Figure 8-13. Survival with hormone-refractory prostate cancer. Survival of patients with hormone-refractory prostate cancer has become progressively longer, but no peer-reviewed study or prospective randomized trial has yet shown a survival advantage of one treatment over another. The survival of patients in various trials has depended primarily on the type of patients enrolled in that trial rather than the therapy used. Recent studies have shown longer survival compared with older trials, but this may be due to lead-time bias from the use of prostate-specific antigen values, rather than symptoms, when enrolling patients in hormone-refractory protocols.
Figure 8-14. Treatment options for hormone-refractory prostate cancer. The treatment options for hormone-refractory prostate cancer can be divided into withdrawal therapies, secondary hormonal therapies, irradiation, chemotherapy, and experimental approaches. Withdrawal therapies have been described in recent years and can influence both patient care and clinical trial results.Some patients in whom initial hormonal therapy with standard approaches fails (eg, luteinizing hormone–releasing hormone analogues, orchiectomy) can have subjective and objective responses to secondary hormonal manipulation. Radiation therapy for advanced prostate cancer can be delivered by either external beam or intravenous methods.
Figure 8-15. Normal versus mutant androgen receptor activity. A, Normal androgen receptor actions are blocked by antiandrogens. B, Mutant androgen receptor can be activated by antiandrogens. Although the clinical significance of mutant androgen receptors is debated, most investigators agree that mutations can be detected in selected patients with prostate cancer . Most of the controversy relates to the frequency, location, and role of these mutations. Because the androgen receptor gene is X-linked, there is only one allele per cell. Thus, any genetic change in these sequences would not be complemented by the action of a normal gene expressed on another chromosome. The potential importance of mutations is therefore magnified when compared with biallelic genes. The first androgen receptor mutation described in patient-derived material was sequenced from the LNCaP cell line. The LNCaP androgen receptor possesses a point mutation within the hormone-binding domain , resulting in the functional ability to recognize a variety of ligands in a promiscuous manner. Instead of specific receptor activation by androgens and blockage by antiandrogens, mutant receptor activation could be triggered by a variety of membrane-soluble compounds including antiandrogens, estrogens, and progesterone. In patients with hormone-refractory prostate cancer, clinical antitumor responses after antiandrogen withdrawal may be linked to the presence of such mutations in the hormone-binding domain of the androgen receptors expressed at sufficient levels. References: . Taplin ME, Bubley GJ, Shuster TD, et al. Androgen receptor mutations in metastatic androgen independent prostate cancer. N Engl J Med 1995 332 1393-1398 . Veldscholte J, Ris-Stalpers C, Kuipper GGJM, et al. A mutation in the ligand binding domain of the androgen receptor of human LNCaP cells affects steroid binding characteristics and response to antiandrogens. Biochem Biophys Res Commun 1990 173 534-540
Figure 8-16. Secondary hormonal treatments for hormone-refractory prostate cancer. Antiandrogens , glucocorticoids , adrenal suppressive agents such as ketoconazole , megestrol acetate , estrogens , and estramustine  are all known to interact with hormonal receptors and have some activity in patients with hormone-refractory prostate cancer. The duration of responses typically is limited to 2 to 4 months. The described activity of these hormonal agents in patients with cancer progression despite androgen deprivation underscores the ambiguity of the current nomenclature; a more accurate sequence may be as follows: hormone-sensitive to hormone-responsive to truly hormone-refractory disease. References: . Fowler JE, Jr., Endocrine therapy for localized prostate cancer. Urol Ann 1996 10 57-77 . Tannock IF, Osoba D, Stockler MR, et al. Chemotherapy with mitoxantrone plus prednisone or prednisone alone for symptomatic hormone-resistant prostate cancer: a Canadian randomized trial with palliative end points. J Clin Oncol 1996 14 1756-1764 . Small EJ, Baron AD, Fippin L, Apodaca D, Ketoconazole retains activity in advanced prostate cancer patients with progression despite flutamide withdrawal. J Urol 1997 157 1204-1207 . Osbom JL, Smith DC, Trump DL, Megestrol acetate in the treatment of hormone refractory prostate cancer. Am J Clin Oncol 1997 20 308-310 . Smith DC, Redman BG, Flaherty LE, et al. A phase II trial of oral diethylstilbestrol as a second line hormonal agent in patients with advanced prostate cancer. Urology 1998 52 257-260 . Walzer Y, Oswalt J, Soloway MS, Estramustine phosphate-hormone, chemotherapeutic agent, or both? Urology 1984 24 53-58
Figure 8-17. Radioisotopes in the treatment of hormone-refractory prostate cancer. Radiation therapy has long been known to provide effective palliation for patients with advanced prostate cancer. Although external beam radiation has been the most popular modality, newer data suggest that radioisotopes administered intravenously also have significant therapeutic effects, particularly in patients with painful bony metastasis. Radioactive phosphorus (32P) has long been available, but in recent years several other therapeutic bone-seeking radioisotopes have been introduced, including 89Sr and 153Sm. A comparison of these isotopes demonstrates significant differences in physical half-life and particle energy.
