New methods of endocrine management of prostatic cancer

Controversies Involving the Systemic Treatment for Metastatic Prostatic Cancer

In the United States, 1987 estimates of cancer incidence by site indicate that prostatic cancer is equal to lung cancer as the first in incidence in adult males. Over 90,000 new cases are diagnosed and between 25-30,000 patients die of this disease each year. While early prostatic cancer is a surgically curable disease, the majority of patients present with widely metastatic cancer, where the main objective of treatment is palliation.

The effect of prostate cancer and antiandrogenic therapy on lipid peroxidation and antioxidant systems

In living organism, excessive free radicals or oxidative damage which occur as a result of deficient antioxidant defensive mechanisms by the effect of endogenous and exogenous factors, influences especially developmental steps of chemically induced cancers. In our study, plasma malondialdehyde level (MDA) as an indicator of lipid peroxidation, erythrocyte glutathione (GSH) level as an indicator of antioxidant state, glutathione reductase (GSH-Red), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) as an antioxidant enzymes and plasma vitamin E level were detected in patients with prostate cancer (21 males; age, 69.4 +/- 4.8 years) before and after three months of antiandrogenic therapy with goserelin acetate as luteinizing hormone releasing hormone (LHRH) analogue. Healthy people evaluated as a control group (20 males; age, 63.7 +/- 3.9). Erythrocyte GSH levels, the activities of GSH-Red and GSH-Px and plasma vitamin E levels were found significantly low in patients with prostate cancer when compared with the healthy subjects (p < 0.01, p < 0.05, p < or = 0.001 and p < or = 0.001 respectively). Plasma MDA level and erythrocyte GST activity of patient group were significantly higher than the levels of control group (p < or = 0.001 and p < or = 0.001 respectively). After antiandrogenic therapy erythrocyte GSH level, GSH-Red, GSH-Px activity and plasma vitamin E level were found unchanged. Significant decrease in plasma MDA level and significant increase in erythrocyte GST activity were detected in patient group (p < 0.05 and p < or = 0.01 respectively). The study has revealed the shift in the oxidant-antioxidant balance towards oxidative state in patients with metastatic prostate cancer. Our results showed that antiandrogenic therapy increased in GST activity, decreased in lipid peroxidation.

Interim report of image-guided conformal high-dose-rate brachytherapy for patients with unfavorable prostate cancer: the William Beaumont phase II dose-escalating trial

PURPOSE

We analyzed our institution's experience treating patients with unfavorable prostate cancer in a prospective Phase II dose-escalating trial of external beam radiation therapy (EBRT) integrated with conformal high-dose-rate (HDR) brachytherapy boosts. This interim report discusses treatment outcome and prognostic factors using this treatment approach.

METHODS AND MATERIALS

From November 1991 through February 1998, 142 patients with unfavorable prostate cancer were prospectively treated in a dose-escalating trial with pelvic EBRT in combination with outpatient HDR brachytherapy at William Beaumont Hospital. Patients with any of the following characteristics were eligible: pretreatment prostate-specific antigen (PSA) >/= 10.0 ng/ml, Gleason score >/= 7, or clinical stage T2b or higher. All patients received pelvic EBRT to a median total dose of 46.0 Gy. Pelvic EBRT was integrated with ultrasound-guided transperineal conformal interstitial iridium-192 HDR implants. From 1991 to 1995, 58 patients underwent three conformal interstitial HDR implants during the first, second, and third weeks of pelvic EBRT. After October 1995, 84 patients received two interstitial implants during the first and third weeks of pelvic EBRT. The dose delivered via interstitial brachytherapy was escalated from 5.50 Gy to 6.50 Gy for each implant in those patients receiving three implants, and subsequently, from 8.25 Gy to 9.50 Gy per fraction in those patients receiving two implants. To improve implant quality and reduce operator dependency, an on-line, image-guided interactive dose optimization program was utilized during each HDR implant. No patient received hormonal therapy unless treatment failure was documented. The median follow-up was 2.1 years (range: 0.2-7.2 years). Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition.

RESULTS

The pretreatment PSA level was >/= 10.0 ng/ml in 51% of patients. The biopsy Gleason score was >/= 7 in 58% of cases, and 75% of cases were clinical stage T2b or higher. Despite the high frequency of these poor prognostic factors, the actuarial biochemical control rate was 89% at 2 years and 63% at 5 years. On multivariate analysis, a higher pretreatment PSA level, higher Gleason score, higher PSA nadir level, and shorter time to nadir were associated with biochemical failure. In the entire population, 14 patients (10%) experienced clinical failure at a median interval of 1.7 years (range: 0.2-4.5 years) after completing RT. The 5-year actuarial clinical failure rate was 22%. The 5-year actuarial rates of local failure and distant metastasis were 16% and 14%, respectively. For all patients, the 5-year disease-free survival, overall survival, and cause-specific survival rates were 89%, 95%, and 96%, respectively. The 5-year actuarial rate of RTOG Grade 3 late complications was 9% with no patient experiencing Grade 4 or 5 acute or late toxicity.

