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D K Chopin

Publications and source records attributed to D K Chopin.

At least 55 records · Page 3Linked to original sources
PubMed1999

Blood-based reverse transcriptase polymerase chain reaction assays for prostatic specific antigen: long term follow-up confirms the potential utility of this assay in identifying patients more likely to have biochemical recurrence (rising PSA) following radical prostatectomy.

Reverse transcriptase polymerase chain reaction (RT-PCR) assay is a sensitive technique to detect circulating cells expressing prostate-specific antigen (PSA) in blood or bone marrow from patients with prostate cancer. When applied to prostate cancer patients at our institution, this technique identifies those patients with a greater likelihood of extra-prostatic disease. We evaluated RT-PCR PSA as a predictor of PSA recurrence and compared it with pre-operative (serum PSA, digital rectal examination, Gleason score on biopsy) and post-operative parameters (pathological findings). Three hundred nineteen men scheduled for radical prostatectomy had an enhanced RT-PCR PSA assay before surgery. The enhanced RT-PCR PSA protocol has been previously described. PSA recurrence was defined as any serum PSA value above 0.2 microgram/l. Forty-six patients had PSA recurrence. The mean follow-up was 25.4 months. Recurrence free survival was 53% for patients with positive RT-PCR PSA vs. 84% if RT-PCR PSA was negative. By using multivariate analyses, RT-PCR PSA status was not an independent predictor of PSA recurrence compared to pathological stage pT3, Gleason score on prostate specimen and serum PSA. If only pre-operative parameters were studied, serum PSA and RT-PCR PSA status were 2 independent pre-operative predictors of PSA recurrence compared with Gleason score on biopsy and digital rectal examination. Int. J. Cancer (Pred. Oncol.) 84:360-364, 1999.

Disease-Free Survival↗
PubMed1999

Partial nephrectomy with retroperitoneal laparoscopy.

PURPOSE: Laparoscopy has gradually gained acceptance for a variety of ablative procedures of the retroperitoneal organs, and the indications are being extended to more complex reconstructive and organ preserving procedures. We report our experience with retroperitoneal laparoscopic partial nephrectomy. MATERIALS AND METHODS: Retroperitoneal laparoscopic partial nephrectomy was performed for benign conditions in 6, equivocal solid masses in 4 and indeterminate cysts in 3 patients. If malignancy was suspected, laparoscopic sonography was used to assess the intrarenal anatomy and the mass. To facilitate parenchymal closure during nephron sparing surgery we used a hemostatic biological glue that consisted of gelatin, resorcinol and formaldehyde. RESULTS: Average operating time was 113 minutes and average blood loss was 72 ml. Histological examination revealed malignancy in 1 of the 3 cystic lesions and 2 of the 4 equivocal solid masses. There were 2 postoperative urinomas. CONCLUSIONS: Partial nephrectomy with retroperitoneal laparoscopy is feasible, and has a reasonable operating time and blood loss. Laparoscopic ultrasound was an important decision making aid during surgery. The use of biological glue simplified hemostasis and closure of the collecting system but good quality drainage of the collecting system is still required to decrease the risk of urinoma. The development of surgical tools that allow bloodless and nontraumatic section of the renal parenchyma is required to facilitate laparoscopic nephron sparing surgery. The ultrasonic scalpel needs further evaluation in this setting.

Adolescent↗
PubMed1999

Expression of transforming growth factor beta1 and its receptors in normal human urothelium and human transitional cell carcinomas.

Previous studies indicated that transforming growth factor beta1 (TGFbeta1) is expressed by normal urothelial cells and exerts regulatory autocrine functions in urothelial maintenance and wound healing. However, little is known about the expression patterns of TGFbeta1 and its receptors in bladder tumors. Therefore, we studied the protein and mRNA localization of TGFbeta1 and TGFbeta receptor types I and II (TGFbetaRI and TGFbetaRII) in normal human urothelium and transitional cell carcinomas (TCCs) of different grades and stages. Expression of TGFbeta1 and its receptors was examined by immunocytochemistry and mRNA in situ hybridization in normal urothelium and TCCs using a semiquantitative method. By immunocytochemistry, the expression of TGFbeta1 and TGFbetaRII was higher in superficial and basal cell layers of normal urothelium than in the intermediate layer. A similar localization was seen in superficial TCCs. TGFbetaRI was mainly present in basal and intermediate cell layers of normal urothelium and superficial TCCs. In contrast, in muscle invasive TCCs, all tumor cells stained intensely for all three proteins. No correlation was found between immunostaining and TCC grade. In situ hybridization pointed out that all cell layers in normal urothelium exhibit similar TGFbeta1 mRNA levels. Elevated TGFbeta1 mRNA levels were noted in TCCs irrespective of grade or stage. In conclusion, these data indicate that in normal urothelium TGFbeta1, TGFbetaRI, and TGFbetaRII expression depend on maturation and differentiation. This pattern is particularly lost in muscle invasive TCCs, in which the expression of the three proteins is enhanced. These data suggest autocrine TGFbeta1 mechanisms in human TCC cells that may be more pronounced in muscle invasive TCC cells.