Figure 8-1. Typical regions of metastatic disease. A, Localized prostate cancer. B, Regional and para-aortic lymph node metastases. C, Bony metastases. Appropriate management of prostate cancer relies on the sensitive and specific detection of locoregional and distant metastatic disease. The most common sites of prostate cancer metastasis identified in pathologic studies are regional lymph nodes and bone; lung and liver metastases can also be found . Identification of distant soft tissue metastases has traditionally relied on cross-sectional imaging with CT or MRI. Bone scans are the preferred method for detecting lesions in the bone. Contemporary imaging studies include radioimmunoscintigraphy and positron emission tomography. Prostate-specific antigen–producing cells can be detected with high sensitivity by the molecular technique of polymerase chain reaction. Definitive local therapy alone is doomed to failure, however, in those with underlying metastatic disease; thus, timely detection and some form of systemic therapy are required for optimal treatment in these patients. References: . Franks LM, The spread of prostate carcinoma. J Pathol 1956 72 603-611
Figure 8-2. The probability of positive bone scans as predicted by serum prostate-specific antigen (PSA). Modern techniques of PSA determination and disease staging have greatly reduced the need for routine bone scans in patients diagnosed with clinically localized prostate cancer. If the serum PSA level is less than 10 ng/mL, the probability of detecting bony metastases by bone scan is low . Furthermore, bone scans are not recommended in the post–radical prostatectomy patient with an undetectable PSA level  or PSA recurrence less than 30 to 40 ng/mL . References: . Lee CT, Oesterling JE, Using prostate-specific antigen to eliminate the staging radionuclide bone scan. Urol Clin North Am 1997 24 389-394 . Terris MK, Klonecke AS, McDougall IR, Stamey TA, Utilization of bone scans in conjunction with prostate specific antigen levels in the surveillance for recurrence of adenocarcinoma after radical prostatectomy. J Nucl Med 1991 32 1713-1718 . Cher ML, Bianco FJ, Jr, Lam JS, et al. Limited role of radionuclide bone scintigraphy in patients with prostate specific antigen elevations after radical prostatectomy. J Urol 1998 160 1387-1391
Figure 8-3. The radioscintigraphic bone scan is the most sensitive imaging method to detect metastases to bone. These lesions typically appear as asymmetric areas of increased tracer uptake, particularly in the axial skeleton. The advantages of bone scintigraphy include its high overall sensitivity, ability to evaluate the entire skeletal system, and relatively low cost. However, bone scans are limited because of the nonspecific information provided. Areas of increased radiotracer uptake can be associated with a number of nonmalignant etiologies, such as trauma, arthritis, and Paget’s disease. (From Manyak ; with permission.) References: . Manyak M, Advances in imaging prostate cancer. Advances in Prostate Cancer 1997 1 5-7
Figure 8-4. Application of a radiolabeled monoclonal antibody for detection of prostate cancer. A, Product formulation of this radiolabeled monoclonal antibody (ProstaScint; Cytogen, Princeton, NJ). B and C, Images of metastatic disease obtained using capromab pendetide radioimmunoscintigraphy. Although CT and MRI are well-accepted for staging many malignancies, studies in prostate cancer indicate that these modalities have poor sensitivity in detecting early metastases. In 1996, the Food and Drug Administration approved the use of a radiolabeled monoclonal antibody to prostate-specific membrane antigen in patients with 1) newly diagnosed prostate cancer at high risk for lymph node metastases, and 2) a rising prostate-specific antigen and no demonstrable site of recurrence after prostatectomy. This radiolabeled antibody (111In-labeled capromab pendetide) is able to image prostate cancer soft tissue metastases with greater