WISH-PC2: a unique xenograft model of human prostatic small cell carcinoma

Prostatic small cell carcinoma is an aggressive subtype of prostate cancer that usually appears as a progression of the original adenocarcinoma. We describe here the WISH-PC2, a novel neuroendocrine xenograft of small cell carcinoma of the prostate. This xenograft was established from a poorly differentiated prostate adenocarcinoma and is serially transplanted in immune-compromised mice where it grows within the prostate, liver, and bone, inducing osteolytic lesions with foci of osteoblastic activity. It secretes to the mouse Chromogranin A and expresses prostate plasma carcinoma tumor antigen-1, six-transmembrane epithelial antigen of the prostate, and members of the Erb-B receptor family. It does not express prostate-specific antigen, prostate stem cell antigen, prostate-specific membrane antigen, and androgen receptor, and it grows independently of androgen. Altogether, WISH-PC2 provides an unlimited source in which to study the involvement of neuroendocrine cells in the progression of prostatic adenocarcinoma and can serve as a novel model for the testing of new therapeutic strategies for prostatic small cell carcinoma.

Blood loss and the need for transfusion in patients who undergo partial or radical nephrectomy for renal cell carcinoma

PURPOSE

We assessed blood loss and subsequent transfusion associated with nephrectomy performed for suspected renal cell carcinoma to establish guidelines for preoperative autologous blood donation and identify a subgroup of patients that may benefit from erythropoietin administration.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 211 patients who underwent partial (73%) or radical (23%) nephrectomy for presumed renal cell carcinoma at our institution between 1990 and 1999. Patients were divided into groups 1-44.5% treated with radical nephrectomy for localized disease, 2-21.3% radical nephrectomy for metastatic lesions invading the renal vasculature or inferior vena cava, 3-8% radical nephrectomy for metastatic disease with locally extensive lesions and 4-26.5% partial nephrectomy for localized lesions. Patient charts were evaluated for preoperative and postoperative hematocrit, estimated blood loss, transfusions received, surgical complications and underlying disease.

RESULTS

Median estimated blood loss was 200, 400, 250 and 555 cc in groups 1 to 4, respectively. However, patients in groups 2 and 3 had a substantially greater range of blood loss than those in groups 1 and 4, respectively. The incidence of those with a blood loss of greater than 1 l. was 7%, 36%, 24% and 11% in groups 1, to 4, respectively. The incidence of those requiring transfusion was significantly lower in group 1 than in groups 2 to 4 (18% versus 44%, 24% and 30%, respectively, p <0.009). Mean transfusion requirement plus or minus standard deviation was significantly greater in groups 2 and 3 than in 1 and 4 (2.3 +/- 1.08, 5.5 +/- 4.4, 11.3 +/- 9.6 and 2.3 +/- 1.7 units, respectively, p <0.05). No significant difference was noted in the change in hematocrit as a result of surgery in the 4 groups (p >0.05). Similarly underlying disease and operative complications did not have a significant effect on blood loss or transfusion (p >0. 05).

CONCLUSIONS

Radical or partial nephrectomy for localized renal cell carcinoma leads to consistent and well tolerated operative blood loss that rarely results in the need for substantial transfusion. In contrast, nephrectomy for advanced disease may cause a risk of greater blood loss and subsequent need for the transfusion of multiple units of blood. While preoperative autologous blood donation may have limited value in this regard due to the high cost and number of units needed, preoperative erythropoietin administration may be a viable option. Prospective randomized studies are currently planned.

Androgen deprivation induces selective outgrowth of aggressive hormone-refractory prostate cancer clones expressing distinct cellular and molecular properties not present in parental androgen-dependent cancer cells

PURPOSE

The mechanism of progression of human prostate cancer (CaP) cells under androgen ablation therapy remains unclear. To study the alternative pathways of CaP cell growth under conditions of androgen deprivation, androgen-independent CaP variants were selected and expanded from an androgen-dependent CaP line via an in vitro androgen deprivation treatment. Cellular and molecular properties of these androgen-independent variants were characterized both in vitro and in vivo and compared with those of their parental androgen-dependent cells.

