Heavy-Load Lifting: Acute Response in Breast Cancer Survivors at Risk for Lymphedema

A mini-review-cancer energy reprogramming on drug resistance and immune response

With the growing interest to harness cancer metabolism and energy reprogramming, this mini review aimed to explain the metabolic programming revealing the mechanisms regarding the treatment resistance. This mini review summarized the prominent cancer metabolic reprogramming on macromolecules. In addition, metabolic reprogramming explaining immune response and treatment resistance as well as energy reprogramming mechanisms are briefly discussed. Finally, some prospects in MR for reversing cancer drug resistance are highlighted.

Physical activity and pain in people with and without cancer

BACKGROUND

Performing physical activity may provide analgesic benefit, although this effect is more established for noncancer pain rather than cancer pain. The relationship between physical activity and pain outcomes in adults with and without a history of cancer was examined.

METHODS

Totals of 51,439 adults without a cancer history and 10,651 adults with a cancer history from the Cancer Prevention Study II Nutrition Cohort were included. Exposures included self-reported moderate to vigorous physical activity (MVPA) as well as 2-year change in MVPA. Pain outcomes included pain intensity (primary outcome) and analgesic use (secondary outcome).

RESULTS

MVPA was inversely associated with pain intensity for adults with (odds ratio [OR], 0.84 [≥15 metabolic equivalent of task (MET) h/week vs. <7.5 MET h/week]; 95% confidence interval [CI], 0.76-0.93) and without (OR, 0.79; 95% CI, 0.75-0.82) a history of cancer. Compared to remaining inactive, participants who became sufficiently active (cancer: OR, 0.76; 95% CI, 0.68-0.86; no cancer: OR, 0.73; 95% CI, 0.69-0.77), became inactive (cancer: OR, 0.79; 95% CI, 0.71-0.88; no cancer: OR, 0.84; 95% CI, 0.80-0.89), or remained sufficiently active (cancer: OR, 0.66; 95% CI, 0.60-0.72; no cancer: OR, 0.62; 95% CI, 0.60-0.65) also reported less pain. Physical activity was not related to analgesic use.

CONCLUSIONS

The relationship between physical activity and pain intensity was not substantially different between people with and without a history of cancer. Cancer survivors who perform more activity, or who increase their activity, may experience less pain than cancer survivors who consistently perform less.

PLAIN LANGUAGE SUMMARY

People who have had cancer often experience ongoing pain. Being physically active may help reduce the intensity of the pain they experience.

Physical activity and pain in people with cancer: a systematic review and meta-analysis

PURPOSE

Physical activity can provide analgesic benefit but its effect on cancer-related pain is unclear. This review synthesised and appraised the evidence for the effect of physical activity on pain in people living with or beyond cancer.

METHODS

A systematic search of Ovid Medline and Embase was performed to identify randomised controlled trials (RCTs), randomised cross-over studies (RXTs), and prospective observational studies that examined physical activity and pain outcomes in adults living with or beyond cancer. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the GRADE system was used to assess evidence quality.

RESULTS

One hundred twenty-one studies (n = 13,806), including 102 RCTs, 6 RXTs, and 13 observational studies, met the criteria for inclusion. Meta-analyses of RCTs identified a decrease in pain intensity (n = 3734; standardised mean difference (SMD) - 0.30; 95% confidence interval (CI) - 0.45, - 0.15) and bodily pain (n = 1170; SMD 0.28; 95% CI 0.01, 0.56) but not pain interference (n = 207; SMD - 0.13, 95% CI - 0.42, 0.15) following physical activity interventions. Individual studies also identified a reduction in pain sensitivity but not analgesic use, although meta-analysis was not possible for these outcomes. High heterogeneity between studies, low certainty in some effect estimates, and possible publication bias meant that evidence quality was graded as very low to low.

CONCLUSION

Physical activity may decrease pain in people living with and beyond cancer; however, high heterogeneity limits the ability to generalise this finding to all people with cancer or to specific types of cancer-related pain.

