Pathogenic variants in HGF give rise to childhood-to-late onset primary lymphoedema by loss of function.

Developmental and functional defects in the lymphatic system are responsible for primary lymphoedema (PL). PL is a chronic debilitating disease caused by increased accumulation of interstitial fluid, predisposing to inflammation, infections and fibrosis. There is no cure, only symptomatic treatment is available. Thirty-two genes or loci have been linked to PL, and another 22 are suggested, including Hepatocyte Growth Factor (HGF). We searched for HGF variants in 770 index patients from the Brussels PL cohort. We identified ten variants predicted to cause HGF loss-of-function (six nonsense, two frameshifts, and two splice-site changes; 1.3% of our cohort), and 14 missense variants predicted to be pathogenic in 17 families (2.21%). We studied co-segregation within families, mRNA stability for non-sense variants, and in vitro functional effects of the missense variants. Analyses of the mRNA of patient cells revealed degradation of the nonsense mutant allele. Reduced protein secretion was detected for nine of the 14 missense variants expressed in COS-7 cells. Stimulation of lymphatic endothelial cells with these 14 HGF variant proteins resulted in decreased activation of the downstream targets AKT and ERK1/2 for three of them. Clinically, HGF-associated PL was diverse, but predominantly bilateral in the lower limbs with onset varying from early childhood to adulthood. Finally, aggregation study in a second independent cohort underscored that rare likely pathogenic variants in HGF explain about 2% of PL. Therefore, HGF signalling seems crucial for lymphatic development and/or maintenance in human beings and HGF should be included in diagnostic genetic screens for PL.

Meningeal lymphatic vessels at the skull base drain cerebrospinal fluid.

Recent work has shown that meningeal lymphatic vessels (mLVs), mainly in the dorsal part of the skull, are involved in the clearance of cerebrospinal fluid (CSF), but the precise route of CSF drainage is still unknown. Here we reveal the importance of mLVs in the basal part of the skull for this process by visualizing their distinct anatomical location and characterizing their specialized morphological features, which facilitate the uptake and drainage of CSF. Unlike dorsal mLVs, basal mLVs have lymphatic valves and capillaries located adjacent to the subarachnoid space in mice. We also show that basal mLVs are hotspots for the clearance of CSF macromolecules and that both mLV integrity and CSF drainage are impaired with ageing. Our findings should increase the understanding of how mLVs contribute to the neuropathophysiological processes that are associated with ageing.

Abnormal Lymphatic Sphingosine-1-Phosphate Signaling Aggravates Lymphatic Dysfunction and Tissue Inflammation.

BACKGROUND: Lymphedema is a global health problem with no effective drug treatment. Enhanced T-cell immunity and abnormal lymphatic endothelial cell (LEC) signaling are promising therapeutic targets for this condition. Sphingosine-1-phosphate (S1P) mediates a key signaling pathway required for normal LEC function, and altered S1P signaling in LECs could lead to lymphatic disease and pathogenic T-cell activation. Characterizing this biology is relevant for developing much needed therapies. METHODS: Human and mouse lymphedema was studied. Lymphedema was induced in mice by surgically ligating the tail lymphatics. Lymphedematous dermal tissue was assessed for S1P signaling. To verify the role of altered S1P signaling effects in lymphatic cells, LEC-specific S1pr1-deficient (S1pr1LECKO) mice were generated. Disease progression was quantified by tail-volumetric and -histopathologic measurements over time. LECs from mice and humans, with S1P signaling inhibition, were then cocultured with CD4 T cells, followed by an analysis of CD4 T-cell activation and pathway signaling. Last, animals were treated with a monoclonal antibody specific to P-selectin to assess its efficacy in reducing lymphedema and T-cell activation. RESULTS: Human and experimental lymphedema tissues exhibited decreased LEC S1P signaling through S1P receptor 1 (S1PR1). LEC S1pr1 loss-of-function exacerbated lymphatic vascular insufficiency, tail swelling, and increased CD4 T-cell infiltration in mouse lymphedema. LECs, isolated from S1pr1LECKO mice and cocultured with CD4 T cells, resulted in augmented lymphocyte differentiation. Inhibiting S1PR1 signaling in human dermal LECs promoted T-helper type 1 and 2 (Th1 and Th2) cell differentiation through direct cell contact with lymphocytes. Human dermal LECs with dampened S1P signaling exhibited enhanced P-selectin, an important cell adhesion molecule expressed on activated vascular cells. In vitro, P-selectin blockade reduced the activation and differentiation of Th cells cocultured with shS1PR1-treated human dermal LECs. P-selectin-directed antibody treatment improved tail swelling and reduced Th1/Th2 immune responses in mouse lymphedema. CONCLUSIONS: This study suggests that reduction of the LEC S1P signaling aggravates lymphedema by enhancing LEC adhesion and amplifying pathogenic CD4 T-cell responses. P-selectin inhibitors are suggested as a possible treatment for this pervasive condition.

