Treatment of superficial carcinoma of the bladder

[Cell cycle and apoptosis mechanisms implicated in intravesical chemotherapy resistances in superficial bladder cancer]

It is well documented the effectiveness of intravesical chemotherapy following transurethral resection to prevent recurrences of superficial bladder cancer. But it is also known that efficacy may be limited by tumour cell resistance to one or several of the drugs available for instillation. In addition to the genetically determined unicellular mechanisms classically described in the literature such as glycoprotein P-170 expression (mdr-1), overexpression of Bcl-2 or glutation S-transferase activity, it has been recently shown that multicellular mechanisms may also be involved in drug resistance. Multicellular resistance can only be demonstrated in three-dimensional cultures and fails to be shown in monolayers or cell suspensions. This is explained by the fact that cell-to-cell and cell-to-stroma adhesion limits drug penetration and by the variable susceptibility to cytotoxicity determined by oxygen and tissue proliferation gradients. A better understanding of the molecular mechanisms involved in drug resistance is necessary to increase intravesical chemotherapy effectiveness. Current research includes improving drug penetration, searching resistance reversing agents and developing in vitro chemosensitivity tests to identify drug resistance.

Peripheral blood lymphocyte response in patients with superficial transitional cell carcinoma of the bladder treated with intravesical Bacillus Calmette-Guérin--a useful marker of response?

Intravesical instillation of Bacillus Calmette-Guérin (BCG) offers safe and effective short-term/long-term treatment for superficial transitional cell carcinoma (TCC) and TCC in situ of the bladder. However, 17 to 42% of patients may experience recurrence in spite of this therapy and a marker of effective treatment is of paramount importance. In this study the in vitro response of peripheral blood lymphocytes (PBL) to BCG was analysed in 10 patients with superficial TCC and TCC in situ before and during BCG instillations. The in vitro response of PBL to BCG, expressed as a stimulatory index (SI), revealed that 6 patients had a SI > 5 and 4 patients had a SI < 5. None of the former patients had recurrence of TCC during a mean follow-up of 17 months, while all of the latter patients experienced recurrence of TCC within 9 months. It was concluded that the in vitro response of PBL to BCG may be used as a marker of response to intravesical BCG treatment.

Clinical significance of natural killer activity in patients with transitional cell carcinoma of the bladder

We studied the relationship of natural killer activity from peripheral blood mononuclear cells with clinical stage of disease and the different modalities of treatment in 67 untreated patients with transitional cell carcinoma of the bladder and 29 normal controls. Peripheral blood mononuclear cells from 39 patients with superficial bladder tumor (stages Ta and T1) showed a natural killer cell activity similar to that of controls (p greater than 0.05), while in 28 patients with infiltrating tumors (stages T2, T3 and T4) this activity was significantly depressed (p less than 0.01). This functional phenomenon cannot be ascribed to a deficient number of natural killer cells in patients with infiltrating tumors, since the amounts of HNK-1+ (Leu 7), CD16+ (Leu 11) and CD11b+ (OKM1) cells in peripheral blood mononuclear cells were similar in the 3 groups of subjects (p greater than 0.05). Furthermore, the natural killer activity of peripheral blood mononuclear cells was normal (p greater than 0.05) in patients who underwent transurethral resection of the tumors and intracavitary cytostatic therapy with doxorubicin who remained free of disease at least 6 months after treatment. However, in patients with superficial recurrent tumor a significant decrease in the natural killer activity of peripheral blood mononuclear cells was observed (p less than 0.05), which was more pronounced in those with infiltrating recurrence. Also, in the latter patients total cystoprostatectomy was associated with a relevant increase in the spontaneous level of peripheral blood mononuclear cells. We conclude that in patients with transitional cell carcinoma of the bladder there is a correlation of the levels of natural killer activity in peripheral blood mononuclear cells with clinical evolution and pathological stage of disease. The determination of this activity is useful to monitor patients with transitional cell carcinoma of the bladder.