METHODS

Androgen deprivation treatment of an androgen-dependent CaP cell line, LNCaP, was carried out by replacing culture medium with RPMI 1640 medium plus 10% charcoal-stripped serum. Cells that survived through the androgen deprivation treatment were harvested and expanded in the androgen-deficient culture medium and were designated CL-1. The CL-1 cells were also recultured in androgen-containing medium and designated CL-2. The growth (cell cycle analysis, 3H-thymidine incorporation assay, growth expansion, and colonization efficiency), expression of CaP-associated markers (semiquantitative reverse transcriptase polymerase chain reaction), interaction with endothelial and bone marrow stromal cells, sensitivity to anticancer agents and radiation (growth inhibition), and tumorigenicity of CL-1 and CL-2 cells were determined and compared with these characteristics in parental LNCaP cells.

RESULTS

CL-1 and CL-2 cells are fast-growing cells when compared with parental LNCaP cells. They were capable of potentiating the growth of endothelial and bone marrow stromal cells in co-culture experiments and acquired significant resistance to radiation and to anticancer cytotoxic agents (Taxol paclitaxel, vinblastine, and etoposide). In contrast to the poorly tumorigenic parental LNCaP cells, CL-1 and CL-2 lines proved highly tumorigenic, exhibiting invasive and metastatic characteristics in intact and castrated mice or in female mice within a short period of 3 to 4 weeks. No growth supplements (e.g., Matrigel) were needed. When transfected with the green fluorescence protein (GFP) gene and transplanted orthotopically in the accessory sex gland, extensive metastatic disease from the primary CL tumor could be identified in bone, lymph nodes, lung, liver, spleen, kidney, and brain. Semiquantitative reverse transcriptase polymerase chain reaction analysis revealed a markedly distinct molecular expression profile in the CL lines: overexpression of basic fibroblast growth factor, interleukin-6, interleukin-8, vascular endothelial growth factor, transforming growth factor-beta, epidermal growth factor receptor, caveolin, and bcl-2 messenger RNAs and marked down-regulation of E-cadherin, p-53, and pentaerythritol tetranitrate.

CONCLUSIONS

Early administration of hormonal therapy after failure of first-line treatment is associated with a profound clonal selection of aggressive AI variants, such as CL-1 and CL-2 lines. These tumor lines, with their parental counterparts, can serve as valuable tools for studying the cellular and molecular mechanisms of CaP progression and metastasis under hormonal therapy. CL-1 and CL-2 offer a unique and reproducible model for the evaluation of drug sensitivity and for other therapeutic modalities for advanced prostate cancer.

Adoptive cellular therapy

We provide a current review of adoptive cellular therapy in the management of metastatic renal cell carcinoma. A comprehensive literature review of peer-reviewed articles on the development and use of adoptive cellular immunotherapy was performed. Renal cell carcinoma is a highly immunogenic tumor that has proven resistant to standard cytotoxic chemotherapy, but has shown reproducible response to immune-based therapy. In an effort to improve responses, a variety of adoptive cellular strategies have been devised and tested in the setting of metastatic disease. Among the techniques developed, the use of lymphokine-activated killer (LAK) cells, autolymphocyte therapy (ALT), and tumor-infiltrating lymphocytes (TIL) have been the best studied. While further trials are ongoing, thus far, these approaches have not consistently shown benefit in comparison to standard immune-based treatment with biologic response modifiers, most importantly, high-dose bolus interleukin-2 (IL-2). Future approaches, including the use of dendritic cells (DC) to facilitate the development of tumor vaccines, are encouraging. Advanced renal cell carcinoma continues to inspire research of promising new cellular immunotherapeutics. The experience with LAK, ALT, and TIL has greatly increased our understanding of tumor immunobiology, and has led to the ongoing development of new technology, including DC, vaccine, and antibody therapy.

Prognostic indicators for renal cell carcinoma: a multivariate analysis of 643 patients using the revised 1997 TNM staging criteria

PURPOSE

We determine independent prognostic indicators for renal cell carcinoma using the revised 1997 TNM staging criteria.