Andrographolide promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema.

Lymphedema, a prevalent, multifaceted, and chronic ailment, is mainly managed through physical manipulation and suffers from a lack of specific pharmacological treatments. Secondary lymphedema is mainly caused by impaired lymphatic drainage. Therapeutic lymphangiogenesis is a promising strategy in the treatment of lymphedema. Andrographolide, a natural product from Andrographis paniculata, is unknown whether andrographolide promotes lymphangiogenesis to improve secondary lymphedema. By using the murine tail lymphedema model, we demonstrated that andrographolide can reduce the thickness of subcutaneous tissue in the mice's tail and enhance lymphatic drainage. Moreover, immunofluorescence staining showed that the number of capillary lymphatic vessels in the ANDRO25 group was significantly more than that in the ANDRO50 and Model groups. Near-infrared lymphography images showed that highlighted sciatic lymph nodes could be seen in the ANDRO25 and ANDRO50 groups. In vitro, andrographolide could promote the proliferation and migration of LEC. In conclusion, andrographolide enhanced the recovery of lymphatic vessels, and promoted lymphatic drainage in the murine tail lymphedema model by promoting the proliferation of lymphatic endothelial cells, thereby reducing the symptoms of lymphedema. This suggested andrographolide may be used as a potential therapeutic drug or medical food ingredient to help patients with secondary lymphedema.

Impact of neoadjuvant chemotherapy on breast cancer-related lymphedema after axillary lymph node dissection: a retrospective cohort study.

PURPOSE: We aimed to evaluate whether neoadjuvant chemotherapy (NAC) could be a risk factor for breast cancer-related lymphedema (BCRL) associated with axillary lymph node dissection (ALND). PATIENTS AND METHODS: A total of 596 patients with cT0-4N0-3M0 breast cancer who underwent ALND and chemotherapy were retrospectively analyzed between March 2012 and March 2022. NAC was administered in 188 patients (31.5%), while up-front surgery in 408 (68.5%). Univariate and multivariable Cox regression analyses were performed to determine whether NAC was an independent risk factor for BCRL. With propensity score matching (PSM), the NAC group and up-front surgery group were matched 1:1 by age, body mass index (BMI), molecular subtypes, type of breast surgery, and the number of positive lymph nodes. Kaplan-Meier survival analyses were performed for BCRL between groups before and after PSM. Subgroup analyses were conducted to explore whether NAC differed for BCRL occurrence in people with different characteristics. RESULTS: At a median follow-up of 36.3 months, 130 patients (21.8%) experienced BCRL [NAC, 50/188 (26.60%) vs. up-front surgery, 80/408 (19.61%); P = 0.030]. Multivariable analysis identified that NAC [hazard ratio, 1.503; 95% CI (1.03, 2.19); P = 0.033] was an independent risk factor for BCRL. In addition, the hormone receptor-negative/human epidermal growth factor receptor 2-negative (HR-/HER2-) subtype, breast-conserving surgery (BCS), and increased positive lymph nodes significantly increased BCRL risk. After PSM, NAC remained a risk factor for BCRL [hazard ratio, 1.896; 95% CI (1.18, 3.04); P = 0.007]. Subgroup analyses showed that NAC had a consistent BCRL risk in most clinical subgroups. CONCLUSION: NAC receipt has a statistically significant increase in BCRL risk in patients with ALND. These patients should be closely monitored and may benefit from early BCRL intervention.

Risk Factors for Breast Cancer-Related Lymphedema: An Umbrella Review.

