Introduction

Breast cancer–related lymphedema (BCRL) impacts approximately 19% of survivors of breast cancer (BC), most commonly within the first 2 years after treatment [1, 2]. Individuals who develop lymphedema often demonstrate upper quadrant functional impairments, decreased participation in social activities, higher medical costs, and a lower quality of life [1,2,3,4,5,6,7]. Additionally, the impact of BCRL may result in a myriad of psychosocial responses, such as high levels of anxiety, depression, uncertainty, and lower self-esteem that occur throughout survivorship [8].

Due to the negative impact of BCRL, an educational intervention has the potential to increase the individual’s awareness of risk factors, early signs and symptoms, and treatment options that could lead to earlier detection and better control of BCRL [9,10,11]. Once BCRL does develop, education is also needed on skin hygiene, prevention of infection, and self-care practices. Healthcare professionals and those diagnosed with BC agree patient education is a key component of both prevention and treatment of BCRL; however, individuals diagnosed with BC report having inadequate knowledge about lymphedema and its sequela across the trajectory of survivorship [12,13,14]. A contributing factor may be the lack of guidance for healthcare professionals when developing an educational intervention throughout survivorship [15].

The goal of this systematic review was to evaluate the available evidence on BCRL education for individuals at risk and those who have developed the condition and to identify gaps in the literature to direct future research. The primary aim of this systematic review is to identify the impact of the different (a) components of BCRL educational content, (b) modes of education, and (c) timing of educational intervention across the trajectory of BC care. The secondary aim is to examine the effect of patient education on arm volume, quality of life, function, complications associated with BCRL, adherence to interventions, and knowledge acquisition in individuals diagnosed with BC.

Methodology

Study design and search strategy

This systematic review (PROSPERO registration number: CRD42021253084) was conducted following the Preferred Reported Items for Systematic Review and Meta-analysis (PRISMA) guidelines. A literature search with the assistance of an academic librarian from the University of Southern California using the timeframe from January 1, 2011 to December 31, 2021 was conducted. Electronic databases searched included PubMed, CINAHL, Web of Science, Google Scholar, and Scopus. The final search terms were Lymphedema, Elephantiasis, and truncated text words lymphedema*, lymphoedema*, elephantiasis, patient education, risk reduction practices, precautions, prospective surveillance, and BC. Two independent reviewers screened the title and abstracts and applied the inclusion and exclusion criteria. Inclusion criteria included the following: quantitative study design; adults ≥ 18 years old; BC, at risk or with secondary lymphedema; education as an intervention; one measure related to quality of life, function, volume measures, adherence, complications, knowledge assessment, and English language studies only. Exclusion criteria included the following: case reports, case series, qualitative study design, literature reviews, editorial, letter, presentations, dissertations, and comments; studies including the terms filariasis, parasites, congenital, hereditary; adolescents < 18 years old, primary lymphedema; other cancer-related lymphedema; other causes of secondary lymphedema; lower extremity lymphedema; pelvic or genital lymphedema, and animal studies (Fig. 1).

Fig. 1
figure 1

PRISMA flow chart illustrating the inclusion and quality rating of studies reviewed

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Quality appraisal

Study quality was assessed using the American Physical Therapy Association’s (APTA) Critical Appraisal Tool for Experimental Intervention Studies (CAT-EI). [16]. The CAT-EI assesses bias risk in clinical research and was used to assign a quality rating. Two reviewers independently appraised 3 studies to establish a quality rating agreement. The same reviewers then independently appraised the remaining studies and if quality-rating consensus did not agree, a third reviewer was used. The quality level rating was based on the APTA Clinical Practice Guideline recommendations [16]. The reviewers followed the recommendations for the APTA CAT-EI manual for determining quality ratings. The review group agreed upon the following essential scoring criteria that need to be met with a “YES” answer in order to be assigned a quality rating [16]. The following questions were utilized from the CAT-EI:

  1. 1.

    Was the patient population appropriate for the study question?

  2. 2.

    Was the study a randomized control trial?

  3. 3.