MATERIALS AND METHODS

The records of 643 consecutive patients undergoing partial or radical nephrectomy at our institution between 1987 and 1998 were reviewed. Preoperative evaluation of functional status using the Eastern Cooperative Oncology Group (ECOG) criteria was performed in all cases. Renal cell carcinoma grade and stage were evaluated using the 1997 American Joint Committee on Cancer grading and TNM staging criteria, respectively. Patients were followed for a mean plus or minus standard deviation of 47+/-40 months (median 87). Kaplan-Meier survival curves were used to determine 5-year cancer specific survival for all patient groups. Univariate analysis using log rank sum tests was performed to evaluate the prognostic significance of overall TNM stage, tumor stage, disease grade and ECOG status. Multivariate analysis was performed to determine which factors had an independent impact on survival of patients with renal cell carcinoma.

RESULTS

The 5-year cancer specific survival rate was 91%, 74%, 67% and 32% for TNM stages I, II, III and IV lesions, respectively (p<0.001). Analysis demonstrated a survival rate of 83% for stage T1, 57% for stage T2, 42% for stage T3 and 28% for stage T4 disease (p<0.001), and 89% for grade 1, 65% for grade 2, and 46% for grades 3 and 4 (p<0.001). Multivariate analysis revealed that overall TNM stage and grade of disease were the most important prognostic indicators for renal cell carcinoma (p<0.001). ECOG classification was a less significant predictor (p = 0.031) and tumor stage was not shown to have any independent impact on patient survival (p = 0.138).

CONCLUSIONS

Better survival rates of patients with localized and advanced renal cell carcinoma can be demonstrated with recent advances in diagnosis and treatment. The revised 1997 TNM criteria manifest an appropriate adjustment in staging renal cell carcinoma based on these improvements, with overall stage correlating with cancer specific survival. In contrast, while effectively predicting survival, tumor stage did not demonstrate an independent impact on renal cell carcinoma prognosis under multivariate analysis. Instead, other factors, such as ECOG status and more importantly grade of disease, appeared to affect survival significantly as independent elements. Based on our recent experience with patients treated for renal cell carcinoma in the era of enhanced technology and improved survival, tumor grade and molecular markers may serve as useful adjuncts to TNM staging in guiding treatment and predicting survival outcomes.

Is adrenalectomy a necessary component of radical nephrectomy? UCLA experience with 511 radical nephrectomies

PURPOSE

We determine the incidence and characteristics of adrenal involvement in localized and advanced renal cell carcinoma, and evaluate the role of adrenalectomy as part of radical nephrectomy.

MATERIALS AND METHODS

The records of 511 patients undergoing radical nephrectomy with ipsilateral adrenalectomy for renal cell carcinoma at our medical center between 1986 and 1998 were reviewed. Mean patient age was 63.2 years (range 38 to 85), and 78% of the subjects were males and 22% were females. Patients were divided into subgroups of 164 with localized (stage T1-2 tumor, group 1) and 347 with advanced (stage T3-4N01M01, group 2) renal cell carcinoma. Staging of tumors was performed according to the 1997 TNM guidelines. A retrospective review of preoperative computerized tomography (CT) of the abdomen was performed. Radiographic findings were subsequently compared to postoperative histopathological findings to assess the predictive value of tumor characteristics and imaging in determining adrenal metastasis.

RESULTS

Of the 511 patients 29 (5.7%) had adrenal involvement. Average size of the adrenal tumor was 3.86 cm. (standard deviation 1.89). Tumor stage correlated with probability of adrenal spread, with T4, T3 and T1-2 tumors accounting for 40%, 7.8% and 0.6% of cases, respectively. Upper pole intrarenal renal cell carcinoma most likely to spread was local extension to the adrenal glands, representing 58.6% of adrenal involvement. In contrast, multifocal, lower pole and mid region renal cell carcinoma tumors metastasized hematogenously, representing 32%, 7% and 4% of adrenal metastasis, respectively. The relationship between intrarenal tumor size (mean 8.9 cm., range 3 to 17) and adrenal involvement (independent of stage) was not statistically significant. Renal vein thrombus involvement was demonstrated in 8 of 12 cases (67%) with left and 2 of 9 (22%) with right adrenal involvement. Preoperative CT demonstrated 99.6% specificity, 99.4% negative predictive value, 89.6% sensitivity and 92.8% positive predictive value for adrenal involvement by renal cell carcinoma.

