Shomik Sengupta

Use of a computer-controlled bipolar diathermy system in radical prostatectomies and other open urological surgery

Background: Ligasure® is a computer‐controlled bipolar diathermy system, designed to optimally seal vessels ≤ 7 mm in diameter. The aim of the present study was to evaluate its application to open urological surgery.

Local excision of rectal cancer

PURPOSE: Although local excision of rectal cancers is a less morbid alternative to radical resection, its role as a curative procedure is unclear. The role of adjuvant therapy after local excision is also controversial. This review aims to examine current evidence on local excision of rectal cancers and how it fits into the management algorithm for rectal cancer. METHODS: A literature review was undertaken through the MEDLINE database and by cross-referencing previous publications, thus identifying 41 studies on curative local excision of rectal cancer published in English. Details of preoperative staging, surgical procedures, adjuvant therapy, follow-up, and outcome measures, including complications, survival data, recurrences, and salvage were examined. RESULTS: Preoperative staging of rectal cancers is variable. Digital rectal examination and computerized tomography are used in most studies. Endorectal ultrasound is used in some patients in 9 of 41 studies. Local excision preserves anorectal function, and seems to have limited morbidity (0–22 percent). Local excision alone is associated with local recurrences in 9.7 (range, 0–24) percent of T1, 25 (range, 0–67) percent of T2 and 38 (range, 0–100) percent of T3 cancers. The addition of adjuvant chemoradiotherapy after local excision yields local recurrence rates of 9.5 (range, 0–50) percent for T1, 13.6 (range, 0–24) percent for T2, and 13.8 (range, 0–50) percent for T3 cancers. Data on local excision after preoperative chemoradiotherapy for tumor down staging are limited. Factors other than T-stage that lead to higher local recurrence rates after local excision include poor histologic grade, the presence of lymphovascular invasion, and positive margins. Local recurrences after local excision can be surgically salvaged (84 of 114 patients in 15 studies), with a disease-free survival rates between 40 and 100 percent at a follow-up of 0.1 to 13.5 years. CONCLUSIONS: Local excision for rectal cancers is associated with a low morbidity and provides satisfactory local control and disease-free survival rates for T1 rectal cancers. There is, however, a need for a randomized, controlled trial for T2 cancers, comparing local excision with adjuvant chemoradiotherapy to radical resection.

Uro-oncology multidisciplinary meetings at an Australian tertiary referral centre--impact on clinical decision-making and implications for patient inclusion.

To analyse the impact of the uro‐oncology multidisciplinary meeting (MDM) at an Australian tertiary centre on patient management decisions, and to develop criteria for patient inclusion in MDMs.

Renal lesions with low R.E.N.A.L nephrometry score are associated with more indolent renal cell carcinomas (RCCs) or benign histology: findings in an Australian cohort.

•  To validate the relationship of the R.E.N.A.L nephrometry score to histological features of renal lesions treated by surgical excision by radical nephrectomy (RN) or nephron‐sparing surgery (NSS) at an Australian tertiary referral centre.

Dietary fiber and colorectal neoplasia

PURPOSE: Dietary fiber has been implicated in colorectal neoplasia, despite conflicting evidence. This is a review of the currently available data on the role of dietary fiber in colorectal carcinogenesis. METHODS: A literature search was conducted using the MEDLINE database. All case-control, longitudinal, and randomized, controlled studies published in English between 1988 and 2000 were identified, as were animal model studies in the period 1986 to 2000. Data from the various studies were tabulated and systematically analyzed, with particular emphasis on the effect of dietary fiber on tumor incidence and luminal parameters such as short chain fatty acids. RESULTS: Epidemiologic correlation studies show a high intake of dietary fiber to be associated with a lower risk of colorectal neoplasia. Thirteen of the 24 case-control studies reviewed demonstrated a protective effect of dietary fiber against colorectal neoplasia, and 16 showed a protective effect of vegetables or vegetable fiber. On the other hand, of 13 longitudinal studies in various cohorts, only 3 demonstrated a protective effect of fiber and 4 a protective effect of vegetables or vegetable fiber. The five published randomized, controlled trials all investigated the effect of increased fiber intake on short-term adenoma recurrence; however, none showed any significant protective effect. Among 19 experimental studies in animal models, 15 showed a protective effect of fiber against tumor induction compared with controls. Animal studies also showed that poorly fermentable fibers (e.g., wheat bran and cellulose) were more protective than soluble fibers (e.g., guar gum and oat bran), which sometimes enhanced carcinogenesis. No clear correlation was found between luminal pH or short chain fatty acids and tumor induction. CONCLUSIONS: On the basis of current data, there is little evidence to support the use of dietary fiber supplements to reduce the risk of colorectal neoplasia. Lifelong and early exposure may be important but are difficult to study. Other risk factors interact with the effects of dietary fiber.