CONCLUSION

Pelvic EBRT in combination with image-guided conformal HDR brachytherapy boosts appears to be an effective treatment for patients with unfavorable prostate cancer with minimal associated morbidity. Our dose-escalating trial will continue.

Pituitary lactotroph adenomas develop after prolonged lactotroph hyperplasia in dopamine D2 receptor-deficient mice

Tuberoinfundibular dopamine tonically inhibits PRL expression and secretion from the pituitary gland by the activation of dopamine D2 receptors (D2R) localized on lactotrophs. Mutant female mice that lack D2Rs have persistent hyperprolactinemia but also develop extensive hyperplasia of pituitary lactotrophs and peliosis of the adenohypophysis at 9 to 12 months of age, while age-matched male D2R-deficient mice have no morphologic adenohypophysial lesion. We now report that both female and male D2R-deficient mice 17 to 20 months of age develop pituitary lactotroph adenomas. Of 12 aged female mice examined, all developed monohormonal PRL-immunoreactive neoplasms that had a characteristic juxtanuclear Golgi pattern of PRL staining and loss of the reticulin fiber network. Several of these adenomas were 50-fold larger than normal glands with marked suprasellar extension and invasion of brain but no gross evidence of distant metastases. They also had striking peliosis that was more marked than the lesion seen in the hyperplastic pituitaries of the younger females. These findings demonstrate that a chronic loss of neurohormonal dopamine inhibition promotes the hyperplasia-neoplasia sequence in adenohypophysial lactotrophs. Our results are analogous to previous data indicating that protracted stimulation of adenohypophysial cells by hormones or growth factors results in proliferation with initial hyperplasia followed by the development of neoplasia. Six aged male D2R-deficient mice had slightly enlarged anterior pituitaries similar in size to normal female glands. However, each case exhibited multifocal, microscopic lactotroph adenomas with strong nuclear immunoreactivity for estrogen receptors and Pit-1 transcription factor. The unexpected development of adenomas in males without preexisting or concomitant hyperplasia suggests that prolonged loss of dopamine inhibition may also cause neoplasia by distinct cellular mechanisms in male and female animals.

Pattern of progression and survival in hormonally treated metastatic prostate cancer

BACKGROUND

Patients with prostate cancer generally respond to androgen ablation therapy, but progression to androgen-independence is frequently observed. To further evaluate disease progression, the pattern of progression and survival in hormonally treated metastatic prostate cancer was examined.

METHODS

One hundred and ninety-three patients with untreated metastatic prostate cancer (TxNxM ) who received endocrine therapy between 1986 and 1995 were included in the present study. The pattern of progression was evaluated in these patients.

RESULTS

One hundred and eighteen of the 193 patients (61.1%) had disease progression: 33 had local progression, 73 had distant progression and 12 had distant with local progression. Patients with only local progression had a longer interval to disease progression and longer survival than those with distant progression. The interval from disease progression to death in patients with local progression was longer than in those with distant progression. The patients whose prostate-specific antigen (PSA) had not been normalized 3 months after the start of endocrine therapy had a tendency to progression either into the prostate or into distant sites. Patients with extent of disease (EOD) scores of 3 and 4 progress, especially to distant sites, after endocrine treatment.

CONCLUSIONS

In untreated metastatic prostate cancer, patients with a poor response of PSA levels and patients with a high volume of bone metastasis (i.e. EOD 3, 4) were in the high-risk group for progression, especially to distant sites. Progression into distant sites was a poor prognostic factor for patients with recurrence to endocrine therapy.

Palliative therapy with bone seeking radiopharmaceuticals

Pain palliation with unsealed source therapy is an effective and cost effective treatment for patients with cancer metastatic to bone who present with progressive pain. Used in the appropriate setting this form of therapy can make an enormous contribution to a very large number of patients.

Tamoxifen for flutamide/finasteride-induced gynecomastia

OBJECTIVES

Current therapies for advanced prostate carcinoma lead to a marked decrease in serum testosterone levels, which renders patients impotent. In preliminary studies, combination therapy with flutamide and finasteride has been used as an alternative therapy for the treatment of prostate carcinoma because potency can be preserved. Both of these agents can cause gynecomastia and breast/nipple tenderness.

METHODS

Six men being treated for advanced prostate carcinoma with flutamide/finasteride combination therapy developed painful gynecomastia, which was treated with tamoxifen 10 to 30 mg/day for 1 month. Clinical follow-up included breast measurements and determination of prostate-specific antigen (PSA), testosterone, and estradiol levels.

RESULTS

While on this combination therapy for prostate carcinoma, 4 of 6 patients experienced a decrease in PSA level to less than 0.5 ng/mL. All patients remained potent. Serum testosterone increased in each patient who had a baseline level drawn. Estradiol levels were noted to be elevated in 4 of 6 patients at the time of evaluation for gynecomastia. After treatment with tamoxifen, circulating estradiol levels increased in 3 patients from 1.3 to 2.2 times the baseline level. Five patients experienced complete resolution of breast and nipple pain on tamoxifen 10 mg/day within the first month. The other patient had to be treated with 30 mg/day for 1 additional month, which subsequently resulted in pain resolution.