CONCLUSIONS

With a low incidence of 0.6%, adrenal involvement is not likely in patients with localized, early stage renal cell carcinoma and adrenalectomy is unnecessary, particularly when CT is negative. In contrast, the 8.1% incidence of adrenal involvement with advanced renal cell carcinoma supports the need for adrenalectomy. Careful review of preoperative imaging is required to determine the need for adrenalectomy in patients at increased risk with high stage lesions, renal vein thrombus and upper pole or multifocal intrarenal tumors. With a negative predictive value of 99.4%, negative CT should decrease the need for adrenalectomy. In contrast, positive findings are less reliable given the relatively lower positive predictive value of this imaging modality. Although such positive findings may raise suspicion of adrenal involvement, they may not necessarily indicate adrenalectomy given the low incidence, unless renal cell carcinoma with risk factors, such as high stage, upper pole location, multifocality and renal vein thrombus, is present.

Renal cell carcinoma: prognostic significance of incidentally detected tumors

PURPOSE

We determined the prognostic significance of incidentally discovered renal cell carcinoma in the era of increased incidental detection.

MATERIALS AND METHODS

We reviewed the records of 633 consecutive patients who underwent radical or partial nephrectomy for renal cell carcinoma at our institution between 1987 and 1998. Patients were divided into those who were asymptomatic and tumor was diagnosed incidentally and those diagnosed after presenting with any of the classic symptoms of renal cell carcinoma or subsequent metastasis. All renal cell carcinoma lesions were assigned a stage and grade according to 1997 TNM criteria. All patients were followed postoperatively to assess survival rates, and monitor recurrence and metastasis.

RESULTS

Of the 633 patients 95 (15%) were treated for incidentally discovered renal cell carcinoma and 538 (85%) presented with symptoms secondary to renal cell carcinoma at diagnosis. Patient age and sex distribution were similar in the 2 groups. Stage I lesions were observed in 62.1% of patients with incidental renal cell carcinoma and in 23% with symptomatic renal cell carcinoma. In contrast, stage IV lesions were present in 27.4% of patients with incidental versus 54% with symptomatic renal cell carcinoma. Thus, incidental lesions were of significantly lower stage than those causing symptoms (p <0.001). Similarly 15.8% of incidental but 42.4% of symptomatic lesions were grade 3 or 4 (p = 0.006). Patients were followed postoperatively for a mean of 47 months plus or minus 40 months. The 5-year cancer specific survival rate was significantly higher for incidental than for symptomatic tumors (85.3% versus 62.5%). Likewise, the local and distal recurrence rates were higher for symptomatic lesions. When adjusted for stage, no difference in survival was noted in the 2 groups for stages I to III disease and a minimally significant difference was noted for stage IV cancer. Multivariate analysis of stage and grade attributed the survival difference in stage IV disease to the significantly higher grade of symptomatic lesions.

CONCLUSIONS

At presentation incidental tumors are of significantly lower stage and grade than tumors producing symptoms. Subsequently these clinically and histologically less aggressive lesions lead to better patient survival and decreased recurrence. Thus, the detection of renal cell carcinoma before symptom onset enables treatment of less aggressive tumors and provides a better prognosis for patients. Given these data efforts should be directed toward the development of a screening protocol to detect these lesions early, so that they may be prevented from progressing to the point when symptoms are apparent and prognosis becomes worse. In addition, the significant correlation of tumor grade with survival in our study further demonstrates the prognostic value of tumor grade and molecular markers for the future evaluation and treatment of renal cell carcinoma.

Expanding the indications for surgery and adjuvant interleukin-2-based immunotherapy in patients with advanced renal cell carcinoma

PURPOSE

To determine the role of surgery and adjuvant interleukin (IL)-2-based immunotherapy in the treatment of patients with advanced metastatic renal cell carcinoma

PATIENTS AND METHODS

The survival of 354 consecutive patients with metastatic renal cell carcinoma treated with IL-2-based immunotherapy through the UCLA Medical Center Kidney Cancer Program was analyzed There were five groups of patients. Patients who initially presented with metastatic disease received either (1) IL-2 therapy with primary tumor in place; (2) nephrectomy followed by IL-2 therapy, or (3) nephrectomy followed by immunotherapy with IL-2 plus tumor-infiltrating lymphocytes. Patients who underwent nephrectomy for localized disease were divided into two groups: (4) those who developed metastatic disease > or = 6 months after nephrectomy and then received IL-2 therapy; and (5) those who developed metastatic disease < 6 months after nephrectomy and then received IL-2 therapy. Kaplan-Meier survival curves were generated for all patient groups.

