Pil Moon Kang

Incidental abnormal FDG uptake in the prostate on 18-fluoro-2-deoxyglucose positron emission tomography-computed tomography scans.

18-fluoro-2-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scans are commonly used for the staging and restaging of various malignancies, such as head and neck, breast, colorectal and gynecological cancers. However, the value of FDG PET/CT for detecting prostate cancer is unknown. The aim of this study was to evaluate the clinical value of incidental prostate 18F-FDG uptake on PET/CT scans. We reviewed 18F-FDG PET/CT scan reports from September 2009 to September 2013, and selected cases that reported focal/diffuse FDG uptake in the prostate. We analyzed the correlation between 18F-FDG PET/CT scan findings and data collected during evaluations such as serum prostate-specific antigen (PSA) levels, digital rectal examination (DRE), transrectal ultrasound (TRUS), and/or biopsy to confirm prostate cancer. Of a total of 18,393 cases, 106 (0.6%) exhibited abnormal hypermetabolism in the prostate. Additional evaluations were performed in 66 patients. Serum PSA levels were not significantly correlated with maximum standardized uptake values (SUVmax) in all patients (rho 0.483, p=0.132). Prostate biopsies were performed in 15 patients, and prostate cancer was confirmed in 11. The median serum PSA level was 4.8 (0.55-7.06) ng/mL and 127.4 (1.06-495) ng/mL in the benign and prostate cancer groups, respectively. The median SUVmax was higher in the prostate cancer group (mean 10.1, range 3.8-24.5) than in the benign group (mean 4.3, range 3.1-8.8), but the difference was not statistically significant (p=0.078). There was no significant correlation between SUVmax and serum PSA, prostatic volume, or Gleason score. 18F-FDG PET/CT scans did not reliably differentiate malignant or benign from abnormal uptake lesions in the prostate, and routine prostate biopsy was not usually recommended in patients with abnormal FDG uptake. Nevertheless, patients with incidental prostate uptake on 18F-FDG PET/ CT scans should not be ignored and should be undergo further clinical evaluations, such as PSA and DRE.

Wnt signaling promotes androgen-independent prostate cancer cell proliferation through up-regulation of the hippo pathway effector YAP

Aberrant up-regulation of Wnt/β-catenin signaling is associated with the development and progression of prostate cancer, but the underlying mechanism is unclear. Here we show that in the absence of androgens, the Wnt/β-catenin pathway activates AR-mediated transcription through up-regulation of the Hippo pathway effector Yes-associated protein (YAP). Wnt3a-conditioned medium (Wnt3a-CM) promotes the growth of LNCaP cells and increases AR and YAP protein levels. Moreover, Wnt3a-CM induces the nuclear translocation of YAP and the AR, but not β-catenin, thereby activating the expression of AR- and YAP-dependent genes, in an androgen-independent manner. In addition, depletion of YAP with small interfering RNA (siRNA) prevented Wnt3a-CM-mediated up-regulation of AR-dependent gene expression. Thus, our findings provide mechanistic insight into the proposed cross-talk between the Wnt/β-catenin and Hippo pathways in androgen-independent prostate cancer development.

Correlation between postoperative prostate-specific antigen and biochemical recurrence in positive surgical margin patients: Single surgeon series

Background To evaluate the relationship between postoperative prostate-specific antigen (PSA) levels and biochemical recurrence (BCR) after radical prostatectomy, especially in patients with positive surgical margins (PSMs). Materials and methods A total of 144 patients who underwent radical prostatectomies performed by a single surgeon without any neoadjuvant or adjuvant treatment were analyzed. Differences in clinicopathological factors were compared by surgical margin status, and the relationship between postoperative PSA level and BCR in patients with PSMs was evaluated. Results Fifty of the 144 patients (34.7%) had PSMs. Of these, 74% experienced BCR. The negative surgical margins and PSMs groups differed significantly in terms of PSA level at diagnosis, clinical T stage, and risk group by the cancer of the prostate risk assessment score (P = 0.002, P = 0.002, and P = 0.004, respectively). Also, the nadir PSA level, tumor volume, and BCR rate differed between the two groups (P = 0.007, P = 0.015, and P = 0.005, respectively) On Kaplan–Meier analysis, BCR-free survival was better in the negative surgical margins than the PSMs group (64.1 vs. 55.4 months, log-rank test, P = 0.011). BCR-free survival did not differ significantly in PSMs patients according to whether PSA level was or was not detectable at 1 month postoperatively. However, BCR-free survival improved when the nadir PSA level was undetectable (compared to detectable) in PSMs patients (64.3 vs. 26.1 months, log-rank test, P < 0.001). In PSMs patients belonging to the high risk group by cancer of the prostate risk assessment score, BCR-free survival was significantly better when the PSA level attained the nadir within 3 months, compared to > 6 months, postoperatively (64.2 vs. 29.5 months, log-rank test, P = 0.022). Conclusion If PSA is detectable in PSMs patients until 1 month after operation, cautious observation may be possible. If the nadir is attained within 3 months postoperatively in high-risk patients with PSMs, better BCR-free survival may be expected.

Laparoscopic -2port Varicocelectomy with Scarless Periumblical Mini-Incision: Initial Experience in Approach and Outcomes

PURPOSEnAs with other areas, there have been many efforts for minimally invasive surgery in varicocelectomy. We present our initial experience with laparoscopic varicocelectomy with a two-port scarless periumbilical mini-incision.nnnMATERIALS AND METHODSnThe study enrolled 18 patients who underwent laparoscopic varicocelectomy with a twoportscarless periumbilical mini-incision from February 2012 to April 2013. The laparoscopic varicocelectomy was performed using two 5-mm ports at periumbilical sites in skin creases. Here, the surgical procedure is introduced and the outcomes of the case series are summarized. We reviewed other laparoscopic techniques and compared them with our technique.nnnRESULTSnThe mean patient age was 34.8 years. Of the 18 patients, 15 had grade 3 varicoceles. The mean operatingtime was 62.5 minutes. Postoperatively, the scrotal pain level decreased immediately from a mean VAS score of 6.3 to 4.4 and then to 1.7 by 24 hours postoperatively. The mean hospital stay was 2.8 days. Complications included one hydrocele and two recurrent varicoceles. The operating time decreased as the surgeons experience increased.nnnCONCLUSIONnLaparoscopic varicocelectomy with a two-port scarless periumbilical mini-incision is a feasible technique that can be mastered relatively easily. Prospective and comparative studies are required to validate this new technique.

A back-to-back tumor composed of papillary renal cell carcinoma and oncocytoma treated by laparoscopic partial nephrectomy: a case report

BackgroundRenal oncocytoma is the most common benign renal tumor, and papillary renal cell carcinoma is the second most common histologic subtype of renal cell carcinoma. Renal tumors containing different components such as papillary renal cell carcinoma and oncocytoma are extremely rare.Case presentationA renal mass was incidentally detected in a 52-year-old Korean woman, and a computed tomographic scan showed a 32-mm multicystic mass with some calcifications in the lower pole of the right kidney. She underwent laparoscopic partial nephrectomy without any perioperative complications. We found a papillary renal cell carcinoma and an oncocytoma in a tumor mass.ConclusionsThe possibility of a mixed malignant tumor should be considered while treating benign tumors such as oncocytoma.