Mathematical model to predict risk for lymphoedema after treatment of cutaneous melanoma

Integrative lymph node-mimicking models created with biomaterials and computational tools to study the immune system

The lymph node (LN) is a vital organ of the lymphatic and immune system that enables timely detection, response, and clearance of harmful substances from the body. Each LN comprises of distinct substructures, which host a plethora of immune cell types working in tandem to coordinate complex innate and adaptive immune responses. An improved understanding of LN biology could facilitate treatment in LN-associated pathologies and immunotherapeutic interventions, yet at present, animal models, which often have poor physiological relevance, are the most popular experimental platforms. Emerging biomaterial engineering offers powerful alternatives, with the potential to circumvent limitations of animal models, for in-depth characterization and engineering of the lymphatic and adaptive immune system. In addition, mathematical and computational approaches, particularly in the current age of big data research, are reliable tools to verify and complement biomaterial works. In this review, we first discuss the importance of lymph node in immunity protection followed by recent advances using biomaterials to create in vitro/vivo LN-mimicking models to recreate the lymphoid tissue microstructure and microenvironment, as well as to describe the related immuno-functionality for biological investigation. We also explore the great potential of mathematical and computational models to serve as in silico supports. Furthermore, we suggest how both in vitro/vivo and in silico approaches can be integrated to strengthen basic patho-biological research, translational drug screening and clinical personalized therapies. We hope that this review will promote synergistic collaborations to accelerate progress of LN-mimicking systems to enhance understanding of immuno-complexity.

Factors associated with melanoma-related limb lymphoedema

BACKGROUND

Melanoma-related limb lymphoedema is a well-known late effect following sentinel node biopsy (SNB), and lymph node dissection (LND) in patients treated of melanoma. However, data on associated risk factors are sparse. This study aimed to investigate factors associated with melanoma-related limb lymphoedema.

METHODS

The present cross-sectional single-center clinical study included patients between 18 and 75 years with American Joint Committee on Cancer Stages I-III melanoma treated with wide local excision (WLE) and unilateral axillary or inguinal SNB and/or completion LND (CLND) or therapeutic LND (TLND). The diagnosis of secondary unilateral limb lymphoedema was based on the history, symptoms, and physical examination and staged according to the International Society of Lymphology (ISL). Data on factors associated with lymphoedema were analysed with binary logistic regression models.

RESULTS

In total, 642 patients were eligible, of which 435 (68%) patients participated in the study. Among these 431 patients, 109 (25%) had lymphoedema of which 48 (44%), and 61 (56%) were classified with ISL Stages I and II-III, respectively. Multivariate analyses identified primary tumour on the limb (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.17-4.56; p value .017), inguinal surgery (OR, 6.91; 95% CI, 3.49-14.11; p value <.0001), LND (OR, 6.45; 95% CI, 3.18-13.57; p value <.0001), and persistent pain at the site of lymph node surgery as factors associated with lymphoedema (OR, 3.52; 95% CI, 1.54-8.19; p value .003). Multivariable analysis of ISL Stage II-III lymphoedema further identified limb cellulitis to be associated with lymphoedema (OR 5.74; 95% CI, 2.11-15.99; p value .0006).

CONCLUSIONS

Melanoma-related limb lymphoedema is associated with inguinal surgery, LND, primary tumour on the limb, persistent pain at the site of lymph node surgery, and cellulitis of the limb. This study highlights the importance of increasing awareness, improving prevention, and treatment of melanoma-related limb lymphoedema.

Histopathologic Features of Lymphedema: A Molecular Review

An estimated 5 million people in the United States are affected by secondary lymphedema, with most cases attributed to malignancies or malignancy-related treatments. The pathogenesis of secondary lymphedema has historically been attributed to lymphatic injury or dysfunction; however, recent studies illustrate the complexity of lymphedema as a disease process in which many of its clinical features such as inflammation, fibrosis, adipogenesis, and recurrent infections contribute to on-going lymphatic dysfunction in a vicious cycle. Investigations into the molecular underpinning of these features further our understanding of the pathophysiology of this disease and suggests new therapeutics.

Impact of seamless compression garments on limb functionality, comfort and quality of life

