Body Weight Loss≧5% during Radiotherapy Confers a Better Overall Survival in NPC Patients with Pretreatment BMI≧25

放射治療前後體重減輕程度≧5%與鼻咽癌病人的整體存活率之間存在正相關性

沈奕良(Yi-Liang Shen) ； 林信吟(Shinn-Yn Lin) ； 洪志宏(Ji-Hong Hong) ； 白冰清(Ping-Ching Pai) ； 林倩伃(Chien-Yu Lin) ； 曾振淦(Chen-Kan Tseng) ； 曾雁明(Ngan-Ming Tsang)

《放射治療與腫瘤學》 19卷3期 (2012/09) Pp. 167-179

https://doi.org/10.6316/TRO/201219(3)167

摘要

目的：少有研究討論放射治療（以下簡稱“放療”）療程前後體重變化對存活率之影響。本文除了探討放療療程前後體重變化與鼻咽癌病人存活率間的相關性，也同時討論放療前身體質量指數（BMI）是否影響上述的相關性。材料與方法：本研究回溯收錄1583位，從1995至2007年於林口長庚醫院接受過根治性放療之鼻咽癌病患，分別根據放療療程前後體重變化（≧5% vs.＜5%）與放療前BMI（≧25 VS.＜25）分群後，進行存活率分析；最後進行存活率的多變項分析，納入統計分析模型的關鍵性因子包括放療前後體重變化、放療前BMI，與其他臨床相關因子。結果：放療療程前後體重下降程度是否超過5%會受到病患年齡、化療給予與否、放療療程總天數和治療前BMI的影響。針對全部病人進行單變項和多變項分析時，放療療程前後體重變化狀況與鼻咽癌病患存活率之間的相關性皆達統計上的顯著意義；若進一步依據放療前BMI（≧25或＜25）分群後，發現放療療程前後體重減少程度超過5%對存活率之正面影響只出現在BMI≧25（放療前過重或肥胖）之次族群，具有統計上顯著意義（p=0.046, log-rank test）。結論：本研究觀察到鼻咽癌病患中，放療療程前後體重減少程度超過5%者擁有較佳的存活率，特別是在放療前BMI≧25之次族群。關於此現象之可能解釋尚需更深入的研究，包括其潛有的生物機轉與鼻咽癌的復發形態。

關鍵字

鼻咽癌 ； 預後 ； 體重變化 ； 身體質量指數 ； 肥胖 ； 放射治療

並列摘要

Objectives/Hypothesis: The association between weight loss during radiotherapy (RT) and patients' survival has not been assessed in patients with nasopharyngeal carcinoma (NPC). This study was aimed to investigate this association and also determine whether pretreatment body mass index (BMI) affects the association between weight loss and overall survival.Methods: 1583 NPC patients diagnosed between 1995 and 2007 undergoing definitive RT were consecutively enrolled. Survival analyses were performed with stratification according to weight change (≧5% vs.＜5%) and pretreatment BMI (≧25 vs.＜25) respectively. Cox proportional hazards model was carried out to evaluate the impact of weight change, pretreatment BMI on survival controlling for the other clinically relevant factors.Results: Weight change (≧5%) during RT is significantly influenced by age, chemotherapy, RT duration and pretreatment BMI. A statistically significant association between the status of weight change and overall survival could be identified both in univariate and multivariate analyses. After further stratification by BMI (≧25 or＜25), there is a significantly positive impact of weight loss≧5% on survival particularly among the patients who are overweight or obese (p=0.046, log-rank test).Conclusions: A weight loss≧5% during RT confers a more favorable overall survival in NPC patients who are initially overweight or obese (BMI≧25). The explanation for this phenomenon warrants further analyses with regard to locoregional control and underlying biological mechanisms.

並列關鍵字

Nasopharyngeal carcinoma ； Prognosis ； Weight change ； Body mass index ； Obesity ； Radiotherapy