Biomedical subjects

A T Porter

Publications and source records attributed to A T Porter.

At least 19 recordsLinked to original sources

PubMed2003

Prostate cancer DNA ploidy and response to salvage hormone therapy after radiotherapy with or without short-term total androgen blockade: an analysis of RTOG 8610.

PURPOSE: DNA ploidy has consistently been found to be a correlate of prostate cancer patient outcome. However, a minority of studies have used pretreatment diagnostic material and have involved radiotherapy (RT)-treated patients. In this retrospective study, the predictive value of DNA ploidy was evaluated in patients entered into Radiation Therapy Oncology Group protocol 8610. The protocol treatment randomization was RT alone versus RT plus short-course (approximately 4 months) neoadjuvant and concurrent total androgen blockade (RT+TAB). PATIENTS AND METHODS: The study population consisted of 149 patients, of whom 74 received RT alone and 75 received RT+TAB. DNA content was determined by image analysis of Feulgen stained tissue sections; 94 patients were diploid and 55 patients were nondiploid. Kaplan-Meier univariate survival, the cumulative incidence method, and Cox proportional hazards multivariate analyses were used to evaluate the relationship of DNA ploidy to distant metastasis and overall survival. RESULTS: DNA nondiploidy was not associated with any of the other prognostic factors in univariate analyses. In Kaplan-Meier analyses, 5-year overall survival was 70% for those with diploid tumors and 42% for nondiploid tumors. Cox proportional hazards regression revealed that nondiploidy was independently associated with reduced overall survival. No correlation was observed between DNA ploidy and distant metastasis. The diminished survival in the absence of an increase in distant metastasis was related to a reduction in the effect of salvage androgen ablation; patients treated initially with RT+TAB and who had nondiploid tumors had reduced survival after salvage androgen ablation. CONCLUSIONS: Nondiploidy was associated with shorter survival, which seemed to be related to reduced response to salvage hormone therapy for those previously exposed to short-term TAB.

Aged↗

PubMed2001

Neoadjuvant estramustine and etoposide followed by concurrent estramustine and definitive radiotherapy for locally advanced prostate cancer: feasibility and preliminary results.

PURPOSE: Current therapy for locally advanced prostate cancer is suboptimal. A treatment regimen was designed to improve systemic control by neoadjuvant targeting of hormone-sensitive and -insensitive micrometastatic disease and to improve local control by escalating the biologic effective dose to the prostate using estramustine (EMP) concurrently with radiotherapy. PATIENTS AND METHODS: Eighteen patients with locally advanced prostate cancer (Stages T3/T4 or T1c/T2b/T2c with a Gleason score of > or =7 and a serum PSA >15 ng/ml) were entered onto this trial. Therapy consisted of two 21-day cycles of oral estramustine (10 mg/kg/day) in three divided doses and oral etoposide (50 mg/m(2)/day, in two divided doses), followed by concurrent estramustine (10 mg/kg/day, PO) and three-dimensional conformal radiotherapy. RESULTS: Two patients required discontinuation of chemotherapy due to development of Grade 3 and 4 toxicity. All others completed both components of therapy per protocol guidelines. Minor toxicities included alopecia (100% of patients), anemia (69%), leukopenia (37%), thrombocytopenia (19%), and nausea (6%) but did not require dose modifications. There were no fatalities. Actuarial 3-year overall survival and disease-free survival (DFS) were 88% and 73%, respectively. Local control rate, assessed by repeated prostate biopsies at 18 months post completion of therapy, was 71%. CONCLUSION: The described regimen is well tolerated, and preliminary efficacy data are encouraging. The underlying concepts of early targeting of both hormone-sensitive and -insensitive micrometastatic clones, in combination with aggressive local therapy, warrant further investigation.

Aged↗

PubMed2000

Therapeutic Strategies for Localized Prostate Cancer II: Perineal Prostatectomy, X-Rays, Protons, Neutrons, and Combination Brachytherapy.

Application of improved imaging, diagnostic, and computer techniques is beginning to have an impact on the management of localized prostate cancer. It is possible to perform a range of surgical and radiation procedures with less morbidity than in the past. The changes in therapy for patients with localized disease derive from better knowledge of anatomy for invasive procedures and optimization of virtual planning for noninvasive methods. Perineal prostatectomy and combinations of beam and seed radiation offer both patient and physician reasonable therapeutic options.