BACKGROUND: Identification of risk factors facilitates the prevention of breast cancer-related lymphedema (BCRL). Several published systematic reviews have already addressed the risk factors for BCRL. This study aimed to systematically identify potential risk factors for BCRL and evaluate the quality of evidence. METHODS: The study followed methodologic guidance from the Joanna Briggs Institute, and the Cochrane Handbook. The following electronic databases were systematically searched from inception to 15 November 2022: PubMed, Embase, CINAHL, Web of Science, Scopus, CNKI, SinoMed, Wanfang, JBI Database, Cochrane Database, ProQuest, and PROSPERO. Two authors independently screened studies, extracted data, and assessed methodologic quality using AMSTAR2, risk of bias using ROBIS, and evidence quality using GRADE. The study evaluated overlap, assessed the small-study effect, and calculated the I2 statistic and Egger's P value as needed. RESULTS: The study included 14 publications comprising 10 meta-analyses and 4 systematic reviews. The authors identified 39 factors and 30 unique meta-analyses. In the study, 13 innate personal trait-related risk factors, such as higher body mass index (BMI) and axillary lymph nodes dissection, showed statistically significant associations with BCRL incidence. Breast reconstruction was found to be a protective factor. The methodologic quality was low or critically low. The majority of the systematic reviews and/or meta-analyses were rated as having a high risk of bias. Evidence quality was low for 22 associations and moderate for 8 associations. CONCLUSIONS: The currently identified risk factors for BCRL all are innate personal trait-related factors. Future well-designed studies and robust meta-analyses are needed to explore potential associations between behavioral-, interpersonal-, and environmental-related factors and BCRL, as well as the role of genetic variations and pathophysiologic factors.

Establishment and Feasibility of an Immediate Lymphatic Reconstruction Program in a Community Health System.

BACKGROUND: Breast cancer-related lymphedema (BCRL) remains a significant post-surgical complication of breast cancer treatment. Immediate lymphatic reconstruction (ILR) at the time of axillary lymph node dissection (ALND) has shown promise in preventing BCRL. While the primary literature supporting ILR comes from academic institutions, the majority of breast cancer care in the USA occurs in the community setting. This study evaluated a preventative lymphedema program performing ILR at a community health system. PATIENTS AND METHODS: A prospective database including all patients who underwent ALND with concurrently attempted ILR from 2019 to 2021 was retrospectively reviewed. The historical benchmark lymphedema rate was calculated through retrospective review of electronic medical records for all patients who underwent ALND without ILR from 2011 to 2021. RESULTS: Ninety patients underwent ALND with ILR, of which ILR was successful in 69 (76.7%). ILR was more likely to be aborted in smokers (p < 0.05) and those with fewer lymphatic channels (p < 0.05) or a higher body mass index (BMI) (p = 0.08). Patients with successful versus aborted ILR had lower lymphedema rates (10.9% versus 66.7%, p < 0.01) and improved Disability of the Arm, Shoulder, and Hand (DASH) scores (8.7 versus 19.8, p = 0.25), and lower lymphedema rates than the historical benchmark (10.9% versus 50.2%, p < 0.01). Among patients with successful ILR, older patients were more likely to develop lymphedema (p < 0.05). CONCLUSIONS: Successful ILR after ALND significantly reduced the lymphedema rate when compared with patients with aborted ILR and our institution's historical benchmark. Our experience supports the efficacy of ILR and highlights the feasibility of ILR within a community health system.

Lymphatic endothelial cell RXRα is critical for 9-cis-retinoic acid-mediated lymphangiogenesis and prevention of secondary lymphedema.

Secondary lymphedema is a debilitating disease characterized by abnormal soft tissue swelling and caused by lymphatic system dysfunction. Despite a high prevalence of secondary lymphedema after cancer treatments, current management is supportive and there are no approved therapeutic agents that can thwart disease progression. We have previously demonstrated that 9-cis-retinoic acid (9-cisRA) has the potential to be repurposed for lymphedema as it mitigates disease by promoting lymphangiogenesis at the site of lymphatic injury. Although the efficacy of 9-cisRA has been demonstrated in previous studies, the mechanism of action is not completely understood. In this study, we demonstrate that when RXRα is specifically deleted in lymphatic endothelial cells, 9-cisRA fails to induce lymphangiogenesis in vitro and prevent pathologic progression of postsurgical lymphedema in vivo. These findings demonstrate that downstream nuclear receptor RXRα plays a critical role in the therapeutic efficacy of 9-cisRA in postsurgical lymphedema.

