Vrieling Alina, Olsson Linnea T, Kleuters Guyon, Maurits Jake S F, Aben Katja, Sedelaar J P Michiel, Furberg Helena, Kiemeney Lambertus A L M
IQ Health Science Department, Radboud University Medical Center, Nijmegen, The Netherlands.
Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Cancer Causes Control. 2025 May;36(5):497-507. doi: 10.1007/s10552-024-01957-2. Epub 2025 Jan 6.
Obesity in mid-life is a well-established risk factor for developing renal cell carcinoma (RCC); however, patients with RCC who are obese at the time of diagnosis have more favorable survival outcomes. To get better insight into the obesity paradox and determine the extent to which weight around diagnosis is stable, we examined pre- and post-diagnosis weight changes in patients with localized RCC.
We included 334 patients with localized RCC from the prospective cohort ReLife who self-reported body weight at multiple time points ranging from 2 years before to 2 years after diagnosis. Multivariable linear mixed-effects regression models were used to compare weight at each timepoint to weight at diagnosis for the overall study population, as well as stratified by BMI at diagnosis, tumor stage, and tumor grade.
Most patients were classified as overweight (38.3%) or obese (29.6%) at diagnosis. Overall, patients experienced on average 1.45 kg (95% confidence interval (CI) 0.84, 2.06) weight loss in the 2 years before diagnosis. Pre-diagnosis weight loss was higher in patients who were non-obese at diagnosis, and who presented with higher tumor stage and grade. On average, pre-diagnosis weight loss was at least partially regained within two years after diagnosis.
Patients who were non-obese and patients with higher stage and grade tumors had higher pre-diagnosis weight loss, which was at least partially regained after treatment. These patterns suggest there are subgroups of patients with localized RCC who experience disease-related weight loss, which could contribute to the obesity paradox.
中年肥胖是发生肾细胞癌（RCC）的一个公认风险因素；然而，诊断时肥胖的RCC患者生存结局更有利。为了更好地理解肥胖悖论，并确定诊断前后体重的稳定程度，我们研究了局限性RCC患者诊断前后的体重变化。
我们纳入了前瞻性队列ReLife中的334例局限性RCC患者，这些患者在诊断前2年至诊断后2年的多个时间点自行报告体重。使用多变量线性混合效应回归模型，将总体研究人群中每个时间点的体重与诊断时的体重进行比较，并按诊断时的BMI、肿瘤分期和肿瘤分级进行分层比较。
大多数患者在诊断时被归类为超重（38.3%）或肥胖（29.6%）。总体而言，患者在诊断前2年平均体重减轻1.45千克（95%置信区间（CI）0.84，2.06）。诊断时非肥胖、肿瘤分期和分级较高的患者诊断前体重减轻更多。平均而言，诊断前减轻的体重在诊断后两年内至少部分恢复。
非肥胖患者以及肿瘤分期和分级较高的患者诊断前体重减轻更多，治疗后至少部分恢复。这些模式表明，局限性RCC患者中存在经历与疾病相关体重减轻的亚组，这可能导致肥胖悖论。