Journal Article↗

PubMed1999

The impact of race on biochemical disease-free survival in early-stage prostate cancer patients treated with surgery or radiation therapy.

PURPOSE: To assess the impact of race on biochemical freedom from recurrence in patients with early-stage prostate cancer treated either by radical prostatectomy or radiation therapy. METHODS: Between July 1989 and December 1994, 693 patients with early-stage prostate cancer were treated with radiation (302 patients) or by radical prostatectomy (391 patients) at Barbara Ann Karmanos Cancer Institute/Wayne State University. Stage, Gleason score, race, pretreatment PSA, and follow-up PSA values were abstracted. There were 387 Caucasian males (CM) and 306 African-American males (AAM). None of the patients received hormone therapy. Radiation therapy was delivered using photon irradiation (249 patients, median dose 69 Gy) or mixed neutron/photon irradiation (53 patients, median dose 10 NGy + 38 PGy). Median follow-up was 36 months (range 2-70) for CM and 35 months (range 1-70) for AAM. RESULTS: Thirty-seven percent of patients treated surgically were AAM, compared to 53% in the radiation group (p = 0001). AAM had a higher median prostate-specific antigen (PSA) than CM (9.78 ng/ml vs. 8.0 ng/ml, p = 0.01). Thirty-three percent of AAM had a pretreatment PSA greater than 15 ng/ml compared to 20% of CM (p = 0.00001). Disease-free survival (DFS) by race was equivalent at 36 months, 81% for CM and 77% for AAM (p = NS). For patients with PSA < or =15, DFS rates were 87% and 85% for CM and AAM, respectively. DFS rates for patients with PSA >15 were 61% for CM and 64% for AAM (p = NS). Significant prognostic factors on multivariate analysis included pretreatment PSA (p = 0.0001) and Gleason score (p = 0.0001). CONCLUSION: Race does not appear to adversely affect biochemical disease-free survival in males treated for early-stage prostate cancer. African-American males with early-stage prostate cancer should expect similar biochemical disease-free survival rates to those seen in Caucasian males.

Black People↗

PubMed1999

External beam radiotherapy for painful osseous metastases: pooled data dose response analysis.

PURPOSE: Although the effectiveness of external beam irradiation in palliation of pain from osseous metastases is well established, the optimal fractionation schedule has not been determined. Clinical studies to date have failed to demonstrate an advantage for higher doses. To further address this issue, we conducted a pooled dose response analysis using data from published Phase III clinical trials. METHODS AND MATERIALS: Complete response (CR) was used as an endpoint because it was felt to be least susceptible to inconsistencies in assessment.The biological effective dose (BED) was calculated for each schedule using the linear-quadratic model and an alpha/beta of 10. Using SAS version 6.12, the data were fitted using a weighted linear regression, a logistic model, and the spline technique. Finally, BED was categorized, and odds ratios for each level were calculated. RESULTS: CR was assessed early and late in 383 and 1,007 patients, respectively. Linear regression on the early-response data yielded a poor fit and a nonsignificant dose coefficient. With the late-response data, there was an excellent fit (R-square = 0.842) and a highly significant dose coefficient (p = 0.0002). Fitting early CR to a logistic model, we could not establish a significant dose response relationship. However, with the late-response data there was an excellent fit and the dose coefficient was significantly different from zero (0.017 +/- 0.00524; p = 0.0012). Application of the spline technique or removal of an outlier resulted in an improved fit (p = 0.048 and p = 0.0001, respectively). Using BED of < 14.4 Gy as a reference level, the odds ratios for late CR were 2.29-3.32 (BED of 19.5-51.4 Gy, respectively). CONCLUSION: Our results demonstrate a clear dose-response for pain relief. Further testing of high intensity regiments is warranted.

Bone Neoplasms↗

PubMed1999

Apoptosis induction by a novel anti-prostate cancer compound, BMD188 (a fatty acid-containing hydroxamic acid), requires the mitochondrial respiratory chain.