Lymphoedema is a chronic disease affecting the patients' quality of life (QoL) especially with regard to mobility and daily activities. Lymphoedema cannot be cured but symptoms can effectively be improved by a comprehensive approach and the continuous use of compression therapy. An appropriate fitted compression garment is essential for compliance and thus a prerequisite for successful lymphoedema management. Compression garments with bulky seams are not only uncomfortable they also can lead to severe pressure marks or even reduce the mobility and function of the affected limb, which may negatively impact the already reduced QoL of lymphoedema patients. A prospective multicentre observational study was conducted to compare compression garments without and with a seam for hands and toes in 143 patients with lymphoedema. Product performance, lymphoedema symptoms, functionality of hands/toes, QoL and patient satisfaction were documented for the previously worn compression garment as well as for the 3D flat knitted JOBST® Elvarex Plus compression garment without a seam. The JOBST Elvarex Plus glove was perceived very positively by patients, who rated the mobility of the fingers, the adaptability to the shape of the hand/fingers, the fit of cuffs/welts, and the tactile sense of the fingers to be significantly better compared to the previous glove. Also pressure marks between fingers/toes and pressure marks due to cuffs/welts were significantly less frequent when wearing JOBST Elvarex Plus. Also pain, sensation of heaviness, swelling, tightness and dryness of skin were significantly improved when wearing JOBST Elvarex Plus gloves. Furthermore, 80% of the patients rated the wearing comfort of JOBST Elvarex Plus to be better than their previous garments with a seam. Regarding functionality, patients were significantly less limited in their daily activities when wearing JOBST Elvarex Plus garments. Finally, when wearing JOBST Elvarex Plus gloves and toe caps, patients rated the negative effect of their lymphoedema on their QoL to be significantly lower. In conclusion, the application of anatomically adapted compression garments without a seam led to improving patient's reported lymphoedema symptoms, increased patient's satisfaction with the compression garment and supported a better QoL.

Evaluation of inter-rater reliability of subjective and objective criteria for diagnosis of lymphedema in upper and lower limbs

BACKGROUND: The diagnosis of lymphedema can be obtained objectively by measurement methods, and also by subjective methods, based on the patient's complaint. OBJECTIVE: To evaluate inter-rater reliability of objective and subjective criteria used for diagnosis of lymphedema and to propose a lymphedema cut-off for differences in volume between affected and control limbs. METHODS: We studied 84 patients who had undergone lymphadenectomy for treatment of cutaneous melanoma. Physical measures were obtained by manual perimetry (MP). The subjective criteria analyzed were clinical diagnosis of lymphedema in patients' medical records and self-report of feelings of heaviness and/or increase in volume in the affected limb. RESULTS: For upper limbs, the subjective criteria clinical observation (k 0.754, P<0.001) and heaviness and swelling (k 0.689, P<0.001) both exhibited strong agreement with MP results and there was moderate agreement between MP results and swelling (k 0.483 P<0.001), heaviness (k 0.576, P<0.001) and heaviness or swelling (k 0.412, P=0.001). For lower limbs there was moderate agreement between MP results and clinical observation (k 0.423, P=0.003) and regular agreement between MP and self-report of swelling (k 0.383, P=0.003). Cut-off values for diagnosing lymphedema were defined as a 9.7% difference between an affected upper limb and control upper limb and a 5.7% difference between lower limbs. CONCLUSION: Manual perimetry, medical criteria, and self-report of heaviness and/or swelling exhibited better agreement for upper limbs than for lower limbs for diagnosis of lymphedema.

A mathematical model for the deficiency-excess mechanism of yin-yang in five viscera

To raise traditional medicine to a higher level of scientific research, a mathematical model has been proposed using symbolic notations and operators to describe several disease symptoms generally recognized in traditional medicine. Even though this model to a certain degree offers a mathematical approach to identify the relationships between yin-yang and the five viscera, it is not an efficient means of explaining the pathology in traditional medicine due to its use of superfluous notations and definitions. In this paper, we introduce two concise operators, a self-development operator and an action operator: the former describes the effect of a viscus in the unbalanced state on other viscera: the latter explains the engendering and restraining relationships between the two viscera. These tools are useful to elucidate the interactions among the states of the five viscera based on yin-yang and the five elements theory. Our mathematical model with these two operators facilitates description for the scheme of deficiency-excess of yin-yang in the five viscera. Accordingly, we have mathematically refined the existing results and shown clinical applications as well.

Prospective assessment of lymphedema incidence and lymphedema-associated symptoms following lymph node surgery for melanoma

We aimed to prospectively assess limb volume change (LVC) and associated symptoms in patients with melanoma undergoing sentinel lymph node biopsy and/or therapeutic lymph node dissection. Limb volume was measured preoperatively and postoperatively at 6 and 12 months using a perometer (1000 mol/l). LVC was calculated and used to define three groups: less than 5%, 5-10%, and greater than 10%. A 19-item lymphedema symptom questionnaire was administered at baseline, 6, and 12 months. One hundred and eighty-two patients were enrolled. Twelve months after axillary surgery, 9% had LVC 5-10% and 13% had LVC greater than 10%. Twelve months after inguinofemoral surgery, 10% had LVC 5-10% and 13% had LVC greater than 10%. There was a significant seven- to nine-fold increase in symptoms for patients with LVC greater than 10% compared with those with LVC less than 5% (P<0.05). On multivariate analysis, therapeutic lymph node dissection versus sentinel lymph node biopsy (odds ratio=3.18; P<0.01) and borderline significance for lower-extremity versus upper-extremity procedures (odds ratio=1.72; P=0.07) were associated with LVC greater than 5%. LVC greater than 5% is common at 12 months following nodal surgery for melanoma and is associated with symptoms. Informed consent for melanoma patients undergoing lymph node surgery should include a discussion of the risks of postoperative lymphedema.