The obesity paradox: defining the impact of body mass index and diabetes mellitus for patients with non‐muscle‐invasive bladder cancer treated with bacillus Calmette–Guérin

Abstract

Objectives To evaluate if the obesity paradox, wherein obesity portends worse overall prognosis for a disease but improved outcomes for patients receiving immunotherapy, exists for patients receiving bacillus Calmette–Guérin (BCG) in a contemporary cohort. Patients and Methods We performed an Institutional Review Board‐approved database review to identify patients with non‐muscle‐invasive bladder cancer (NMIBC) completing at least an induction course of BCG. Clinicopathological variables collected included: body mass index (BMI), medications, and diabetes mellitus (DM). Outcomes of interest included: recurrence‐free (RFS), progression‐free (PFS), cancer‐specific (CSS), and overall survival (OS). Univariate and multivariate modelling were used to evaluate the association between outcomes and clinical factors. Results A total of 579 patients (median follow‐up 4.6 years) received BCG induction for NMIBC; 90% had high‐grade disease (47.2% clinical stage T1). In all, 75.7% of patients were overweight or obese and 18% had DM. Aspirin, statins, metformin and β‐blockers were used in 34%, 42%, 11%, and 29% of patients, respectively. Overweight and obese patients had improved PFS, CSS and OS. DM was associated with worse RFS. Medications of interest had no association with outcomes. Conclusion Elevated BMI is associated with improved outcomes in patients with NMIBC treated with BCG immunotherapy. Patients with DM are at increased risk of recurrence. These findings support a potential obesity paradox in bladder cancer. Evaluation of the underlying mechanism and the role of global patient assessment, counselling, and risk factor modification are warranted.

Preoperative systemic immune‐inflammation index as a significant prognostic factor after TURBT in patients with non‐muscle‐invasive bladder cancer: A retrospective study based on propensity score matching analysis

“…This finding supports a potential paradox in previous bladder cancer studies related to the effects of obesity. As per our understanding, this result may be related to the choice of the treatment regimen, which is consistent with the findings of Brooks et al 39 In 2019, Kim et al 40 first proposed gross hematuria as a potential predictor of NMIBC recurrence. However, in our study, gross hematuria was not statistically significant in the univariate regression, neither before nor after PSM.…”

The ambiguous role of obesity in oncology by promoting cancer but boosting antitumor immunotherapy

“…Review of clinical and epidemiological literature shows some types of cancer also fit the obesity paradox. In patients with lung, bladder, breast cancer (premenopausal), and melanoma, to name a few, overweight/obese patients displayed better long-term survival rate, reduced overall morbidity, and reduced in-hospital mortality [ 142 , 152 ].…”

Two‐sided roles of adipose tissue: Rethinking the obesity paradox in various human diseases from a new perspective

“…69,70 Numerous studies indicate that the number of Growing evidence suggests that several cancer types are also considered as part of the obesity paradox, such as non-small-cell lung cancer (NSCLC), bladder cancer, renal cell carcinoma, melanoma, and breast cancer, where obesity is associated with long-term survival benefits, reduced mortality, and better immunotherapy efficacy of patients. [82][83][84][85][86][87] The existence of the obesity paradox in tumors suggests that adipose tissue plays complex roles in tumorigenesis, and…”