Seminars in urologic oncology最新文献

Tremendous progress has been made in the treatment of testicular seminoma over the past 25 years. The advent of curative cytotoxic chemotherapy, even for patients with advanced metastatic disease, has led to a paradigm shift toward minimizing additional oncologic therapies and their potential side effects. Despite these advances, controversial issues still exist in managing patients with this disease. Patients with stage I disease can now be managed successfully with close surveillance or postoperative radiotherapy (RT). Although deemed safe, considerable debate persists about surveillance including issues of compliance, cost, and secondary effects of routine RT. Aside from RT, patients with stage I disease also can be managed with one- or 2-dose single-agent carboplatin. Although this appears safe and efficacious, an ongoing randomized study is underway to compare its effectiveness with that of RT. Residual mass after chemotherapy for seminoma is not uncommon and therapeutic options include observation, RT, or retroperitoneal lymphadenectomy. Although most agree that patients with small (<3 cm) or ill-defined masses can be observed, debate persists as to the optimal management of patients with well-defined masses greater than 3 cm. For many years, patients with bulky retroperitoneal disease (>5 cm) were treated with up-front radiotherapy and chemotherapy at relapse. The high failure rate outside the treatment field has now changed this paradigm to one of up-front chemotherapy.

The prognostic classification developed by the International Germ Cell Consensus group (IGCCC) enables appropriate choice of initial treatment, and provides consistent eligibility criteria for clinical trials and more accurate assessment of published results. The standard therapy for IGCCC poor- and intermediate-prognosis germ-cell tumors is 4 cycles of bleomycin, etoposide, and cisplatin chemotherapy followed by surgical resection of residual masses, if the serum tumor markers have returned to normal. Improved outcomes are achieved by centers that treat a larger number of cases. The unsatisfactory results achieved with current therapy warrant entry of these patients into appropriate clinical trials. Future improvements in therapy are likely to require a better understanding of the molecular mechanisms of resistance and the development of novel therapeutic approaches that target these mechanisms.

About 5% of all patients with unilateral testis cancer harbor testicular intraepithelial neoplasia (TIN) in their contralateral testicle, which will progress into an invasive germ-cell tumor over time. Accurate diagnosis of TIN by a random surgical testis biopsy examination and effective therapy by local radiation has led to the concept of a contralateral screening biopsy procedure in all testis cancer patients. Screening and preventive treatment, however, only are indicated if (1) therapeutic outcome of the screened population is improved and (2) physiologic function of the affected organ might be maintained. Based on a critical review of the literature, some drawbacks of this policy have to be considered and the routine indication for contralateral testis biopsy procedure has to be questioned: (1) all TIN-negative patients still have to undergo meticulous follow-up evaluation for metachronous testis cancer owing to a false-negative biopsy diagnosis rate of 0.3%; (2) testis biopsy procedure is associated with a 15% to 20% complication rate, which might a negative impact on endocrine and exocrine testicular function; (3) local radiation of TIN results in irreversible infertility owing to eradication of spermatogenesis; (4) local radiation of TIN results in an impairment of endocrine Leydig cell function in 25% of patients; (5) therapeutic outcome and prognosis will not be improved in irradiated patients as compared with patients on surveillance; (6) local tumor resection for the management of metachronous testicular cancer represents an effective and viable option. The current literature does not support the strategy to perform contralateral testis biopsy procedures in all patients with unilateral testicular germ-cell tumors. Testis biopsy procedures might, however, be offered to high-risk (34%) patients for contralateral TIN with a testicular volume less than 12 mL, a history of cryptorchidism, and an age less than 30 years.

Following orchiectomy in patients with stage 1 nonseminomatous germ-cell tumors (NSGCT), there are three treatment options. Retroperitoneal lymph-node dissection (RPLND) is currently the treatment of choice in the United States and can be both diagnostic and therapeutic but is associated with surgical morbidities. Surveillance is the least invasive but carries the highest potential for relapse and can be timely and costly for both patient and physician. Primary chemotherapy avoids the morbidity of surgery while achieving similar survival rates, albeit with potentially significant side effects. The advantages and disadvantages of each treatment modality are discussed.

Adjunctive surgical resection of residual disease after chemotherapy is a critical part of the comprehensive management of patients with advanced nonseminomatous germ-cell tumor (NSGCT). Surgical resection is indicated in the presence of residual radiographic abnormalities and normal serum tumor markers. Necrosis, teratoma, and viable carcinoma can be found at any resected site. After induction chemotherapy, necrosis comprises approximately 50% of histologic findings, teratoma 40%, and viable GCT the remaining 10%. A number of investigators have attempted to predict the presence of necrosis in an effort to obviate surgery. A number of variables predictive of necrosis have been identified and tested prospectively, including: degree of tumor shrinkage, size of pre- and posttreatment mass(es), prechemotherapy markers, and teratomatous components in the orchiectomy specimen. However, the risk for a false-negative prediction remains approximately 20%. The most rigorous approach remains a retroperitoneal lymph node dissection (RPLND). Furthermore, the histologic discordance between different sites ranges from 29% to 46%; thus, all sites of residual disease should be resected. The patient's prognosis is influenced by: (1) completeness of resection, and (2) biology of the tumor (histology of residual mass(es), marker status at the time of RPLND, and prior burden of therapy). Surgical boundaries and completeness of dissection should not be compromised in an attempt to preserve ejaculation.

Management options for patients with stage II nonseminomatous germ-cell tumors (NSGCT), completely resected at retroperitoneal lymph node dissection (RPLND), include 2 cycles of adjuvant cisplatin-based chemotherapy, or close surveillance, with chemotherapy reserved for patients who relapse. Both options are associated with cure in an equally high percentage of patients. The decision to choose one of these options over the other is influenced by the extent of the tumor resected and patient compliance. Surveillance is a strong consideration for patients with low-volume nodal disease at RPLND (pN1), because the relapse proportion is 30% or less. In contrast, patients with high-volume nodal involvement at RPLND (pN2) have a relapse rate of 50% to 90% with surveillance alone. Adjuvant chemotherapy is the preferable option in the latter group. A prospective trial of 2 cycles of etoposide plus cisplatin adjuvant chemotherapy for patients with pN2 tumors showed that this regimen was highly effective in achieving relapse-free survival.

Patients with good-risk germ-cell tumors have a high likelihood of cure with an approach that integrates cisplatin-based chemotherapy, surgery, radiation, and observation. This article addresses risk group allocation as well as the controversies regarding the composition, number of cycles, and dosages of chemotherapy regimens used in this population. Recent data from randomized trials demonstrate that carboplatin is inferior to cisplatin and that the dose of etoposide should be 500 mg/m(2) per course. Bleomycin remains controversial in good-risk germ-cell tumors, but the literature suggests that both E(500)P for four cycles or BE(500)P for three cycles may be considered standard.

In the past few years, radiologists have begun to design a single imaging test to thoroughly evaluate the urinary tract. Multidetector computed tomography urography (MDCTU) is a novel imaging technique that provides high-resolution images of the entire renal collecting system in a single helical run. This technique lends itself to creating detailed 3-dimensional urograms. Combining the known strengths of CT axial data and the 3-dimensional urograms can provide a comprehensive evaluation of the genitourinary tract.