Faculty Bibliography

OBJECTIVE: To determine the association between baseline factors, post-treatment factors, and long-term satisfaction after radical prostatectomy (RP). METHODS: Between January 2000 and March 2009, 1425 men who underwent RP by a single surgeon were enrolled in an institutional review board-approved, prospective, longitudinal outcomes study. Baseline characteristics and post-treatment functional and oncologic outcomes were captured through 2013. Patient survey responses from 875 (61.4%) of these men were used to evaluate satisfaction with treatment outcome and treatment decision. RESULTS: Overall, 88.2% and 91.0% men were satisfied to very satisfied with treatment outcome and treatment decision, respectively. Baseline sexual function was associated with satisfaction with both treatment outcome (adjusted odds ratio [aOR] = 1.40; 95% confidence interval [CI], 1.01-1.93) and treatment decision (aOR = 1.47; 95% CI, 1.08-2.01). Among post-treatment factors, higher University of California, Los Angeles Prostate Cancer Sexual Function (aOR = 2.95; 95% CI, 2.06-4.22), University of California, Los Angeles Prostate Cancer Urinary Function (aOR = 2.38; 95% CI, 1.66-3.40), and lower urinary tract symptom scores (aOR = 1.91; 95% CI, 1.19-3.06) were predictors of satisfaction with outcome. Bother due to incontinence and sexual dysfunction, and perception of cure were independent predictors of both satisfaction with treatment outcome and treatment decision. CONCLUSION: Nearly 90% of men are satisfied with both their treatment outcome and treatment decision after open RP. Improving long-term satisfaction after RP requires efforts to provide realistic expectations and improve functional outcomes.

OBJECTIVE: To examine public and media response to the United States Preventive Services Task Force's (USPSTF) draft (October 2011) and finalized (May 2012) recommendations against prostate-specific antigen (PSA) testing using Twitter, a popular social network with over 200 million active users. MATERIALS AND METHODS: We used a mixed methods design to analyze posts on Twitter, called "tweets." Using the search term "prostate cancer," we archived tweets in the 24 hour periods following the release of the USPSTF draft and finalized recommendations. We recorded tweet rate per hour and developed a coding system to assess type of user and sentiment expressed in tweets and linked articles. RESULTS: After the draft and finalized recommendations, 2042 and 5357 tweets focused on the USPSTF report, respectively. Tweet rate nearly doubled within two hours of both announcements. Fewer than 10% of tweets expressed an opinion about screening, and the majority of these were pro-screening during both periods. In contrast, anti-screening articles were tweeted more frequently in both draft and finalized study periods. From the draft to the finalized recommendations, the proportion of anti-screening tweets and anti-screening article links increased (p= 0.03 and p<0.01, respectively). CONCLUSIONS: There was increased Twitter activity surrounding the USPSTF draft and finalized recommendations. The percentage of anti-screening tweets and articles appeared to increase, perhaps due to the interval public comment period. Despite this, most tweets did not express an opinion, suggesting a missed opportunity in this important arena for advocacy.

Laser interstitial thermal therapy (LITT) is a new therapeutic strategy being explored in prostate cancer (CaP), which involves focal ablation of organlocalized tumor via an interstitial laser fiber. While little is known about treatment-related changes following LITT, studying post-LITT changes via imaging is extremely significant for enabling early image-guided intervention and follow-up. In this work, we present the first attempt at examining focal treatment-related changes on a per-voxel basis via quantitative comparison of MRI features pre- and post-LITT, and hence identifying computerized MRI features that are highly sensitive as well as specific to post-LITT changes within the ablation zone in the prostate. A retrospective cohort of 5 patient datasets comprising both pre- and post-LITT T2-weighted (T2w) and diffusion-weighted (DWI) acquisitions was considered, where DWI MRI yielded an Apparent Diffusion Co-efficient (ADC) map. Our scheme involved (1) inter-protocol registration of T2w and ADC MRI, as well as inter-acquisition registration of pre- and post-LITT MRI, (2) quantitation of MRI parameters by correcting for intensity drift in order to examine tissuespecific response, and (3) quantification of the information captured by T2w MRI and ADC maps via texture and intensity features. Correction of parameter drift resulted in visually discernible improvements in highlighting tissue-specific response in different MRI features. Quantitative, voxel-wise comparison of the changes in different MRI features indicated that steerable and non-steerable gradient texture features, rather than the original T2w intensity and ADC values, were highly sensitive as well as specific in identifying changes within the ablation zone pre- and post-LITT. The highest ranked texture feature yielded a normalized percentage change of 186% within the ablation zone and 43% in a spatially distinct normal region, relative to its pre-LITT value. By comparison, both the original T2w intensity and ADC value demonstrated a markedly less sensitive and specific response to changes within the ablation zone. Qualitative as well as quantitative evaluation of co-occurrence texture features indicated the presence of LITT-related effects such as edema adjacent to the ablation zone, which were indiscernible on the original T2w and ADC images. Our preliminary results thus indicate great potential for non-invasive computerized MRI imaging features for determining focal treatment related changes, informing image-guided interventions, as well as predicting long- and short-term patient outcome.

Focal therapy of prostate cancer is an evolving treatment strategy that destroys a predefined region of the prostate gland that harbors clinically significant disease. Although long-term oncologic control has yet to be demonstrated, focal therapy is associated with a marked decrease in treatment-related morbidity. Focal laser ablation is an emerging modality that has several advantages, most notably real-time magnetic resonance imaging (MRI) compatibility. This review presents the principles of laser ablation, the role of multiparametric MRI for delineating the site of significant prostate cancer, a summary of published clinical studies, and our initial experience with 23 patients, criteria for selecting candidates for focal prostate ablation, and speculation regarding future directions.

Tobacco smoke (TS) is a major cause of human bladder cancer (BC). Two components in TS, 4-aminobiphenyl (4-ABP) and acrolein, which also are environmental contaminants, can cause bladder tumor in rat models. Their role in TS related BC has not been forthcoming. To establish the relationship between acrolein and 4-ABP exposure and BC, we analyzed acrolein-deoxyguanosine (dG) and 4-ABP-DNA adducts in normal human urothelial mucosa (NHUM) and bladder tumor tissues (BTT), and measured their mutagenicity in human urothelial cells. We found that the acrolein-dG levels in NHUM and BTT are 10-30 fold higher than 4-ABP-DNA adduct levels and that the acrolein-dG levels in BTT are 2 fold higher than in NHUM. Both acrolein-dG and 4-ABP-DNA adducts are mutagenic; however, the former are 5 fold more mutagenic than the latter. These two types of DNA adducts induce different mutational signatures and spectra. We found that acrolein inhibits nucleotide excision and base excision repair and induces repair protein degradation in urothelial cells. Since acrolein is abundant in TS, inhaled acrolein is excreted into urine and accumulates in the bladder and because acrolein inhibits DNA repair and acrolein-dG DNA adducts are mutagenic, we propose that acrolein is a major bladder carcinogen in TS.