Activin Receptors, Type I↗
PubMed1999

Retroperitoneal laparoscopic versus open radical nephrectomy.

PURPOSE: We analyze the retroperitoneal approach to laparoscopic radical nephrectomy in regard to feasibility, safety, morbidity and cancer control, and compare results and outcomes in patients who underwent retroperitoneal laparoscopic or open radical nephrectomy from 1995 to 1998. MATERIALS AND METHODS: The records of 58 consecutive patients with renal cancer who underwent radical nephrectomy from 1995 through 1998 were reviewed. Of the patients 29 underwent open radical nephrectomy (group 1) and 29 underwent retroperitoneal laparoscopic radical nephrectomy (group 2). Various parameters were compared and statistical analyses were performed. RESULTS: The 2 groups were similar in regard to age, gender and side of the tumor. Operative time was slightly shorter in group 1 (mean 121.4 versus 145 minutes in group 2, p = 0.047). Mean tumor size plus or minus standard deviation was larger in group 1 (5.71 +/- 2.01 versus 4.02 +/- 1.87 cm. in group 2). Group 2 patients had significantly less operative blood loss (mean 100.0 versus 284.5 ml. in group 1, p < 0.005) and used significantly less parenteral pain medication (p < 0.05). Postoperative hospital stay was significantly longer in group 1 (9.7 +/- 3.6 versus 4.8 +/- 2.0 days in group 2, p < 0.001), and the complication rate was higher (24 versus 8%, respectively). One group 1 patient died of renal cancer (pT2G2) after 14 months and local recurrence with hepatic metastasis occurred after 9 months in a group 2 patient with a pT3G2 tumor. CONCLUSIONS: Retroperitoneal laparoscopic nephrectomy for kidney cancer requires further assessment. It seems to have several advantages over open radical nephrectomy, and to be effective and safe for less than 50 cm. renal tumors but a risk of spillage cannot be ruled out for larger tumors.

Adult↗
PubMed1999

Retroperitoneoscopic nephroureterectomy for renal pelvic tumors with a single iliac incision.

PURPOSE: Retroperitoneal laparoscopy, by providing direct access to the retroperitoneal cavity, is a useful approach to urological surgery. We applied this technique to nephroureterectomy in patients with tumors of the renal pelvis. MATERIALS AND METHODS: Between January 1995 and March 1997 we performed 4 retroperitoneal laparoscopic nephroureterectomies in patients with tumors of the renal pelvis. The patients were placed in the lateral decubitus position. Five trocars were used. Balloon dilation was not contributory. Radical nephrectomy was performed and the kidney was left in the retroperitoneal space. Via an iliac incision ureterectomy with a bladder cuff was performed and the specimen was removed (kidney and ureter) en bloc via this incision without opening the urinary tract. RESULTS: One right and 3 left nephroureterectomies were performed with an average operating time of 220 minutes (range 160 to 300). Average kidney size was 110 mm. (range 100 to 120). Average hospital stay was 5.7 days (range 5 to 7). Blood loss was minimal and postoperative analgesic requirements were moderate. Conversion to open surgery was never necessary. The morbidity rate was zero. The pathological stages were pT2 G2, pT3 G2, pT3G3 and pT3 G2-G3 N+. A local recurrence was observed in a patient with a pT3 G3 tumor. CONCLUSIONS: Nephroureterectomy can be performed by retroperitoneal laparoscopy. The perioperative morbidity and hospital stay are reduced. Further followup is required to evaluate long-term results in terms of cancer outcome.

Aged↗
PubMed1998

Immune response following intravesical bacillus Calmette-Guerin instillations in superficial bladder cancer: a review.

