Primary and secondary prevention of breast cancer in China: a scoping review

Abstract

BackgroundBreast cancer is the most commonly diagnosed cancer in women in China, with an annual incidence of 41·32 per 100 000 women. The total expense of cancer treatment in China was estimated to be 221·4 billion RMB. This scoping review summarises the current process of breast cancer primary and secondary prevention and identifies how China can improve prevention. MethodsWe identified articles from MEDLINE, Embase, CINAHL, and Web of Science, published in English between Jan 1, 1990 and Sept 25, 2018. Key search terms were breast cancer AND (primary prevention OR secondary prevention) AND China. We used WHO's definition for primary and secondary preventions and study population should be women 18 years or older. We excluded study protocols, abstracts, and studies focused on lifestyle interventions not directly concerning breast cancer. We assessed the quality of evidence using appraisal tools depending on the study design (including Cochrane risk of bias tool and risk of bias in non-randomised studies of interventions). We analysed breast cancer knowledge, attitudes, and practice and education interventions. FindingsOur search yielded 1967 articles and 16 eligible studies, which are cross-sectional (n=6), diagnostic (n=2), randomised control trial (RCT; n=4), cohort (n=2), mathematical modelling (n=1), and review (n=1). All six cross-sectional studies were relevant regarding women's knowledge, attitude, or practice. 86·3% of urban women aged 35–69 years old were reported to be knowledgeable of breast cancer by a cross-sectional study (n=1200), whereas this proportion was only 18·6% among women aged 25–70 years old in another cross-sectional study (n=122 058). The most common reason (24·8–58% of cases) for not attending breast cancer screening was absence of any symptoms. 24·0–26·5% women had received previous mammogram; 17·5–23·0% women have been imaged with ultrasound; and 21·7–43·6% women have received any form of breast cancer screening. Four studies reported on the effect of education programmes. One cohort study reported that breast cancer education interventions increased mammogram screening participation from 10·3% to 72·6% (p<0·001). One RCT showed that education programmes increased breast cancer knowledge from 20·4% to 62·8% (p<0·01); and one that education programmes increased frequency of breast self-examination from 9% to 34% (p<0·001). However, one RCT in the 1990s found that breast self-examination education itself does not reduce breast cancer mortality. InterpretationLimited number of primary and secondary interventions have been identified in China. Chinese women are still poorly aware of breast cancer and have low screening participation. FundingNone.