CONCLUSIONS

These preliminary results suggest that low-dose tamoxifen is useful in treating painful gynecomastia for those patients on flutamide/finasteride combination therapy for advanced prostate carcinoma.

Pain caused by bone metastasis in endocrine-therapy-refractory prostate cancer

It is of clinical importance to control pain in the management of patients with endocrine-therapy-refractory prostate cancer. To evaluate factors influencing the manifestation of pain and the relationship between characteristics of pain and prognosis, patients with pain from bone metastasis were analyzed. A total of 48 patients with endocrine-therapy-refractory prostate cancer, who showed progression of bone metastasis and were followed-up until death, comprised the present study. The patients were divided into three groups according to the grade of pain: no need for analgesics, a need for non-opioid analgesics, and a need for opioid analgesics. The time interval between the diagnosis of the endocrine-therapy-refractory state and the requirement for analgesics was estimated. Survivals from the endocrine-therapy-refractory state were calculated according to the grade of pain or the time interval to requirement for analgesics. In addition, the extent of disease, the doubling time of tumor markers at the refractory state, any change of alkaline phosphatase, and other prognostic factors were examined in relation to pain. All 22 endocrine-therapy-resistant cases at initial treatment and 18 of 26 (69%) relapsed cases required analgesics during the clinical course until death. No difference in survival was observed between the grades of pain. The patients who needed analgesics within 1 year after becoming refractory to endocrine therapy showed significantly shorter survival than those without or with analgesics more than 1 year later. Although the time elapsing before analgesics were needed was not related to the extent of disease, the patients who showed a shorter doubling time for tumor markers and/or an exponential increase in alkaline phosphatase tended to require analgesics within 1 year. In endocrine-therapy-refractory prostate cancer, the early requirement for analgesics suggests poor prognosis, and the onset of pain may be attributable not to the extent of the disease but rather to the rapid expansion of bone metastasis.

Quantitative bone scintigraphy in patients with prostatic carcinoma treated with LH-RH analogues

In 14 men with prostatic carcinoma, quantitative scintigraphy of the vertebrae from Th10 to L5 was performed before and 2 weeks and 2 and 6 months after start of treatment with luteinizing hormone-releasing hormone (LH-RH) analogues. Serum prostate-specific antigen (PSA) was also determined. The patients with normal bone scintigram showed no change in gamma camera count rate during the study, but fall in PSA values. The patients with abnormal bone scintigram responded to treatment with flare phenomenon, with increased count rate at 2 weeks, followed by fall to pretreatment level at 2 months. PSA showed decrease as early as 2 weeks after the start of treatment. Bone scintigraphy was found to be useful before therapy, especially in patients with elevated PSA levels, and after 2 months, when the flare phenomenon had subsided. Serial measurement of PSA provided a guide to disease activity.

Radiation inactivation and in situ renaturation of protein tyrosine kinases reveal a major 50-kDa enzyme as part of a membrane complex present in dividing but not in resting prostatic epithelial cells

Because protein tyrosine kinases play a crucial role in the regulation of cell division and carcinogenesis, we have herein measured such enzyme activities (specific activity and subcellular distribution) and compared their characteristics with respect to hydrodynamic properties and radiation inactivation sizes as well as renaturation after electrophoresis in denaturing conditions in canine prostatic epithelial cells either in a resting (freshly isolated) or in a dividing (cultured cells) state. In quiescent cells, most protein tyrosine kinase activity was expressed by soluble proteins with a Stokes' radius (Rs) of 3.05 nm, a sedimentation coefficient (S20,w) of 4.0 S, and a molecular mass of 50 kDa. By contrast, in dividing cells (three days in primary culture), the specific activity was higher and the enzyme was mainly membrane bound. The use of a detergent (Triton X-100) allowed the extraction of most of that enzyme; its partial specific volume, S20,w and Rs were then 0.883 cm3/g, 4.0 S, and 5.6 nm, respectively, hence yielding a molecular mass of 215 kDa, which decreased to 125-145 kDa when corrected for detergent binding. Probing these chromatography-peak fractions, 50 kDa from cytosol of resting cells and 215 kDa from membrane extracts of dividing cells, with a phosphotyrosine antibody following their incubation with ATP and electrophoresis in denaturing conditions revealed the presence of a common 50-kDa phosphotyrosylated protein along with three other bands (130, 75, and 40 kDa) in the high-Mr peak of enzyme. However, the radiation inactivation size for protein tyrosine kinases expressed in both resting and dividing cells were similar, 47.2 +/- 8.7 and 44.5 +/- 6.1 kDa, respectively. Furthermore, by renaturation after electrophoresis in denaturing conditions, major protein tyrosine kinase polypeptides of 50 kDa were identified in both cell populations. Taken together, these results indicate that, in dividing prostatic epithelial cells, membrane-bound protein tyrosine kinases of low molecular weight with properties similar to those of monomeric soluble forms present in quiescent cells are part of high-molecular weight complexes. This activation process may be critical for hormone-independent proliferation of prostatic epithelial cells.

