PubMed Health⌕ Search

Biomedical subjects

M A Bagshaw

Publications and source records attributed to M A Bagshaw.

At least 19 recordsLinked to original sources
PubMed2001

Outcomes for men with clinically nonmetastatic prostate carcinoma managed with radical prostactectomy, external beam radiotherapy, or expectant management: a retrospective analysis.

BACKGROUND: With a lack of data from randomized trials, the optimal management of men with nonmetastatic prostate carcinoma is controversial. The authors sought to define the outcomes of three common strategies for managing patients with nonmetastatic prostate carcinoma: expectant management, radiotherapy, and radical prostatectomy. METHODS: The authors conducted a retrospective cohort study with standardized collection of key prognostic data, including centralized assignment of Gleason grades from original biopsy specimens. Participants included all Connecticut hospitals (the expectant management cohort) and three academic medical centers in other states (the radiotherapy and surgery cohorts). Two thousand three hundred eleven consecutive men ages 55-74 years who were diagnosed during 1971-1984 with nonmetastatic prostate carcinoma and were treated at the participating sites were included. RESULTS: Kaplan-Meier estimates with 95% confidence intervals (95% CI) of overall survival at 10 years for each cohort were as follows: expectant management cohort, 42% of patients (95% CI, 38-46%); radiotherapy cohort, 52% of patients (95% CI, 46-58%); and radical prostatectomy cohort, 69% of patients (95% CI, 67-71%); for disease specific mortality, the estimates were as follows: expectant management cohort, 75% of patients (95% CI, 71-79%); radiotherapy cohort, 67% of patients (95% CI, 61-73%); and radical prostatectomy cohort, 86% of patients (95% CI, 84-88%). There were large differences in distributions of important prognostic factors among men in the different treatment groups. CONCLUSIONS: These data provide precise estimates of the outcomes of patients who have been treated with different modalities for nonmetastatic prostate carcinoma in the recent past. Direct comparisons of outcomes between treatment groups are inadvisable because of the different characteristics of patients who select these alternative management strategies.

Aged↗
PubMed1998

Effect of combined transient androgen deprivation and irradiation following radical prostatectomy for prostatic cancer.

PURPOSE: To evaluate whether transient androgen deprivation improves outcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence. METHODS AND MATERIALS: Records of 105 consecutive patients who were treated with pelvic irradiation after radical retropubic prostatectomy between August 1985 and December 1995 were reviewed. Seventy-four patients received radiation alone (mean follow up: 4.6 years), and 31 received transient androgen blockade with a gonadotropin-releasing hormone agonist (4) androgen receptor blocker (1) or both (24) beginning 2 months prior to irradiation (mean follow-up 3.0 years) for a mean duration of 6 months. Two of these patients were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dose of 60-70 Gy at 2 Gy per fraction; 48 patients also received pelvic nodal irradiation to a median dose of 50 Gy. Survival, freedom from clinical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml. RESULTS: At 5 years after irradiation, actuarial survival for all patients was 92%, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during radiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p = 0.004). FFCR was also superior for the combined treatment group (100 vs. 70% at 5 years, p = 0.014). Potential clinical prognostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic score, lymph node status, indication for treatment, and PSA levels before surgery or subsequent treatment. Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure. CONCLUSION: This retrospective study of irradiation after radical prostatectomy suggests that transient androgen blockade and irradiation may improve freedom from early biochemical and clinically evident relapse compared to radiotherapy alone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates.

Aged↗
PubMed1997

Adenocarcinoma of the prostate: innovations in management.

Adenocarcinoma of the prostate (CaP) in the Western world has become the most common noncutaneous human tumor. CaP is also the second most important cause of cancer deaths among the male population in the United States. Major progress was made in the past decade in better understanding this disease process, as well as in improved diagnostic accuracy. This improved diagnostic accuracy was due to wide application of prostate-specific antigen (PSA), use of transrectal ultrasound (TRUS), and greater awareness among clinicians of CaP. The use of PSA in clinical practice has resulted in a sharp increase in the number of patients diagnosed with capsule-confined tumors. The optimal treatment for capsule-confined CaP is in the process of being defined. Radical prostatectomy in the United States is currently the most commonly applied treatment for younger patients. Excellent treatment results with a 10-year actuarial survival > 80% are readily obtainable in properly selected patients. Nerve-sparing procedures helped reduce the high incidence of impotence that occurs in patients after radical retropubic prostatectomy. Radiotherapy remains the other curative treatment method in the management of CaP patients, with long-term survival rates similar to those reported in surgical series. Due to the problem of frequent preoperative tumor understaging, a routine use of postoperative irradiation to the prostatic fossa produces an excellent (> 95%) incidence of local tumor control. Management of patients with metastatic disease has undergone a considerable evolution with the development of modern hormonal management and treatment with strontium-89 to control intractable bone pain. Newer treatment methods such as hyperthermia are currently being investigated. Major efforts are directed toward the reduction of short- and long-term treatment toxicity associated with surgery, radiotherapy, and hormonal management, thus improving patient quality of life.