We recently developed a class of novel anti-prostate cancer compounds, cyclic hydroxamates that elicit a potent apoptotic response in many tumor cells cultured in vitro (D.G. Tang et al., Biochem. Biophys. Res. Commun., 242: 380-384, 1998). The lead compound, termed BMD188, induces programmed cell death in a variety of prostate cancer cells in vitro as well as in vivo (L. Li et al., Anticancer Res., 19: 51-70, 1999). BMD188 kills androgen-independent prostate cancer cells as well as prostate cancer cells with a multidrug-resistance phenotype. The apoptotic effect of BMD188 in prostate cancer cells does not depend on cell cycle, p53 status, or its purported target, arachidonate 12-lipoxygenase, but does require caspase activation and seems to involve mitochondria. To synthesize more specific and effective anti-prostate cancer hydroxamic acid compounds, it is important to understand their mechanism(s) of action. In the present study, we studied the role of mitochondrial respiratory chain (MRC) in BMD188-induced apoptosis in androgen-independent prostate cancer PC3 cells and compared its effect with that of staurosporine (STS), a widely used apoptosis inducer. Several lines of evidence indicate that BMD188-induced cell death depends on MRC: (a) the death could be significantly inhibited by several complex-specific respiration inhibitors; (b) respiration-deficient rho0 cells were more resistant than wild-type parent cells to apoptosis induction by BMD188; and (c) BMD188 induced a rapid increase in reactive oxygen species in mitochondria, an up-regulation of cytochrome c oxidase subunits, a biphasic alteration (i.e., an early hyperpolarization, followed by later hypopolarization) in the mitochondrial membrane potential (delta psi(m)), dramatic changes in mitochondrial morphology and distribution prior to caspase activation, and an abnormal proliferation of mitochondria at the ultrastructural level. By contrast, STS-induced PC3 apoptosis seemed not to depend on MRC. Taken together, the data suggest that the MRC represents a functional target for anti-prostate cancer hydroxamates.

Antineoplastic Agents↗

PubMed1999

Prostate secretory protein (PSP94) suppresses the growth of androgen-independent prostate cancer cell line (PC3) and xenografts by inducing apoptosis.

BACKGROUND: PSP94 (prostate secretory protein of 94 aa; also called PIP), one of the predominant proteins secreted into the seminal fluid, was proposed as an independent diagnostic/prognostic marker for prostate cancers. It was also shown to inhibit rat prostate cancer growth. In this study, we investigated the effect of purified PSP94 on the growth of androgen-independent human prostate cancer cells (PC3) and its potential mechanism of action. METHODS AND RESULTS: PSP94, in a dose- and time-dependent manner, inhibited the growth of PC3 cells. The protein demonstrated a stronger inhibitory effect on the colony-forming ability of PC3 cells in soft agar. A daily injection of PSP94 at 5 microg/kg/body weight resulted in a 50-60% inhibition in the growth of PC3 xenografts in athymic mice. PC3 cell growth inhibition by PSP94 resulted from cell death characteristic of morphological apoptosis, which was confirmed by dual fluorescence microscopy, electron microscopy, and DNA fragmentation assays. Mechanistic studies indicated that PSP94 enhanced the expression of proapoptotic protein Bax without affecting Bcl-2 levels. CONCLUSIONS: This study suggests that PSP94 may represent a novel, apoptosis-based, antitumor agent applicable to the treatment of hormone-refractory human prostate cancers.

Androgens↗

PubMed1999

The cost-effectiveness of mixed beam neutron-photon radiation therapy in the treatment of adenocarcinoma of the prostate.

The results of clinical trials in the treatment of adenocarcinoma of the prostate using, mixed beam neutron/photon therapy, neutrons alone and photon therapy in combination with hormone treatment are compared. These trials indicate that neutron therapy is superior to photon/hormone therapy in achieving local control. The costs of delivering these two different therapies in a large US academic radiation oncology center at Wayne State University (WSU) are compared. The cost of a full course of mixed beam therapy is $20,142 compared to $18,871 for the photon/hormone treatment. Although the WSU neutron facility is a state-of-the-art installation, it is also a prototype device; it is estimated that a modern neutron facility based on this design would operate more cost effectively reducing the cost of a course of mixed beam therapy to $18,532.

Adenocarcinoma↗

PubMed1999

Hormone-refractory prostate cancer cells express functional follicle-stimulating hormone receptor (FSHR).