The role of cystectomy in elderly patients - a multicentre analysis.

Life expectancy in developed countries is continuously increasing. Hence elderly patients are becoming more common in our clinical practice. Currently, one of the greatest challenges of medicine is balancing the life expectancy of elderly patients against aggressive treatments that carry significant risks.

The effects of nonspecific HIF1α inhibitors on development of castrate resistance and metastases in prostate cancer

Expression of hypoxia‐inducible factor (HIF)1α increases the risk of castrate‐resistant prostate cancer (CRPC) and metastases in patients on androgen deprivation therapy (ADT) for prostate cancer (PC). We aimed to investigate the effects of nonspecific HIF1α inhibitors (Digoxin, metformin, and angiotensin‐2 receptor blockers) on development of CRPC and metastases while on ADT. A retrospective review of prospectively collected medical records was conducted of all men who had continuous ADT as first‐line therapy for CRPC at the Austin Hospital from 1983 to 2011. Association between HIF1α inhibitor medications and time to develop CRPC was investigated using actuarial statistics. Ninety‐eight patients meeting the criteria were identified. Eighteen patients (21.4%) were treated with the nonspecific HIF1α inhibitors. Both groups had similar characteristics, apart from patients on HIF1α inhibitors being older (70 years vs. 63.9 years). The median CRPC‐free survival was longer in men using HIF1α inhibitors compared to those not on inhibitors (6.7 years vs. 2.7 years, P = 0.01) and there was a 71% reduction in the risk of developing CRPC (HR 0.29 [95% CI 0.10–0.78] P = 0.02) after adjustment for Gleason score, age, and prostate‐specific antigen (PSA). The median metastasis‐free survival in men on HIF1α inhibitors was also significantly longer compared to those on no inhibitors (5.1 years vs. 2.6 years, P = 0.01) with an 81% reduction in the risk of developing metastases (HR 0.19 [CI 0.05–0.76] P = 0.02) after adjustment for Gleason score, age, and PSA. Nonspecific HIF1α inhibitors appear to increase the progression‐free survival and reduce the risk of developing CRPC and metastases in patients on continuous ADT.

Early effects of pharmacological androgen deprivation in human prostate cancer

To assess the early histological effects of pharmacological androgen deprivation (AD), which have been assessed only over longer periods, as surgical castration leads rapidly to diminished cell proliferation and enhanced cell death within the prostate.

Trends in the use of of nephron-sparing surgery (NSS) at an Australian tertiary referral centre: an analysis of surgical decision-making using the R.E.N.A.L. nephrometry scoring system.

Study Type – Therapy (case series)

A new preoperative nomogram to predict minimal prostate cancer: Accuracy and error rates compared to other tools to select patients for active surveillance

PURPOSE We designed and fully evaluated the performance of a nomogram to identify patients with prostate cancer who may be suitable for active surveillance. MATERIALS AND METHODS We developed a nomogram to predict the probability of minimal prostate cancer (total tumor volume less than 0.5 cc, organ confined disease and no Gleason pattern 4 or 5) using preoperative data on 2,525 Australian patients who underwent radical prostatectomy. Accuracy and error rates at multiple probability cutoffs were compared with those of contemporary Epstein criteria and the Prostate Cancer Research International: Active Surveillance trial inclusion criteria when applied to these patients. High risk disease was defined as 1 or more adverse characteristics (including positive surgical margins, seminal vesicle invasion, extracapsular extension, 50% or greater Gleason pattern 4/5 and/or tumor volume 4.0 cc or greater) at radical prostatectomy. RESULTS Minimal cancer was confirmed in 152 men (6.0%) at prostatectomy. The bootstrap corrected predictive accuracy of our nomogram was 93.3% vs 89.1% and 91.0% for Prostate Cancer Research International: Active Surveillance and Epstein criteria, respectively. For men with a nomogram derived minimal cancer probability of 0% to 4.9%, 5.0% to 19.9%, 20.0% to 34.9%, 35.0% to 49.9% and 50.0% to 71.0% the rate of high risk disease was 70.8%, 37.8%, 22.4%, 9.0% and 3.8%, respectively. In contrast, the rate of high risk disease for men who met Prostate Cancer Research International: Active Surveillance and Epstein criteria were 17.1% and 13.9%, respectively. CONCLUSIONS A detailed breakdown of the expected rates of false-positive results and high risk disease associated with the nomogram derived probability of minimal cancer would provide more complete information to clinicians and patients on which to base therapeutic clinical decisions for presumed early stage prostate cancer.