In Vivo Dynamic and Static Analysis of Lymphatic Dysfunction in Lymphedema Using Near-Infrared Fluorescence Indocyanine Green Lymphangiography.

BACKGROUND: Near-infrared fluorescence indocyanine green lymphangiography, a primary modality for detecting lymphedema, which is a disease due to lymphatic obstruction, enables real-time observations of lymphatics and reveals not only the spatial distribution of drainage (static analysis) but also information on the lymphatic contraction (dynamic analysis). METHODS: We have produced total lymphatic obstruction in the upper limbs of 18 Sprague-Dawley rats through the dissection of proximal (brachial and axillary) lymph nodes and 20-Gy radiation (dissection limbs). After the model formation for 1 week, 9 animal models were observed for 6 weeks using near-infrared fluorescence indocyanine green lymphangiography by injecting 6-µL ICG-BSA (indocyanine green-bovine serum albumin) solution of 20-µg/mL concentration. The drainage pattern and leakage of lymph fluid were evaluated and time-domain signals of lymphatic contraction were observed in the distal lymphatic vessels. The obtained signals were converted to frequency-domain spectrums using signal processing. RESULTS: The results of both static and dynamic analyses proved to be effective in accurately identifying the extent of lymphatic disruption in the dissection limbs. The static analysis showed abnormal drainage patterns and increased leakage of lymph fluid to the periphery of the vessels compared with the control (normal) limbs. Meanwhile, the waveforms were changed and the contractile signal frequency increased by 58% in the dynamic analysis. Specifically, our findings revealed that regular lymphatic contractions, observed at a frequency range of 0.08 to 0.13 Hz in the control limbs, were absent in the dissection limbs. The contractile regularity was not fully restored for the follow-up period, indicating a persistent lymphatic obstruction. CONCLUSIONS: The dynamic analysis could detect the abnormalities of lymphatic circulation by observing the characteristics of signals, and it provided additional evaluation indicators that cannot be provided by the static analysis. Our findings may be useful for the early detection of the circulation problem as a functional evaluation indicator of the lymphatic system.

Surgical lymphedema models in the mice hindlimb-A systematic review and quality assessment.

BACKGROUND: Lymphedema constitutes a major unsolved problem in plastic surgery. To identify novel lymphedema treatments, preclinical studies are vital. The surgical mouse lymphedema model is popular and cost-effective; nonetheless, a synthesis and overview of the literature with evidence-based guidelines is needed. The aim of this review was to perform a systematic review to establish best practice and support future high-quality animal studies exploring lymphedema treatments. METHODS: We performed a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching four databases (PubMed, Embase, Web of Science, and Scopus) from inception-September 2022. The Animals in Research Reporting In Vivo Experiments 2.0 (ARRIVE 2.0) guidelines were used to evaluate reporting quality. Studies claiming to surgically induce lymphedema in the hindlimb of mice were included. RESULTS: Thirty-seven studies were included. Four main models were used. (1) Irradiation+surgery. (2) A variation of the surgery used by (1) + irradiation. (3) Surgery only (SPDF-model). (4) Surgery only (PLND-model). Remaining studies used other techniques. The most common measurement modality was the caliper. Mean quality coefficient was 0.57. Eighteen studies (49%) successfully induced sustained lymphedema. Combination of methods seemed to yield the best results, with an overrepresentation of irradiation, the removal of two lymph nodes, and the disruption of both the deep and superficial lymph vessels in the 18 studies. CONCLUSION: Surgical mouse hindlimb lymphedema models are challenged by two related problems: (1) retaining lymphedema for an extended period, that is, establishing a (chronic) lymphedema model (2) distinguishing lymphedema from post-operative edema. Most studies failed to induce lymphedema and used error-prone measurements. We provide an overview of studies claiming to induce lymphedema and advocate improved research via five evidence-based recommendations to use: (1) a proven lymphedema model; (2) sufficient follow-up time, (3) validated measurement methods; (4) ARRIVE-guidelines; (5) contralateral hindlimb as control.