Local immunotherapy with bacillus Calmette-Guerin (BCG) can prevent recurrences and progression of superficial bladder cancer, but the antitumoral mechanism of BCG is still unclear. The first event seems to be binding of BCG to urothelial cells via fibronectin, and processing of mycobacterial antigens by antigen-presenting cells. Experimental data suggest that bacterial antigens can also be processed by urothelial cells. CD4 lymphocytes subsequently recognize antigenic peptides presented by HLA class II molecules. The most common profile of urinary cytokines is interleukin-2 and interferon-gamma, suggesting the predominant involvement of the Th1 lymphocyte subpopulation. Natural killer cells, lymphocyte-activated killer cells, BCG-activated killer cells and macrophages are able to kill bladder tumor cells in vitro, but there is no evidence that a major histocompatibility complex (MHC)-restricted specific T cytotoxic response is involved in BCG antitumor activity.

Antigen Presentation↗
PubMed1998

Laparoscopic adrenalectomy: the retroperitoneal approach.

PURPOSE: Retroperitoneal laparoscopy, by providing direct access to the retroperitoneal cavity, is an interesting approach to urological surgery. We report our initial experience with retroperitoneal laparoscopic adrenalectomy. MATERIALS AND METHODS: Between January 1995 and April 1997, 23 adrenalectomies were performed by retroperitoneal laparoscopy in 10 men and 12 women. The patients were placed in the lateral decubitus position and 5 trocars were used. The retroperitoneal working space was created by digital dissection and was completed by insufflation without balloon dissection. The surgical indications were Conn's adenoma in 12 cases, Cushing's adenoma in 4, bilateral adrenal hyperplasia (Cushing's disease) in 1 (treated in a single procedure), a nonfunctioning adenoma in 2, pheochromocytoma in 2 and adrenal metastasis in 1. RESULTS: We removed 7 right and 16 left adrenal glands in an average operating time of 97 minutes (range 45 to 160). Average tumor size was 26 mm. (range 10 to 40). Average hospital stay was 3.3 days (range 1 to 10). Blood loss was minimal. Postoperative analgesic requirements were moderate. Conversion to open surgery was not necessary. The morbidity rate was low, with 1 postoperative hematoma and 1 case of persistent fever (greater than 38.5C). CONCLUSIONS: Retroperitoneal adrenalectomy is a reliable and effective technique. At our institution retroperitoneal laparoscopy is now the standard adrenal surgery procedure for tumors less than 5 cm.

Adenoma↗
PubMed1998

Modulation of cytokeratin subtype, EGF receptor, and androgen receptor expression during progression of prostate cancer.

After initial regression in response to androgen deprivation, most prostate cancers develop resistance to endocrine therapy. Identification of cellular and molecular changes occurring during endocrine therapy-induced regression and subsequent hormone insensitivity may point to mechanisms underlying the transition to hormone-independent prostate cancer. A series of untreated (n = 24), regressed (n = 15), and endocrine therapy-resistant (n = 10) prostatic adenocarcinomas were analyzed using immunohistochemistry with regard to cytokeratin 5 and 18, androgen receptor (AR), and epidermal growth factor receptor (EGF-R) expression in tumor cells. Using semiquantitative reverse transcription-polymerase chain reaction, the amount of AR mRNA also was determined. In regressed and therapy-resistant prostate cancers, an increase in cytokeratin 5-positive tumor cells was noted when compared with untreated carcinomas. Similarly, the proportion of EGF-R-positive tumor cells increased in the treated cases, whereas the proportion of AR-positive tumor cells dropped in regressed carcinomas and increased in hormone-refractory cancers. In the latter group, an eightfold higher level of AR mRNA was observed when compared with the other cases. Changes in the proportion of cytokeratin 5 and EGF-R-positive tumor cells suggests that during androgen deprivation an enlarged subpopulation of tumor cells with combined features of basal and secretory phenotypes arises. The increased proportion of AR-positive tumor cells during the transition from the regression phase to the hormone escape phase points to an important role of AR overexpression in this process.

Adenocarcinoma↗
PubMed1998

Use of three additional mid biopsies to improve local assessment of prostate cancer in patients with one positive sextant biopsy.