RESULTS

Among patients who received IL-2-based immunotherapy with their primary tumor in place (group 1; n = 36), 1- and 2-year survival rates were 29% and 4%, respectively, compared with 1- and 2-year survival rates of 67% and 44%, respectively, for all similar patients who underwent nephrectomy prior to IL-2 therapy (n = 235). Among patients initially presenting with metastatic disease who underwent nephrectomy followed by IL-2 therapy without tumor-infiltrating lymphocytes (group 2; n = 69), the 1- and 2-year survival rates were 53% and 25%, respectively. The best survival was observed in patients treated with nephrectomy followed by IL-2 plus tumor-infiltrating lymphocyte therapy (group 3; n = 102), which yielded 1- and 2-year survival rates of 73% and 55%, respectively. Among patients initially undergoing nephrectomy for localized disease, patients receiving IL-2-based therapy for subsequent metastasis > or = 6 months following nephrectomy (group 4; n = 128) had 1- and 2-year survival rates of 64% and 40%, respectively, compared with 45% and 15%, respectively, for patients developing metastasis < 6 months after nephrectomy (group 5; n = 19).

CONCLUSION

The role of surgery prior to IL-2-based immunotherapy remains controversial Our data demonstrate that aggressive surgery is safe, causing minimal morbidity despite extensive tumor involvement, and significantly improves survival outcomes in patients with metastatic renal cell carcinoma when carried out in conjunction with an IL2-based immunotherapy regimen.

Immune and genetic therapies for advanced renal cell carcinoma

Although we have witnessed advances in many aspects of cancer research and therapy in recent years, the ability to cure the majority of patients with advanced renal cell carcinoma (RCC) remains elusive. At the same time, it has become increasingly apparent that a better understanding of the genetic alterations and immune dysregulations in RCC will play a key role in finding a treatment. Therefore, clinical trials directed at specific genetic alterations and studies exploiting components of the immune system are being conducted. These studies provide new hope for an improved outlook for patients presenting with advanced RCC. The future prospects of RCC therapy will be, without doubt, built on the foundation of current investigative efforts in gene and immune therapy. This article reviews the current role of immunotherapy and gene therapy in the management of metastatic RCC. Finally, current clinical trials focusing on gene and immune therapies are listed.

Immunomodulatory dendritic cells generated from nonfractionated bulk peripheral blood mononuclear cell cultures induce growth of cytotoxic T cells against renal cell carcinoma

Dendritic cells (DCs) loaded with tumor antigens have the potential to become a powerful tool for clinical cancer treatment. Recently, the authors showed that a tumor-specific immune response can be elicited in culture via stimulation with autologous renal tumor lysate (Tuly)-loaded DCs that were generated from cytokine-cultured adherent peripheral blood mononuclear cells (PBMCs). Here, the authors show that immunomodulatory DCs can be generated directly from nonfractionated bulk PBMC cultures. Kinetic studies of DC differentiation and maturation in PBMC cultures were performed by monitoring the acquisition of DC-associated molecules using fluorescence-activated cell sorting analysis to determine the percentage of positive immunostained cells and the mean relative linear fluorescence intensity (MRLFI). Compared with conventional adherent CD14+ cultures, which have mostly natural killer, T, and B cells removed before cytokine culture, bulk PBMC cultures exhibited an early loss of CD14+ cells (day 0 = 78.8%, day 2 = 29.6% versus day 0 = 74%, day 2 = 75%) with an increase in yield of mature DCs (DC19- CD83+) (day 5 = 17%, day 6 = 21%, day 7 = 22% versus day 5 = 11%, day 6 = 15%, day 7 = 23%). Although a comparable percentage of DCs expressing CD86+ (B7-2), CD40+, and HLA-DR+ were detected in both cultures, higher expression levels were detected in DCs derived from bulk culture (CD86 = MRLFI 3665.1 versus 2662.1 on day 6; CD40 = MRLFI 1786 versus 681.2 on day 6; HLA-DR = MRLFI 6018.2 versus 3444.9 on day 2). Cytokines involved in DC maturation were determined by polymerase chain reaction demonstrating interleukin-6 (IL-6), IL-12, interferon-gamma, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-alpha mRNA expression by bulk culture cells during the entire 9-day culture period. This same cytokine mRNA profile was not found in the conventional adherent DC culture. Autologous renal Tuly (30 micrograms protein/10(7) PBMCs) enhanced human leukocyte antigen expression by DCs (class I = 7367.6 versus 4085.4 MRFLI; class II = 8277.2 versus 6175.7 MRFLI) and upregulated cytokine mRNAs levels. Concurrently, CD3+ CD56-, CD3+ CD25+, and CD3+ TCR+ cell populations increased and cytotoxicity against autologous renal cell carcinoma tumor target was induced. Specific cytotoxicity was augmented when cultures were boosted continuously with IL-2 (20 U/mL biological response modifier program) plus Tuly stimulation. These results suggest that nonadherent PBMCs may participate in enhancing DC maturation. Besides the simplicity of this culture technique, bulk DC cultures potentially may be used with the same efficiency as conventional purified DCs. Furthermore, bulk culture-derived DCs may be used directly in vivo as a tumor vaccine, or for further ex vivo expansion of co-cultured cytotoxic T cells to be used for adoptive immunotherapy.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) for treatment of prostate cancer: first results and review of the literature

