To explore whether emotional expressivity and the patterns of language use could predict benefits from expressive writing (EW) of breast cancer (BC) patients in a culture that strongly discourages emotional disclosure.

Data were obtained from a recent trial in which we compared the health outcomes between a prolonged EW group (12 sessions) and a standard EW group (four sessions) (n = 56 per group) of BC patients receiving chemotherapy. The Chinese texts were tokenized using the THU Lexical Analyser for Chinese. Then, LIWC2015 was used to quantify positive and negative affect word use.

Our first hypothesis that BC patients with higher levels of emotional expressivity tended to use higher levels of positive and negative affect words in texts was not supported (r = 0.067, p = 0.549 and r = 0.065, p = 0.559, respectively). The level of emotional expressivity has a significant effect on the quality of life (QOL), and those who used more positive or fewer negative affective words in texts had a better QOL (all p < 0.05). However, no significant difference was identified in physical and psychological well-being (all p > 0.05). Furthermore, the patterns of affective word use during EW did not mediate the effects of emotional expressivity on health outcomes (all p > 0.05).

Our findings suggest that the level of emotional expressivity and the pattern of affective word use could be factors that may moderate the effects of EW on QOL, which may help clinicians identify the individuals most likely to benefit from such writing exercises in China.