Estrogen and progesterone receptors in salivary gland adenoid cystic carcinoma

Adenoid cystic carcinomas of salivary glands occur more frequently in women and bear remarkable similarity to adenoid cystic carcinomas of the breast. In addition, breast carcinomas express estrogen and progesterone receptors that impact prognostic significance. This suggests a possible role for sex steroid hormones in the development and progression of salivary gland adenoid cystic carcinoma. On this basis, 12 samples of formalin-fixed, paraffin-embedded salivary gland adenoid cystic carcinomas and 12 samples of normal salivary gland tissue were immunohistochemically evaluated for estrogen and progesterone receptor protein expression. Estrogen receptors were not detected in either group; however, a significantly higher progesterone receptor level was evident in the neoplastic group compared with normal tissue (p < 0.01). These data confirm the presence of progesterone receptors within normal and neoplastic salivary gland tissue. Progesterone receptor expression may be of possible prognostic and therapeutic value in some cases of adenoid cystic carcinoma.

Cancer in the elderly

This article reviews geriatric oncology and assesses options for treatment and care of the elderly patient with cancer. The size of the population over 65 years old is defined, with particular reference to the continuing growth of this subsection of the community. The high incidence of many cancers and their associated mortality rates in the elderly are identified and the epidemiology of such diseases in the geriatric population is addressed. Given the discrepancies in incidence and survival rates between patients younger and older than 65 years, the association between tumorigenesis and the aging process is explored. Specific aspects of tumor growth in the elderly are considered. General considerations of therapy for elderly patients with cancer are discussed, including the pharmacokinetics and pharmacodynamics of chemotherapy in those over 65 years old, surgical options, the use of radiotherapy, and overall patient assessment. Next, treatment options for individual cancer states are reviewed, with particular emphasis on newer treatment options designed specifically for the elderly. Sections on cancer screening and supportive care are also included, the latter dealing with aspects of symptom control, quality of life assessment, and the physical and psychologic rehabilitation of the elderly patient with cancer who is undergoing treatment. Conclusions are then drawn as to the extent of the oncological process in those over 65 years old, with particular emphasis on the underdiagnosis and undertreatment of many malignancies in the past. The challenge created by the growing elderly population is underscored and necessary plans of action for oncologists in the future are defined. Such proposals are necessary if inroads are to be made into the unacceptable morbidity and mortality rates borne by our elderly patients with cancer.

Differential changes of adrenoceptor- and muscarinic receptor-linked prostacyclin synthesis by the aorta and urinary bladder of the diabetic rat

1. The effect of experimental diabetes mellitus (DM; hyperglycaemic, non-ketototic; 2 months duration) in the rat on receptor-linked prostacyclin (PGI2) synthesis (measured as 6-oxo-PGF1 alpha by radioimmunoassay) was studied in the aorta and urinary bladder using adrenaline, angiotensin II (AII) and acetylcholine (ACh). Signal transduction systems were studied via stimulation of PGI2 synthesis with phorbol ester dibutyrate (PDBU; a protein kinase C activator [PKC]), Ca2+ ionophore A23187 (A23187) and thapsigargin (both elevate intracellular Ca2+, activating phospholipase A2 [PLA2]) and arachidonate (AA; substrate for PGI2 synthesis). 2. In response to adrenaline, AII and phorbol ester, aortic PGI2 release was markedly reduced (all > 75%) in diabetic rats compared to controls. EC50s of the dose-response curves for adrenaline, AII and PDBU were also markedly increased in aortae from DM rats compared to controls. Although there was decreased output of PGI2 in response to A23187 by aortae from diabetic rats compared to controls, there was no difference in the EC50s (mean +/- s.e. mean: diabetic, 2.7 +/- 0.2 x 10(-6) M; controls 2 +/- 0.18 x 10(-6) M). There were no differences in PGI2 release (or in the EC50s) in response to thapsigargin or AA between aortae from diabetic and control rats. 3. In the urinary bladder, there was a marked increase in PGI2 output in response to ACh and a marked decrease in EC50s for the ACh-PGI2 dose-response curves in diabetic rats (EC50 = 5.8 +/- 0.32 x 10(-7) M) compared to controls (EC50 = 2.2 +/- 0.15 x 10(-6) M). Although there was an increase in PGI2 output in the urinary bladders from diabetic rats in response to A23187, there were no differences in the EC50s (control, 1.8 +/- 0.2 x 10-6 M; diabetic, 1.1 +/- 0.15 X 10-6 M). In the urinary bladders, there were no differences in PGI2 output (or the EC50s) in response to PDBU, thapsigargin or AA between diabetic or control rats.4. These data indicate that: (i) reduced PGI2 synthesis coupled to adrenoceptors and AII receptors in the aortae of diabetic rats may be due to diminished PKC activity and not to changes in receptor density and/or affinity, Ca2+ stores, PLA2, cyclo-oxygenase or PGI2 synthase; (ii) the diametrically opposite effect of DM on ACh-stimulated PGI2 synthesis is not due to an increase in PKC activity, but possibly to an increase in muscarine receptor number and/or affinity; (iii) changes in receptor-linked PGI2 synthesis are not ubiquitous in experimental DM and may be organ-specific.