We present the involvement and association of TNF-related apoptosis-inducing ligand (TRAIL) with apoptosis. Its potential application as a therapeutic agent in urologic oncology is discussed. We have examined the sensitivity of prostate carcinoma cell lines DU145, PC3 and LNCaP to TRAIL-induced apoptosis and the expression of TRAIL receptors. Furthermore we looked into the sensitization of those prostate carcinoma cell lines to TRAIL-mediated apoptosis by low toxic levels of actinomycin-D. Furthermore, we review and discuss the pertinent literature on the molecular biology of TRAIL, its receptors and future potential for therapy in urologic oncology. Recent discovery and characterization of TRAIL has led to further broadening and insights into the apoptotic process. Based on preceding in-vitro studies, the first in-vivo study using TRAIL has been conducted and published in 1999. Systemic application of TRAIL in severe combined immune deficient (SCID) mice resulted in tumor regression of subcutaneous implanted mammary and colon cancer and several groups are looking into TRAIL sensitivity of prostate cancer and renal cancer cellines. Our in-vitro data revealed a significant increase of apoptotic cell death rate following the combined application of TRAIL with actinomycin-D. Our results suggest that the combination of TRAIL and ActD may be a therapeutic option in the treatment of drug/hormone refractory prostate carcinoma. In the future TRAIL may be used in combination therapy with other immunotherapies or gene therapies providing a synergistic effect or enhancing the efficacy of chemotherapeutic or radiotherapeutic regimens.

Evidence for clonal outgrowth of androgen-independent prostate cancer cells from androgen-dependent tumors through a two-step process

Prostate cancers require androgen for growth but progress to an androgen-independent stage under the selective pressure of androgen ablation therapy. Here we describe a novel human prostate cancer xenograft (LAPC-9) propagated by serial passage in male severe combined immunodeficient mice that expresses prostate-specific antigen and wild-type androgen receptor. In response to castration, LAPC-9 cells undergo growth arrest and persist in a dormant, androgen-responsive state for at least 6 months. After prolonged periods of androgen deprivation, spontaneous androgen-independent outgrowths develop. Thus, prostate cancers progress to androgen independence through two distinct stages, initially escaping dependence on androgen for survival and, subsequently, for growth. Through the use of serial dilution and fluctuation analysis, we provide evidence that the latter stage of androgen independence results from clonal expansion of androgen-independent cells that are present at a frequency of about 1 per 10(5)-10(6) androgen-dependent cells. We conclude that prostate cancers contain heterogeneous mixtures of cells that vary in their dependence on androgen for growth and survival and that treatment with antiandrogen therapy provides selective pressure and alters the relative frequency of these cells, thereby leading to outgrowths of androgen-independent cancers.