Acute Effects of Remedial Exercises with and without Compression on Breast-Cancer-Related Lymphedema

Remedial exercises are an important part of the treatment for lymphedema, but there is little evidence to support the acute effects of remedial exercises with or without compression. The aim of this study was to investigate whether and how daily (performed within 24 h) remedial exercises with and without compression bandaging acutely affect the severity of lymphedema and its symptoms in breast-cancer-related lymphedema (BCRL). In total, 34 patients with BCRL completed three sets of remedial exercises (within 24 h) with and without compression bandaging in a randomized order separated by a 3-day wash-out period. The severity of lymphedema and extracellular water ratio were assessed before and 24 h post exercise by using bilateral circumferential measurements and bioimpedance spectroscopy (in L-dex score), respectively, and the severity of self-reported symptoms (swelling, heaviness, and tightness) was assessed using a visual analogue scale. While there was no difference in all outcomes at 24 h post exercise without compression (p > 0.05), all outcomes decreased significantly compared to baseline at 24 h after the exercise with compression (p < 0.001). The remedial exercises performed in the absence of compression within 24 h do not acutely increase the lymphedema and symptoms in BCRL. These are important preliminary findings, which can be used to inform future prospective evaluation of the long-term effects of remedial exercise performed without compression.

The role of exercise for pain management in adults living with and beyond cancer: a systematic review and meta-analysis

BACKGROUND

Pain is a common side effect of cancer or cancer treatment that negatively impacts biopsychosocial wellbeing and quality of life. Exercise is a potential intervention to manage pain that is safe and has multiple benefits. The objective was to determine the role of exercise in cancer pain management.

METHODS

We completed a systematic review and meta-analysis of exercise interventions in adults with any type or stage of cancer by searching Ovid MEDLINE®, Embase, APA PsycInfo, the Cochrane Central Register of Controlled Trials, CINAHL, and SPORTDiscus. We included experimental and quasi-experimental designs where pain was measured as an outcome. Data synthesis included narrative and tabular summary. A meta-analysis was performed on studies powered to detect the effect of exercise on pain. Study quality was evaluated using the Cochrane risk of bias tool and certainty of evidence was evaluated using the GRADE tool.

RESULTS

Seventy-six studies were included. Studies were predominantly conducted in breast cancer and exercise usually included a combination of aerobic and strength training. Ten studies were included in the meta-analysis demonstrating a significant effect for exercise in decreasing pain (estimated average standard mean difference (SMD) was g =  - 0.73 (95% CI: - 1.16 to - 0.30)); however, the overall effect prediction interval was large. Overall risk of bias for most studies was rated as some concerns and the grading of evidence certainty was low.

CONCLUSION

There are limitations in the evidence for exercise to manage cancer-related pain. Further research is needed to understand the role of exercise in a multimodal pain management strategy.

Breast cancer-related lymphoedema and resistance exercise: An evidence-based review of guidelines, consensus statements and systematic reviews

AIMS AND OBJECTIVES

Breast cancer-related lymphoedema (BCRL) is a side effect of cancer treatment and can be alleviated by resistance exercise. This systematic, evidence-based review examined the existing best evidence on resistance exercise for BCRL to accurately describe the current status of the field and offer recommendations for clinicians.

METHODS

This review adheres to the PRISMA guidelines. Clinical practice guidelines, consensus documents, systematic reviews and other related evidence-based resources about resistance exercise for BCRL were retrieved through the English databases and guideline websites. The publication data limit was set to December 2020. The following search terms were used: 'breast cancer/breast neoplasm/breast carcinoma/breast tumor/breast malignancy, lymphedema/swelling/edema/lymphoedema, resistance/weight/strength training, best practice/clinical practice/guideline/consensus documents'. The quality of the included studies was evaluated by two authors independently using AGREE II and AMSTAR II tools. Evidence-based recommendations on resistance exercise relevant for BCRL were synthesised and categorised.

RESULTS

Twenty two articles (seven guidelines, four consensus documents and eleven systematic reviews) were included. The overall quality of the eleven eligible guidelines and consensus documents was moderate to high according to the AGREE II criteria. The quality of the eleven systematic reviews was critically low to high according to the AMSTAR criteria. Six clinical topics involving 43 recommendations were identified. Recommendations were categorised by safety of resistance training, effectiveness of resistance training, evaluation prior to resistance exercise, resistance exercise prescription, resistance training outcome index and points for attention.

CONCLUSIONS

This study summarises 43 recommendations for resistance training for BCRL and provides guidance for clinicians. Based on randomised trials and systematic reviews published in recent years, there is an urgent need to update the guidelines and consensus documents in terms of topics, for example effectiveness of resistance training and resistance training outcome index.

