Kenneth S. Koeneman

Histopathology of surgically managed renal tumors: analysis of a contemporary series

OBJECTIVES To review the pathologic findings of a contemporary series of surgically treated renal tumors suspicious for malignancy to assess the frequency of benign disease in the modern era. The extensive application of modern imaging techniques has led to an increase in the number of incidentally discovered solid renal masses, many of which are small. A significant proportion of small renal tumors are benign or are low-grade malignancies. METHODS The records of all patients at our institution who underwent treatment for a renal mass suspicious for malignancy between November 1999 and July 2002 were retrospectively reviewed. RESULTS A total of 173 patients with 186 renal tumors had pathologic information available for analysis. Of the 186 tumors, 48% were discovered incidentally. For masses 4 cm or less, the percentage of incidentally discovered tumors increased to 58%. The pathologic evaluation demonstrated malignancy in 160 (86%) and benignity in 26 (14%) overall. For tumors 4 cm or less, 18 (20%) of 90 were benign; for tumors between 4 and 7 cm, 8 (17%) of 47 benign. No tumors greater than 7 cm were benign. All renal cell carcinomas less than 2 cm in size were Fuhrman grade 1 or 2. CONCLUSIONS Small renal tumors, many of which are incidentally discovered, are often benign or are low-grade malignancies. For tumors 4 cm or less, the frequency of benign pathologic findings is greater than previously quoted in published reports. As a result, we recommend parenchymal-sparing approaches whenever possible.

Phase I Dose Escalation Clinical Trial of Adenovirus Vector Carrying Osteocalcin Promoter-Driven Herpes Simplex Virus Thymidine Kinase in Localized and Metastatic Hormone-Refractory Prostate Cancer

Osteocalcin (OC), a major noncollagenous bone matrix protein, is expressed prevalently in prostate cancer epithelial cells, adjacent fibromuscular stromal cells, and osteoblasts in locally recurrent prostate cancer and prostate cancer bone metastasis [Matsubara, S., Wada, Y., Gardner, T.A., Egawa, M., Park, M.S., Hsieh, C.L., Zhau, H.E., Kao, C., Kamidono, S., Gillenwater, J.Y., and Chung, L.W. (2001). Cancer Res. 61, 6012-6019]. We constructed an adenovirus vector carrying osteocalcin promoter-driven herpes simplex virus thymidine kinase (Ad-OC-hsv-TK) to cotarget prostate cancer cells and their surrounding stromal cells. A phase I dose escalation clinical trial of the intralesional administration of Ad-OC-hsv-TK followed by oral valacyclovir was conducted at the University of Virginia (Charlottesville, VA) in 11 men with localized recurrent and metastatic hormone-refractory prostate cancer (2 local recurrent, 5 osseous metastasis, and 4 lymph node metastasis) in order to determine the usefulness of this vector for the palliation of androgen-independent prostate cancer metastasis. This is the first clinical trial in which therapeutic adenoviruses are injected directly into prostate cancer lymph node and bone metastasis. Results show that (1). all patients tolerated this therapy with no serious adverse events; (2). local cell death was observed in treated lesions in seven patients (63.6%) as assessed by TUNEL assay, and histomorphological change (mediation of fibrosis) was detected in all posttreated specimens; (3). one patient showed stabilization of the treated lesion for 317 days with no alternative therapy. Of the two patients who complained of tumor-associated symptoms before the treatment, one patient with bone pain had resolution of pain, although significant remission of treated lesions was not observed by image examination; (4). CD8-positive T cells were predominant compared with CD4-positive T cells, B cells (L26 positive), and natural killer cells (CD56 positive) in posttreated tissue specimens; (5). levels of HSV TK gene transduction correlated well with coxsackie-adenovirus receptor expression but less well with the titers of adenovirus injected; and (6). intrinsic OC expression and the efficiency of HSV TK gene transduction affected the levels of HSV TK protein expression in clinical specimens. Our data suggest that this form of gene therapy requires further development for the treatment of androgen-independent prostate cancer metastasis although histopathological and immunohistochemical evidence of apoptosis was observed in the specimens treated. Further studies including the development of viral delivery will enhance the efficacy of Ad-OC-hsv-TK.

