Biomedical subjects

R Kooner

Publications and source records attributed to R Kooner.

4 recordsLinked to original sources

PubMed2003

Treatment of localized prostate cancer using a combination of high dose rate Iridium-192 brachytherapy and external beam irradiation: initial Australian experience.

Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate- and high-risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate-specific antigen progression-free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability.

Adenocarcinoma↗

PubMed2001

Prognostic significance of pathologic features in localized prostate cancer treated with radical prostatectomy: implications for staging systems and predictive models.

PURPOSE: Although predicting outcome for men with clinically localized prostate cancer (PC) has improved, the staging system and nomograms used to do this are based on results from the North American health system. To be internationally applicable, these models require testing in cohorts from a variety of different health systems based on the predominant PC case identification methods used. PATIENTS AND METHODS: We studied 732 men with localized PC treated with radical prostatectomy and no preoperative therapy between 1986 and 1999 at one Australian institution to determine the effect of clinicopathologic features on disease-free survival. RESULTS: Preoperative serum prostate-specific antigen (PSA) concentration, Gleason score, pathologic stage, and year of surgery were independent predictors of outcome. Although margin status demonstrated only a trend toward significance in multivariate modeling overall, it proved to be independent in subgroups based on later year of surgery (1986 to 1994 v 1995 to 1998), preoperative PSA of less than 10 ng/mL, and Gleason score > or = 7. Adjuvant radiation therapy improved disease-free survival rates in patients with multiple surgical margin involvement. CONCLUSION: This work confirms the prognostic significance of pathologic stage, Gleason score, and preoperative serum PSA. In the context of a contemporaneous screening effect in Australia, these findings may have implications for methods that predict outcome following surgery as screening becomes more prevalent in a population. The independent prognostic effect of margin status may alter with an increase in the proportion of screening-identified PCs. Staging systems and nomograms that predict outcome following surgery require validation in cohorts with different health practices before being universally applied.

Adenocarcinoma↗

PubMed2001

Frequent loss of estrogen receptor-beta expression in prostate cancer.

The role of estrogen and its receptors in the etiology and progression of prostate cancer (PC) is poorly understood. In normal and malignant human prostate, estrogen receptor-alpha is expressed only in the stroma, whereas estrogen receptor-beta (ERbeta) is present in both normal stroma and epithelium. Because loss of ERbeta expression is associated with prostate hyperplasia in ERbeta-null mice, this study determined patterns of ERbeta expression in normal, hyperplastic, and malignant human prostate and associations with clinical outcome. Five normal prostates from organ donors and 159 radical prostatectomy specimens from patients with clinically localized PC were assessed for ERbeta expression using immunohistochemistry. ERbeta-positivity was defined as > or =5% of cells demonstrating nuclear immunoreactivity. All of the five normal prostates showed strong ERbeta-nuclear staining in >95% of the epithelium and 35% of the stromal cells. The number of ERbeta-positive cases declined to 24.2% (38/157) in hyperplasia adjacent to carcinoma and 11.3% (18/159) in PCs. ERbeta-positivity was related to decreased relapse-free survival (log-rank P = 0.04). Thus, loss of ERbeta expression is associated with progression from normal prostate epithelium to PC, whereas those cancers that retained ERbeta expression were associated with a higher rate of recurrence. These data identify the need to further investigate the potential role of ERbeta in the regulation of prostate epithelial cell proliferation and the functional consequences of decreased ERbeta expression in the evolution of PC.

Adult↗

PubMed1998

Vascular interventions during post-chemotherapy retroperitoneal lymph-node dissection for metastatic testis cancer.

AIMS: Complete excision of nodal masses during post-chemotherapy retroperitoneal lymph-node dissection (RPLND) for metastatic non-seminomatous germ-cell tumours (NSGCT) of the testis often requires vascular surgical intervention. We report our experience of vascular interventions and complications in a large series of men undergoing postchemotherapy RPLND. METHODS: A retrospective review of vascular interventions during post-chemotherapy RPLND in 98 patients was undertaken (103 procedures). RESULTS: Macroscopic tumour clearance was complete in 95/98 men (97%). Vascular intervention was required in all cases. Major complications included acute tubular necrosis in one patient who had undergone left nephrectomy and extensive dissection around the right renal artery, progressive atrophy of the ipsilateral kidney in three men and a colonic stricture and associated colocutaneous fistula in one patient after division of the inferior mesenteric artery. Iliac and femoral venous thrombosis developed in both patients in whom the inferior vena cava (IVC) was excised and in one patient after partial IVC excision. Eight of the 98 patients have died. No late vascular complications have occurred to date. CONCLUSION: Complete tumour clearance can be achieved in most post-chemotherapy RPLNDs but invariably involves vascular intervention. Metastatic NSGCT should be treated by surgeons with the ability to undertake the vascular procedures required.

Adolescent↗