Vascular Endothelial Growth Factor C (VEGF-C) Sensitizes Lymphatic Endothelial Cells to Oxidative-Stress-Induced Apoptosis through DNA Damage and Mitochondrial Dysfunction: Implications for Lymphedema.

Secondary lymphedema is caused by damage to the lymphatic system from surgery, cancer treatment, infection, trauma, or obesity. This damage induces stresses such as oxidative stress and hypoxia in lymphatic tissue, impairing the lymphatic system. In response to damage, vascular endothelial growth factor C (VEGF-C) levels increase to induce lymphangiogenesis. Unfortunately, VEGF-C often fails to repair the lymphatic damage in lymphedema. The underlying mechanism contributing to lymphedema is not well understood. In this study, we found that surgery-induced tail lymphedema in a mouse model increased oxidative damage and cell death over 16 days. This corresponded with increased VEGF-C levels in mouse tail lymphedema tissue associated with macrophage infiltration. Similarly, in the plasma of patients with secondary lymphedema, we found a positive correlation between VEGF-C levels and redox imbalance. To determine the effect of oxidative stress in the presence or absence of VEGF-C, we found that hydrogen peroxide (H2O2) induced cell death in human dermal lymphatic endothelial cells (HDLECs), which was potentiated by VEGF-C. The cell death induced by VEGF-C and H2O2 in HDLECs was accompanied by increased reactive oxygen species (ROS) levels and a loss of mitochondrial membrane potential. Antioxidant pre-treatment rescued HDLECs from VEGF-C-induced cell death and decreased ROS under oxidative stress. As expected, VEGF-C increased the number of viable and proliferating HDLECs. However, upon H2O2 treatment, VEGF-C failed to increase either viable or proliferating cells. Since oxidative stress leads to DNA damage, we also determined whether VEGF-C treatment induces DNA damage in HDLECs undergoing oxidative stress. Indeed, DNA damage, detected in the form of gamma H2AX (γH2AX), was increased by VEGF-C under oxidative stress. The potentiation of oxidative stress damage induced by VEFG-C in HDLECs was associated with p53 activation. Finally, the inhibition of vascular endothelial growth factor receptor-3 (VEGFR-3) activation blocked VEGF-C-induced cell death following H2O2 treatment. These results indicate that VEGF-C further sensitizes lymphatic endothelial cells to oxidative stress by increasing ROS and DNA damage, potentially compromising lymphangiogenesis.

Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema.

BACKGROUND: This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema. METHODS: Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures. RESULTS: Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25). CONCLUSION: L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

Increased infiltration of CD4+ T cell in the complement deficient lymphedema model.

BACKGROUND: Lymphedema is an intractable disease that can be caused by injury to lymphatic vessels, such as by surgical treatments for cancer. It can lead to impaired joint mobility in the extremities and reduced quality of life. Chronic inflammation due to infiltration of various immune cells in an area of lymphedema is thought to lead to local fibrosis, but the molecular pathogenesis of lymphedema remains unclear. Development of effective therapies requires elucidation of the immunological mechanisms involved in the progression of lymphedema. The complement system is part of the innate immune system which has a central role in the elimination of invading microbes and acts as a scavenger of altered host cells, such as apoptotic and necrotic cells and cellular debris. Complement-targeted therapies have recently been clinically applied to various diseases caused by complement overactivation. In this context, we aimed to determine whether complement activation is involved in the development of lymphedema. RESULTS: Our mouse tail lymphedema models showed increased expression of C3, and that the classical or lectin pathway was locally activated. Complement activation was suggested to be involved in the progression of lymphedema. In comparison of the C3 knockout (KO) mouse lymphedema model and wild-type mice, there was no difference in the degree of edema at three weeks postoperatively, but the C3 KO mice had a significant increase of TUNEL+ necrotic cells and CD4+ T cells. Infiltration of macrophages and granulocytes was not significantly elevated in C3 KO or C5 KO mice compared with in wild-type mice. Impaired opsonization and decreased migration of macrophages and granulocytes due to C3 deficiency should therefore induce the accumulation of dead cells and may lead to increased infiltration of CD4+ T cells. CONCLUSIONS: Vigilance for exacerbation of lymphedema is necessary when surgical treatments have the potential to injure lymphatic vessels in patients undergoing complement-targeted therapies or with complement deficiency. Future studies should aim to elucidate the molecular mechanism of CD4+ T cell infiltration by accumulated dead cells.