Adenocarcinoma↗
PubMed1995

Prostate specific antigen after radiotherapy for prostate cancer: a reevaluation of long-term biochemical control and the kinetics of recurrence in patients treated at Stanford University.

PURPOSE: We evaluated prostate specific antigen (PSA) evidence for control of prostatic cancer after irradiation. MATERIALS AND METHODS: We studied 110 patients for whom more than 2 PSA measurements were obtained to establish trends and the initial measurement was done between April 1985 and January 1988. RESULTS: A total of 42 patients (38%) had stable, normal PSA levels with followup averaging 12.4 years (range 4.4 to 24.8). Increasing clinical stage or Gleason score correlated significantly with risk for PSA relapse, as did pretreatment PSA level. Short PSA doubling times were associated with distant metastasis rather than with local recurrence. CONCLUSIONS: We found that irradiation durably controlled 38% of prostatic cancers of various stages and grades and is unlikely to accelerate tumor growth.

Aged↗
PubMed1994

Predictors of survival after a positive post-irradiation prostate biopsy.

PURPOSE: Considerable debate persists in the urologic oncology literature with regard to the optimum management of patients with a positive post-irradiation prostate biopsy. This analysis characterizes a group of such patients who have had a favorable course without intervention. METHODS AND MATERIALS: Between 1956 and 1991, 116 patients have had a positive prostate biopsy 12 or more months post-irradiation without hormonal intervention or evidence of distant relapse. The population had an age range of 42 to 82 years (median - 61). American Joint Committee on Cancer stages included 1 T1, 70 T2, 44 T3, and 1 T4. Median actuarial survival for the entire population was 14.4 years (range = 2.2-21.5 years) from presentation and 5.2 years from re-biopsy. RESULTS: Fifty-one of the 116 patients developed metastases subsequent to re-biopsy and 65 remain free from distant relapse. Among these 65 patients, 50 remain alive and otherwise well, 11 have died of other causes, and only four have succumbed to their local disease. The best predictor of distant relapse subsequent to re-biopsy was digital rectal exam. Forty-one of the 51 patients later developing metastases had an abnormal digital rectal exam compared to 37 of 65 with sustained distant control (p = .01). CONCLUSION: These data demonstrate that long-term, disease-free (other than re-biopsy) survival is common following a "positive" post-irradiation biopsy without intervention especially among patients with a normal digital rectal exam. Therefore, routine re-biopsy without clinical indications is not a useful practice.

Adenocarcinoma↗
PubMed1994

Prostate-specific antigen kinetics after external beam irradiation for carcinoma of the prostate.

PURPOSE: A mathematical model that describes the kinetics of prostate-specific antigen measured in patients who received therapeutic doses of radiation therapy is presented. The clinical implications of the model are also investigated. METHODS AND MATERIALS: Data from 122 patients treated at Stanford University between December 1985 and December 1990 were used. The general form of the model contains five parameters, two associated with a decreasing exponential, two with a rising exponential and one additional constant. A nonlinear steepest-descent procedure that minimized chi-squared was used to determine the parameters producing the best fit to a patient's data. The correlation of the model parameters with clinical findings was investigated using standard statistical techniques including multivariate life-table and logistic regression. RESULTS: The data for all patients could be fit with either a decreasing exponential with or without the additional constant (nonrelapsing pattern with two or three parameters) or with a decreasing plus rising exponential (relapsing pattern with three or four parameters). In no instance were all five parameters of the general model required to describe a patient's data. Three of 61 patients with nonrelapsing patterns experienced clinical relapse, whereas 36 of 61 patients with relapsing patterns did. The logarithm of the initial prostate-specific antigen level and the corresponding model parameter correlated with T-stage and Gleason score. Among the patients with relapsing patterns, the nadir in antigen level occurred within 2 years of the start of treatment and the time to nadir, as calculated from the model parameters, was associated with the probability of clinical relapse. In no instance was the rate of initial decline ever exceeded by the rate of subsequent rise. CONCLUSION: The model is capable of describing the kinetics of prostate-specific antigen levels found in patients after receiving radiation therapy. The parameters derived from the model are strong correlates with clinical findings and patient outcome.