    Did the sample size meet power requirements for the outcome of interest?

  4. 4.

    Was the tester and/or data collector blinded to the treatment group of interest?

  5. 5.

    For each outcome of interest, was a measure chosen that had established validity?

  6. 6.

    For each outcome of interest, was a measure chosen that had established reliability?

  7. 7.

    Were the appropriate statistical analysis chosen (e.g., subjects analyzed in the groups to which they were assigned)?

  8. 8.

    Was their adequate follow-up (at least 1 month for intervention studies)?

If the study met all 8 of the essential scoring items by 2 independent reviewers, the study received a “high-quality rating.” For an acceptable quality rating, the study needs to meet 6 of the 8 criteria. Likewise, a low-quality rating score was assigned if the study met between 2 and 5 of the criteria. Finally, an unacceptable quality rating was assigned to those studies scoring 0–1.

The evidence for BCRL patient education as an intervention was appraised and synthesized. The extracted data included (a) the components of BCRL educational content, (b) modes of education, and (c) timing of educational intervention (Table 1).

Table 1 Risk of Bias according to the APTA CAT-EI Tool
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Results

The search identified 968 studies and 45 underwent full-text review. Seventeen studies published between January 2011 and December 2021 met the study inclusion criteria and were included in the review. The review did not yield any high-quality studies, and 2 were deemed unacceptable. As a result, 15 studies of acceptable and low quality were included (4 acceptable and 11 low quality). Five of the studies were conducted in the USA, 2 studies each were conducted in China and Turkey, and 1 study from each of the following countries: Australia, Canada, Italy, Iran, Japan, and Taiwan. There were 9 randomized controlled trials, 1 retrospective, and 5 prospective pre/post study designs.

Study characteristics

Demographic characteristics

Participants across all studies (combined N = 2230) were women diagnosed with BC with or without lymphedema that received education. Participant demographics varied and included at least some or all of the following characteristics: mean age of 53.9 years (range 47.43–61.0), mean body mass index of 25.75 (range 23.91–35.0), stages of BC ranged from I to III, axillary lymph node dissection, sentinel node biopsy, radiation therapy, and chemotherapy [9, 17,18,19,20,21,22,23,24,25,26,27,28,29,30]. Ten of the studies examined education for those at risk of developing BCRL, and 5 studies included women previously diagnosed with BCRL, stage I, II, or III. These participants presented with a wide range of mean duration of lymphedema from 6.86 months (SD 3.7) [20, 29] to > 5 years [27, 30].

BCRL education

Timing of BCRL education occurred at multiple time points across the trajectory of BC care. The pre-operative phase of BC care included one-on-one in person education with a healthcare professional [17, 21,22,23,24]. During this encounter, printed educational materials regarding post-operative BC care and BCRL risk reduction and protective measures were provided. Timing allotted for this educational session varied and either lasted up to 40 min [24] or was not reported [17, 23]. Follow up educational content was repeated either post-operatively [24] or at 6 months [17, 23]. In the studies reviewed, although education was a primary aim, only one investigated knowledge assessment and its acquisition [24]. Additionally, outcome measures varied and focused on function, quality of life, arm volume, BCRL incidence rates, and adherence to self-care. The education provided also varied in timing, mode, content, and frequency across the trajectory of care. The details are provided in Table 2.

Table 2 Summary of breast cancer-related lymphedema educational content, mode, and timing
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The post-operative phase of BC care utilized 3 different modes of education, which included one-on-one [19], small groups (3–4 participants) [18, 20], or social media (WeChat) [26]. During the one-on-one session, printed material with an accompanying visual presentation was conducted. BCRL content included risk reduction practices, shoulder range of motion, self-management, and physical activity. The group sessions offered similar content with the additional inclusion of BCRL behavioral strategies [20]. Education delivered via social media focused on participants’ discussion of self-identified problems followed by group-guided solutions. A healthcare professional then summarized the solutions identified by the participants [26]. Only one study provided follow up education via WhatsApp at 1 and 3 months post-operatively [19]. Unfortunately, the studies did not delineate between the confounding variables, the outcome of the education intervention, and the development of BCRL.

