Purpose: The effect of tea consumption on breast cancer survival remained to be explored. Meanwhile, green tea favorably facilitates lipid metabolisms in breast cancer survivors. This study aimed to examine the effect of tea consumption and the interactions with lipids on breast cancer survival.
Methods: A total of 1551 breast cancer patients were recruited between April 2008 and March 2012 and followed up until 31 December 2017 in Guangzhou. The endpoint was progression-free survival (PFS). Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using multivariate Cox proportional to estimate the associations.
Results: PFS was better among women who regularly drank all teas (mainly green tea) except oolong after cancer diagnosis compared with non-tea drinkers (HR 0.52; 95% CI 0.29 ~ 0.91). This association was more evident among women with normal (HR 0.38; 95% CI 0.18 ~ 0.82) than higher (HR 1.22; 95% CI 0.13 ~ 11.82) total cholesterol, though the interaction was not significant. Moreover, the more they drank (≥ 7 times/week), the better prognosis was (HR 0.30; 95% CI 0.11 ~ 0.84). In contrast, oolong tea was observed to have a potential impaired effect on PFS.
Conclusions: Our findings suggested that regularly drinking all teas (mainly green tea) except oolong after diagnosis was beneficial to breast cancer survival, particularly for women with normal lipids, while oolong tea may have an impaired effect.
Keywords: Breast cancer progression-free survival; Lipids; Tea consumption.