Challenges in the management of prostate cancer

An estimated 32,000 American men will die of prostate cancer this year. Local prostate cancer may be successfully treated by radical prostatectomy or radiotherapy. Advanced cases may necessitate the use of hormonal ablation with bilateral orchiectomy, an approach that is regarded as the gold standard of therapy but not always the preferred treatment of patients. Oestrogen therapy is an alternative but is associated with side effects, such as hot flushes and gynaecomastia, which frequently lead to treatment cessation. Luteinising hormone-releasing hormone (LHRH) analogues work by initially producing a surge of androgen, followed by a down-regulation in hormone production to effect a medical castration. Various groups have studied the effects of androgen blockade administered as monotherapy and as combination therapy (LHRH analogue plus antiandrogen). The National Cancer Institute intergroup protocol 0036, which is the largest cooperative study to date of patients with advanced prostatic cancer, showed that combination therapy with leuprolide and flutamide offered greater benefit in both time to disease progression and median survival while circumventing tumour flare and its associated symptoms. Thus, combination therapy for total androgen ablation may become the new treatment standard for advanced prostatic cancer, pending further studies in the efficacy and cost-effectiveness of all available treatments.

Total androgenic blockade as treatment of prostatic cancer: Our experience with orchiectomy plus antiandrogens

The Authors studied 120 prostatic cancers in a 16-year retrospective study: 68 of them (57%) were stage D and 32 (29%) stage C tumors. Global survival rate of the case reports related to staging was similar to that reported in literature. There was a statistically significant difference between the survival of the group treated by antiandrogens alone and the group treated by total androgenic blockade. The latter was obtained by orchiectomy plus antiandrogens. The increase of the survival rate in the group treated by total androgenic blockade encourage its use “ab initio” for the treatment of metastatic tumor of the prostate.

The prognostic value of prostate-specific antigen and prostatic acid phosphatase in serum of patients with prostate cancer after orchidectomy

Correlations between the serum levels of PAP and PSA before and 1, 3 and 6 months after orchidectomy in 27 prostatic cancer patients (advanced clinical stages C and D according to Whitemore scale) were studied. The PSA values correlated more distinctly than PAP with the general clinical condition. PSA is a reliable tumour marker when used at regular intervals, especially for monitoring therapeutic results. A high preoperative PSA level correlates with a high postoperative level and progression of the disease.

Phase II trial of 5-fluorouracil, high-dose leucovorin calcium, and dipyridamole in advanced prostate cancer

To examine the effect of altering intracellular folate pools on the efficacy of 5-fluorouracil (FUra) in the treatment of advanced prostate cancer, we performed a phase II trial of FUra (300-370 mg m-2 day-1 x 5 as an i.v. bolus) combined with high-dose folinic acid (500 mg m-2 day-1 x 5.5 days by continuous i.v. infusion) and dipyridamole (75 mg p.o. every 6 h x 5.5 days) administered on a 28-day schedule in patients with stage D2 disease. A group of 13 patients have been treated. The median age was 68 years (range 48-78 years); the performance status ranged from 50% to 90%. Among 12 evaluable patients, there were no objective responders; the median time to progression was 1.9 months. Median survival after entry on this trial was 8.6 months. Treatment with FUra, high-dose folinic acid and dipyridamole was well tolerated. Only one episode each of grade 3 leukopenia, granulocytopenia, and thrombocytopenia was observed. These results suggest that, despite previous trials demonstrating activity for FUra in stage D2 prostate cancer, this disease may be relatively resistant to fluoropyrimidines and, thus, less amenable to biochemical modulation with high-dose folinic acid and dipyridamole.

Chemoprevention strategies for prostate cancer: the role of 5 alpha-reductase inhibitors

Prostate cancer is a major health problem for the aging male population. Despite hormonal dependence, the inevitable emergence of androgen insensitive tumors, which have a dismal prognosis, highlights the need to develop prevention strategies such as chemoprevention. An acceptable agent must interfere with either the process of carcinogenesis or tumor growth, and have minimal toxicity. In clinical studies, 5 alpha-reductase inhibitors have been shown to suppress serum and intraprostatic levels of dihydrotestosterone, an important promoter of prostate cancer, leading to reduction in prostate size and suppression of glandular cell activity as measured by prostate specific antigen secretion. In addition, 5 alpha-reductase inhibitors have demonstrated an excellent safety profile and tolerability in 12 month controlled clinical trials. No significant metabolic effects have been observed in gonadotropin secretion, spermatogenesis, serum lipids or glucose tolerance. The efficacy and safety of 5 alpha-reductase inhibitors in studies to date, combined with the androgen dependence of tumor production, strongly supports investigating their use for chemoprevention of prostate cancer.