For individuals who developed BCRL, education was provided in a variety of modes including one-on-one sessions, [27, 28, 30], small group (3–5 participants) [20], social media (Telemessenger) [20], and web-based video presentation [29]. The education used printed materials, visual aids, group discussion, demonstration, and feedback as learning modes [20, 27,28,29,30]. The BCRL education emphasized self-care and self-management, therapeutic exercises, self-manual lymph drainage, and utilization of a compression garment [20, 27,28,29,30]. Timing of each session ranged from 30 to 90 min over 4 to 5 sessions. The 12 web-based videos took 20–45 min to review [29]. Ridner et al. found the shorter the educational time expectation, the higher the completion of the program [29]. Follow up education varied in frequency from weekly, monthly, to 1 year. Mode of follow up education was either by telephone or in person [27, 28, 30].

Outcome measures

The 4 acceptable studies included one or more of the following outcome measures: arm volume via calculated formula or arm circumference, quality of life via the Functional Assessment of Cancer Therapy-Breast (FACT-B) or the Lymphedema Life Impact Scale (LLIS), and functional outcomes via the Disabilities of the Arm, Shoulder, and Hand (DASH), LLIS, or the Subject Perception of Post-operative Functional Impairment of the Arm (SPOFIA) (Table 3). Although Bozdemir 2021 demonstrated significant reduction with arm circumference, volume was not calculated [19]. Clinically, arm circumference by itself is not considered a valid and reliable diagnostic method to detect BCRL in those at risk [31]. In 2 studies, improvement in quality of life was statistically significant as measured by the FACT-B (p = 0.048 at 6 months) and by the LLIS (p = 0.007 at 3 months) [17, 20]. Additionally, functional improvement was statistically significant at 3 months follow up in 2 of the acceptable studies as measured by the DASH (p ≤ 0.05), SPOFIA (p ≤ 0.05) [19], and the LLIS (p = 0.024) [20]. One complication following treatment for BC is post-operative wound infection, which may be a contributing factor to the development of lymphedema [32]. Only one study reported the incidence of postoperative surgical wound infection and adherence to the BCRL education. Infection was insignificant (p = 0.26), and adherence rates (65%) were similar in both the intervention and control groups [18]. Notably, those participants who received BCRL education and requested follow-up sessions with a physical therapist were fully adherent to the post-operative education provided. BCRL education was not examined as an individual intervention in all studies except one; rather, it was a component of the overall plan of care. Therefore, the effect of education on these outcome measures was not specifically examined. In order to determine the impact of BCRL education, knowledge acquisition as an outcome measure pre- and post-education needs to be assessed. Zhang (2020), a low-quality study, attempted to indirectly assess knowledge acquisition in patients with and those at risk for BCRL using the Exercise of Self Care Agency Scale (ESCA) [26]. This scale included 4 domains, one of which investigated level of health knowledge. The problem-based learning intervention group was instructed to perform self-massage, ROM, and utilization of a compression sleeve. Although the ESCA scores demonstrated significant improvement (p < 0.05) at discharge, 1 month, and 3 months post discharge, learning was not directly assessed. This result infers that adherence to self-care practices reflects knowledge acquisition.

Table 3 Outcome measures and results
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Cho (2012) developed a 10-item investigator-designed questionnaire to assess participant knowledge about BC care [24]. The results indicated significantly higher knowledge scores for those who had education 0.36 (95% CI 0.30 − 0.40) compared to no education 0.11 (95% CI 0.07–0.15 p = 0.0001). Overall, the results of these outcome measures could only infer that BCRL education played a role in improvements of quality of life, function, adherence to self-care practices, and early identification of lymphedema [17,18,19,20, 26]. Unfortunately, knowledge acquisition was not directly assessed in any of these studies.

