Obesity and renal cancer incidence and mortality--a systematic review of prospective cohort studies

The Obesity Paradox and Mortality in Older Adults: A Systematic Review

“Obesity paradox” describes the counterintuitive finding that aged overweight and obese people with a particular disease may have better outcomes than their normal weight or underweight counterparts. This systematic review was performed to summarize the publications related to the obesity paradox in older adults, to gain an in-depth understanding of this phenomenon. PubMed©, Embase©, and Scopus© were used to perform literature search for all publications up to 20 March 2022. Studies were included if they reported data from older adults on the relation between BMI and mortality. The following article types were excluded from the study: reviews, editorials, correspondence, and case reports and case series. Publication year, study setting, medical condition, study design, sample size, age, and outcome(s) were extracted. This review has been registered with PROSPERO (no. CRD42021289015). Overall, 2226 studies were identified, of which 58 were included in this systematic review. In all, 20 of the 58 studies included in this review did not find any evidence of an obesity paradox. Of these 20 studies, 16 involved patients with no specific medical condition, 1 involved patients with chronic diseases, and 2 involved patients with type 2 diabetes mellitus. Seven out of the nine studies that looked at short-term mortality found evidence of the obesity paradox. Of the 28 studies that examined longer-term mortality, 15 found evidence of the obesity paradox. In the studies that were conducted in people with a particular medical condition (n = 24), the obesity paradox appeared in 18 cases. Our work supports the existence of an obesity paradox, especially when comorbidities or acute medical problems are present. These findings should help guide strategies for nutritional counselling in older populations.

Prognosis of clear cell renal cell carcinoma patients stratified by age: A research relied on SEER database

Objective

Clear cell renal cell carcinoma may affect patients of any age. To date, there are only a limited number of large data studies on renal clear cell carcinoma in different age groups. This study assessed CCRCC risk factors in different age groups using the Surveillance Epidemiology and End Results (SEER) database.

Methods

We selected 58372 cases from the SEER database. These patients were divided into seven different age groups. Cox regression models were used to find independent risk factors for the survival of CCRCC patients. Based on independent risk factors, a nomogram was drawn with R software. Kaplan-Meier method for survival analysis and X-tile software were used to find the optimal age group for diagnosis.

Results

Univariate analysis revealed that patients’ age, sex, race, marital status, grade, TNM (tumor, node, metastasis) stage, surgery, WHO/ISUP grade were correlated with survival (P<0.01). Age was an independent risk factor for survival in patients with CCRCC according to multivariate Cox regression analysis (p<0.01). All-cause mortality and tumor-specific mortality increased according to the increasing age of the patients. The optimal cut-off values for age were defined as 58 and 76 years and 51 and 76 years, respectively, according to overall survival (OS) and cause-specific survival (CSS).

Conclusion

There is a negative correlation between age and survival of CCRCC patients. The difference in prognosis of patients in different age groups has important implications for clinical treatment. Therefore, the diagnosis and treatment plan should be based on more detailed age grouping, which is more beneficial to improving the prognosis and survival of patients.

53 years old is a reasonable cut-off value to define young and old patients in clear cell renal cell carcinoma: a study based on TCGA and SEER database

Background

The objectives of this study were to screen out cut-off age value and age-related differentially expressed genes (DEGs) in clear cell renal cell carcinoma (CCRCC) from Surveillance Epidemiology and End Results (SEER) database and The Cancer Genome Atlas (TCGA) database.

Methods

We selected 45,974 CCRCC patients from SEER and 530 RNA-seq data from TCGA database. The age cut-off value was defined using the X-tile program. Propensity score matching (PSM) was used to balance the differences between young and old groups. Hazard ratio (HR) was applied to evaluate prognostic risk of age in different subgroups. Age-related DEGs were identified via RNA-seq data. Survival analysis was used to assess the relationship between DEGs and prognosis.

Results

In this study, we divided the patients into young (n = 14,276) and old (n = 31,698) subgroups according to cut-off value (age = 53). Age > 53 years was indicated as independent risk factor for overall survival (OS) and cancer specific survival (CSS) of CCRCC before and after PSM. The prognosis of old group was worse than that in young group. Eleven gene were differential expression between the younger and older groups in CCRCC. The expression levels of PLA2G2A and SIX2 were related to prognosis of the elderly.

Conclusion

Fifty-three years old was cut-off value in CCRCC. The prognosis of the elderly was worse than young people. It remind clinicians that more attention and better treatment should be given to CCRCC patients who are over 53 years old. PLA2G2A and SIX2 were age-related differential genes which might play an important role in the poor prognosis of elderly CCRCC patients.