Effect of Supervised Resistance Training on Arm Volume, Quality of Life and Physical Perfomance Among Women at High Risk for Breast Cancer-Related Lymphedema: A Study Protocol for a Randomized Controlled Trial (STRONG-B)

Objectives

To determine the preventive effects of supervised resistance training on arms volume, quality of life, physical performance, and handgrip strength in Chilean women at high risk for breast cancer-related lymphedema (BCRL) undergoing chemotherapy.

Design

Randomized control trial.

Participants

One hundred and six women at high risk for breast cancer-related lymphedema aged 18 to 70 years.

Interventions

Participants will be randomized into two groups: [a] intervention, who will receive 12 weeks of supervised resistance training (STRONG-B) during adjuvant chemotherapy; and [b] control, who will receive education to promote lymphatic and venous return, maintain range of motion, and promote physical activity.

Main Outcome Measures

The primary outcome will be arms volume measured with an optoelectric device (perometer NT1000). Secondary outcomes will be quality of life, handgrip strength, and physical performance. Primary and secondary outcomes will be measured at baseline, just after the intervention, and 3 and 6 months after. Statistical analysis will be performed following intention-to-treat and per-protocol approaches. The treatment effect will be calculated using linear mixed models.

Discussion

The STRONG-B will be a tailored supervised resistance training that attempts to prevent or mitigate BCRL in a population that, due to both intrinsic and extrinsic factors, will commonly suffer from BCRL.

Clinical Trial Registration

[https://clinicaltrials.gov/ct2/show/NCT04821609], identifier NCT04821609.

Progressive resistance exercise training to prevent lower-limb lymphedema after cervical cancer surgery: A feasibility study

Objective

Radical hysterectomy with pelvic lymphadenectomy is the standard surgical treatment for early stage cervical cancer. One of the most common complications after this surgery is lower extremity lymphedema (LLL). Program of progressive resistance exercise training (PRET) is a possible way to prevent LLL for cervical cancer patients postoperatively. Before we start a randomized controlled trial to evaluate the preventive effect of PRET, we conducted this pilot study to assess the feasibility of PRET after cervical cancer surgery.

Methods

The primary purpose of the pilot study was the feasibility of PRET, as well as the satisfaction and adherence to the PRET assessed by a questionnaire. We conducted a single-arm prospective study involving cervical cancer patients who underwent radical hysterectomy with pelvic lymphadenectomy. Participants exercised twice a day for 24 weeks (two weeks of supervised in hospital and then 22 weeks of home-based training) after surgical treatment. All patients were followed up for 12 months. Information that included the limb volume, BMI, perceived difficulty level and adherence rate was collected.

Results

From February to April 2019, a total of 24 patients participated in the study. None of them dropped out. The adherence rate was more than 75% in majority of the patients, the perceived difficulty level of the PRET was high (for the first phase, the fourth phase and the fifth phase, more than half of the participants felt the intensity of the exercise appropriate), and no serious adverse events in the study were observed.

Conclusions

Exercise training was safe and feasible. The preliminary results offered us the possibility to further test the preventive effect of PRET in a full-scale randomized controlled trial.

Breast edema, from diagnosis to treatment: state of the art

Introduction

Breast edema can arise from different etiologies; however, it is mostly seen after breast conserving surgery and/or radiotherapy. Combining breast conserving surgery and radiotherapy can cause damage to the lymphatic system and reactions to surrounding tissues, which can lead to breast edema; hereby, the breast size can increase by more than one cup size. Swelling of the breast is not the only criterion associated with breast edema. Other common criteria found in literature are peau d’orange, heaviness of the breast, skin thickening, breast pain, redness of the skin, hyperpigmented skin pores and a positive pitting sign. Despite the benefits of breast conserving surgery, breast edema can be uncomfortable, and can negatively influence quality of life in suffering patients. In contrast to lymphedema of the arm, which is well known in clinical practice and in research, breast edema is often underestimated and far less explored in literature. Currently, many aspects still need to be reviewed.

Purpose and importance to practice

This masterclass aims at providing the state of the art of breast edema for all health care workers and researchers involved in the treatment and monitoring of breast cancer patients. It includes current and future perspectives on its diagnosis, longitudinal course and treatment. Furthermore, recommendations for clinical practice and future research are discussed.