The management of intractable bone pain: a clinician's perspective

Bone metastases occur in up to 85% of patients (at autopsy) who have breast, lung, and prostate cancer, and are a common cause of pain and neurological morbidity in patients with these and other cancers. The management of pain, the most common complication of bone metastasis, requires a knowledge of specific clinical syndromes and the associated neurological and orthopedic morbidities, as well as an understanding of current antitumor and pharmacological therapies. Knowledge of these potential complications are important in the design of clinical trials that seek to evaluate the effectiveness of new treatments for bone metastasis. Although radiation therapy in combination with analgesic drug therapies remains the mainstay of treatment, much recent interest in drugs with specific effects on bone elements, especially the osteoclast, offer the promise of providing effective pain relief with fewer side effects than is currently possible with conventional therapies.

Monotherapy with nilutamide, a pure nonsteroidal antiandrogen, in untreated patients with metastatic carcinoma of the prostate. The Italian Prostatic Cancer Project

A total of 26 previously untreated patients with metastatic carcinoma of the prostate received the pure nonsteroidal antiandrogen nilutamide as a single agent. Objective response rate was 38.5 +/- 18.7% (95% confidence interval). Median progression-free survival and median survival were 9 and 23 months, respectively. Of 13 patients with progression on antiandrogen 5 showed an additional objective response to a second-line endocrine treatment. The drug was generally well tolerated, except for 2 patients who discontinued treatment because of moderate gastrointestinal symptoms. Approximately a third of the patients complained of decreased adaptation to darkness. An electroretinogram and dark adaptation test revealed the presence of functional damage and visual complaints reversed in all patients on cessation of therapy. The other most frequent side effects were slight nausea (26.9% of the patients) and alcohol intolerance (19.2%). A nonsignificant increase in testosterone levels was shown within 1 month of treatment, after which the levels remained stable. Approximately half of the sexually active men claimed maintenance of libido and sexual potency during treatment. A slightly significant increase in hemoglobin was observed during the long term, suggesting the occurrence of a trophic effect by androgens on erythropoiesis. The results indicate that nilutamide as a single agent has an acceptable toxicity and a moderate activity, and may maintain sexual interest in a discrete number of cases. Whether monotherapy with nonsteroidal antiandrogens offers a valid option in the palliation of advanced disease remains to be seen in comparative prospective trials.

Evaluation of Win 49,596, a novel steroidal androgen receptor antagonist, in animal models of prostate cancer

A series of experiments were conducted to evaluate the effects of Win 49,596, a novel steroidal androgen receptor antagonist, in animal models of prostate cancer. In the first experiment, oral administration of Win 49,596 at doses of 30, 100, or 300 mg/kg/day for 28 days inhibited (P less than 0.05) the growth of the androgen-sensitive PAP variant of the Dunning R-3327 prostatic carcinoma in intact male rats relative to intact controls. The degree of inhibition at 100 and 300 mg/kg/day Win 49,596 was similar (P greater than 0.10) to that observed in castrate controls as well as in intact rats administered the nonsteroidal androgen receptor antagonist flutamide orally at 15 mg/kg/day. Castration as well as treatment with either Win 49,596 or flutamide also decreased (P less than 0.05) the weight of the prostate in tumor-bearing animals. Additional studies were conducted to determine the effect of Win 49,596 on the growth of the androgen-dependent PC-82 human prostatic carcinoma xenografted into athymic nude male mice. Oral administration of Win 49,596 at 30, 100, or 300 mg/kg/day for 35 days inhibited (P less than 0.05) tumor growth relative to intact controls. The degree of tumor inhibition was similar to that observed in intact male mice administered the nonsteroidal androgen receptor antagonist flutamide orally at 30 mg/kg/day but was less than that observed following castration. Ventral prostate weights were also reduced (P less than 0.05) in castrate mice as well as in intact mice administered either Win 49,596 or flutamide. In the last experiment, at equivalent total daily dosages of either 150 or 300 mg/kg/day Win 49,596, twice a day (BID) dosing was more effective than once a day (SID) dosing in inhibiting tumor growth. The inhibitory effects of Win 49,596 at 150 mg/kg BID on tumor growth were similar to those observed following castration. Although Win 49,596 treatment reduced (P less than 0.05) ventral prostate weights relative to intact controls, there was no difference (P greater than 0.10) between SID vs. BID dosing. Based on the results of these studies and subject to further testing, Win 49,596 may have utility in the treatment of hormonally dependent metastatic prostate cancer in humans.

