營養素攝取、飲食型態與停經前後乳癌風險之關聯性-病例對照研究

前言：台灣乳癌發生率位居女性癌症首位及死亡率第四位。與西方國家相較，亞洲與台灣乳癌發生率急遽增加且有年輕化的趨勢。目的：本研究設計為以醫院爲基礎的病例對照研究，探討代謝因素、飲食因素 (營養素攝取量、飲食型態)，及遵循World Cancer Research Fund International(WCRF) /American Institute for Cancer Research (AICR)之癌症預防建議與停經前後乳癌風險之相關性。方法: 本研究個案來自台灣大學附設醫院腫瘤醫學部，共招募285位乳癌病人，及醫院對照組297位。資料收集包含體位測量及生化檢測，以57題半定量飲食頻率問卷調查個案發病前之飲食習慣，並以主成分分析確定飲食型態(外食、植物性、動物性蛋白質飲食型態)。更進一步調整干擾因子，探討各種飲食因素與乳癌風險間的獨立相關性。結果: 單變量分析結果顯示，停經前乳癌病人之基礎代謝率≤1200大卡/天及三酸甘油酯≥150mg/dL比例高於對照組；但停經後乳癌病人與對照組則無顯著不同。而在多變量分析後，基礎代謝率≤1200大卡/天及三酸甘油酯≥150mg/dL則與停經前乳癌並無顯著相關性。在飲食因素方面，調整干擾因子後，在停經前婦女中，碳水化合物攝取量≥55%(熱量比)（OR = 0.48，95% CI 0.25-0.93）和纖維≥25g/天（OR = 0.34，95% CI 0.14-0.86）與停經前乳癌風險顯著負相關（all p <0.05）；而脂肪攝取量≥35%（OR = 2.28，95% CI 1.16-4.49）與停經前乳癌風險顯著正（p <0.05）相關。而在停經後婦女觀察到，高蛋白 (≥15%)和高纖維 (≥25g/天) 與停經後癌症風險呈負相關，而脂肪攝取≥35%與癌症風險為正相關。飲食型態方面，植物性飲食型態之分數第三等份與停經前（OR = 0.25）和停經後婦女（OR = 0.27）的乳癌風險顯著負相關（均p <0.05）。而在遵循WCRF / AICR建議方面，其中具運動習慣（OR = 0.52, p =0.001）和膳食纖維攝取量≥25g/天（OR = 0.20, p <0.001）之建議與乳癌風險降低有顯著相關。結論：我們的研究結果顯示，脂肪攝取<35％，膳食纖維攝取量≥25g/天，與停經前後乳癌風險呈負相關。而植物性飲食型態 (富含種子和堅果，大豆製品，水果，海藻類) 對停經前及停經後婦女罹患乳癌的風險可能具保護作用。在代謝相關因素方面，未來需要擴大樣本數進一步確認其與停經前乳癌風險之關聯性及機轉。

關鍵字

乳癌；停經前後；飲食型態

並列摘要

Background: Compared with Western countries, the incidence of breast cancer among younger women in Asia and Taiwan is increasing rapidly. Most studies explored nutrients, food items or dietary pattern in Caucasian, and only few studies have been investigated in Asia population. Aim: The objective of this study is to explore relations between dietary factors including nutrient intakes, dietary patterns, and adherence to the WCRF/AICR cancer prevention recommendations on a hospital-based case-control study design. Methods: A total of 285malignant breast cancer patients were recruited from the Department of Oncology, and 297 hospital control women were recruited from National Taiwan University Hospital. A recently-validated semi-quantitative Food Frequency Questionnaire (FFQ)was used to assess the nutrient intakes and specific dietary patterns using principal component analysis. Three dietary patterns were identified as follow: eating out, plant-based, and animal protein dietary patterns. Multiple logistic regression analysis was employed to examine various dietary factors and breast cancer risks. Results: Upon adjusting for confounding factors, carbohydrate≧55% (OR=0.48) and fiber≧25g/day(OR=0.34) intakes were significantly and negatively(p<0.05) correlated with breast cancer risks among premenopausal women, and fat intakes≧35% (OR=2.28) were positively (p<0.05) associated. Similar trends were observed for postmenopausal women, high protein and high fiber seemed to be protective against cancer risks and high fat to be a risk factor for cancer. For dietary pattern, tertile levels of plant-based dietary factors score were significantly and negatively (both p<0.05) associated with decreased risks of breast cancer in both premenopausal (OR=0.25) and postmenopausal women (OR=0.27).Adherence to two of the WCRF/AICR recommendations including habits of having physical activity (OR=0.52) and fiber intakes≧25g/day (OR=0.20) was also found to correlate significantly with lower breast cancer risks in both subgroups. Conclusion: Our results suggest that fat distribution to be lower than 35% and fiber to be higher than 25g per day seems to be beneficial to lowered risks in pre-as well as post-menopausal women. Besides, plant-based dietary patterns rich seeds and nuts, soy products, fruits, seaweeds appears to be protective of breast cancer risks in both groups of women. Our study confirm the beneficial effects of healthy diet on lowered breast cancer risks.

並列關鍵字

breast cancer ； Pre- and post- menopause ； dietary patterns

參考文獻

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1. Bray, F., et al., Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin, 2018. 68(6): p. 394-424.