Clinical implications

It is recommended to closely monitor those patients in whom breast edema symptoms do not decline within 6 months after termination of radiotherapy and provide them with the appropriate therapy. Since evidence concerning the treatment of breast edema is currently lacking, we recommend the complex decongestive therapy (CDT) to the utmost extent, by analogy with the lymphedema treatment of the extremities. This treatment involves skin care, exercise therapy and compression. Additionally, all patients should be informed about the normal course of breast edema development.

Future research priorities

A consensus should be reached among clinicians and researchers concerning the definition, assessment methods and best treatment of breast edema. Furthermore, high quality studies are necessary to prove the effectiveness of the CDT for breast edema.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-021-00103-4.

Reliability and validity of the Upper Limb Functional Test (ULIFT) for women after breast cancer surgery

PURPOSE

To evaluate the reliability and convergent validity of the Upper Limb Functional Test (ULIFT) in women after breast cancer surgery.

MATERIALS AND METHODS

A cross-sectional study with 25 women (mean age 50 ± 7.3 years) with breast cancer submitted to a surgery intervention within a minimum period of three years. Intraclass correlation coefficients (ICCs) were calculated to assess the test-retest reliability. A Bland-Altman plot examined the agreement between the times to complete two tests. Validity was established by correlating the ULIFT and DASH total score. The receiver operating characteristic (ROC) curve was used to determine the cut-off point for ULIFT in order to discriminate patients with some level of upper limb dysfunction.

RESULTS

The ULIFT showed high reproducibility (ICC = 0.89; p < 0.001), learning effect of 7.21%, and a moderate correlation with the DASH total score (r = 0.536; R² = 0.28; p = 0.006). The standard error of measurement was 6.9 s and the smallest real difference was 19.1 s. The ROC curve indicated a cut-off point of 109.2 s (sensitivity = 68.7%; specificity = 77.8%; area under ROC curve = 0.77).

CONCLUSIONS

The ULIFT could be a valid and reliable test to assess upper limb functionality in patients submitted to breast cancer surgery.Implications for rehabilitationThe ULIFT is a reliable and valid test to assess upper limb function in women after breast cancer surgery, considering specifically the lifting and range of motion construct of unilateral upper limb function.The ULIFT could help identify those most at risk of developing upper limb dysfunction after breast cancer surgery and could benefit the follow-up of a postoperative rehabilitation program.Two ULIFTs should be performed in order to achieve patient's best performance.

Interrater Reliability of Dynamic Muscle Testing After Breast Cancer Surgery in Women at High Risk of Lymphedema: To Improve Quality in Clinical Practice

Background: The purpose of this study is to determine the interrater reliability of dynamic muscle tests in the early rehabilitation phase in women after breast cancer surgery with axillary lymph node dissection (ALND) based on the "preventive intervention against lymphedema after breast cancer" (LYCA) randomised controlled trial. Methods: Fifteen women treated with breast cancer surgery including ALND were recruited from participants in the LYCA trial. In this interrater reliability study, women were tested in 4 dynamic muscle tests by 2 physiotherapists at a Capital Hospital in Denmark. Intraclass correlation coefficients (ICCs) with 95% confidence intervals (CIs) was used to assess the relative reliability between raters. A Bland-Altman plot and limits of agreement were calculated to describe the absolute reliability. Results: All 6 subtests displayed high interrater reliability. ICC values were: leg press 0.96 (95% CI = 0.87-0.99), elbow flexion (contralateral) 0.94 (0.83-0.98), elbow flexion (affected arm) 0.93 (0.80-0.98), elbow extension 0.80 (0.41-0.93), shoulder abduction (contralateral) 0.89 (0.68-0.96), and shoulder abduction (affected arm) 0.91 (0.74-0.97). Cumulated interrater reliability for the test battery was very high (ICC = 0.99, 95% CI = 0.990-1.0). The absolute reliability of this study was considered high, and the absence of large shifts between mean and the line of 0 difference suggest no systematic bias that could influence clinical interpretation. Conclusions: The dynamic muscle tests evaluated in this study had high interrater reliability and can be used reliably in women in the postoperative phase after breast cancer surgery with ALND.