sensitivity than traditional radiographic tests , . Unfortunately, the test is cumbersome to administer, requiring a period of 3 to 4 days, and both false-negative and false-positive results are obtained in up to 30% of cases. Newer imaging agents, such as 18F-fluorodeoxyglucose and 11C-methionine, take advantage of differences in the metabolic activity between benign and malignant tissues . However, the clinical role of positron emission tomography in prostate cancer requires further investigation (Panels B and C from Manyak ; with permission.) References: . Manyak M, Advances in imaging prostate cancer. Advances in Prostate Cancer 1997 1 5-7 . Kahn D, Williams RD, Manyak MJ, et al. 111-Indium-capromab pendetide in the evaluation of patients with residual or recurrent prostate cancer after radical prostatectomy. J Urol 1998 159 2041-2047 . Maguire RT, 111-In Capromab pendetide (ProstaScint) for presurgical staging of patients with prostate cancer. J Nucl Med 1995 29 108-113 . Hoh CK, Seltzer MR, Franklin J, et al. Positron emission tomography in urologic oncology. J Urol 1998 159 347-356
Figure 8-5. Detection of prostate-specific antigen (PSA)–producing cells by reverse transcription polymerase chain reaction (RT-PCR). This method can potentially detect one PSA-producing cell in a background of 10,000,000 non-PSA–producing cells. RT-PCR has been used to detect PSA-producing cells from several sources, including blood, bone marrow, and lymph nodes , , . Messenger RNA is purified from a cellular source and reverse transcribed, and then PSA-specific message is amplified using specific primers and the polymerase chain reaction. Debate surrounds this extremely sensitive method of molecular staging, with the uncertain relevance of detecting PSA-specific messenger RNA in the bloodstream . The clinical validity of observations related to RT-PCR must be confirmed in multicenter trials. A variety of other potential prostate-specific messenger RNAs (eg, prostate-specific membrane antigen) can also be assayed by RT-PCR. References: . Moreno JG, Croce CM, Fischer R, et al. Detection of hematogenous micrometastases in patients with prostate cancer. Cancer Res 1992 52 6110-6112 . Deguchi T, Doi T, Ehara H, et al. Detection of micrometastatic prostate cancer cells in lymph nodes by reverse transcriptase-polymerase chain reaction. Cancer Res 1993 53 5350-5354 . Wood DP, Jr, Beaman A, Banerjee M, et al. Effect of neoadjuvant deprivation on circulating prostate cells in the bone marrow of men undergoing radical prostatectomy. Clin Cancer Res 1998 4 2119-2123
Figure 8-6. Sources of androgen production and control of androgen secretion. Luteinizing hormone–releasing hormone (LHRH) is secreted into the hypophyseal portal system in pulses and circulates to the pituitary, where it stimulates the release of luteinizing hormone (LH) from gonadotrophs. LH binds to specific receptors in testicular Leydig cells, resulting in the production and secretion of testosterone into the bloodstream. This pathway accounts for approximately 95% of circulating testosterone. The remaining 5% is derived from the adrenal cortex, under the control of pituitary adrenocorticotropic hormone (ACTH). DHT—dihydrotestosterone; T—testosterone.
Figure 8-7. Conversion of testosterone to dihydrotestosterone is catalyzed by 5a-reductase enzymes. Although testosterone is the primary plasma androgen secreted by the testes, testosterone is converted to dihydrotestosterone, a more potent androgen, by the enzyme 5a-reductase. The two isoforms of 5a-reductase, type I and II, are specifically found in the skin/liver, and prostate, respectively. Selective inhibition of type II 5a-reductase activity by the 4-azasteroid finasteride (Proscar; Merck & Co., Inc., Whitehouse Station, NJ) decreases serum prostate-specific antigen (PSA) and reduces prostate gland size. Inhibitors of 5a-reductase, both alone and in conjunction with other agents, are being evaluated as anticancer therapy.