Superficial and functional imaging of the tricipital lymphatic pathway: a modern reintroduction.

PURPOSE: The tricipital, or Caplan's, lymphatic pathway has been previously identified in cadavers and described as a potential compensatory pathway for lymphatic drainage of the upper extremity, as it may drain lymphatic fluid directly to the scapular lymph nodes, avoiding the axillary lymph node groups. The aim of this study was to map the anatomy of the tricipital pathway in vivo in patients without lymphatic disease. METHODS: A retrospective review was performed to identify patients with unilateral breast cancer undergoing preoperative Indocyanine green (ICG) lymphography prior to axillary lymph node dissection from May 2021 through January 2022. Exclusion criteria were evidence or known history of upper extremity lymphedema or non-linear channels visualized on ICG. Demographic, oncologic, and ICG imaging data were extracted from a Lymphatic Surgery Database. The primary outcome of this study was the presence and absence of the tricipital pathway. The secondary outcome was major anatomical variations among those with a tricipital pathway. RESULTS: Thirty patients underwent preoperative ICG lymphography in the study period. The tricipital pathway was visualized in the posterior upper arm in 90% of patients. In 63% of patients, the pathway had a functional connection to the forearm (long bundle variant) and in 27%, the pathway was isolated to the upper arm without a connection to the forearm (short bundle variant). In those with a long bundle, the contribution was predominantly from the posterior ulnar lymphosome. Anatomic destinations of the tricipital pathway included the deltotricipital groove and the medial upper arm channel, which drains to the axilla. CONCLUSION: When present, the tricipital pathway coursed along the posterior upper arm with variability in its connections to the forearm distally, and the torso proximally. Long-term follow-up studies will help determine the significance of these anatomic variations in terms of individual risk of lymphedema after axillary nodal dissection.

The SENTIREC-endo study - Risks and benefits of a national adoption of sentinel node mapping in low and intermediate risk endometrial cancer.

OBJECTIVE: The SENTIREC-endo study aims to investigate risks and benefits of a national protocolled adoption of sentinel lymph node (SLN) mapping in women with early-stage low-grade endometrial cancer (EC) with low- (LR) and intermediate-risk (IR) of lymph node metastases. METHODS: We performed a national multicenter prospective study of SLN-mapping in women with LR and IR EC from March 2017-February 2022. Postoperative complications were classified according to Clavien-Dindo. Lymphedema was assessed as a change score and as incidence of swelling and heaviness evaluated by validated patient-reported outcome measures at baseline and three months postoperatively. RESULTS: 627 women were included in the analyses; 458 with LR- and 169 with IR EC. The SLN detection rate was 94.3% (591/627). The overall incidence of lymph node metastases was 9.3% (58/627); 4.4% (20/458) in the LR- and 22.5% (38/169) in the IR group. Ultrastaging identified 62% (36/58) of metastases. The incidence of postoperative complications was 8% (50/627) but only 0.3% (2/627) experienced an intraoperative complication associated with the SLN procedure. The lymphedema change score was below the threshold for clinical importance 4.5/100 CI: (2.9-6.0), and the incidence of swelling and heaviness was low; 5.2% and 5.8%, respectively. CONCLUSION: SLN mapping in women with LR and IR EC carries a very low risk of early lymphedema and peri- and postoperative complications. The national change in clinical practice contributed to a more correct treatment allocation for both risk groups and thus supports further international implementation of the SLN technique in early stage, low grade EC.

Morbidity and risk factors for complications of inguinal lymph node dissection in penile cancer.

PURPOSE: To assess the morbidity of inguinal lymph node dissection (ILND) in penile cancer, then to compare this morbidity with that of ILND performed in the context of skin cancer treatment. METHODS: We retrospectively included all patients having undergone ILND between 1 January 2004 and 31 December 2019 in our centre's urology department in the context of treatment of penile cancer or skin cancer. Postoperative complications were reported in accordance with the Clavien-Dindo classification system. RESULTS: Two hundred forty-two ILNDs were performed in 122 patients with penile cancer and 56 ILNDs were performed in 56 patients with skin cancer. The most common early complication was postoperative fluid collection (lymphocele or haematoma), which complicated 44% of ILNDs overall and 60% of radical lymphadenectomies. The most common late complication was leg lymphoedema, found in up to 36% of radical lymphadenectomies. Major complications (grade ≥ III) were very rare (4% of radical lymphadenectomies). Radical lymphadenectomies resulted in significantly more cases of postoperative fluid collection, skin necrosis and dehiscence, as well as leg lymphoedema, than modified lymphadenectomy techniques. Two factors significantly increasing postoperative morbidity were demonstrated: ASA score = 3 (OR = 3.09) and operating time (OR = 1.01). CONCLUSION: ILNDs are morbid surgical procedures for which the indications must be well defined. However, the complications are almost exclusively minor, for a major oncological benefit.

