Obesity and its implications on oncological urological surgery

Body mass index and survival among patients with advanced biliary tract cancer: a single-institutional study with nationwide data-based validation

BACKGROUND

Excess body weight may modulate the progression of various cancer types. The prognostic relevance of body mass index (BMI) has not been fully examined in patients with biliary tract cancer.

METHODS

Using a single-institutional cohort of 360 patients receiving gemcitabine-based chemotherapy for advanced biliary tract cancer, we examined the association of BMI with overall survival (OS). Using the Cox regression model with adjustment for potential confounders, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for OS according to BMI. The findings were validated using a Japanese nationwide inpatient database including 8324 patients treated at 201 hospitals.

RESULTS

In the clinical cohort, BMI was not associated with OS (Ptrend = 0.34). Compared to patients with BMI = 18.5-24.9 kg/m2, patients with BMI < 18.5 kg/m2 and ≥ 25.0 kg/m2 had adjusted HRs for OS of 1.06 (95% CI, 0.78-1.45) and 1.01 (95% CI, 0.74-1.39), respectively. There was no evidence on a non-linear relationship between BMI and OS (Pnonlinearity = 0.63). In the nationwide cohort, the null findings were validated (Ptrend = 0.18) with adjusted HRs of 1.07 (95% CI, 0.98-1.18) for BMI < 18.5 kg/m2 and 1.05 (95% CI, 0.96-1.14) for BMI ≥ 25.0 kg/m2 (vs. BMI = 18.5-24.9 kg/m2). In the clinical cohort, BMI was not associated with progression-free survival (Ptrend = 0.81).

CONCLUSIONS

BMI was not associated with survival outcomes of patients with advanced biliary tract cancer. Further research is warranted incorporating more detailed body composition metrics to explore the prognostic role of adiposity in biliary tract cancer.

Minimally invasive transperitoneal partial versus radical nephrectomy in obese patients: perioperative and long-term functional outcomes from a large perspective contemporary series (RECORd2 project)

BACKGROUND

The aim of this study is to evaluate the perioperative and long-term functional outcomes of laparoscopic (LPN) and robot-assisted partial nephrectomy (RAPN) in comparison to laparoscopic radical nephrectomy (LRN) in obese patients diagnosed with renal cell carcinoma.

METHODS

Clinical data of 4325 consecutive patients from The Italian REgistry of COnservative and Radical Surgery for cortical renal tumor Disease (RECORD 2 Project) were gathered. Only patients treated with transperitoneal LPN, RAPN, or LRN with Body Mass Index (BMI) ≥30 kg/m2, clinical T1 renal tumor and preoperative estimated glomerular filtration rate (eGFR) ≥60 mL/min, were included. Perioperative, and long-term functional outcomes were examined.

RESULTS

Overall, 388 patients were included, of these 123 (31.7%), 120 (30.9%) and 145 (37.4%) patients were treated with LRN, LPN, and RAPN, respectively. No significant difference was observed in preoperative characteristics. Overall, intra and postoperative complication rates were comparable among the groups. The LRN group had a significantly increased occurrence of acute kidney injury (AKI) compared to LPN and RAPN (40.6% vs. 15.3% vs. 7.6%, P=0.001). Laparoscopic RN showed a statistically significant higher renal function decline at 60-month follow-up assessment compared to LPN and RAPN. A significant renal function loss was recorded in 30.1% of patients treated with LRN compared to 16.7% and 10.3% of patients treated with LPN and RAPN (P=0.01).

CONCLUSIONS

In obese patients, both LPN and RAPN showcased comparable complication rates and higher renal function preservation than LRN. These findings highlighted the potential benefits of minimally invasive PN over radical surgery in the context of obese individuals.

Body mass index, triglyceride-glucose index, and prostate cancer death: a mediation analysis in eight European cohorts

BACKGROUND

Insulin resistance is a hypothesised biological mechanism linking obesity with prostate cancer (PCa) death. Data in support of this hypothesis is limited.

METHODS

We included 259,884 men from eight European cohorts, with 11,760 incident PCa's and 1784 PCa deaths during follow-up. We used the triglyceride-glucose (TyG) index as indicator of insulin resistance. We analysed PCa cases with follow-up from PCa diagnosis, and the full cohort with follow-up from the baseline cancer-free state, thus incorporating both PCa incidence and death. We calculated hazard ratios (HR) and the proportion of the total effect of body mass index (BMI) on PCa death mediated through TyG index.

RESULTS

In the PCa-case-only analysis, baseline TyG index was positively associated with PCa death (HR per 1-standard deviation: 1.11, 95% confidence interval (CI); 1.01-1.22), and mediated a substantial proportion of the baseline BMI effect on PCa death (HRtotal effect per 5-kg/m2 BMI: 1.24; 1.14-1.35, of which 28%; 4%-52%, mediated). In contrast, in the full cohort, the TyG index was not associated with PCa death (HR: 1.03; 0.94-1.13), hence did not substantially mediate the effect of BMI on PCa death.

CONCLUSIONS

Insulin resistance could be an important pathway through which obesity accelerates PCa progression to death.