Figure 8-8. Androgenic actions are mediated by a ligand-dependent transcriptional regulator: the androgen receptor. The androgen receptor is a member of the nuclear steroid receptor superfamily that includes the progesterone, estrogen, and glucocorticoid receptors . Three distinct domains characterize the 917-amino acid protein: 1) a central DNA-binding domain flanked by 2) an amino-terminal transactivation domain, and 3) a carboxy-terminal hormone-binding domain. The transactivation domain contains a variable number of glutamine (CAG) repeats that modulate function. Androgen binding to the receptor results in protein conformational change, homodimerization, and binding to specific hormone-response elements with subsequent transcriptional regulation . These changes in gene expression, in turn, regulate growth and differentiation in a variety of androgen-sensitive tissues, including the prostate. The recent discovery of coregulatory proteins has suggested mechanisms for the development of androgen-independent growth and novel targets of therapy . References: . Chang C, Kokontis J, Liao S, Molecular cloning of the human and rat complementary DNA encoding androgen receptors. Science 1988 240 324-326 . Beato M, Gene regulation by steroid hormones. Cell 1989 56 335-344 . Onate S, Tsai S, Tsai M, et al. Sequence and characterization of a coactivator for the steroid hormone receptor superfamily. Science 1995 270 1354-1357
Figure 8-9. Blockade of androgen action. Blockade of androgen action can be achieved via many routes. Elucidating the hormonal control mechanisms underlying prostate growth has given physicians multiple potential targets for therapeutic intervention. The gold standard for eliminating gonadal androgen secretion remains bilateral orchiectomy, a procedure reported over 50 years ago for the treatment of prostate cancer . Within hours of surgical castration, 95% reduction in serum testosterone levels is achieved. The luteinizing hormone–releasing hormone (LHRH) analogues currently approved by the US Food and Drug Administration potently bind and stimulate the pituitary LHRH receptors. This sustained agonist activity initially results in a marked increase in luteinizing hormone (LH) and testosterone (T) secretion, but is followed by a paradoxic decline to castrate testosterone levels after 2 to 4 weeks. Current LHRH agonists, such as leuprolide and goserelin acetate, are available in depot formulations capable of suppressing testosterone secretion for 3, 4, or 12 months per subcutaneous injection . Estrogens such as diethylstilbestrol (DES) have been used in the treatment of prostate cancer for decades. DES, no longer manufactured in the United States, acts as a potent inhibitor of LH secretion , thereby indirectly lowering testosterone secretion. Antiandrogens block the effects of androgens by competitively binding the androgen receptor. Both steroidal (cyproterone acetate) and nonsteroidal (flutamide, bicalutamide, and nilutamide) antiandrogens have been used in the treatment of prostate cancer. These agents inhibit the effects of androgens on the pituitary as well as prostatic tissue; however, only pure (nonsteroidal) antiandrogen monotherapy is associated with a temporary rise in plasma testosterone . A variety of agents can inhibit adrenal androgen secretion. Those most commonly used in prostate cancer are ketoconazole and aminoglutethimide, which interfere with cytochrome P-450 hydroxylation reactions. Ketoconazole also inhibits testicular androgen production and can be used to rapidly achieve castrate levels of testosterone within 24 to 48 hours . ATCH—corticotropin; DHT—dihydrotestosterone. References: . Huggins C, Hodges CV, Studies on prostate cancer: I. The effect of castration of estrogen and of androgen injection on serum phosphatases in metastatic carcinoma of the prostate. Cancer Res 1941 1 293-297 . Sharifi R, Knoll LD, Smith J, Kramolowsky E, Leuprolide acetate (30 mg depot every 4 months) in the treatment of advanced prostate cancer. Urology 1998 51 271-276 . Shupnik MA, Schreihofer DA, Molecular aspects of steroid hormone action in the male reproductive axis. J Androl 1997 18 341-344 . Kaisary AV, Current clinical studies with a new nonsteroidal antiandrogen, casodex. Prostate 1994 5 (suppl) 27-33 . Bamberger MH, Lowe FC, Ketoconazole in initial management and treatment of metastatic prostate cancer to spine. Urology 1988 32 301-303
рефрактерный и метастатический рак простаты
Criteria for diagnosing hormone-refractory prostate cancer Критерии диагностики гормон-рефрактерного рака простаты
Natural history of hormone-refractory prostate cancer Естественная хронология гормон-рефрактерного рака простаты
Survival with hormone-refractory prostate cancer Выживаемость при гормон-рефрактерном раке простаты
<ul><li>Withdrawal therapies </li></ul><ul><li>Secondary hormonal therapies </li></ul><ul><li>Radiation therapies </li></ul><ul><li>Chemotherapy </li></ul><ul><li>Experimental therapies </li></ul><ul><ul><li>Antiangiogenesis </li></ul></ul><ul><ul><li>Suramin </li></ul></ul><ul><ul><li>Gene therapy </li></ul></ul><ul><ul><li>Immunotherapy </li></ul></ul><ul><li>Терапия изьятия </li></ul><ul><li>Вторичная гормонотерапия </li></ul><ul><li>Лучевая терапия </li></ul><ul><li>Химиотерапия </li></ul><ul><li>Экспериментальная терапия </li></ul><ul><ul><li>Антиандрогены </li></ul></ul><ul><ul><li>Сурамин </li></ul></ul><ul><ul><li>Гентерапия </li></ul></ul><ul><ul><li>Иммунотерапия </li></ul></ul>Treatment options for hormone-refractory prostate cancer Тактика лечения гормон-рефрактерного рака простаты
Normal versus mutant androgen receptor activity Нормальная и мутантная рецепторная активность