Our understanding of the molecular biology of bladder cancer is still evolving [14]. The simplest molecular predictors of outcome have correlated with tumor differentiation. For example, absence of expression of ABO blood group substances on the surface of noninvasive bladder cancer cells is associated with higher rates of relapse and progression to invasion [15]. Similarly, the presence of aneuploid populations of cells is also associated with an increased prevalence of relapse and tumor progression, although most invasive bladder cancers actually are aneuploid.

Noninvasive and invasive bladder cancers have different patterns of molecular pathogenesis. Noninvasive disease is particularly characterized by a loss of heterozygosity of chromosome 9, which is where the most important associated gene(s) may reside [16]; fibroblast growth factor (FGF)-3 and RAS are two of the genes associated with noninvasive bladder cancer. With the development of more invasive and undifferentiated disease, aberrations of chromosome 17 are detected, in association with mutations of P53 [17]. Similarly, increased expression of RAS and its variants appears to be associated with loss of differentiation and a worse prognosis [18, 19], and may correlate with P53 function [18].

The functions of P53 and P21 are linked, functioning in a complex, and thus accurate molecular characterization of bladder cancer requires the study of both genes, with outcome being linked to the combination of presence/absence of each gene. In addition, the deletion of the Rb gene confers an adverse prognosis, and its normal function is influenced by the action of the P53/P21 complex [20]. Immunohistochemical studies of a relatively small number of bladder cancer specimens obtained by radical cystectomy have shown that the most favorable prognosis appears to be associated with expression of wild-type P53 and normal expression of P21 [21]. The presence of mutant P53 with deletion of expression of P21 has been reported to predict a high relapse rate. Initial studies from the University of Southern California (USC) have shown that expression of P53 mutation confers prognostic information additional to that afforded by stage and grade [17, 21]. This became the basis of an international randomized trial (see below), which reassessed the true importance of P53 mutations in a much larger sample size (as discussed in detail below) (Table 34.1).

Another relevant gene with a locus on chromosome 9 is p16^INK4a, which functions as a tumor suppressor. It probably inhibits cyclin D function, and is particularly associated with the evolution of squamous carcinoma and bilharzial bladder cancer [22].

The expression of the epidermal growth factor receptor (EGFR) is another molecular determinant of prognosis [23]. This cell surface protein, with known cell growth regulatory functions, is correlated with expression of P53, aneuploidy, and invasive growth [24], but has been shown independently to have prognostic implications for several malignancies. As discussed below, it may also play a role in resistance to cytotoxic agents, such as cisplatin. The transferrin receptor [25], also located on the surface of bladder cancer cells, appears to be another independent prognostic determinant, although the nature of this function is unknown, as is its relationship to the expression of EGFR and other molecular determinants.

The genes that control vascular invasion and angiogenesis also seem to have important prognostic implications. It is known that microvessel density, the extent of tumor vascularity per high power field, is associated with metastasis and prognosis – the higher the microvessel density, the worse the prognosis [26]. Cote and colleagues have also studied the expression of thrombospondin-1 in bladder cancer. This is a glycoprotein component of the extracellular matrix, which inhibits angiogenesis [27], and its expression is directly correlated with prognosis. These studies also have suggested that P53 mutation is associated with suppression of expression of thrombospondin-1.

Investigators at Memorial Sloan Kettering Cancer Center have used oligonucleotide arrays to analyze the transcript profiles bladder tumors and have carried out immunohistochemical analyses on bladder cancer tissue arrays to validate the associations between marker expression, staging and outcome. They were able to achieve a greater than 80 % accuracy in prognostication [28].

Overlapping and interacting molecular functions regulate growth, differentiation and prognosis of bladder cancer. Several of these oncogenes and suppressor genes may be suitable candidates for gene therapy, or for downstream regulation through inhibitors of transcription and translation.

Studies in the late 1980s revealed higher objective response rates from the use of combination chemotherapy regimens than were achieved with single agents, both for the treatment of metastatic bladder cancer and in the neoadjuvant setting [5, 29]. For many tumor types, there is an increasing level of focus on the molecular biology of tumor response to chemotherapy.

We have previously studied the expression of the intracellular scavenger, glutathione, which decreases the available level of cytotoxic agents, such as cisplatin, within tumor cells [30]. In a series of bladder cancer xenografts, high levels of glutathione were identified, representing higher concentrations than are found in malignant melanoma and ovarian cancer, the classical models of the role of glutathione in cytotoxic resistance. In addition, we showed that higher levels of glutathione are expressed in human tumor biopsy specimens than in biopsies from patients with a past history of bladder cancer, and in turn, these levels were higher than those found in normal bladder tissue. The measurement of this protein has not become a standard predictive test in the management of bladder cancer, although there are several sets of preliminary data that implicate glutathione and glutathione-S-transferase in the biology of responses to chemotherapy.