Osteocalcin-directed gene therapy for prostate-cancer bone metastasis

Abstract Osteocalcin (OC) is a major noncollagenous bone protein whose expression is limited almost exclusively to osteotropic tumors and mature calcified tissue (differentiated osteoblasts). The function of OC, a highly conserved gamma-carboxyglutamic acid-containing protein, relies in part on its ability to bind hydroxyapatite and act as a chemoattractant for bone-resorbing cells. Serum osteocalcin levels are used clinically as an index of active bone turnover. Research in our laboratory has revealed that OC is expressed in several solid tumors, including osteosarcoma and ovarian, lung, brain, and prostate cancers. Evidence arising from reverse-transcription polymerase chain reaction (RT-PCR; detection of OC mRNA), immunohistochemical staining (detection of OC protein), and transient transfection and reporter assay (detection of OC mRNA transcription) reveals that OC expression is up-regulated in numerous solid tumors, with its expression being further elevated in androgen-independent prostate cancers. A recombinant, replication-defective adenovirus, Ad-OC-TK (OC promoter-driven herpes-simplex-virus thymidine kinase) was constructed and, when combined with the appropriate prodrug, either ganciclovir (GCV) or acyclovir (ACV), was found to be effective at destroying prostate-cancer cell lines in vitro and prostate tumor xenografts in vivo in both subcutaneous and bone sites. Additionally, via use of the OC promoter the supporting bone stromal cells are cotargeted when the prostate cancer interdigitates with bone stroma at the metastatic skeletal sites. Thus, maximal tissue-specific cell toxicity is achieved by the interruption of cellular communication between the prostate cancer and the bone stroma. We describe herein the preclinical foundation as well as the design and implementation of an ongoing phase I clinical trial at the University of Virginia that targets androgen-independent metastatic prostate cancer using the Ad-OC-TK vector.

Reassessment of the 1997 TNM Classification System for Renal Cell Carcinoma: A 5-cm T1/T2 Cutoff Is a Better Predictor of Clinical Outcome

The 1997 TNM staging classification for renal cell carcinoma (RCC) defined Stage I tumors as organ‐confined tumors measuring up to 7 cm in size. The authors evaluated the validity of this cutoff size by assessing the survival of patients with Stage I RCC according to a series of alternative size cutoff values. In addition, the authors determined how these size cutoffs affected the risk of having nonorgan‐confined tumors, regional lymph node involvement, and metastatic disease.

Cellular interactions in the tropism of prostate cancer to bone

At autopsy ≥80% of prostate cancers have established macrometastases in marrow containing bone. The mechanism(s) to explain this remarkable level of bone involvement remain to be elucidated. We examined the adhesive and invasive behavior of prostate cancer cells to osteoblastic and human bone marrow endothelial cells (HBME‐1) in an attempt to explain the tropism of prostate cells for bone. We found an inverse relationship between adhesion and prostate cell tumorigenicity and metastatic potential. Relative cell adhesion of P69 between cell lines was 1.74‐fold (95% confidence interval [CI] = 1.15–2.64) and 1.58‐fold (95% CI = 0.94–2.68) greater at 1 hr and 2 hr, respectively, than LNCaP that was essentially equivalent to C4‐2 cells when using an osteoblastic cell line, D1 as the substrate. Similar results were acquired when HBME‐1 were used as substratum. There was a marked increase in adhesion of the poorly tumorigenic cell line P69 as compared to the cancer cells to HBME‐1. P69 adhesion was 2.78‐fold (95% CI = 1.87–4.84) and 2.0‐fold (95% CI = 1.43–2.80) greater at 1 hr and 2 hr, respectively when compared to LNCaP or C4‐2 cells. D1 cells, a bone homing osteoblastic precursor, behaved contrary to the metastatic, bone‐colonizing C4‐2 cell line and bound best to other bone cells but not as well as a non‐homing fetal bone marrow‐derived cell line, D2. Invasion of prostate cancer cells through HBME‐1 lawns was examined at 8 hr and 16 hr. In contrast to the adhesion studies, the invasion of the more aggressive C4‐2 cells was 3.46‐fold (95% CI = 1.18–10.17) and 2.65‐fold (95% CI = 1.26–5.56) greater at 8 hr and 16 hr, respectively than LNCaP cells. Similarly, LNCaP cell invasion was 1.73‐fold (95% CI = 0.69–4.37) and 2.35‐fold (95% CI = 1.41–3.93) greater at 8 hr and 16 hr, respectively than P69 cells at the invasion of HBME‐1 monolayers. At 8 hr, C4‐2 cells had 6.0‐fold (95% CI = 2.63,13.65) higher invasive potential than P69 cells. Phage display biopanning of LNCaP cells versus C4‐2 cells in vitro using 4 separate techniques repeatedly identified the same peptide in support of minimal cell surface changes associated with the ability of C4‐2 cells to metastasize to bone. As integrins are vital to cell adhesion and migration, we examined the integrin subunit expression in the prostate cell lines. The expression of integrin subunits is much higher in the nontumorigenic cell line, P69, whereas the differences in integrin expression between LNCaP and C4‐2 are negligible. Only α2 and β5 integrin subunits increase from LNCaP to C4‐2. Given that C4‐2 cells spontaneously metastasize to bone in vivo and LNCaP cells do not, these studies imply that the ability of a metastatic prostate cancer cell to colonize the bone is not completely dependent upon the ability of the cancer cell to adhere to either osteoblastic cells or to the bone marrow endothelial cell lining. Therefore, the initial interaction between the bone endothelium or stroma and prostate cells is not accurately referred to as a tropic or homing response. The invasion assay results indicate that the invasive potential of the cell more accurately reflects the bone colonizing potential of a prostate cancer cell. It is likely that bidirectional paracrine interactions, subsequent to marrow adhesion, between prostate cancer cells and the bone microenvironment are what determine the successful colonization of the bone by prostate cancer cells. Further, functional changes in surface proteins that are involved in invasion are likely to occur without major changes in levels of cell surface protein expression. Functional integrin association, substratum usage and outside in signaling are more likely to predict metastatic behavior.