Expected and paradoxical effects of obesity on cancer treatment response

Obesity, whose prevalence is pandemic and continuing to increase, is a major preventable and modifiable risk factor for diabetes and cardiovascular diseases, as well as for cancer. Furthermore, epidemiological studies have shown that obesity is a negative independent prognostic factor for several oncological outcomes, including overall and cancer-specific survival, for several site-specific cancers as well as for all cancers combined. Yet, a recently growing body of evidence suggests that sometimes overweight and obesity may associate with better outcomes, and that immunotherapy may show improved response among obese patients compared with patients with a normal weight. The so-called 'obesity paradox' has been reported in several advanced cancer as well as in other diseases, albeit the mechanisms behind this unexpected relationship are still not clear. Aim of this review is to explore the expected as well as the paradoxical relationship between obesity and cancer prognosis, with a particular emphasis on the effects of cancer therapies in obese people.

Height, body mass index and prostate cancer risk and mortality by way of detection and cancer risk category

Obesity is a risk factor for advanced, but not localised, prostate cancer (PCa), and for poor prognosis. However, the detection of localised PCa through asymptomatic screening might influence these associations. We investigated height and body mass index (BMI) among 431 902 men in five Swedish cohorts in relation to PCa risk, according to cancer risk category and detection mode, and PCa-specific mortality using Cox regression. Statistical tests were two-sided. Height was positively associated with localised intermediate-risk PCa (HR per 5 cm, 1.03, 95% CI 1.01-1.05), while overweight and obesity were negatively associated with localised low- and intermediate-risk PCa (HRs per 5 kg/m² , 0.86, 95% CI 0.81-0.90, and 0.92, 95% CI 0.88-0.97). However, these associations were partially driven by PCa's detected by asymptomatic screening and, for height, also by symptoms unrelated to PCa. The HR of localised PCa's, per 5 kg/m² , was 0.88, 95% CI 0.83 to 0.92 for screen-detected PCa's and 0.96, 95% CI 0.90 to 1.01 for PCa's detected through lower urinary tract symptoms. BMI was positively associated with PCa-specific mortality in the full population and in case-only analysis of each PCa risk category (HRs per 5 kg/m² , 1.11-1.22, P for heterogeneity = .14). More active health-seeking behaviour among tall and normal-weight men may partially explain their higher risk of localised PCa. The higher PCa-specific mortality among obese men across all PCa risk categories in our study suggests obesity as a potential target to improve the prognosis of obese PCa patients.

Differences in risk factors for biochemical recurrence after radical prostatectomy stratified by the degree of obesity: Focused on surgical methods

This study aims to evaluate differences in the risk factors for biochemical recurrence (BCR) for radical prostatectomy stratified by degree of obesity, focusing on the surgical method used. All 3099 patients who underwent radical prostatectomy in two medical centres from January 2008 to March 2018 were retrospectively reviewed. Patients were divided into three groups based on body mass index: ‘normal’, ‘overweight’, and ‘obese’. Risk factors associated with biochemical recurrence were compared between different degrees of obesity. We analysed the contributing risk factors of BCR-free survival using univariate and multivariable Cox hazard models. There were 378 (12.2%) and 1815 (58.6%) patients in the ‘obese’ and ‘overweight’ groups, respectively. Accordingly, 1324 patients underwent retropubic radical prostatectomy (RRP), and 1775 underwent robotic-assisted laparoscopic prostatectomy (RALP). Multivariable analysis showed that patients who underwent RALP had significantly lower BCR free survival in the ‘overweight’ and ‘obese’ groups than those who underwent RRP, with adjusted hazard ratios of 0.75 (95% CI 0.59–0.95, p-value = 0.01) and 0.55 (95% CI 0.33–0.90, p-value = 0.02), respectively. The degree of obesity was not directly associated with BCR-free survival. Robotic prostatectomy showed greater benefits in BCR-free survival than open prostatectomy in the ‘overweight’ and ‘obese’ groups.

Predictors of early postoperative and mid-term functional outcomes in patients treated with Endoscopic Robot-Assisted Simple Enucleation (ERASE): results from a tertiary referral center

BACKGROUND

The aim of this study was to assess the early and mid-term functional outcomes of Endoscopic Robot Assisted Simple Enucleation (ERASE) verified through a standardized tumor-resection reporting system (Surface Intermediate Base [SIB] score) and to investigate for predictors of renal function (RF) loss in patients with T1 renal tumors treated in a tertiary referral institution.

METHODS

Data of 553 patients treated with ERASE were analyzed. Only patients with SIB score of 0-1 and negative oncological follow-up were included. A ≥25% drop from baseline of estimated glomerular filtration rate (eGFR) was considered as a clinically meaningful functional loss. Multivariable regression models tested the relation between clinical features and RF loss at postoperative day (POD) 3 and at last follow-up.

RESULTS

Overall, 347 patients with SIB 0-1 entered the study. A RF drop ≥25% was observed in 178 (37%) patients in POD 3 and in 91 (18.9%) patients at a median follow-up of 36 months, respectively. At multivariable analysis, age at surgery and PADUA score were significant predictive factors of clinically significant RF loss at POD 3, while age at surgery, female gender, higher BMI, Charlson Comorbidity Index (CCI) and preoperative eGFR were significant predictors of RF loss at last follow-up.

CONCLUSIONS

Age at surgery and higher PADUA score are significant predictors of early postoperative RF loss after ERASE for T1 renal tumors, while age at surgery, female gender, higher BMI, CCI and baseline RF significantly affect mid-term RF. Larger studies and a longer follow-up are needed to confirm these results.