Aged↗
PubMed1994

Thermometry of interstitial hyperthermia given as an adjuvant to brachytherapy for the treatment of carcinoma of the prostate.

PURPOSE: Recurrence in the prostatic gland remains a significant problem in the management of locally advanced prostatic cancer. Transperineal thermobrachytherapy has been utilized in an attempt to improve local tumor control. The purpose of this study was to quantitate the temperature distributions obtained in carcinoma of the prostate treated with interstitial radiofrequency-induced hyperthermia given in conjunction with 192Ir brachytherapy in a Phase I study. METHODS AND MATERIALS: From 1987 until 1992, 36 patients (5 with locally recurrent, 15 with Stage B, and 16 Stage C prostate cancers) were treated with interstitial brachytherapy implants supplemented with radiofrequency-induced hyperthermia. An array of 7-32 stainless steel trocar electrodes (outer diameter = 1.5 mm, interelectrode spacing = 8 mm) were implanted into the prostate gland through a perineal approach utilizing a specially designed template. Each trocar was electrically insulated along the length which traversed surrounding normal tissues. One to three additional plastic catheters were implanted for automated temperature mapping. Thirty-four of these procedures were performed following lymph node sampling. However, the last two removable interstitial hyperthermic prostate implants were done by the transperineal route under ultrasound guidance. A hyperthermia treatment (goal of 43 degrees C for 45 minutes) was given immediately prior to the insertion and immediately following the removal of the 192Ir. A computer-controlled radiofrequency-based generator (freq. 0.5 MHz) implementing electrode multiplexing was used to induce and maintain elevated temperatures. RESULTS: Transient local pain was the most common treatment limiting factor. The average values of the measured minimum, mean, and maximum temperatures were 38.9 degrees C, 41.9 degrees C, and 45.7 degrees C in tumor, and 37.7 degrees C, 39.8 degrees C, and 42.9 degrees C in surrounding normal tissue, respectively. The percentages of mapped temperatures exceeding 41 degrees C, 42 degrees C, and 43 degrees C were 67%, 46%, and 27% in tumor, and 26%, 11%, and 4% in normal surrounding tissue, respectively. CONCLUSION: From this study we conclude that heterogeneous temperature distributions were induced in the prostate; significant normal tissue protection was realized in part through the selective insulation of sections of each electrode; and interstitial radiofrequency-induced hyperthermia of the prostate is feasible and well tolerated, with further technical developments warranted.

Adenocarcinoma↗
PubMed1994

Radiotherapy for prostatic cancer: patient selection and the impact of local control.

OBJECTIVE: To analyze the long-term results of external beam radiation therapy in patients under the age of sixty treated with early-stage prostate cancer. A comparison is also made between patients with early-stage, node-negative disease and those with locally advanced node-negative prostate cancer. METHODS: In this retrospective study, 54 patients who were treated with external beam radiation, when under the age of sixty with Stanford stage T1a and T1b (equivalent to urologic stage B1), are compared to 75 patients with similar staged disease who were sixty to seventy years old at time of treatment. In addition, 17 men who underwent open lymph node dissection with Stanford stage T1a and T1b N0M0 (equivalent to urologic stage B1, pathologic node negative) were compared to 30 patients with Stanford stage T3N0M0 (equivalent to urologic stage C, pathologic node negative) prostatic carcinoma. RESULTS: Patients under the age of sixty with clinically staged early prostate cancer exhibited a similar rate of local and metastatic control when compared to men treated when sixty to seventy years of age. Overall survival was not different than the expected survival in both groups. In patients with laparotomy-proven node-negative prostate cancer, those with locally advanced tumors had a poorer rate of local control, disease-specific survival, freedom from relapse, and survival when compared to patients with early-stage disease. CONCLUSIONS: These results suggest that men under sixty years old are candidates for radiotherapy, and these results are comparable to those attained with prostatectomy. Treatment approaches for controlling bulky local disease in patients without lymph node metastases have a potential to improve local control that may have an impact on survival.