PURPOSE: Understanding growth regulation in hormone-refractory prostate cancer may provide avenues for novel treatment interventions. This study was conducted to characterize the expression of the receptor (FSHR) for follicle-stimulating hormone (FSH) in androgen-independent prostate cancer cell lines and in human malignant prostate tissues. MATERIALS AND METHODS: Western blotting, immunohistochemistry (IHC), and flow cytometric analysis were used to study the expression of FSHR. The effect of FSH on cell growth and clonogenicity was studied using proliferation and clonogenic assays. RESULTS: Immunohistochemistry revealed expression of FSH in PC3 and Du145 cells. FSHR was identified in PC3 and Du145 cells, as well as in human adenocarcinoma of the prostate. The specificity of the FSHR detected on prostate cancer tissues or cells by IHC and Western blotting was confirmed by preabsorbing the antibodies with the immunizing antigens. Stimulation of these hormone-refractory cells with FSH triggered a proliferative response in vitro, suggesting that the receptor is biologically active. CONCLUSION: Hormone-refractory prostate cancer cells express FSH and biologically active FSHR. Our results suggest that FSHR and its ligand may play a role in the regulation of the growth of hormone-refractory prostate cancers.

Androgen Antagonists↗

PubMed1998

Extended survivability of prostate cancer cells in the absence of trophic factors: increased proliferation, evasion of apoptosis, and the role of apoptosis proteins.

This project was undertaken to study the survival properties of various prostate cells, including normal (NHP), BPH (benign prostate hyperplasia), primary carcinoma (PCA), and metastatic prostate cancer cells (LNCaP, PC3, and Du145), in the absence of trophic factors. Cell proliferation and cell death were quantitated by enumerating the number of live cells using MTS/PMS kit and of dead (apoptotic) cells using 4',6-diamidino-2-phenylindole dihydrochloride nuclear staining. These cells demonstrated an overall survivability in the order of BPH < NHP < LNCaP < PC3 < PCA < Du145. Upon growth factor deprivation, NHP/BPH cells rapidly underwent apoptosis, leading to a decreased number of live cells. PCA/PC3/Du145 cells, in contrast, demonstrated an initial phase of aggressive growth during which apoptosis rarely occurred, followed by a "plateau" phase in which cell loss by apoptosis was compensated by cell proliferation, followed by a later phase in which apoptosis exceeded the cell proliferation. LNCaP cells demonstrated survival characteristics between those of NHP/BPH and PCA/PC3/Du145 cells. We concluded that the increased survivability in prostate cancer cells results from enhanced cell proliferation as well as decreased apoptosis. The molecular mechanisms for evasion of apoptosis in prostate cancer cells were subsequently investigated. Quantitative Western blotting was used to examine the protein expression of P53 and P21WAF-1, Bcl-2 and Bcl-X(L) (anti-apoptotic proteins), and Bax, Bak, and Bad (proapoptotic proteins). The results revealed that, upon trophic factor withdrawal, NHP and BPH cells upregulated wild-type p53 and proapoptotic proteins Bax/Bad/Bak and down-regulated the expression of P21. Furthermore, NHP and BPH cells endogenously expressed little or no Bcl-2. In sharp contrast, prostate cancer cells expressed nonfunctional P53 and various amounts of Bcl-2 proteins. Upon deprivation, these cancer cells up-regulated P21 and Bcl-2 and/or BclX(L), lost response to withdrawal-induced up-regulation of Bax/Bad/Bak or decreased or even completely lost Bax expression and expressed some novel proteins such as P25 and P54/55 complex. These data together suggest that prostate cancer cells may use multiple molecular mechanisms to evade apoptosis, which, together with increased proliferation, contribute to extended survivability of prostate cancer cells in the absence trophic factors.

Apoptosis↗

PubMed1998

Role of alphaII(b)beta3 integrin in prostate cancer metastasis.