Body mass index and other risk factors for kidney cancer in men: a cohort study in Lithuania

OBJECTIVES

Previous studies have observed notable unexplained geographic differences in incidence of kidney cancer in Europe. Lithuania is among the countries with the highest incidence and mortality. Our objective was to investigate the effect of different lifestyle, anthropometric and biological factors on the risk of kidney cancer in Lithuanian men.

METHODS

This population-based cohort study included 6,849 men initially free from cancer. During the follow-up (1978-2008), 79 incident cases of kidney cancer were identified. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and corresponding 95% confidence intervals (95% CI).

RESULTS

Risk of kidney cancer was significantly associated with increasing body mass index (BMI), the adjusted HR for ≥ 35 vs. < 25 kg/m² was 3.00, 95% CI 1.10-8.19 and the HR per 1 unit increment of BMI was 1.07, 95% CI 1.01-1.14. In overweight men (BMI ≥ 25 kg/m²), the HRs for kidney cancer per 10 mmHg increment of systolic or diastolic blood pressure were 1.10, 95% CI 0.96-1.25 and 1.26, 95% CI 1.01-1.56, respectively. We found no significant association between smoking, alcohol consumption or total serum cholesterol level and kidney cancer risk.

CONCLUSIONS

This study supports a link between increased BMI and the development of kidney cancer among men in Lithuania. Hypertension appears to be associated with risk of kidney cancer in overweight men, although the assessment was limited by the lack of statistical power.

Obesity and Risk for Second Malignant Neoplasms in Childhood Cancer Survivors: A Case-Control Study Utilizing the California Cancer Registry

BACKGROUND

Obesity is a known modifiable risk factor associated with adverse outcomes in children with cancer. We sought to determine whether obesity during childhood cancer treatment increases risk for second malignant neoplasms (SMN).

METHODS

In this case-control study, cases (with SMN) and controls (with a single-primary cancer) were selected from the California Cancer Registry who had primary cancer diagnosed <21 years treated at Children's Hospital Los Angeles between 1988 and 2014. Controls were matched 3:1 to cases at the registry level by clinical factors. Medical records were abstracted for cancer treatment exposures, cancer predisposition syndrome, body mass index (BMI), BMI Z-score, and BMI category at diagnosis and end of therapy (EOT).

RESULTS

A total of 59 cases and 130 controls were included. Median age at primary cancer diagnosis was 6 years, 64.5% were male, median time from primary cancer to SMN was 7.5 years, and 31.7% were obese or overweight. In matched multivariable analyses, there were elevated but nonsignificant associations between SMN and higher BMI Z-score at diagnosis [OR 1.27 (0.99-1.63)] and higher BMI categories at diagnosis [adjusted OR (aOR) overweight, 1.25 (0.55-2.52); aOR obese, 2.51 (1.00-6.29)]. There was a significantly increased risk for SMN among patients who were obese at both diagnosis and EOT [aOR, 4.44 (1.37-14.34)].

CONCLUSIONS

This study suggests that obesity during childhood cancer treatment may be associated with increased risk for SMNs, particularly among those obese throughout therapy.

IMPACT

Additional studies to confirm these findings and to develop interventions have the potential to impact SMN development in children with cancer.

External validation of a nomogram including the computed tomography imaging score to predict indolent renal masses

PURPOSE

To assess a nomogram including the computed tomography (CT) score and body mass index (BMI) that was constructed to predict indolent diseases in a cohort of patients with renal masses.

MATERIALS AND METHODS

The data collected from patients undergoing partial nephrectomy (PN) or radical nephrectomy (RN) between January 2012 and September 2016 were analyzed. Two urologic surgeons and a radiologist reviewed the images to determine the CT score. Postoperative pathological assessment was performed to categorize renal masses as either indolent or aggressive. The BMI and CT scores were included in the nomogram to identify the risk of indolent disease. The performance of the novel model was assessed by using discrimination, calibration plots, and decision curve analysis (DCA).

RESULTS

Two hundred and two participants (with 202 masses) who underwent RN or PN were included; 37% of the masses were indolent. The predictive performances of the nomogram revealed areas under the curve of 0.866 for masses of all cases and 0.808 for cT1 masses without visible fat. DCA revealed that the nomogram was moderately clinically useful. The calibration plots showed a reasonable calibration and systematic overestimation of indolent disease based on nomogram predictions.

CONCLUSIONS

The CT score nomogram discriminated well between indolent and aggressive renal masses. The model had a reasonable calibration in our cohort for discriminating indolent from aggressive lesions. Further research to validate and assess the nomogram is required.