Background: Breast cancer is one of the most common cancers worldwide, and anxiety is a psychological morbidity that is inevitable. Many researchers have investigated the prevalence and detrimental effects of anxiety in breast cancer treatment, but little is known about differences in anxiety level among women receiving different breast cancer treatments. A systematic review of all available literature was needed to attain better understanding of anxiety in patients undergoing treatment for breast cancer.

Aim: This review aimed to determine the best available evidence on the level of anxiety among women with breast cancer who were undergoing cancer treatment(s), and the factor(s) contributing to anxiety in various treatment modalities.

Methods: The search sought to gather data from published and unpublished studies conducted between 1990 and 2010. An initial search on CINAHL and Medline was done to identify relevant search terms. A search strategy was then developed, using MeSH headings and key words. The following databases were searched: CINAHL, PubMed, ScienceDirect, PsycINFO, Cochrane Database of Systematic Review, Scopus, Wiley InterScience and PsycARTICLES. All papers are quantitative papers (randomised controlled trials and descriptive studies) that examined anxiety level in women with breast cancer of stage 0 to stage IIIA, over and equal to 21 and below 65 years of age, who were undergoing/had undergone treatment restricted to chemotherapy, radiotherapy and/or surgery, and these quantitative papers have made correlations between women's anxiety levels and contributing factors. The Hospital Anxiety and Depression Scale and State-Trait Anxiety Inventory were the two tools most frequently used by these papers to quantify the anxiety level. Two reviewers independently assessed the eligibility of the papers for inclusion. Eighteen papers were selected based on relevance, and assessed for methodological quality using MAStARI. Ten research papers that met our methodological standard were included in the review. Both reviewers agreed on the papers to be included and excluded. Due to the methodological heterogeneity of the included papers, a meta-analysis was not possible. The studies were hence presented in narrative summary.

Results: Anxiety seems to be ubiquitous, presenting itself in all treatment types for breast cancer. Anxiety level in women who underwent chemotherapy was highest before the first chemotherapy infusion, mediated by age and trait anxiety. Radiotherapy regimes did not affect anxiety level in radiotherapy-treated patients, and most research concluded that anxiety level was higher among women who underwent mastectomy than those who underwent breast conservation therapy.

Conclusions: The prevalence and intensity of anxiety have been shown to be pronounced among breast cancer women who were undergoing/had undergone one or more of the three treatments. Chemotherapy, as compared to other treatments, is shown to be associated with a higher anxiety level. With the prevalence, intensity and correlated factors of anxiety identified through this review, future research may investigate the interventions that could help alleviate anxiety among these patients. Anxiety is prevalent in women with breast cancer undergoing treatment, especially those undergoing chemotherapy. Healthcare professionals should pay greater attention to identify signs of anxiety in patients and design interventions to help alleviate it earlier.