Comparison of helical computerized tomography, positron emission tomography and monoclonal antibody scans for evaluation of lymph node metastases in patients with prostate specific antigen relapse after treatment for localized prostate cancer

PURPOSE

We compare the detection of metastatic disease by helical computerized tomography (CT), positron emission tomography (PET) with F-18 fluorodeoxyglucose and monoclonal antibody scan with 111indium capromab pendetide in patients with an elevated prostate specific antigen (PSA) after treatment for localized prostate cancer.

MATERIALS AND METHODS

A total of 45 patients with an elevated PSA (median 3.8 ng./ml.) were studied following definitive local therapy with radical prostatectomy in 33, radiation therapy in 9 and cryosurgery in 3. CT of the abdomen and pelvis, and whole body PET were performed in all patients, of whom 21 also underwent monoclonal antibody scan. Lymph nodes 1 cm. in diameter or greater on CT were considered abnormal and were sampled by fine needle aspiration in 12 patients.

RESULTS

PET and CT were positive for distant disease in 50% of 22 patients with PSA greater than 4, and in 4 and 17%, respectively, of 23 with PSA less than 4 ng./ml. The detection rate for metastatic disease was similar for CT and PET, and higher overall than that for monoclonal antibody scan. Monoclonal antibody scan was true positive in only 1 of 6 patients, while PET was true positive in 6 of 9 with CT guided fine needle aspiration proved metastases.

CONCLUSIONS

CT and PET each detected evidence of metastatic disease in 50% of all patients with a high PSA or PSA velocity (greater than 4 ng./ml. or greater than 0.2 ng./ml. per month, respectively). Both techniques are limited for detecting metastatic disease in patients with a low PSA or PSA velocity. Our data suggest that monoclonal antibody scan has a lower detection rate than CT or PET.

Sensitization of immunoresistant prostate carcinoma cell lines to Fas/Fas ligand-mediated killing by cytotoxic lymphocytes: independence of de novo protein synthesis

BACKGROUND

We recently reported that drug-resistant prostate tumor cells (DU145, PC-3) are resistant to Fas-mediated killing by cytotoxic lymphocytes, and that this resistance can be overcome by treatment with subtoxic concentrations of chemotherapeutic drugs. Fas belongs to the tumor necrosis factor (TNF) family of receptors. Since resistance to TNF-alpha-mediated killing has been shown to be due, in part, to the presence of protective factors and that inhibitors of protein synthesis can sensitize cells to TNF-alpha killing, we hypothesized that resistance to Fas-mediated killing may be due to similar mechanisms. Since sensitization is achieved with chemotherapeutic drugs, and some chemotherapeutic drugs can also inhibit protein synthesis, we tested whether sensitization of prostate tumor cells to Fas ligand (Fas-L) occurred through inhibition of protein synthesis in a manner analogous to that of TNF-alpha.

METHODS

The effect of chemotherapeutic drugs on protein synthesis in DU145 and PC-3 cells was characterized by (3)H-leucine incorporation assays. We also determined the ability of inhibitors of protein synthesis and chemotherapeutic drugs to sensitize Fas and TNF-resistant DU145 cells to killing. The ability of RNA (actinomycin-D, Act-D) and protein synthesis inhibitors (cyclohexamide (CHX), emetine) to block drug-mediated sensitization to Fas-L killing was analyzed. Sensitivity to Fas-L killing was determined by the (51)Cr-release assay using human lymphokine-activated killer cells (LAK) and tumor-infiltrating lymphocyte (TIL) effector cells and the murine Fas-L-expressing PMMI cells.

RESULTS

The drugs cis-diamminedichloroplatinum (II) (CDDP), adriamycin (ADR), and etoposide (VP-16) sensitized DU145 and PC-3 cells to Fas killing. CDDP and ADR, which sensitized DU145 and PC-3 cells to Fas-L- and TNF-mediated killing, inhibited de novo protein synthesis in both cell lines, while VP-16 only inhibited protein synthesis in DU145 cells. Further, neither CHX nor emetine sensitized DU145 or PC-3 cells to Fas-L-mediated killing, despite blocking >90% de novo protein synthesis. In contrast, CDDP, VP-16, and the protein synthesis inhibitors, Act-D and CHX sensitized DU145 cells to TNF-alpha killing. Finally, pretreating cells with protein synthesis inhibitors (CHX, emetine) did not abrogate drug-mediated sensitization to Fas-mediated killing.