BACKGROUND: Integrins participate in cell-cell and cell-matrix interactions. In this study we determined whether alphaII(b)beta3 integrin is involved in metastasis of human prostate adenocarcinoma cells. METHODS: Prostate adenocarcinoma PC-3 and DU-145 cell lines express alphaII(b)beta3. Northern blotting, 5'-RACE, and immunofluorescent localization confirmed expression of alphaIIb integrin in prostate adenocarcinoma cells. We used orthotopic/ectopic site of implantation and lung colonization assays in SCID mice to determine whether alphaII(b)beta3 participates in metastatasis of tumor cells. RESULTS: Immunofluorescent localization of alphaIIb integrin in fibronectin-adherent DU-145 and PC-3 cells is remarkably different. In DU-145 cells the integrin localizes to focal contact sites, whereas it is predominantly intracellular in PC-3 cells. Both tumor cell lines are tumorigenic when implanted subcutaneously or intraprostatically in SCID mice, but only DU-145 cells injected intraprostatically metastasize. Flow cytometry with a mAb directed to alphaII(b)beta3 revealed higher expression of alphaII(b)beta3 in DU-145 tumor cell suspensions isolated from the prostate when compared to DU-145 tumor cells from the subcutis. Function-blocking mAbs to alphaII(b)beta3 inhibit lung colonization of tail vein-injected DU-145 cells. CONCLUSIONS: Altogether, the data suggest that alphaII(b)beta3 integrin participates in the metastatic progression of prostatic adenocarcinoma.

Adenocarcinoma↗

PubMed1998

Radiation therapy for endometrial cancer in patients treated for postoperative recurrence.

PURPOSE: To retrospectively evaluate the outcome and risk factors in patients treated with radiation for endometrial cancer at time of recurrence. MATERIALS AND METHODS: Three hundred ninety-nine women were treated with radiation therapy for endometrial cancer at KCI/WSU from January 1980 to December 1994. Of these, 26 patients treated primarily with surgery received radiation therapy at the time of recurrence. Median time to recurrence after surgery was 8 months, with all recurrences occurring within 24 months. Twenty-four patients had recurrences in the vaginal cuff, vagina, or pelvis. These patients received external-beam radiation to the pelvis (45.00-50.40 Gy) and periaortic lymph nodes (45.00-50.00 Gy), along with a boost given by external-beam radiation or brachytherapy (16.00-30.00 Gy). Mean follow-up was 15 months (range 1-85 months). RESULTS: The 2-year survival was 50% and median survival was 16 months (survival range 1-85 months). Of 26 patients, 54% (14) failed locally following radiation therapy. Factors indicative of poor survival included histology (sarcoma, poorly differentiated adenocarcinoma), grade, and lymph node positivity. Histological differentiation influenced local control; lymphovascular space invasion was of borderline significance with regard to local control. CONCLUSION: Local control and survival for surgically treated endometrial cancer patients who receive radiation at the time of recurrence are poor, with the exception of those patients with recurrent disease limited to the vagina. Early detection of recurrence may improve outcome. Pathologic risk factors may identify those patients at risk for extrapelvic recurrence. Alternative treatment modalities need to be developed for this high-risk group of patients.

Adult↗

PubMed1998

Radiotherapeutic management of osseous metastases: a survey of current patterns of care.

PURPOSE: Radiotherapy plays a major role in the management of painful osseous metastases. This survey was conducted to study the current approaches to this clinical problem in the radiotherapy community. METHODS AND MATERIALS: A questionnaire was sent to 2500 members of the American Society for Therapeutic Radiology and Oncology. It consisted of 30 multiple-choice questions regarding four hypothetical clinical scenarios likely to be encountered in daily practice. Questions related to the technique of choice [local field (LF) vs. hemibody radiotherapy (HBI)], the use of systemic radionuclides (SR), fractionation schemes, dose, the integration of modalities, and the follow-up of these patients. The analysis is based on 817 (33%) responses received regarding 3268 cases. RESULTS: Local field is the most common form of therapy. Overall, LF was used, alone or in combination with other forms of therapy, in 54% and 74% of patients, respectively. LF was used more frequently in patients with breast cancer than in patients with prostate cancer (79% vs. 45%; p = 0.0001). Long fractionation schemes were used by 90% of physicians in 96% of cases. Short fractionation schemes were used by 7% of physicians in 4% of cases. This tendency was more pronounced in private practice than in the university or government/ multidisciplinary settings (p = 0.008) and in physicians starting their practice before 1982 (p = 0.05). The most common schedule was 30 Gy in 10 fractions, used by 77% of physicians in 64% of cases. HBI was used, alone or in combination with other forms of therapy, in 1% and 2% of patients, respectively. It was used more frequently in patients with prostate cancer than in patients with breast cancer (1.2% vs. 0.1%, respectively; p < 0.0001). SR were used alone or in combination with local-field irradiation in 21% and 40% of cases, respectively. SR were used more frequently in patients with prostate cancer than in those with breast cancer (28% vs. 0.2%, respectively;p < 0.00001). The most common radionuclide in use is Sr-89 (99%) at a dose of 4 mCi (73%) or 10.8 mCi (26%). CONCLUSIONS: Although LF remains the mainstay of therapy, our results demonstrate the emergence of a new pattern of practice: LF to the painful site in combination with SR for clinically occult metastases. Despite an ongoing academic debate regarding fractionation schemes, the vast majority of American practitioners advocate long schedules.

