Systemic chemotherapy of transitional cell carcinoma of the urothelium

Urothelial Carcinoma of the Bladder With Primary Metastasis to the Brain: A Case Report and Literature Review

Brain metastases are the most common type of brain tumor in adults, commonly arising from primary tumor sites of the lung, breast, skin (melanoma), colon, and kidney. Isolated central nervous system (CNS) metastasis arising from urothelial carcinoma (UC) is a rare presentation yielding a poor prognosis.

A 71-year-old male patient with a history of urothelial carcinoma, treated one year prior with partial cystectomy and adjuvant gemcitabine and cisplatin (GC) therapy, presented with worsening neurological symptoms, including progressively worsening dizziness, shuffling gait, drifting, expressive aphasia, and confusion. MRI revealed a left frontal 4.0 x 3.6 cm brightly contrast-enhancing tumor with possible hemorrhage, extensive vasogenic edema, and moderate mass effect. An additional smaller right cerebellar lesion was also noted. Outpatient CT of his chest, abdomen, and pelvis revealed no evidence of other malignant sites. He ultimately underwent a left craniotomy with a total resection of his left frontal mass. Pathological examination revealed a urothelial primary. Post-operative MRI revealed complete resection of the left frontal mass and the patient was discharged with no neurologic deficits on exam.

In many cases, brain metastases may present years later following initial therapy of UC as the CNS may act as a sanctuary site during systemic chemotherapy. Chemotherapeutics such as gemcitabine with better penetration of the blood-brain barrier may be beneficial in delaying the onset of these metastases.

Use of green fluorescent protein to measure tumor growth in an implanted bladder tumor model

PURPOSE

Bladder cancer is a common malignancy in which local recurrence and distant failure contribute to poor patient outcome. The search for improved therapies remains a high priority in this disease. For most experimental therapies animal tumor models represent an important step between in vitro testing and clinical trials. A useful animal model of bladder cancer involves the orthotopic implantation of bladder tumor cells in sygeneic animals. This model offers the opportunity to test the efficacy of therapies administered systemically or intravesically. However, quantitation of tumor growth has been difficult.

MATERIALS AND METHODS

To allow the quantitative assessment of tumor mass in this model and differentiate tumor cells from normal bladder epithelium at early stages of tumor growth we transfected cells of the MBT2 murine bladder cancer cell line with a vector encoding enhanced green fluorescent protein and devised an enzyme-linked immunosorbent assay that enables the detection of green fluorescent protein in cells at the pg. level.

RESULTS

Using this assay tumor growth can be detected 7 days after implantation and by 14 days levels of green fluorescent protein are more than 500-fold greater than in controls.

CONCLUSIONS

Combined with the enzyme-linked immunosorbent assay use of this MBT2 green fluorescent protein transfectant allows tumor cell growth to be monitored with sensitivity and reproducibility. It reduces the time required to measure effects on tumor growth to 2 weeks, while preserving the advantages of this orthotopic tumor model.

Genetic alterations and biological pathways in human bladder cancer pathogenesis

Human bladder cancers are heterogeneous. For example, at first presentation papillary transitional cell carcinomas (TCCs) are typically superficial and often multifocal. Papillary TCCs frequently recur, but most never progress to invasive TCC. In contrast, bladder carcinoma in situ (CIS) usually presents as a solitary flat lesion and, if left untreated, invariably progresses to invasive TCC. Some TCC are already invasive at the time of presentation. Squamous cell carcinoma (SCC) tends to present at a later stage than most TCCs and has a relatively aggressive clinical course. Multiple genetic alterations have been identified in invasive human bladder cancers and are present in different combinations and in different frequencies in the different manifestations of bladder cancer described above. A high percentage ( approximately 67%) of superficial papillary TCCs show early losses involving chromosome 9q, while very few show either a TP53 or a CDKN2/16 mutation. Thus, loss of 9q may be the earliest event in initiation of papillary TCC. In contrast, bladder CIS and SCC show relatively low percentages of 9q loss. However, approximately 65% of bladder CIS contain a TP53 alteration and approximately 67% of bladder SCC contain a CDKN2/p16 alteration. Mutations in these two tumor suppressor genes have powerful implications for loss of genome stability and cell growth regulation, respectively, consistent with the aggressive phenotypes of these cancers. Thus, these data suggest a model of bladder cancer pathogenesis in which the predominant genetic alteration may be the "initiating event" in cancer pathogenesis and may play a role in determining the biological potential of the tumor.

Current concepts in assessment and treatment of bladder cancer

Transitional cell carcinoma of the bladder is comprised of a variety of cancer diatheses that manifest a spectrum of distinct biologic potentials. The challenge is to control superficial disease recurrence and progression and to identify invasive carcinoma at an earlier stage, when it may be more amenable to cure.

pH and drug resistance in tumors

Uptake of weakly ionizing drugs by tumours is greatly influenced by the interstitial and intracellular pH, and the ionization properties of the drug. Extracellular pH in tumors is acidic, while the intracellular pH is in the neutral-to-alkaline range. Tumors of the bladder, kidney and gastrointestinal system in particular are exposed to extremes of pH. Strategies for exhancing and exploiting acid-outside plasmalemmal pH gradients to drive the uptake of weak acid drugs into tumors are discussed, as are techniques for alkalinizing tissues to improve response to weak base drugs. The participation of acidic intracellular vesicles in non-specific drug resistance is explored. Copyright 2000 Harcourt Publishers Ltd.

A phase II trial of methotrexate, cisplatin, 5-fluorouracil, and leucovorin in the treatment of invasive and metastatic urothelial carcinoma

BACKGROUND

The current treatment of advanced urothelial carcinoma generates high response rates but is associated with poor overall survival. The current study evaluated the efficacy and toxicity of a new combination of active drugs in the treatment of urothelial carcinoma.

METHODS

Twenty-four patients with muscle invasive or metastatic urothelial carcinoma were enrolled. Fifteen patients (63%) had metastatic disease whereas 9 patients had T2-T4 disease. Three patients were unevaluable for response because of significant toxicity. Patients were treated every 28 days with methotrexate, 60 mg/m(2), intravenously (i.v.) on Day 1; cisplatin, 25 mg/m(2)/day, by continuous i.v. infusion on Days 2-6; 5-flurouracil (5-FU) 800 mg/m(2)/day by continuous i.v. infusion on Days 3-6; and leucovorin, 500 mg/m(2)/day, by continuous i.v. infusion on Days 2-6. Dosage in subsequent cycles was adjusted according to toxicity.

RESULTS

The median follow-up was 81 months (range, 53-97+ months). The overall response rate (complete response + partial response) for all 24 patients was 63% (95% confidence interval, 41-81%). The median survival was 65 months in the patients with muscle invasive disease and 17 months in the patients with metastatic disease. The duration of response in patients with metastatic disease was 6 months (range, 4-19 months). Toxicity was significant, with 82% of patients experiencing Common Toxicity Criteria Grade 3 or 4 neutropenia and 63% experiencing Grade 3 or 4 thrombocytopenia. However, only three patients developed febrile neutropenia and gastrointestinal and neurologic toxicity was moderate.

CONCLUSIONS

The combination of methotrexate, cisplatin, 5-fluorouracil, and leucovorin represents an active regimen in the treatment of urothelial carcinoma with a moderate toxicity profile. As new drugs are found to treat urothelial carcinoma, further studies will be needed to evaluate the role of traditional agents such as 5-fluorouracil and methotrexate in new combination chemotherapeutic regimens.