Actuarial Analysis↗
PubMed1994

Control of prostate cancer with radiotherapy: long-term results.

The long-term outcome for 1,245 patients with carcinoma of the prostate treated with external beam radiation therapy is presented. The median survival for all patients without evidence of distant metastases but irrespective of T stage of the primary tumor, histopathological grade or lymph node status was 10 years compared to 15 years for an age-matched cohort of California men. The cause specific survival at 15 years was 52%. The data base is subdivided into a series of subsets that demonstrate the impact of T stage, Gleason pattern score and lymph node involvement on long-term outcome. The best results were shown in stages T1 and T2a cases with histopathologically proved negative lymph nodes. Survival at 15 years was 53%, which was essentially identical to the 55% survival rate of an age-matched cohort. The actuarial survival at 15 years for all stages T1 and T2N0M0 cancer patients was 45% compared to 56% for an age-matched cohort.

Actuarial Analysis↗
PubMed1993

Prostate cancer. Radiation therapy for localized disease.

BACKGROUND: Since 1910, a variety of radiation modalities, including radioactive isotopes, photons, and particle beams, have been used to treat prostatic cancer. METHODS: This report focuses on external beam x-irradiation produced by medium energy linear accelerators. Between 1956 and 1990, 1119 patients have been treated with curative intent at Stanford University. Tumor doses of 70 Gy delivered at 10 Gy/wk have been safe and effective. RESULTS: Fifteen-year survival rates ranging from 50%, equivalent to that of an age-matched cohort, for the least extensively localized tumors to 18% for the most extensive have been achieved. Survival is inversely proportional to clinical stage and histopathologic grade. CONCLUSION: Although external beam radiation therapy has been found to be safe and effective for the treatment of prostatic cancer, improvement in results of treatment of the more advanced tumors might be achieved by combining external beam and interstitial irradiation. This would achieve a higher radiation dose within the tumor. Alternatively, the treatment can be augmented with hyperthermia or other sensitizers in order to achieve a higher biological dose.

Adult↗
PubMed1993

Prostate specific antigen after external beam radiotherapy for prostatic cancer: followup.

Between 1986 and 1989, 117 patients with pretreatment and serial posttreatment prostate specific antigen values received external beam radiotherapy at our hospital. Followup ranged from 0.6 to 5.9 years (mean 2.7). No patient had hormonal manipulation before distant recurrence. Biochemical relapse, defined as an increasing prostate specific antigen level after treatment, was observed in 44 patients. To date 30 of these 44 patients (68%) have had clinical relapse. The prognostic factors of advanced local stage, high Gleason score and high elevations of pretreatment prostate specific antigen values predicted for biochemical relapse and subsequent clinical failure. The interval between biochemical and clinical relapse was 156 +/- 46 days. Biochemical relapse is an important end point that can be used to determine the effect of treatment in prostatic cancer research.

Actuarial Analysis↗
PubMed1992

Radiation treatment of prostate bone metastases and the biological considerations.

This contribution on the biology and management of bone metastases from prostatic cancer is divided into three parts. The first details a study conducted at Stanford University on the prevention of bone metastases in the lumbar spine, in patients in whom the lumbar spine has been irradiated coincidental to the radiation treatment of the paraaortic lymph nodes. The incidence of metastases was significantly reduced in 71 patients in whom the apparently normal lumbar spine was irradiated, as compared to the incidence of metastases in 65 patients who received no lumbar irradiation. The implications of these observations on developing strategies for early, or preemptive, irradiation for bone metastases are discussed. In the second part, the optimum radiation dose and fractionation scheme for the palliation of overt bone metastases is addressed. Drawing largely from the work of Arcangeli et al., a total dose of 40-50 Gy*, fractionated at 2 Gy per day, seems to be the regimen of choice for enduring pain relief for most patients with prostatic metastases to bone. Finally, the recent utilization of strontium-89 in the palliation of advanced bone metastases is addressed. *The Gy is the current international unit of radiation. 1Gy = 100 Rad; 1cGy (centigray) = 1 Rad.

Bone Neoplasms↗
PubMed1992

Serum prostate-specific antigen after post-prostatectomy radiotherapy.

