Background Most women living in low- and middle-income countries (LMICs) present with advanced-stage breast cancer. Limitations of poor serviceable health systems, restricted access to treatment facilities, and lack of breast cancer screening programmes all likely contribute to the late presentation of women with breast cancer living in these countries. Women are diagnosed with advanced disease and frequently do not complete their care due to a number of factors, including financial reasons as health expenditure is largely out of pocket resulting in financial toxicity; health system failures, such as missing services or health worker lack of awareness on common signs and symptoms of cancer; and sociocultural barriers, such as stigma and use of alternative therapies. Clinical breast examination (CBE) is an inexpensive early detection technique for breast cancer in women with palpable breast masses. Training health workers from LMICs to conduct CBE has the potential to improve the quality of the technique and the ability of health workers to detect breast cancers early. Objectives To assess whether training in CBE affects the ability of health workers in LMICs to detect early breast cancer. Search methods We searched the Cochrane Breast Cancer Specialised Registry, CENTRAL, MEDLINE, Embase, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal, and ClinicalTrials.gov up to 17 July 2021. Selection criteria We included randomised controlled trials (RCTs) (including individual and cluster-RCTs), quasi-experimental studies and controlled before-and-after studies if they fulfilled the eligibility criteria. Data collection and analysis Two review authors independently screened studies for inclusion, and extracted data, assessed risk of bias, and assessed the certainty of the evidence using the GRADE approach. We performed statistical analysis using Review Manager software and presented the main findings of the review in a summary of findings table. Main results We included four RCTs that screened a total population of 947,190 women for breast cancer, out of which 593 breast cancers were diagnosed. All included studies were cluster-RCTs; two were conducted in India, one in the Philippines, and one in Rwanda. Health workers trained to perform CBE in the included studies were primary health workers, nurses, midwives, and community health workers. Three of the four included studies reported on the primary outcome (breast cancer stage at the time of presentation). Amongst secondary outcomes, included studies reported CBE coverage, follow-up, accuracy of health worker-performed CBE, and breast cancer mortality. None of the included studies reported knowledge attitude practice (KAP) outcomes and cost-effectiveness. Three studies reported diagnosis of breast cancer at early stage (at stage 0+I+II), suggesting that training health workers in CBE may increase the number of women detected with breast cancer at an early stage compared to the non-training group (45% detected versus 31% detected; risk ratio (RR) 1.44, 95% confidence interval (CI) 1.01 to 2.06; three studies; 593 participants; I-2 = 0%; low-certainty evidence). Three studies reported diagnosis at late stage (III+IV) suggesting that training health workers in CBE may slightly reduce the number of women detected with breast cancer at late stage compared to the non-training group (13% detected versus 42%, RR 0.58, 95% CI 0.36 to 0.94; three studies; 593 participants; I-2 = 52%; low-certainty evidence). Regarding secondary outcomes, two studies reported breast cancer mortality, implying that the evidence is uncertain for the impact on breast cancer mortality (RR 0.88, 95% CI 0.24 to 3.26; two studies; 355 participants; I-2 = 68%; very low-certainty evidence). Due to the study heterogeneity, we could not conduct meta-analysis for accuracy of health worker-performed CBE, CBE coverage, and completion of follow-up, and therefore reported narratively using the 'Synthesis without meta-analysis' (SWiM) guideline. Sensitivity of health worker-performed CBE was reported to be 53.2% and 51.7%; while specificity was reported to be 100% and 94.3% respectively in two included studies (very low-certainty evidence). One trial reported CBE coverage with a mean adherence of 67.07% for the first four screening rounds (low-certainty evidence). One trial reported follow-up suggesting that compliance rates for diagnostic confirmation following a positive CBE were 68.29%, 71.20%, 78.84% and 79.98% during the respective first four rounds of screening in the intervention group compared to 90.88%, 82.96%, 79.56% and 80.39% during the respective four rounds of screening in the control group. Authors' conclusions Our review findings suggest some benefit of training health workers from LMICs in CBE on early detection of breast cancer. However, the evidence regarding mortality, accuracy of health worker-performed CBE, and completion of follow up is uncertain and requires further evaluation.