Bone Neoplasms↗

PubMed1998

Sociodemographic analysis of patients in radiation therapy oncology group clinical trials.

PURPOSE: To assess the degree to which the sociodemographic characteristics of patients enrolled in Radiation Therapy Oncology Group (RTOG) clinical trails are representative of the general population. METHODS AND MATERIALS: Sociodemographic data were collected on 4016 patients entered in 33 open RTOG studies between July 1991 and June 1994. The data analyzed included educational attainment, age, gender, and race. For comparison, we obtained similar data from the U.S. Department of Census. We also compared our RTOG data with Surveillance Epidemiology and End Results (SEER) data for patients who received radiation therapy, to determine how RTOG patients compared with cancer patients in general, and with patients with cancers at sites typically treated with radiotherapy. RESULTS: Overall, the sociodemographic characteristics of patients entered in RTOG trials were similar to those of the Census data. We found that, in every age group of African-American men and at nearly every level of educational attainment, the proportion of RTOG trial participants mirrored the proportion in the census data. Significant differences were noted only in the youngest category of African-American men, where the RTOG accrues more in the lower educational categories and fewer with college experience. For African-American women, we found a similar pattern in every age group and at each level of educational attainment. As with men, RTOG trials accrued a considerably larger proportion of younger, less educated African-American women than the census reported. Using SEER for comparison, the RTOG enrolled proportionately more African-American men to trials all cancer sites combined, and for prostate and head and neck cancer. In head and neck trials, the RTOG enrolled nearly twice as many African-American men than would be predicted by SEER data. In lung cancer trials, RTOG underrepresented African-American men significantly; however, there was no difference for brain cancer trials. There were no racial differences in RTOG accrual and SEER incidence data for women on trials in brain, lung, and head and neck cancer. However, the RTOG trials accrued nearly twice the proportion of African-American women in cervical cancer trials and in all sites combined, compared to the SEER data. CONCLUSIONS: Comparisons with the U.S. Census and SEER show that African-Americans are proportionally well represented in cancer clinical trials conducted by the Radiation Therapy Oncology Group. The comparative analysis indicates that all educational levels in each age group of African-Americans generally mirror the U.S. Census, with one exception. The exception is a significant overrepresentation of less-educated African-Americans in the youngest age category. This exception is counter to the expectation that better-educated patients are more likely to enroll in trials. When compared with SEER data, the RTOG trials either parallel or overrepresent African-American men and women, with the only exception being in lung cancer, where men are underrepresented. These results show that, in comparison to the Census and SEER data, the RTOG has fulfilled its commitment to enroll African-American patients in its clinical trials.

Adult↗

PubMed1998

BMD188, A novel hydroxamic acid compound, demonstrates potent anti-prostate cancer effects in vitro and in vivo by inducing apoptosis: requirements for mitochondria, reactive oxygen species, and proteases.

A newly synthesized cyclic hydroxamic acid compound, BMD188 [cis-1-hydroxy-4-(1-naphthyl)-6-octylpiperidine-2-one], was found to induce the apoptotic death of cultured prostate cancer cells by activating caspase-3. Orally administered BMD188 significantly inhibited the primary growth of prostate cancer cells (Du145) orthotopically implanted into SCID mice. Mechanistic studies indicated that BMD188 did not alter the protein levels of several Bcl-2 family members. In contrast, the BMD188 effect required three essential factors: reactive oxygen species (ROS), the mitochondrial respiratory chain function, and proteases. First, the apoptosis-inducing effect of BMD188 could be blocked by ROS scavengers such as Desferal. Second, both BMD188-induced PARP cleavage as well as PC3 cell apoptosis could be dramatically inhibited by several complex-specific mitochondrial respiration blockers. The involvement of mitochondria was also supported by the observations that BMD188 dramatically altered the mitochondrial distribution and morphology without affecting the cellular ATP levels. Finally, the apoptosis-inducing effect of BMD188 in PC3 cells could be significantly inhibited by serine protease inhibitors (TPCK and TLCK) as well as by caspase inhibitors (zVAD-fmk and DEVD-CHO). Collectively, the present study suggests that BMD188 and its analogs may find clinical applications in the treatment of prostate cancer patients by inducing apoptotic death of prostate cancer cells.