External beam radiotherapy was administered to 39 patients after radical prostatectomy for adenocarcinoma. Thirty-seven of 39 patients had detectable levels of serum prostate-specific antigen (PSA) prior to irradiation as evidence of residual carcinoma (biochemical evidence of disease). Two patients also had palpable recurrences. Pathologic analysis of the surgical specimens suggested that positive surgical margins, seminal vesicle or lymph node involvement, or high Gleason pattern scores are associated with measurable PSA after surgery. Follow-up ranged from two to seventy-four months (mean 26.8 months). To date, local control has been achieved in all but 1 patient (including 2 patients with palpable tumor prior to radiotherapy). Two distinct risk groups for the development of distant metastases based on the trend of the PSA in relation to the duration of follow-up after radiotherapy are defined. In the high-risk group (those patients with a rising PSA), in 9 of the 18 bone metastases have developed, while none of the 17 low-risk patients have metastatic disease.

Adenocarcinoma↗
PubMed1992

Stereotaxic radiosurgery for brain metastases: the importance of adjuvant whole brain irradiation.

Stereotaxic radiosurgery delivered from a modified 4 MV linear accelerator was used to treat 47 brain metastases in 27 patients at Stanford. Response was assessed in 41 lesions. Histopathologies included adenocarcinoma (24 lesions), renal cell carcinoma (9 lesions), melanoma (6 lesions), and squamous cell carcinoma (2 lesions). Follow-up ranged from 1.0-16.5 months, with a median of 5.0 months. Radiographic local control was achieved in 88% of the lesions. Three patients developed enlarging contrast-enhancing lesions in the radiosurgical field; one of these was biopsied and revealed necrosis with no viable tumor. Adjuvant whole brain irradiation (10 patients) was associated with regional intracranial control in 80% of patients. This was statistically superior (p = 0.0007) to the regional intracranial control rate achieved when radiosurgery alone was employed (6 patients). Most patients reported resolution of their neurologic symptoms, and were able to discontinue dexamethasone without impairment of neurologic function.

Adult↗
PubMed1992

Parameters predictive for complications of treatment with combined hyperthermia and radiation therapy.

Pretreatment and treatment related factors were reviewed for 996 hyperthermia sessions involving 268 separate treatment fields in 131 patients managed with hyperthermia for biopsy confirmed local-regionally advanced or recurrent malignancies to ascertain parameters associated with the development of complications. A subset of 249 fields were identified in which multipoint or mapped temperature data were available for at least one treatment session per field. A total of 198 fields involved superficially located tumors (less than or equal to 3 cm from the surface), whereas 51 fields involved more deeply located tumors. Most of these patients had received extensive prior therapy: 77% had surgery, 75% chemotherapy, 65% radiation therapy and 28% hormonal therapy. They were treated with hyperthermia in conjunction with radiation therapy (244 fields) or hyperthermia alone (5 fields). The hyperthermia treatment objectives were to elevate intratumoral temperatures to a minimum of 43.0 degrees C for 45 minutes while maintaining maximum normal tissue temperatures to less than or equal to 43 degrees C and maximum intratumoral temperatures to less than or equal to 50 degrees C. The hyperthermia was given within 30 to 60 minutes following radiation therapy without the administration of additional analgesics. Hyperthermia treatment regimens using radiative electromagnetic, ultrasound, or radiofrequency interstitial techniques were individualized, with 3 to 4 days between hyperthermia treatments and an average of 3.6 treatments (range 1-14; standard deviation 2.2) utilized per field. A total of 38 complications in 33 treatment fields were noted; an incidence of 27/198 (13.6%) for fields with superficially located tumors, and 6/51 (11.8%) in fields with more deeply located tumors. Univariate analyses demonstrated statistically significant correlations between the maximum tumor temperature (p = 0.0005), average of the maximum tumor temperatures (p = 0.0006), the average of the % tumor temperatures greater than 43.5 degrees C (p = 0.0071), and the average number of hyperthermia treatments (p = 0.033), with the development of complications. The average of the maximum measured tumor temperature for fields without complications was 44.6 degrees C compared with 45.9 degrees C for fields with complications. The complication rate increased from 7.5% (9/120) in fields that received one or two hyperthermia treatments to 18.6% (24/129) in fields that received greater than two hyperthermia treatments. Multivariate logistic regression analyses revealed the best bivariate model predictive of the development of complications included average of the maximum tumor temperature and the number of treatments per field (p = 0.00012 for the bivariate model).(ABSTRACT TRUNCATED AT 400 WORDS)

Combined Modality Therapy↗