Objectives This literature review examined research into the impact of a previous ‘all-clear’ or non-cancer diagnosis following symptomatic presentation (‘false alarm’) on symptom attribution and delays in help seeking for subsequent possible cancer symptoms.

Design and setting The comprehensive literature review included original research based on quantitative, qualitative and mixed data collection methods. We used a combination of search strategies, including in-depth searches of electronic databases (PubMed, EMBASE, PsychInfo), searching key authors and articles listed as ‘related’ in PubMed, and reference lists. We performed a narrative synthesis of key themes shared across studies.

Participants The review included studies published after 1990 and before February 2014 reporting information on adult patients having experienced a false alarm following symptomatic presentation. We excluded false alarms in the context of screening.

Primary and secondary outcome measures We evaluated the effect of a ‘false alarm’ on symptom attribution and help seeking for new or recurrent possible cancer symptoms.

Results Overall, 1442 papers were screened and 121 retrieved for full-text evaluation. Among them, 19 reported on false alarms and subsequent symptom attribution or help seeking. They used qualitative (n=14), quantitative (n=3) and mixed methods (n=2). Breast (n=7), gynaecological (n=3), colorectal (n=2), testicular (n=2), and head and neck cancers (n=2) were the most studied. Two broad themes emerged underlying delays in help seeking: (1) over-reassurance from the previous ‘all-clear’ diagnosis leading to subsequent symptoms being interpreted as benign, and (2) unsupportive healthcare experiences in which symptoms were dismissed, leaving patients concerned about appearing hypochondriacal or uncertain about the appropriate next actions. The evidence suggested that the effect of a false alarm can persist for months and even years.

Conclusions In conclusion, over-reassurance and undersupport of patients after a false alarm can undermine help seeking in the case of new or recurrent potential cancer symptoms, highlighting the need for appropriate patient information when investigations rule out cancer.