Adjuvant chemotherapy in lymph node positive bladder cancer

Current and recent clinical trials for perioperative systemic therapy for muscle invasive bladder cancer: a systematic review

BACKGROUND

Although Muscle Invasive Bladder Cancer (MIBC) is increasing in incidence, treatment has largely remained limited to radical cystectomy with or without cisplatin-based neoadjuvant and/or adjuvant chemotherapy. We reviewed the current and recent clinical trials evaluating perioperative chemotherapy, targeted therapy, and novel therapeutic regimens for MIBC patients undergoing radical cystectomy.

METHODS

An overview of perioperative MIBC management was conducted initially using MEDLINE. The Clinical Trials Registry and MEDLINE were further searched specifically for perioperative MIBC chemotherapy, targeted therapy, and other novel therapeutic approaches. Trials involving non-perioperative management, operative management other than radical cystectomy, multiple tumors, or purely superficial or metastatic disease were excluded from selection. These criteria were not specifically fulfilled for mTOR inhibitor and immune therapy trials. Only phase III chemotherapy and phase II targeted therapy trials found in the Clinical Trials Registry were selected. MEDLINE searches of specific treatments were limited to January 2009 to January 2014 whereas the Clinical Trials Registry search had no timeline. Systematic MEDLINE searches had no phase restrictions. Trials known by the authors to fulfill search criteria but were not found via searches were also selected.

RESULTS

Twenty-five trials were selected from the Clinical Trials Registry including 7 phase III chemotherapy trials, 11 Phase II targeted therapy trials, 3 immune therapy trials, 1 mammalian target of rapamycin (mTOR) inhibitor trial, and 3 gene and vaccine therapy trials. Nine trials have been completed and 5 have been terminated early or withdrawn. Nine trials have data available when individually searched using MEDLINE and/or Google. Systematic searches of MEDLINE separately found 12 trials in the past 5 years. Two phase III chemotherapy trials were selected based on knowledge by the authors. No phase III trials of targeted therapy have been registered or published.

CONCLUSIONS

New trials are currently being conducted that may revolutionize MIBC treatment preceding or following cystectomy. Head-to-head phase III trials of perioperative chemotherapy and further phase II and phase III trials of targeted therapy and other therapeutic approaches are necessary before the current cisplatin-based perioperative chemotherapy paradigm is altered.

Lymph node-positive bladder cancer: surgical, pathologic, molecular and prognostic aspects

The presence of lymphatic metastasis is associated with markedly worse prognosis in patients with bladder cancer, although surgical resection and chemotherapy can still provide long-term survival for selected patients. The prognostic stratification of patients with positive lymph nodes has been broadly discussed in the current literature and a more extensive pelvic lymph node dissection and thorough pathologic assessment has been advocated. It is clear that stratification using the tumor node metastasis staging system is insufficient to adequately discriminate prognosis between patients with different lymph node involvement. Lymph node density and extranodal extension have been extensively investigated and appear to influence the prognosis of these patients. Molecular markers have been developed to improve the diagnosis of micrometastatic disease, and new targeted therapies have shown promising preclinical results and are now being tested in different clinical scenarios.

External validation of extranodal extension and lymph node density as predictors of survival in node-positive bladder cancer after radical cystectomy

BACKGROUND

Prognostic factors in pathologic node-positive patients after radical cystectomy are debated. Extranodal extension (ENE) and lymph node density (LND) are strong predictors of survival. The aim of this study was to assess factors predictive of survival and to evaluate the prognostic significance of the tumor, node, metastasis staging system (TNM) nodal classification in a retrospective cohort of node-positive bladder cancers after radical cystectomy.

METHODS

We retrospectively reviewed the data of 75 patients with node-positive bladder cancer after radical cystectomy. Node pathological examination was performed by two experienced uropathologists. Cox regression analysis was performed to identify factors predictive of progression.

RESULTS

The median number of removed lymph node was 18 (range 3-49). The median number of positive lymph nodes was 3 (range 1-35). Overall progression-free and cancer-specific survival were 5 and 12 %. In multivariate analysis, ENE, LND with a 20 % cutoff, and adjuvant chemotherapy were independent predictors of progression-free survival (p = 0.007, 0.006, <0.0001). Neither the 2002 nor the 2009 TNM nodal classification was associated with recurrence.

CONCLUSIONS

ENE and LND are strong predictors of clinical outcome in patients with node-positive bladder cancer treated by cystectomy. The actual TNM classification could probably be improved using these criteria, allowing better prognostic classification of node-positive bladder cancer after radical cystectomy.

Lymph node dissection for bladder cancer: the issue of extent and feasibility in the minimally invasive era

Lymph node dissection in bladder cancer is an integral part of radical cystectomy. It allows for accurate staging of the patient and will, therefore, serve to dictate additional treatment and add prognostic information. The issue of what is an adequate lymphadenectomy as to the extent and boundaries of the operation, specifically the cephalad extent, has been the focus of recent debate. Some have suggested that lymph node yield, in terms of number, could serve as a surrogate for the adequacy of the node dissection and, thus, the oncologic efficacy of the operation. It has also been suggested that it is a marker for the experience of the operating surgeon. What is meant by a limited, standard and extended lymph node dissection varies among different publications. Recent evidence suggests that an 'extended' node dissection infers oncologic efficacy. With the advent of minimally invasive and, specifically, robotic-assisted surgery, more cystectomies are approached robotically. As such, there has been recent debate as to whether a robotic-assisted procedure can emulate the open approach, satisfying the accepted boundaries and extent of dissection and ultimately leading to equivalent oncologic outcomes without increasing morbidity. In this review, we focus on the extent of lymphadenectomy in bladder cancer by reviewing the lymphatic drainage and arguments in favor of a more extended dissection. We will then address the minimally invasive techniques, focusing on robotic-assisted surgery, and review the evidence suggesting that this is a promising new technique that results in acceptable nodal yield and potentially equivalent oncologic outcomes with no added morbidity.