One particularly controversial issue has been the clinical significance of mutation of the P53 suppressor gene in the context of resistance to cytotoxic chemotherapy. Innate resistance to chemotherapy may be a function of expression of P53, although there are conflicting data on whether mutation of P53 confers increased responsiveness [31, 32] or increased resistance [33] to the impact of chemotherapy. Cote and colleagues have reported a post hoc study of immuno-histochemical staining of tumor biopsies from a randomized study of adjuvant platinum-based chemotherapy [32] and suggested that tumors exhibiting mutation of P53 benefited from adjuvant chemotherapy [31]. By contrast, those with wild-type P53 did not exhibit any difference in survival between the control population and those receiving adjuvant chemotherapy. The major problem with this study was small sample size and its post hoc nature.

Studies from Memorial Sloan Kettering Cancer Center initially suggested that P53 mutation was associated with resistance to neoadjuvant chemotherapy with the methotrexate-vinblastine-doxorubicin(Adriamycin^R)-cisplatin (MVAC) regimen [33]. A detailed study of molecular prognosticators in patients treated with the MVAC or cisplatin-methotrexate-vinblastine (CMV) regimens for advanced bladder cancer at Princess Margaret Hospital, Toronto, did not identify any prognostic impact from expression of P53 immunohistochemically [34]. It was not clear whether this reflected a true lack of prognostic relevance or is an artifact of methodology or small sample size. That said, in this small study, another marker (metallothionein expression) did have statistically significant prognostic implications.

The data regarding the prognostic role of metallothionein expression are interesting. Metallothioneins are a family of sulfhydryl-containing cysteine residues that are involved in absorption, transport and metabolism of heavy. Previous studies have suggested that these proteins may be related to resistance to cisplatin and alkylating agents [35]. Satoh et al. demonstrated that an increase in the concentration of metallothionein in mice caused a reduction of nephrotoxicity, accompanied by cisplatin resistance in a mouse bladder cancer [36]. Siu et al. [34] showed in univariate analysis that good performance status, low percentage of metallothionein staining, and high tumor grade were significant positive predictors of response to cisplatin chemotherapy, but that the latter factor was lost in multivariate analysis.

In a detailed study of cell lines, Kielb et al. [37] showed that P53 mutation is required for paclitaxel to induce cell death in vitro in human bladder cancer cells, whereas cells with normal P53 function were not affected by this agent. By contrast, the cytotoxic impact of gemcitabine was not influenced by P53 mutations, suggesting a potentially different spectrum of responses to this agent in bladder cancer.

Multidrug or pleiotropic resistance, in which cell surface protein complexes function as efflux pumps or modulators of intracellular cytotoxic drug concentrations, appears to be relevant to bladder cancer. A family of multidrug resistance (mdr) proteins, including p-glycoprotein, correlates with resistance to the taxanes, vinca alkaloids and anthracycline antibiotics. This phenomenon has been found to be particularly relevant in ovarian cancer and multiple myeloma, but studies of expression of mdr in bladder cancer have been difficult, for reasons that are not fully clear. For example, our xenograft studies identified major clonal differences in response to doxorubicin and vinblastine, but we were unable to demonstrate clear and reproducible expression of p-glycoprotein in the tumor specimens. Others have encountered similar problems. Siu et al. [34], studying patients treated with MVAC or CMV chemotherapy, did not find any prognostic significance from expression of p-glycoprotein, although any impact for response or resistance to chemotherapy might have been overcome by the presence of cisplatin in both regimens, an agent that is not influenced by mdr expression.

However, Petrylak et al. [38] were able to demonstrate clear enhancement of expression of p-glycoprotein in pre- and post-treatment biopsies of human tumors treated with the MVAC regimen. The highest proportion of tumor cells expressing p-glycoprotein was observed in metastases from patients treated with six or more cycles of chemotherapy. These workers speculated that mdr could contribute significantly to the patterns of resistance seen in the use of the MVAC regimen. However, this technology has not been applied routinely to the treatment of invasive bladder cancer, largely because of the difficulty of demonstrating mdr expression in bladder cancer tissues.

Adopting a more technically sophisticated approach, investigators at Memorial Sloan Kettering Cancer Center have studied the transcript profiles of more than 100 bladder specimens, representing the spectrum from normal to relatively benign to malignant disease, in an attempt to identify useful novel prognosticators [28]. In an elegant study that will require validation, they identified a hierarchy of determinants, including peptidyl propyl isomerase A, nuclear RNA export factor 1, tetratricopeptide repeat domain G, hematopoietic cell specific Lyn substrate 1, ankyrin G, baculoviral IAP repeat-containing 3, intercellular adhesion molecule 1 and TP53-activated protein 1. In each instance, Kaplan-Meier curves identified differences in survival based on expression, but further study will be required to identify the utility of such gene expression in predicting the outcome of specific chemotherapy regimens.