Resistance exercise and breast cancer-related lymphedema-a systematic review update and meta-analysis

BACKGROUND

The purpose of this systematic review update and meta-analysis was to analyze resistance exercise (RE) intervention trials in breast cancer survivors (BCS) regarding their effect on breast cancer-related lymphedema (BCRL) status and upper and lower extremity strength.

METHODS

Systematic literature search was conducted utilizing PubMed, MEDLINE, and Embase databases. Any exercise intervention studies-both randomized controlled and uncontrolled-which assessed the effects of RE on BCRL in BCS in at least one intervention group published between 1966 and 31st January 2020 were included. Included articles were analyzed regarding their level of evidence and their methodological quality using respective tools for randomized and nonrandomized trials of the Cochrane collaboration. Meta-analysis for bioimpedance spectroscopy (BIS) values as well as upper and lower extremity strength was conducted.

RESULTS

Altogether, 29 studies were included in the systematic review. Results of six studies with altogether twelve RE intervention groups could be pooled for meta-analysis of the BCRL. A significant reduction of BCRL after RE was seen in BIS values (95% CI - 1.10 [- 2.19, - 0.01] L-Dex score). Furthermore, strength results of six studies could be pooled and meta-analysis showed significant improvements of muscular strength in the upper and lower extremities (95% CI 8.96 [3.42, 14.51] kg and 95% CI 23.42 [11.95, 34.88] kg, respectively).

CONCLUSION

RE does not have a systematic negative effect on BCRL and, on the contrary, potentially decreases it.

Heavy-load resistance exercise during chemotherapy in physically inactive breast cancer survivors at risk for lymphedema: a randomized trial

Background: Due to long-standing concerns that heavy-load lifting could increase the risk of developing lymphedema, breast cancer survivors have been advised to refrain from resistance exercise with heavy loads. This study prospectively evaluated the effect of heavy-load resistance exercise on lymphedema development in women receiving chemotherapy for breast cancer.Material and Methods: Physically inactive women receiving adjuvant chemotherapy for breast cancer (n = 153) were randomized to a HIGH (supervised, multimodal exercise including heavy-load resistance exercise: 85-90% 1 repetition maximum [RM], three sets of 5-8 repetitions) versus LOW (pedometer and one-on-one consultations) 12-week intervention. Outcomes (baseline, 12 and 39 weeks) included lymphedema status (extracellular fluid [bioimpedance spectroscopy] and inter-arm volume % difference [dual-energy X-ray absorptiometry], lymphedema symptoms [numeric rating scale 0-10]), upper-extremity strength (1 RM), and quality of life domains (EORTC- BR23). Linear mixed models were used to evaluate equivalence between groups for lymphedema outcomes (equivalence margins for L-Dex, % difference and symptoms scale: ±5, ±3% and ±1, respectively). Superiority analysis was conducted for muscle strength and quality of life domains.Results: Postintervention equivalence between groups was found for extracellular fluid (0.4; 90% CI -2.5 to 3.2) and symptoms of heaviness (-0.2; -0.6 to 0.2), tightness (-0.1; -0.8 to 0.6) and swelling (0.2; -0.4 to 0.8). Nonequivalence was found for inter-arm volume % difference (-3.5%; -17.3 to 10.3) and pain (-0.7; -1.3 to 0), favoring HIGH. Strength gains were superior in the HIGH versus LOW group (3 kg; 1 to 5, p < .05). Further, clinically relevant reductions in breast (-11; -15 to -7) and arm (-6; -10 to -1) symptoms were found in the HIGH group.Conclusion: Findings suggest that physically inactive breast cancer survivors can benefit from supervised heavy-load resistance exercise during chemotherapy without increasing lymphedema risk. Trial registration: ISRCTN13816000.

Progressive resistance training to prevent arm lymphedema in the first year after breast cancer surgery: Results of a randomized controlled trial

BACKGROUND

Existing research suggests that progressive resistance training (PRT) after breast cancer (BC) surgery is safe, but the preventive effect on arm lymphedema has yet to be determined.

