlation was found between the total GS and the number of lymph nodes; while this correlation was significant (p = 0.0038), there was no significant difference between lymph nodes counts and other scanned parameters. The average pelvic lymph node numbers of patients with GS of 6-7 and 8 were 10.4-11.5 and 13.2, respectively. Lymph nodes metastases were found in 3 (4.2 %) patients whose average pelvic lymph node number was 17.3.

CONCLUSION

The chance of cure or decreased recurrence is much more possible in patients who had received extended PLND or at least standard one, because of the removal of much more lymph node tissues that have a high probability of disseminating cancer cells. This position can especially be considered in patients with high GS.

Characteristics of Pelvic Lymph Node Metastases in Prostatic Adenocarcinoma

Pelvic lymph node dissection (PLND) is currently the most accurate staging modality for lymph node metastases in prostate adenocarcinoma. There is no consensus on the optimal sampling method of PLND specimens among pathologists. This study analyzed the effectiveness of the submission of entire adipose tissue in 451 cases and its impact on total lymph node yield and detection of positive lymph nodes. The sizes of metastatic foci and positive lymph nodes in 83 cases were also studied. Submission of entire adipose tissue increased the lymph node yield and positive lymph node detection by 36.7 % and 1.99 %, respectively. Three cases had positive lymph nodes exclusively in adipose tissue. Of the patients examined, 68% had the largest positive lymph node, <1 cm. In conclusion, it was noted that metastases from prostate cancer were frequently small and seen within small lymph nodes. Submission of entire adipose tissue substantially increased the lymph node yield, but its impact on the detection of additional positive lymph nodes was low. Submission of the entire adipose tissue may be considered as an option in patients with high-risk factors for lymph node metastases.

Biomarker research in prostate cancer--towards utility, not futility

The identification of an appropriate clinical question is critical for any biomarker project. Despite rapid advances in technology, few biomarkers have been forthcoming for prostate cancer. This could be because the clinical questions under investigation have not actually originated from clinical practice. These clinical questions are difficult to identify in the complex and heterogeneous pathogenesis of prostate cancer. In this Review, we have developed a prostate cancer 'roadmap' to identify the aspects of prostate cancer that may be amenable to biomarker discovery and serve as a guide for future projects in prostate cancer biomarker research.

Curative radiation therapy in prostate cancer

Radiotherapy has experienced an extremely rapid development in recent years. Important improvements such as the introduction of multileaf collimators and computed tomography (CT)-based treatment planning software have enabled three dimensional conformal external beam radiation therapy (3DCRT). The development of treatment planning systems and technology for brachytherapy has been very rapid as well. Development of accelerators with integrated on-board imaging equipment and technology, for example image-guided radiation therapy (IGRT) has further improved the precision with reduced margins to adjacent normal tissues. This has, in turn, led to the possibility to administer even higher doses to the prostate than previously. Although radiotherapy and radical prostatectomy have been used for the last decades as curative treatment modalities, still there are no randomized trials published comparing these two options. Outcome data show that the two treatment modalities are highly comparable when used for low- and intermediate-risk prostate cancer.

High matrix metalloproteinase-to-E-cadherin ratio measured by bicolor fluorescent in situ hybridization is associated with lymphangiogenesis and lymph node metastasis in prostate cancer

OBJECTIVE

The colorimetric in situ hybridization (CISH)-based matrix metalloproteinase (MMP)-to-E-cadherin (ECD) ratio (MER) has been revealed as an excellent marker for the disease stage in prostate cancer. The one aim of this study was investigating a new method for estimation of MER by bicolor fluorescent ISH (bicolor FISH) with a computerized fluorescence detector-based system. Another aim was examination of relation of MER by bicolor FISH with expression of vascular endothelial growth factor-C (VEGF-C).

METHODS

The bicolor FISH technique used cyanin 5 (cy5)-labeled MMP-2 and -9 probes, and a cyanin 3 (cy3)-labeled ECD probe on needle biopsy specimens from 67 prostate cancer cases. The ISH was followed by computerized detection of the signal intensities and cy5-to-cy3 ratios using a fluorescence detector. VEGF-C expression was examined using cy5-labeled VEGF-C by computerized detection.

RESULTS

The bicolor FISH-based MER was well correlated with CISH-based MER (P < 0.0001). The bicolor FISH-based MER correlated with Gleason score and pathologic stage of the cases. VEGF-C mRNA expression was associated with the pathologic stage and maximum lymph vessel density (LVD). The LVD was associated with VEGF-C expression at the tumor area where the maximum MER was detected (P < 0.0001).

CONCLUSION

The MER was correlated with the VEGF-C expression and LVD, indicating lymph node metastasis of prostate cancer. Therefore, this computer-assisted MER is a useful marker for preoperative prediction of disease stage, especially lymph node metastasis, of prostate cancer.