In this context, Takata et al. [39], studying a small number of patients treated with MVAC style chemotherapy, identified another series of potential genetic predictors of outcome using array techniques. Again the significance of their preliminary observations will require clarification, although it was interesting to note that these array studies further implicated P53 gene function and mutation in predicting the outcomes of chemotherapy.

At a more pragmatic level, the Radiation Therapy Oncology Group (RTOG) have carried out retrospective analyses of their series of cases treated with radiotherapy and cisplatin-based chemotherapy, and have demonstrated that expression of EGFR is associated with improved outcome, including response to chemoradiotherapy, whereas expression of the her-2-neu gene correlates in univariate analysis with reduced response and survival after such treatment [40].

As outlined in Table 34.1, validation of these applied technologies in much larger patient sets will be required before this approach becomes a standard of care in clinical practice.

As noted above, mutation of P53 has been shown to have prognostic significance independent of stage and grade for P1-2 urothelial cancer [17, 20, 21]. Consequent upon the promising early data from USC, a randomized trial, carried out by an Intergroup, studied the effect of adjuvant MVAC chemotherapy after radical cystectomy for pathological stage P1-2 tumors with negative lymph nodes and expression of mutated P53 [40]. Nearly 500 patients underwent P53 assessment, of whom 55 % showed immunohistochemical reactivity, and 114 were randomized to 3 cycles of adjuvant MVAC versus observation. Although there were several problems of trial execution, including lack of patient compliance, the study did not confirm the prognostic significance of P53 expression [41]. The recurrence rate was unexpectedly low in both arms, with an overall 5 year probability of recurrence of 0.20, with no differences in outcome, node status or lympho-vascular invasion associated with P53 reactivity.

As discussed elsewhere in this volume, the least aggressive surgical treatment of bladder cancer is transurethral resection (TUR) or fulguration, in which the aim is to remove the tumor completely via a cystoscope, while attempting to spare the bladder. Depending on the care in case selection, the extent of tumor, and the population of patients being treated, TUR may lead to an overall 5 year survival of 30–69 %, the majority of patients retaining an intact bladder [42, 43], with higher long-term survival for patients with T1-2 disease.

Another option that has also allowed bladder preservation has been the use of surgical resection of the portion of the bladder that contains the tumor – partial cystectomy [44]. The general consensus is that this is a technique that should only be used in highly selected cases, provided that the following criteria are met: (a) solitary primary lesion at the dome of the bladder, well removed from the bladder neck and ureters; (b) 2 cm margin of normal bladder tissue around the tumor; (c) likelihood of good bladder capacity and function after the procedure; (d) absence of carcinoma-in-situ from random biopsies. When present, carcinoma-in-situ is associated with superficial recurrence, and lymph node involvement is associated with systemic disease [44].

However, the standard of care for most patients with invasive bladder cancer is radical cystectomy [11, 45, 46], as discussed in detail elsewhere in this volume. The cure rate depends on well-defined prognostic factors, including conventional indices, such as stage and grade, and the more recent correlates discussed above. In addition, it appears that delay in cystectomy may lead to impaired survival [46]. Cure is even possible from surgery alone in advanced stage disease, although the chance is much lower. In well-staged patients in contemporary series, the relapse rate after surgical resection of PS T3-4 tumors remains 50 % or higher, with most relapses occurring at distant sites, indicating that this is a disease with the potential for early micrometastatic spread (which forms the basis for neoadjuvant chemotherapy strategies).

As a result, and in view of the modest successes of chemotherapy for metastatic and recurrent disease (see Chap. 36), attempts have been made to combine systemic therapy with definitive local treatment. In addition, surgical templates and techniques have been modified, including the creation of continent pouches and artificial neo-bladders [11], the use of laparoscopic approaches [47] and the avoidance of prostatectomy [48] in an attempt to ameliorate toxicity for an approach with a high relapse rate.