Discussion/Summary

Based on the evidence appraised, this systematic review was unable to determine the optimal content, mode, and timing for BCRL education across survivorship. The BCRL educational content most consistently taught included definition of lymphedema, risk reduction practices, early signs and symptoms, and self-care management. Several low-quality studies in this review provided this information using previously developed BCRL educational material by the American Cancer Society Guidelines for Lymphedema, National Lymphedema Network, or Australian Cancer Council Lymphedema FACT Sheet [21, 22, 25, 28]. This information varies widely in depth and breadth but provides a general overview of BCRL physiology, pathophysiology, risk reduction practices, and interventions. These organizations provide an educational starting point for clinicians and survivors; however, universal guidelines for BCRL educational content do not exist. Most importantly, BCRL education should be individualized based on the survivors’ needs and preferred learning styles. The educational session may be influenced by the phase and intensity of an individuals’ cancer treatment plan, and therefore, the health care educator may adjust volume and content accordingly. Presently, healthcare providers independently determine what content to include, how to provide the education, and when to deliver it. Future research is needed to develop evidence-based BCRL recommendations on educational content, mode of delivery, and its timing.

Knowledge and retention assessment was not a primary or secondary aim of the reviewed studies. To determine effectiveness of BCRL education delivery, repetition and follow up of BCRL education over time may be needed for an individual to acquire and retain knowledge. Retention of knowledge and follow up with health care professionals may enhance early detection and treatment of BCRL [11]. Further research to assess the individuals’ knowledge acquisition, understanding, and integration of the information received and the value of repeating education over time throughout survivorship are needed.

In the studies reviewed, psychosocial issues regarding the impact of BCRL education timing and volume of information provided were not assessed or discussed. Individuals diagnosed with BC may experience different treatment regiments throughout the trajectory of care, which results in varying demands and stresses. Additionally, it is well known that cancer treatments, especially chemotherapy, can lead to cancer-related fatigue and cognitive impairments that can influence knowledge acquisition [33, 34]. The negative impact of psychosocial issues across survivorship may influence the content, mode, and optimal timing of BCRL education. When developing BCRL education, healthcare professionals may consider balancing the volume of material, the time commitment required, and the individual’s mental health [33]. Studies also reported that individuals have preferred learning styles; therefore, a multi-modal approach to BCRL education is indicated [12]. Healthcare professionals should ask individuals how they would like to receive the education. For example, some individuals prefer web-based education while others prefer one-on-one or in-person group education [12, 35]. Additionally, some individuals prefer the option of reading booklets and handouts prior to discussion [12, 35]. Finally, in these studies, the age of most participants ranged from 47 to 61 years. As age may influence the preference of delivery modes, it will need to be a consideration when designing a BCRL educational program. Further research is needed to explore all the factors contributing to an individual’s ability to acquire knowledge.

Limitations

An overall limitation to this systematic review is the wide variability in methodology. Timing of BCRL education occurred pre/post operatively, or once BCRL developed. Content and volume of BCRL education varied across trajectory of BC care. Knowledge assessment and repetition of education was rarely included in the studies. Additionally, this systematic review included only English language publications from January 1, 2011 to December 31, 2021, which may have limited the authors’ findings. Participant characteristics reflected a wide range of demographics and risk factors, which may influence the content, mode of delivery, timing of education, and total time required to deliver the patient education.

Impact for breast cancer health care professionals and survivors of breast cancer

Conclusion

Based on this systematic review, evidence suggests BCRL education should be provided at multiple time points along the trajectory of care, with varying depth and breadth of content, and be provided via a multi-modal approach. The BC healthcare team should assess the survivors’ BCRL knowledge and its acquisition and reinforce BCRL education appropriately. Education for individuals diagnosed with BC, at a minimum, should include a brief overview of BCRL, early signs and symptoms, a point of contact for questions, and early referral for intervention. Survivors, who are at high risk for developing BCRL, may need a more detailed educational approach emphasizing individualized risk reduction practices. Interventions for individuals with BCRL require a strong focus on self-management and self-efficacy. Future research needs to determine the most appropriate educational content, mode, time point, and follow up for providing BCRL education across the trajectory of survivorship.