Background The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting. Objective We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort. Design, setting, and participants Data were collected retrospectively at 19 centers on patients with clinical cT2–4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013. Intervention NAC and RC Outcome measurements and statistical analysis The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and ≤pT1N0 stages. Results and limitations Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n = 602; 64.4%), followed by MVAC (n = 183; 19.6%) and other regimens (n = 144; 15.4%). The rates of pT0N0 and ≤pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p = 0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61–1.34]; p = 0.6). Conclusions Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined. Patient summary There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer.
Introduction: Randomized controlled trials of platinum-based neoadjuvant chemotherapy (NAC) for bladder cancer have shown that patients who achieve a pathologic response to NAC exhibit 5 y survival rates of approximately 80–90% while NAC resistant (NR) cases exhibit 5 y survival rates of approximately 30–40%. These findings highlight the need to predict who will benefit from conventional NAC and the need for plausible alternatives. Methods: The pre-treatment biopsy tissues from a cohort of 41 patients with muscle invasive bladder who were treated with NAC were incorporated in tissue microarray and immunohistochemistry for PD-L1, CD8, and FOXP3 was performed. Percentage of PD-L1 positive tumor cells was measured. Tumor-infiltrating lymphocytes (TIL) densities, along with CD8 and Treg-specific TILs, were measured. Results: TIL density was strongly correlated with tumor PD-L1 expression, consistent with the mechanism of adaptive immune resistance in bladder cancer. Tumor cell PD-L1 expression was not a significant predictor of response. Neither was the CD8 nor Treg TIL density associated with response. Intriguingly though, the ratio of CD8 to Treg TIL densities was strongly associated with response (p = 0.0003), supporting the hypothesis that the immune system plays a role in the response of bladder cancer to chemotherapy. Discussion: To our knowledge, this is the first report in bladder cancer showing that the CD8 to Treg TIL density in the pre-treatment tissues is predictive for conventional NAC response. These findings warrant further investigations to both better characterize this association in larger cohorts and begin to elucidate the underlying mechanism(s) of this phenomenon.
What's known on the subject? and What does the study add? The administration of Bacillus Calmette‐Guérin (BCG) immunotherapy has become the standard of care for high‐grade non‐muscle invasive bladder cancer (NMIBC) and carcinoma in‐situ (CIS) in terms of prevention of recurrence and progression. While most agree on a 6 week induction cycle, various maintenance schedules (if any at all) have been implemented without a unifying consensus. This review assesses the historical emergence of BCG immunotherapy, beginning with its discovery as a vaccinatin for tuberculosis to its effect on the host immune system and potential therapeutic benefits for various oncologic conditions. The data establishing BCG immunotherapy as the standard of care for high‐grade NMIBC and CIS over other bladder instillation modalities is presented in addition to the effect maintenance BCG therapy has on sustaining the immuno‐protective effect. Bacillus Calmette‐Guérin (BCG) immunotherapy is currently the most effective treatment of non‐muscle invasive bladder cancer and one of the most successful applications of immunotherapy to the treatment of cancer. This review summarises the history and development of BCG as a modern cancer treatment, appraises current optimal application of BCG immunotherapy in bladder cancer, discusses promising new therapies closely related to BCG, and briefly explores the possibility that BCG or related treatments may have an application in other urological malignancies. BCG is a nonspecific stimulant to the reticuloendothelial system and induces a local inflammatory response with the infiltration of granulocytes followed by macrophages and lymphocytes, particularly helper T cells. The initial BCG controlled trial showed a statistically significant reduction in tumour recurrence and found the advantage increased with duration of follow‐up. Similar results were reported in much higher risk patients in an independent concurrent study. Follow‐up suggested that a single 6‐week course of intravesical BCG provided long‐term protection (up to 10 years) from tumour recurrence and even reduced disease progression. While induction BCG (six weekly instillations) reduced recurrence, progression and mortality at 10 years, this advantage was lost by 15 years, and patients remained at high risk for progression without the use of maintenance BCG. In a meta‐analysis by the Cochrane group, induction BCG was found to be markedly superior to mitomycin C in high‐risk patients but not in low‐risk patients. Additionally, the National Comprehensive Cancer Network guidelines lists the use of intravesical BCG as preferred therapy, citing Category 1 data for high‐grade Ta, all T1, and any Tis tumours. Maintenance BCG therapy may be the most important advance in BCG treatment of bladder cancer since the initial introduction. The risk of tumour recurrence and disease progression is life‐long in most patients, but the immune stimulation induced by BCG wanes with time. Logarithmic dose reduction of BCG in patients with increasing side‐effects wi...
Single-minded 1 (Sim1) is a transcription factor necessary for development of the paraventricular nucleus of the hypothalamus (PVH). This nucleus is a critical regulator of appetite, energy expenditure and body weight. Previously we showed that Sim1+/− mice and conditional postnatal Sim1−/− mice exhibit hyperphagia, obesity, increased linear growth and susceptibility to diet-induced obesity, but no decrease in energy expenditure. Bilateral ablation of the PVH causes obesity due to hyperphagia and reduced energy expenditure. It remains unknown whether Sim1 neurons regulate energy expenditure. In this study, Sim1cre mice were bred to homozygous inducible diphtheria toxin receptor (iDTR) mice to generate mice expressing the simian DTR in Sim1 cells. In these mice, Sim1 neuron ablation was performed by intracerebroventricular (ICV) injection of diphtheria toxin. Compared to controls, mice with Sim1 neuron ablation became obese (with increased fat mass) on a chow diet due to increased food intake and reduced energy expenditure. In post-injection mice, we observed a strong inverse correlation between the degree of obesity and hypothalamic Sim1 expression. The reduction in baseline energy expenditure observed in these mice was accompanied by a reduction in activity. This reduction in activity did not fully account for the reduced energy expenditure as these mice exhibited decreased resting energy expenditure, decreased body temperature, decreased brown adipose tissue temperature, and decreased UCP1 expression suggesting an impairment of thermogenesis. In injected mice, hypothalamic gene expression of Sim1, oxytocin (OXT) and thyrotropin releasing hormone (TRH) was reduced by about 50%. These results demonstrate that Sim1 neurons in adult mice regulate both food intake and energy expenditure. Based on the body of work in the field, feeding regulation by Sim1 neurons likely occurs in both the PVH and medial amygdala, in contrast to energy expenditure regulation by Sim1 neurons, which likely is localized to the PVH.
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