Novel NMR approach to assessing gene transfection: 4-fluoro-2-nitrophenyl-β-D-galactopyranoside as a prototype reporter molecule for β-galactosidase

Gene therapy holds great promise for the treatment of diverse diseases. However, widespread implementation is hindered by difficulties in assessing the success of transfection in terms of spatial extent, gene expression, and longevity of expression. The development of noninvasive reporter techniques based on appropriate molecules and imaging modalities may help to assay gene expression. 4‐Fluoro‐2‐nitrophenyl‐β‐D‐galactopyranoside (PFONPG) is a novel prototype NMR‐sensitive molecule, which is highly responsive to the action of β‐galactosidase (β‐gal), the product of the lacZ gene. The molecule is stable in solution and with respect to wild‐type cells, but the enzyme causes very rapid liberation of the aglycone, accompanied by color formation and a 19F NMR chemical shift of 5–10 ppm, depending on pH. Since the product is pH‐sensitive, this opens the possibility for direct pH determinations at the site of enzyme activity. Molecular and 19F NMR characteristics of PFONPG in solution, blood, and prostate tumor cells are presented. This prototype molecule facilitates a novel approach for assaying gene activity in vivo. Magn Reson Med 51:616–620, 2004.

Sutureless laparoscopic heminephrectomy using laser tissue soldering.

BACKGROUND AND PURPOSE Widespread application of laparoscopic partial nephrectomy has been limited by the lack of a reliable means of attaining hemostasis. We describe laser tissue welding using human albumin as a solder to control bleeding and seal the collecting system during laparoscopic heminephrectomy in a porcine model. MATERIALS AND METHODS Laparoscopic left lower-pole heminephrectomy was performed in five female domestic pigs after occluding the hilar vessels. Using an 810-nm pulsed diode laser (20 W), a 50% liquid albumin-indocyanine green solder was welded to the cut edge of the renal parenchyma to seal the collecting system and achieve hemostasis. Two weeks later, an identical procedure was performed on the right kidney, after which, the animals were sacrificed and both kidneys were harvested for ex vivo retrograde pyelograms and histopathologic analysis. RESULTS All 10 heminephrectomies were performed without complication. The mean operative time was 82 minutes, with an average blood loss of 43.5 mL per procedure. The mean warm ischemia time was 11.7 minutes. For each heminephrectomy, a mean of 4.2 mL of solder was welded to the cut parenchymal surface. In three of the five acute kidneys and all five 2-week kidneys, ex vivo retrograde pyelograms demonstrated no extravasation. In addition, no animal had clinical evidence of urinoma or delayed hemorrhage. Histopathologic analysis showed preservation of the renal parenchyma immediately beneath the solder. DISCUSSION Laser tissue welding provided reliable hemostasis and closure of the collecting system while protecting the underlying parenchyma from the deleterious effect of the laser during porcine laparoscopic heminephrectomy.

Predictive value of primary Gleason pattern 4 in patients with Gleason score 7 tumours treated with radical prostatectomy.

To examine whether Gleason score (GS) 3 + 4 and 4 + 3 cancers at radical prostatectomy behave differently and whether this behaviour is independently associated with prostate cancer outcome.

The utility of screening renal ultrasonography: identifying renal cell carcinoma in an elderly asymptomatic population

To evaluate the efficacy and utility of screening renal ultrasonography (RUS) in older patients with a high prevalence of risk factors for renal cell carcinoma (RCC), as with the widespread use of advanced imaging techniques the identification of incidental RCC has increased, and although previous studies in low‐risk groups reported little use for screening RUS, its utility in high‐risk groups is unknown.

Laparoscopic versus open retroperitoneal lymph node dissection: a cost analysis.

PURPOSE Laparoscopic retroperitoneal lymph node dissection is significantly less morbid than open retroperitoneal lymph node dissection but it is generally more costly due to longer operative time and disposable equipment. In response to budgetary pressure at our large county hospital we identified the cost components of laparoscopic retroperitoneal lymph node dissection that could be targeted to decrease procedure costs before expanding our laparoscopic retroperitoneal lymph node dissection program. MATERIALS AND METHODS A comprehensive literature review of open and laparoscopic retroperitoneal lymph node dissection was performed and certain parameters were abstracted, including operative time and equipment, hospital stay, perioperative complications and surgical success rates. Using these data the projected overall cost and individual cost centers at our institution were compared for open and laparoscopic retroperitoneal lymph node dissection. Decision tree analysis models were devised to estimate the cost of each treatment using commercially available software. We performed 1 and 2-way sensitivity analysis to evaluate the effect of individual treatment variables on overall cost. Base case analysis involved a young man with clinical stage I nonseminomatous testicular cancer who was a candidate for retroperitoneal lymph node dissection. RESULTS Based on a review of the costs at our institution open retroperitoneal lymph node dissection was a less costly procedure at