Serum and prostatic growth-promoting factors for steroid-independent epithelial cells of adult dog prostate

A growth factor-like effect has been observed on canine prostatic epithelial cells when cultured in the presence of their homologous serum and prostatic extracts; the mitogenic activities of both preparations were dose-dependent and not altered by charcoal treatment. The effect of dog serum decreased when the density of the epithelial cell cultures increased and was minimal on canine prostatic fibroblasts. Trace amounts of intracellular sex steroids did not contribute to epithelial cell proliferation since the presence of sex steroid action inhibitors did not alter growth rate; in those conditions, cycloheximide completely prevented cell division. When various hormones and known mitogenic agents were tested alone or in combination with steroids, none elicited an increase in the number of epithelial cells cultured in serum-free medium or altered the proliferative effect of dog serum observed in parallel cultures. On gel filtration, dog serum or tissue cytosol showed a major mitogenic activity at an apparent molecular mass of 150 kDa and a minor one of 1.5 kDa as evaluated by gel filtration of dog serum ultrafiltrate. Acidic extraction of prostatic tissue followed by chromatography on a hydrophobic C-18 column and subsequent gel filtration also led to the detection of the low Mr component. Thus, humoral and/or tissular factors present in vivo and different from known mitogens may be of importance as direct modulators of the basal epithelial cell growth in the adult canine prostate.

[Problems and principles of hormone therapy of advanced prostate cancer]

The availability of hormones with few side effects has enlarged the indication for their use: In the presence of metastases, primary endocrine treatment which includes orchiectomy as standard therapy is employed with palliative intent. Adjuvant endocrine treatment is given after radical prostatectomy when positive margins or lymph nodes were present. A salvage endocrine treatment is administered if the primary tumor persists after radiotherapy or recurred after prostatectomy. The term diagnostic hormone treatment is misleading and should not be used. A secondary hormone application is supported by the observation that allaged hormone resistant tumor progressed after testosterone injection. The problem of early versus delayed endocrine therapy is unsolved, however, it is conceivable that the latter therapy is confronted with a larger tumor burden. The principle of endocrine treatment is properly described as means suppressing the androgenic stimuli. There are 5 different routes of androgen deprivation, among which the antiandrogens and LH RH analogs have the highest priority. Phase III-studies are under way to clarify their efficacy.

The role of endocrine therapy in prostatic cancer

When judged by randomized clinical trial, current endocrine therapies offer symptomatic relief to prostatic cancer patients for an average period of 1-2 years following initiation of therapy. Medical castration with LHRH analogues is a safe and effective way of achieving 'castrate' levels of circulating androgens without the undesirable aspects of surgery. While there is some evidence for the value of combined therapies using these agents in combination with anti-androgens for 'total androgen blockade' in some patients, overall this approach has not been shown to offer advantages over castration, either surgical or medical, alone in controlled trials. Secondary endocrine therapy does not offer convincing objective response rates, suggesting that disease progression is independent of androgens.

Systemic management of prostate cancer

The objective of this review is to explore different therapeutic options for metastatic adenocarcinoma of the prostate. Orchiectomy, estrogen therapy, synthetic LHRH analogs and possibly antiandrogens are equally effective frontline treatment modalities. Ketoconazole is indicated in emergency situations, but chronic use is prevented by serious idiosyncratic toxicity and by long term complications. Combined androgen blockade (CAB), with leuprolide (or tryptorelin) and flutamide is more effective than single modality treatment in patients capable of strict treatment compliance. Estramustine phosphate may be as effective as CAB and may be the frontline treatment of choice in sexually active patients. Institution of single modality treatment may be delayed until cancer becomes symptomatic. Controversy lingers over whether the institution of CAB at an earlier time may improve progression free survival (PFS) and survival. Research projects of immediate clinical relevance include: comparison of CAB and estramustine; determination of the optimal time for CAB; study of other forms of CAB; and phase II trials of new cytotoxic agents.

Evidence for testicular impairment after long-term treatment with a luteinizing hormone-releasing hormone agonist in elderly men

Testicular responsiveness to 5,000 IU of human chorionic gonadotropin was evaluated in 14 patients with prostate cancer who were being treated with a slow-release luteinizing hormone-releasing hormone agonist for a median of 21 months. Serum testosterone response to human chorionic gonadotropin was markedly reduced in most patients, with the median level increasing from 0.25 to 1.65 nmol. per l. A second human chorionic gonadotropin test was repeated later in 5 patients who had been off treatment for a median of 6 months. Median serum testosterone levels increased to a maximum of 2.6 nmol. per l. compared to 28.2 nmol. per l. in an age-matched control group (p equals 0.008). Therefore, we conclude that long-term treatment with luteinizing hormone-releasing hormone agonists in elderly men leads to gonadal impairment that may not be as reversible as generally suggested.

Combined androgen blockade

Combined therapy, the treatment of advanced adenocarcinoma of the prostate by total androgen suppression, is still a controversial subject today. Some studies performed during the 1980s support the value of this therapeutic approach, while others have found it to be no more effective than surgical or chemical castration alone. Recently, the results of a randomized, controlled, multicenter intergroup study of combined therapy sponsored by the U.S. National Cancer Institute (NCI) became available. These results suggest that combined therapy offers some advantages over monotherapy in the treatment of advanced prostate cancer. A variety of drugs are available to suppress adrenal androgens. However, the value of these agents in prostate cancer therapy continues to be hotly debated.

Oestrogen dosage in prostatic cancer: the threshold effect?