Animals↗

PubMed1998

Impact of postprostatectomy prostate-specific antigen nadir on outcomes following salvage radiotherapy.

OBJECTIVES: To evaluate the relationship between the postprostatectomy prostate-specific antigen (PSA) nadir and the outcome of patients treated with salvage radiotherapy. METHODS: Seventy-eight patients received definitive external beam radiation for recurrence following radical prostatectomy (RP). The PSA nadir was undetectable in 41 patients (less than 0.05 ng/mL). All patients received salvage radiotherapy (median dose 66 Gy) for a median of 19 months (range 2 to 149) following prostatectomy. The median follow-up time was 25 months (range 1 to 59) from the date of completion of radiation. RESULTS: Among patients having an undetectable or detectable postoperative PSA, 78% and 68% were free of disease, respectively, at the last follow-up. At 3 years, the disease-free survival rates were 65% and 60%, respectively (P = 0.6). Overall, the disease-free survival rate at 3 years was 78% in patients with a PSA level 2 ng/mL or less at the time of radiotherapy compared to 31% with a PSA greater than 2 ng/mL (P < 0.0001). CONCLUSIONS: Many patients who never achieve an undetectable postprostatectomy PSA level may still be salvaged with therapeutic radiotherapy. The best predictor of a favorable outcome is a low (2 ng/mL or less) PSA level at the time of radiation.

Disease-Free Survival↗

PubMed1998

The influence of race on the efficacy of curative radiation therapy for carcinoma of the prostate.

The purpose of this study was to examine the effect of race on the outcome of patients treated curatively with external beam irradiation for carcinoma of the prostate. The study was performed between January 1980 and December 1993 of 1,529 men with prostate cancer. Similar percentages of Caucasian men (CM) and African-American men (AAM) had localized disease (stages T1 and T2) and advanced stage disease (stage T3). There was no difference in crude survival by race (P = .13). At 5 years, crude survival by race was 75% for CM and 73% for AAM. At 10 years, the crude survivals, were 50% and 40%, respectively. Disease-specific survival rates were equivalent for AAM and CM (P = .66). The 5-year disease-specific survival was 83% for CM and 85% for AAM. At 10 years, the disease-specific survival was 65% for CM and 69% for AAM. There was no difference in disease-specific survival by race when stage-for-stage comparisons were made. Among those patients referred for curative radiation therapy, AAM and CM had a similar age, stage, and grade distribution. This study demonstrated that there was no difference in disease-specific survival between CM and AAM treated curatively with radiation for prostate cancer.

Adult↗

PubMed1997

Hyperbaric oxygen therapy for radiation-induced brain injury in children.

BACKGROUND: Radiation-induced necrosis (RIN) of the brain is a complication associated with the use of aggressive focal treatments such as radioactive implants and stereotactic radiosurgery. In an attempt to treat patients with central nervous system (CNS) RIN, ten patients received hyperbaric oxygen treatment (HBOT). METHODS: Patients presented with new or increasing neurologic deficits associated with imaging changes after radiotherapy. Necrosis was proven by biopsy in eight cases. HBOT was comprised of 20-30 sessions at 2.0 to 2.4 atmospheres, for 90 minutes-2 hours. Sites of RIN included the brain stem (n = 2), posterior fossa (n = 1), and supratentorial fossa (n 7). Histologic types included brain stem glioma (n = 2), ependymoma (n = 2), germinoma (n = 2), low grade astrocytoma (n = 1), oligodendroglioma (n = 1), glioblastoma multiforme (n = 1), and arteriovenous malformation (n = 1). RESULTS: Initial improvement or stabilization of symptoms and/or imaging findings were documented in all ten patients studied and no severe HBOT toxicity was observed. Four patients died, with the cause of death attributed to tumor progression. Five of six surviving patients were improved by clinical and imaging criteria; one patient was alive with tumor present at last follow-up. CONCLUSIONS: HBOT may prove to be an important adjunct to surgery and steroid therapy for CNS RIN.

Adolescent↗