The use of radiotherapy as an alternative to cystectomy for invasive bladder cancer was previously favored in parts of Europe and Canada, although the pendulum has swung back somewhat towards radical cystectomy in recent years because of the perception of higher surgical cure rates. It should be noted that this perception may be influenced heavily by the fact that comparisons in the literature, between the results of surgery and radiotherapy for bladder cancer, reflect the comparison of surgical versus clinical staging. Furthermore, patients treated in radiation series are characteristically older and less robust than those subjected to cystectomy. The traditional approaches to radiotherapy included doses of external beam irradiation in the range of 50–70 Gy, with a higher level of local control achieved in series reporting higher dose schedules [9, 10, 49–52]. Ideal radiotherapy candidates have had aggressive pre-radiotherapy TUR, absence of extralesional carcinoma-in-situ, no anemia, and no hydronephrosis.

The techniques used to deliver curative irradiation to the bladder tumor volume, while sparing normal tissue, vary from one institution to another, depending on the availability of equipment an the quality of physics and computer support [10, 49, 50]. Irrespective of field size and technique, it is clear that dose is critically important, with total doses less than 60 Gy being ineffective [51]. Whether the newer techniques of intensity modulated radiation therapy (IMRT) and image guided radiotherapy will truly improve local control and/or reduce local tissue toxicity remains to be seen [49]. What is clear is that careful treatment planning is critical and requires close collaboration between radiation oncologist and urologist [52]. Of particular importance is the definition of the site and size of the tumor, and treatment planning should require a localizing cystogram or planning CT scan; the latter is preferred as extravesical disease or recent evolution of lymph node involvement can be discerned, in the treatment position. Furthermore periodic on-treatment CT scan assessment will ensure adequacy of ongoing coverage of the tumor and tumor bed within the treatment fields. It is clear that the bladder moves to some extent, despite fixity of bony landmarks, but with appropriate treatment planning, the movement of the bladder does not appear to affect treatment outcomes [53]. Various approaches have been studied in an attempt to improve local control, to shorten the duration of treatment or to ameliorate toxicity. To date, attenuated dose schedules with hyper-fractionation appear to have increased toxicity without any improvement in local control or survival [54].

Preservation of a well-functioning bladder is more likely if a portion of the bladder can safely be excluded from the high dose of radiation needed for the bladder cancer itself. Treatment of the entire bladder with high doses per fraction or a high total dose is more likely to results in scarring and contracture, especially for the bladder that has sustained multiple TUR’s. Care should be taken with respect to the known tolerance of the surrounding normal tissues.

One of the key issues of debate has been the respective merits of surgery versus radiotherapy. However, after many decades of comparison, there is still no absolute proof regarding the superiority of radical cystectomy or radical radiotherapy. A recent report from a single institution in the Netherlands suggests that, once differences in staging techniques are taken into account, there is no major difference in outcomes between these modalities of treatment [55]. However, others have claimed that, notwithstanding the problems of comparison of surgical versus clinical staging, radical cystectomy ultimately offers better local control and survival, in part because surgical resection of involved pelvic nodes will allow long-term survival in 20–30 % of cases [11]. This view remains controversial and has not been proven in randomized trials. In our clinical practice, for fit patients without major intercurrent medical disorders, we tend to refer for radical cystectomy for deeply invasive tumors, reasoning that useful information is gleaned from the surgical staging, and that local control is likely to be more robust. The optimal treatment of superficially invasive disease (clinical stage T1 and perhaps T2) is less clearly defined.

Combined modality approaches, incorporating systemic chemotherapy with definitive local modalities, have been studied extensively in the past few years in the hope of sparing the bladder or to improve overall survival [13, 56]. This has been predicated on the following concepts:

However, as around 30–60 % of tumors are absolutely or relatively chemo-resistant, some patients will sustain unnecessary toxicity for no benefit, and there is the risk that effective local treatment will be delayed while ineffective systemic chemotherapy is used.

In a randomized, prospective trial assessing the utility of concurrent chemoradiation, a protocol of single agent cisplatin administered during the period of radiotherapy resulted in 67 % sustained pelvic tumor control compared to 45 % from radiation alone; however, overall survival was not statistically different, although there was a survival trend in favor of the combined modality therapy [57]. It should be noted that this study was not powered to demonstrate a survival benefit.

James et al. [58] have recently reported the results of a randomized comparison of chemoradiation with 5-fluorouracil-mitomycin C versus radiation alone. In a series dominated by patients with clinical stage T2 disease, this trial demonstrated improved response rate, progression-free and overall survival achieved by chemoradiation [58].

We know of no other randomized trials that have tested the impact of chemo-radiation, compared to radiation alone, for invasive bladder cancer, although a range of phase II trials have demonstrated antitumor efficacy (with response rates as high as 80 %) and toxicity (varying with the doses and regimens employed). The Radiation Therapy Oncology Group (RTOG) has completed several studies that have assessed the utility of neoadjuvant or adjuvant chemotherapy in association with concurrent chemo-radiation. However, none of these trials has addressed the comparison of chemo-radiation versus radiation alone.