OBJECTIVES: Routine sextant biopsies have proven useful in the diagnosis and local staging of prostate cancer. A single positive biopsy is more frequently associated with a smaller tumor and a low risk of positive margins. Nevertheless, the risk of positive margins in patients with 1 positive sextant biopsy remains high (20%). A better assessment of local invasion is therefore needed. In addition to standard sextant biopsies, we routinely obtain 3 additional mid biopsies from the apex to the base of the prostate. The aim of this study is to analyze the contribution of these 3 additional mid biopsies to local staging. METHODS: From 1988 to 1996, 177 men underwent sextant biopsies plus 3 additional mid biopsies prior to radical prostatectomy; 59 men had 1 positive sextant biopsy, and 13 also had 1-3 positive mid biopsies. The pathological results of the prostatectomy specimens from these 13 men (group A) were compared with those of the 46 men with only 1 positive sextant biopsy (group B), by means of the Fisher and Mann-Whitney tests. RESULTS: The two groups were similar in terms of age, preoperative prostate-specific antigen, the Gleason score of positive biopsies, the weight of the specimen, the Gleason specimen score, tumor volume and pathological stage. Positive surgical margins were found in 53.8% of group A and 19.4% of group B patients (p = 0.002). The location of the positive additional biopsies matched that of the positive surgical margins. CONCLUSIONS: Additional mid biopsies improve the local assessment of prostate cancer in patients with a single positive sextant biopsy, identifying significantly more positive margins when these additional mid biopsies are positive and indicating the location of the positive surgical margins. These informations could be helpful to avoid positive surgical margins during radical prostatectomy.

Aged↗
PubMed1998

Biopsy-based diagnosis of prostate cancer in 1290 patients referred for prostate examination: results according to the PSA level, digital rectal examination and ultrasonography.

Authors present their retrospective study of 1290 patients referred for prostate evaluation. The risk of cancer was analysed according to PSA, rectal palpation and ultrasound examination. Among the 1290 patients, 54.8% had cancer. The risk of cancer was multiplied by 2.8 when the PSA was between the normal limit and 10 ng/ml, by 7.5 when it exceeded 10 ng/ml, by 4.0 when rectal palpation was abnormal and by 1.6 when a hypoechogenic zone was present. Although a hypoechogenic zone does not improve the detection of cancer compared to PSA and rectal palpation, an increased PSA level even lower than 10 ng/ml indicates biopsies.

Adult↗
PubMed1998

[Intravesical instillation in the treatment of superficial tumors of the bladder].

Bladder instillations represent the most significant progress in the management of superficial bladder cancer over the past twenty years. Intravesical chemotherapy significantly alters the rate of recurrence. Intravesical BCG reduces significantly the risk of recurrence and progression. Side effects are common and in the case of BCG severe but rare complications may be encountered during intravesical instillations. Therefore proper use, prevention of complication and careful follow up for tolerance and efficacy of bladder instillations are mandatory. They represent for high risk superficial bladder cancer a therapeutic test. An early failure for these tumors means a potential aggressiveness requiring radical therapy. These various aspects are developed from a practical point of view.

Administration, Intravesical↗
PubMed1998

Symptomatic caliceal diverticula treated with extraperitoneal laparoscopic marsupialization fulguration and gelatin resorcinol formaldehyde glue obliteration.

PURPOSE: The treatment of symptomatic stone filled caliceal diverticula has evolved from open surgery to less invasive procedures, such as extracorporeal shock wave lithotripsy, percutaneous techniques, retrograde ureteroscopy and laparoscopy, but it remains controversial. We describe a laparoscopic technique for the management of symptomatic caliceal diverticula. MATERIALS AND METHODS: An extraperitoneal laparoscopic procedure was done in 3 women with symptomatic caliceal diverticula. Watertight obliteration of the diverticular cavity was achieved without suturing, using gelatin resorcinol formaldehyde glue. RESULTS: Average operating time was 80 minutes, including ureteral catheterization. All patients became stone-free, there were no complications and average hospital stay was 6.6 days. At 6-month followup the patients remained asymptomatic with no diverticula or stone recurrence. CONCLUSIONS: Retroperitoneoscopy allows safe access to caliceal diverticula regardless of location, and permits complete removal of stone and fulguration of the diverticular neck. Gelatin resorcinol formaldehyde glue minimizes the risk of urinoma formation, and provides a simple, quick and safe alternative for nephrotomy closure.

Adolescent↗
PubMed1997

The prognostic value of p53 nuclear overexpression and MIB-1 as a proliferative marker in transitional cell carcinoma of the bladder.