We present the results of a prospective randomised trial of Estradurin, a long-acting oestrogen preparation (polyoestradiol phosphate), 160 mg per month, compared with bilateral orchiectomy in patients with advanced prostatic carcinoma (T3M1; T4MO/M1). The dose was lower than that usually recommended to induce a consistent fall in serial plasma testosterone levels to within the castrate range. Most patients treated with oestrogen showed an initial clinical and biochemical response equal to that obtained for patients undergoing orchiectomy. The inevitable relapse in hormone sensitivity sometimes occurred very soon after the start of oestrogen treatment. Many patients had poorly suppressed plasma testosterone expressed as a mean of monthly serial measurements, but then responded to secondary orchiectomy. These data only suggest that, in the treatment of hormone-sensitive prostatic carcinoma, it may be necessary to reduce plasma testosterone to midway between castrate and normal ranges. The data support the theory that response to androgen withdrawal is qualitative rather than quantative. The effective dose of oestrogen may therefore be reduced and the risk of thrombo-embolic complications minimised.

Treatable carcinoma of unknown origin

Carcinoma of unknown histogenesis or primary site is an increasingly recognized syndrome regarded by most physicians as having a grim prognosis. Elaborate evaluations using low yield, and often misleading, radiologic studies focused on identifying primary sites in the lung, liver, pancreas, or gastrointestinal tract offer little benefit to the vast majority of patients. Increasing evidence has accumulated showing that subsets of patients within this broad syndrome exist in whom recognition and proper therapy may result in meaningful prolongation of life or potential cure. In this review, clinical clues and diagnostic aids for identification of nine treatable subsets of patients with the carcinoma of unknown origin (CUO) syndrome are emphasized. Current state-of-the-art treatment for each subset with subsequent end results are stated.

The cost of bilateral orchiectomy as a treatment for prostatic carcinoma

Advanced prostatic carcinoma may be treated by a variety of methods of hormonal manipulation which affect the production of the male hormones. This can be achieved by surgical means, usually bilateral orchiectomy, or medically, by a number of drugs. One advantage of surgical over medical castration is that it is a once-only procedure. Another factor, which could be considered a major advantage, is the low cost of the surgical procedure. This report outlines the costs involved in treating prostatic carcinoma by surgical castration and compares them with the costs of some forms of medical treatment.

Relative effectiveness of alternative androgen withdrawal therapies in initiating regression of rat prostate

From a large number of potentially effective androgen withdrawal regimens including bilateral orchiectomy, estrogens, antiandrogens and LHRH agonists alone or in combinations, we compared the ability of 12 different treatment options to mimic the acute results of surgical castration on the rat prostate. Agents were administered s.c. in clinical doses to groups of male rats daily for three days. On day 4 the prostatic tissue was removed and analyzed by conventional methods for whole-tissue and nuclear concentrations of dihydrotestosterone, nuclear androgen receptor and cytoplasmic androgen receptor. Castration-like changes were most pronounced with the synergistic combinations of cyproterone acetate + low-dose diethylstilbestrol, and megestrol acetate + low-dose diethylstilbestrol. Comparing the effectiveness of single agents, low-dose diethylstilbestrol was superior to cyproterone acetate, megestrol acetate, flutamide, leuprolide and RU23908. Leuprolide combined with flutamide was superior to leuprolide + cyproterone acetate, leuprolide + cyproterone acetate + low-dose diethylstilbestrol or leuprolide + RU23908 after three days of administration; however, this advantage disappeared when the treatments were extended to seven days. The observations indicate that the most potent androgen withdrawal therapies such as cyproterone acetate + low-dose diethylstilbestrol and megestrol acetate + low-dose diethylstilbestrol at best approximate but do not surpass the early effects of surgical castration. During the same time course, other regimens are characterized by a slower onset of action and a lesser degree of suppression of androgenic mechanisms within the cell.

Adjuvant estrogen following radiation therapy for stage C adenocarcinoma of the prostate: long-term results of a prospective randomized study

Seventy-eight patients with clinical Stage C adenocarcinoma of the prostate were prospectively randomized to receive either radiation alone or radiation and adjuvant estrogen (diethylstilbestrol). No patient had received any prior definitive treatment for cancer. Forty patients were randomized to receive radiotherapy only and 38 patients to receive radiotherapy and estrogen. The median follow-up for all surviving patients was 14.5 years. Whether analyzed according to the original randomization or according to the treatment actually received, disease-free survival in the adjuvant estrogen group was strikingly and significantly higher than in the radiation-only group. At 5, 10, and 15 years patients receiving adjuvant estrogen had respective disease-free survival rates of 71%, 63%, and 63% compared with 49%, 43%, and 35% in patients having radiation only (p = 0.008). However, because of greater intercurrent disease-related mortality in patients receiving estrogen, there was no improvement in survival. This study suggests that a prospective randomized evaluation of early androgen deprivation with orchiectomy or with one of the nonestrogenic agents should be undertaken and that patients receiving early androgen deprivation should not be included in series reporting on the curative potential of radiation as a single modality.