CONCLUSIONS

These findings demonstrate that downregulation of protective factors by protein synthesis inhibition may not be the primary mechanism of drug-mediated sensitization to Fas-L killing in prostate cell lines. These findings also suggest that drug-mediated sensitization to Fas-L killing may be due to modifications of preexisting gene products that participate in Fas-L-mediated apoptosis.

Efficacy of nephron-sparing surgery for renal cell carcinoma: analysis based on the new 1997 tumor-node-metastasis staging system

PURPOSE

To analyze the experience with nephron-sparing surgery as a treatment modality for renal cell carcinoma (RCC).

PATIENTS AND METHODS

Between 1980 and 1997, 146 patients underwent partial nephrectomy at the University of California-Los Angeles Medical Center. A matched group of 125 patients who underwent radical nephrectomy at the same institution between 1986 and 1997 were selected for comparison. Patients were monitored for an average period of 57 months. Patients were staged according to both the 1997 and 1987 tumor-node-metastasis (TNM) staging criteria. Survival data were calculated in terms of both staging criteria.

RESULTS

When comparing cancer-specific survival rates for patients with T1 lesions under both the 1987 and 1997 TNM staging criteria, no statistically significant difference in survival was noted (P =.53), although most of the tumors in our series measured < or = 4 cm. Patients with T2 lesions (1997 TNM) demonstrated a significant decrease in survival (66%) when compared with patients with T1 lesions (100%; P <.001). No statistically significant difference in survival for patients with T1 RCC treated with either radical or partial nephrectomy was noted (P =.219). Survival rates of partial and radical nephrectomies for patients with unilateral T1 RCC and a normal contralateral kidney also were not significantly different (P =.53). In contrast, for patients with lesions greater than T1, survival rates were significantly higher with radical versus partial nephrectomy (P =.001).

CONCLUSION

Partial nephrectomy has become an effective method of treating T1 RCC lesions as categorized by both the 1987 and the revised 1997 TNM staging criteria. Selected patients with localized unilateral RCC lesions less than 7 cm (ideally, < 4 cm) and a normal contralateral kidney will benefit from partial nephrectomy.

Metastatic renal cell carcinoma with concurrent inferior vena caval invasion: long-term survival after combination therapy with radical nephrectomy, vena caval thrombectomy and postoperative immunotherapy

PURPOSE

We report our experience using aggressive multimodal therapy in a high risk group of patients with metastatic renal cell carcinoma and concurrent inferior vena caval extension.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients in our kidney cancer database who had metastatic renal cell carcinoma and tumor thrombus extension into the inferior vena cava at the initial diagnosis. Patients were included in the study if they underwent radical nephrectomy and inferior venal caval thombectomy, and immunotherapy was planned for the postoperative period. Tumor size and grade, metastatic sites, level of vena caval extension, surgical complications and overall survival were obtained from the medical records. The primary end point analyzed was overall survival.

RESULTS

We identified 31 cases of metastatic renal cell cancer with extensive disease and vena caval extension. Of the patients 23% had an isolated lung metastasis, and 53% had metastasis in the lung and at other sites. The remaining patients had involvement primarily at nonpulmonary metastatic sites, including lymph node in 38%, soft tissue in 13%, liver in 29% and bone in 10%. Average blood loss during nephrectomy was 3,200 cc (median 2,100) and the rate of major complications was 12%. Of the patients 80% underwent the full course of surgery and postoperative immunotherapy. At a mean followup of 18 months (34 for survivors) 26% of the patients are alive. Actuarial overall 5-year survival of the group was 17%. Tumor thrombus level did not correlate with overall survival, while immunotherapy, tumor grade and metastatic site provided significant prognostic information. In patients with an isolated pulmonary metastasis the 5-year survival rate was 43%, while in those with low grade tumors it was 52%.

CONCLUSIONS

In contrast to the poor results of surgery only in patients with renal cell carcinoma and concurrent inferior venal caval invasion, reasonable 5-year survival may be achieved after combined aggressive surgery and immunotherapy. Patients in whom metastasis was limited to the lungs and those with grade 1 to 2 tumors had a better prognosis. With careful planning and experienced immunotherapists therapy may be completed in the majority of this high risk group of patients.