The use of chemotherapy in the treatment of malignant tumors of the genitourinary system serves as a paradigm for a multidisciplinary approach to cancer. The careful integration of surgical and chemotherapeutic treatments has resulted in impressive advances in the management of urologic cancer. By definition, surgical interventions are directed at local management of urologic tumors, whereas chemotherapy and biologic therapy are systemic in nature. Although there is no question that there are times in the natural history of a genitourinary tumor when only one therapeutic method is required, a multidisciplinary approach is always called for. This chapter details the importance of a joint surgical–medical approach to patients with urologic cancer. A practicing urologist should collaborate closely with a medical oncologist and should feel comfortable speaking with patients about the uses, risks, and benefits of chemotherapy.
Clinical Uses of Chemotherapy
Systemic therapy is indicated in the treatment of disseminated cancer when either cure or palliation is the goal. In addition, chemotherapy may be used as part of a multimodality treatment plan in an effort to improve both local and distant control of the tumor. An understanding of the goals and limitations of systemic therapy in each of these settings is essential for its effective use.
Curative Intent of Metastatic Disease
In considering the role of potentially curative chemotherapy in patients with metastatic disease, several factors must be taken into account. The first is the responsiveness of the tumor. Responsiveness is generally defined by the observed partial or complete responses that together constitute the overall objective response rate. The assessment of neoplasms with frequent bony metastases such as prostate cancer, renal cell carcinoma, and transitional cell carcinoma (TCC) is difficult, as a persistently abnormal bone scan does not necessarily imply residual cancer. Patients in whom the only site of disease is bone generally must be considered nonassessable by conventional measures, and if available, intermediate markers of response (such as prostate-specific antigen [PSA]) are required. The transient worsening appearance of a bone scan with therapy but which represents healing bone is termed “bone scan flare,” and can be indistinguishable from true disease progression. For this reason, assessment of all parameters including symptomatology, PSA in prostate cancer patients, CT and MRI is essential. For patients with metastatic prostate cancer in whom bone scan flare is suspected or possible, repeating scans several months later is essential.
If cure is the intent with systemic therapy, the relevant response criterion to consider is the percentage of patients achieving a complete response. This number is less than 10% in patients with metastatic renal cell carcinoma and hormone-refractory prostate cancer, 25% or less in patients with metastatic transitional cell carcinoma, and up to 80% in patients with metastatic germ cell malignancies. Under some circumstances, however (for example, in postchemotherapy residual masses in patients with germ cell carcinoma), an apparent partial response can be converted into a complete response with ...