METHODS

Women aged 18 to 75 years who were undergoing BC surgery with axillary lymph node dissection were eligible for the study. Recruited on the day of surgery, participants were allocated to intervention or usual care by computer randomization. The intervention consisted of PRT 3 times per week: in the first 20 weeks as a supervised group exercise and in the last 30 weeks as a self-administered exercise. The primary outcome was arm lymphedema, which was defined as a >3% increase in the interlimb volume difference by water displacement. Measurements were made at the baseline and at a 12-month follow-up by physiotherapists blinded to group allocation. Analyses of effects included t tests and regression models; missing data were addressed by multiple imputation.

RESULTS

Among the 158 randomized women, no mean group difference was found in arm volume (0.3%; 95% confidence interval, -1.7% to 2.3%) or lymphedema incidence (adjusted odds ratio, 1.2; 95% confidence interval, 0.5-2.8). None of the participants exited the program because of adverse events.

CONCLUSIONS

This study provides no evidence that PRT can prevent arm lymphedema in the first year after BC, but the results corroborate the importance and safety of resistance training for patients, including women at high risk for lymphedema.

Advising Women Undergoing Treatment for Breast Cancer: A Narrative Review

A majority of women undergoing conventional treatment for breast cancer also undertake complementary and integrative approaches. Practitioners knowledgeable about the evidence base behind common integrative approaches can help patients attain improved quality of life, and at times, improved survival. Evidence-based recommendations include the following: a plant-based diet for general health after diagnosis, and carbohydrate restriction for patients with estrogen receptor-positive postmenopausal breast cancer may be prudent. Other dietary recommendations include a 13-h daily overnight fast. Carefully selected patients may choose to fast the day before and the day of chemotherapy to decrease side effects. Specific food recommendations include avoidance or limitation of alcohol, and liberal culinary use of cruciferous vegetables, coffee, green tea, soy, and flaxseed. Promising supplements include diindolylmethane and melatonin. Omega 3 fatty acids may help with bone density in patients on aromatase inhibitors, but may increase chemotherapy resistance. Findings regarding the usefulness of multivitamins, vitamin D, vitamin C, and vitamin E are weak and/or mixed different exercise modalities may have different effects and thus play different roles in breast cancer therapy. Aerobic and resistance training combined during breast cancer chemotherapy may confer a survival benefit, while yoga may improve outcome in lymphedema patients. Current evidence suggests that meditation, yoga, breathing, music therapy, guided imagery, and hypnosis may improve mood and quality of life during breast cancer treatment. Acupuncture is useful for treating side effects of breast cancer therapies, including hot flushes, aromatase inhibitor-induced joint pain, chemotherapy-induced peripheral neuropathy, and vulvodynia. Vaginal moisturizers and vaginal rings supplying low-dose estrogen can be useful in the treatment of symptoms of estrogen-deprivation states caused by breast cancer treatments; such symptoms include vaginal dryness, dyspareunia, and sexual dysfunction. Carbon dioxide laser technology can rejuvenate atrophied vaginal mucosa and relieve dyspareunia, allowing avoidance of estrogen therapy. Tertiary sexual health centers are available for referral.

Lymphedema following breast cancer: The importance of surgical methods and obesity

Background

Breast cancer-related arm lymphedema is a serious complication that can adversely affect quality of life. Identifying risk factors that contribute to the development of lymphedema is vital for identifying avenues for prevention. The aim of this study was to examine the association between the development of arm lymphedema and both treatment and personal (e.g., obesity) risk factors.

Methods

Women diagnosed with breast cancer in Iowa during 2004 and followed through 2010, who met eligibility criteria, were asked to complete a short computer assisted telephone interview about chronic conditions, arm activities, demographics, and lymphedema status. Lymphedema was characterized by a reported physician-diagnosis, a difference between arms in the circumference (> 2cm), or the presence of multiple self-reported arm symptoms (at least two of five major arm symptoms, and at least four total arm symptoms). Relative risks (RR) were estimated using logistic regression.

Results

Arm lymphedema was identified in 102 of 522 participants (19.5%). Participants treated by both axillary dissection and radiation therapy were more likely to have arm lymphedema than treated by either alone. Women with advanced cancer stage, positive nodes, and larger tumors along with a body mass index > 40 were also more likely to develop lymphedema. Arm activity level was not associated with lymphedema.

Conclusions

Surgical methods, cancer characteristics and obesity were found to contribute to the development of arm lymphedema. Vigorous arm activity post-surgery was not found to increase the risk of arm lymphedema.