BACKGROUND: There is controversy regarding the value of biologic markers as prognostic indicators independent of clinicopathologic parameters in transitional cell carcinoma (TCC) of the bladder. The authors examined the prognostic value of p53 tumor suppressor gene expression and the proliferative marker MIB-1 in TCC of the bladder. METHODS: Fresh frozen samples from 114 TCCs of the bladder and 13 normal bladders were studied by immunohistochemistry, using monoclonal antibodies MIB-1 for proliferation and PAb 1801 for p53 nuclear overexpression. Scores were determined in each case by counting at least 500 nuclei per slide in 3-5 selected regions. Patients were stratified for both markers into two groups for time-event analysis, according to the median number of nuclei stained. Patients with nuclear staining below the median value of the score were considered negative in the statistical analysis. Quantitative immunostaining was analyzed in relation to the time to recurrence, progression, and cancer death, and compared with clinical and pathologic parameters for prognostic significance in univariate and multivariate analysis (stepwise logistic regression). RESULTS: Median nuclear overexpression of p53 was 22% and that of MIB-1 28%. There was a strong association between proliferation and p53 nuclear overexpression (P < 0.0001). Progression free and disease specific survival rate estimates (log rank test) were significantly lower in patients with p53 or MIB-1 scores above 22% and 28%, respectively. Multivariate analysis indicated that stage as well as p53 and MIB-1 immunostaining provided independent prognostic information. CONCLUSIONS: Quantitative immunohistochemical evaluation of nuclear p53 and MIB-1 immunostaining inexpensively provides prognostic indicators in cases of TCC of the bladder.

Antibodies, Monoclonal↗
PubMed1997

Expression and functions of EGF, FGF and TGFbeta-growth-factor family members and their receptors in invasive human transitional-cell-carcinoma cells.

Studies on epidermal-growth-factor-like-, fibroblast- and transforming growth factors suggested their implication in tumorigenesis involving effects on tumour-cell proliferation and migration. In human transitional-cell carcinomas (TCC), enhanced expression of TGF alpha and EGF receptors correlated with an aggressive phenotype. However, little is known about functions of these growth factors in invasive TCCs. In this study, we performed protein- and RNA-expression studies on a set of growth factors and their receptors on the newly established invasive human TCC cell line designated 1207. The data were correlated with functional proliferation and migration studies. Similar expression patterns of many cellular markers, growth factors and their receptors were noted both in the original TCC tissue and in its derivative cell line, indicating the relevance of this cell line to the investigation of growth factor functions on TCC cells. The proliferation induction by EGF, TGF alpha, amphiregulin, heregulin alpha, FGF-1 and FGF-7 correlated with the presence of EGF receptors, c-erbB4 and FGFR2 (IIIb), respectively. Amphiregulin and heregulin alpha induced the most proliferation. In conformity with the low expression of TGF beta receptors I and II, TGF beta1, barely inhibited proliferation, while TGF alpha induced invasion of 1207 cells into Matrigel. These data support the notion that notably EGF-like proteins mediate TCC growth and invasion through autocrine pathways which can be reinforced by loss of TGF beta1 regulation.

Animals↗
PubMed1997

[Treatment of superficial bladder tumors].

Superficial bladder cancer, T1, Ta, TIS transitional cell carcinomas of the TNM classification, represent a spectrum disease with different biological behavior. The main difficulty in the management of these tumors is to predict their potential aggressiveness based on clinicopathological parameters. Their management is based on endoscopy findings and histopathological analysis. For low risk tumors, transurethral resection and surveillance allow an adequate tumor control. For high risk tumors, conservative treatment is based on a complete transurethral resection and prophylactic endovesical instillations of bacillus Calmette-Guérin. For intermediate risk lesions, the advantage of prophylactic endovesical instillations have been finally established either using BCG or chemotherapy (mitomycine C). However in this setting, various therapeutic modalities (maintenance therapy, dose, repeat cycles) are proposed and their relative efficacy remains to be established.

Administration, Intravesical↗
PubMed1996

Comparison of phytotherapy (Permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients.

BACKGROUND: Controversy regarding the relative efficacy of treatments for the relief of the symptoms of benign prostatic hyperplasia (BPH). METHODS: This was a 6-month double-blind randomized equivalence study that compared the effects of a plant extract (320 mg Permixon) with those of a 5 alpha-reductase inhibitor (5 mg finasteride) in 1,098 men with moderate BPH using the International Prostate Symptom Score (IPSS) as the primary end-point. RESULTS: Both Permixon and finasteride decreased the IPSS (-37% and -39%, respectively), improved quality of life (by 38 and 41%), and increased peak urinary flow rate (+25% and +30%, P = 0.035), with no statistical difference in the percent of responders with a 3 ml/sec improvement. Finasteride markedly decreased prostate volume (-18%) and serum PSA levels (-41%); Permixon improved symptoms with little effect on volume (-6%) and no change in PSA levels. Permixon fared better than finasteride in a sexual function questionnaire and gave rise to less complaints of decreased libido and impotence. CONCLUSIONS: Both treatments relieve the symptoms of BPH in about two-thirds of patients but, unlike finasteride, Permixon has little effect on so-called androgen-dependent parameters. This suggests that other pathways might also be involved in the symptomatology of BPH.

Aged↗