Body mass index increases the risk of breast cancer-related lymphedema at 6-18 months after surgery: a retrospective study.

PURPOSE: Breast cancer-related lymphedema (BCRL) is an incurable complication occurring after breast cancer treatment. The influence of obesity/overweight on the development of BCRL at different points after surgery was seldom verified. We aimed to determine the cut-off BMI/weight value associated with an increased risk of BCRL at different postoperative time in Chinese breast cancer survivors. METHODS: Patients who underwent breast surgery plus axillary lymph node dissection (ALND) were retrospectively evaluated. Disease and treatment characteristics of participants were collected. BCRL was diagnosed by circumference measurements. Univariate and multivariable logistic regression was used to assess the relationship of lymphedema risk with BMI/weight and other disease- and treatment-related factors. RESULTS: 518 patients were included. Lymphedema occurred more frequently among breast cancer patients with preoperative BMI ≥ 25 kg/m2 (37.88%) than among those with preoperative BMI < 25 kg/m2(23.32%), with significant differences at 6-12 and 12-18 months after surgery (χ2 = 23.183, P = 0.000; χ2 = 5.279, P = 0.022). By multivariable logistics analysis, preoperative BMI ≥ 30 kg/m2 presented a significantly greater risk of lymphedema than a preoperative BMI < 25 kg/m2 (OR [95% CI] = 2.928 [1.565, 5.480]). Other factors, including radiation (breast/chest wall + axilla vs. none: OR [95% CI] = 3.723[2.271-6.104]), was an independent risk factor for lymphedema. CONCLUSIONS: Preoperative obesity was an independent risk factor for BCRL in Chinese breast cancer survivors, and a preoperative BMI ≥ 25 kg/m2 indicated greater likelihood of lymphedema development within 6-18 months postoperatively.

Does sentinel node mapping impact morbidity and quality of life in endometrial cancer?

OBJECTIVES: To evaluate the prevalence of post-operative complications and quality of life (QoL) related to sentinel lymph node (SLN) biopsy vs systematic lymphadenectomy in endometrial cancer. METHODS: A prospective cohort included women with early-stage endometrial carcinoma who underwent lymph node staging, grouped as follows: SLN group (sentinel lymph node only) and SLN+LND group (sentinel lymph node biopsy with addition of systematic lymphadenectomy). The patients had at least 12 months of follow-up, and QoL was assessed by European Organization for Research and Treatment of Cervical Cancer Quality of Life Questionnaire 30 (EORTC-QLQ-C30) and EORTC-QLQ-Cx24. Lymphedema was also assessed by clinical evaluation and perimetry. RESULTS: 152 patients were included: 113 (74.3%) in the SLN group and 39 (25.7%) in the SLN+LND group. Intra-operative surgical complications occurred in 2 (1.3%) cases, and all belonged to SLN+LND group. Patients undergoing SLN+LND had higher overall complication rates than those undergoing SLN alone (33.3% vs 14.2%; p=0.011), even after adjusting for confound factors (OR=3.45, 95% CI 1.40 to 8.47; p=0.007). The SLN+LND group had longer surgical time (p=0.001) and need for admission to the intensive care unit (p=0.001). Moreover, the incidence of lymphocele was found in eight cases in the SLN+LND group (0 vs 20.5%; p<0.001). There were no differences in lymphedema rate after clinical evaluation and perimetry. However, the lymphedema score was highest when lymphedema was reported by clinical examination at 6 months (30.1 vs 7.8; p<0.001) and at 12 months (36.3 vs 6.0; p<0.001). Regarding the overall assessment of QoL, there was no difference between groups at 12 months of follow-up. CONCLUSIONS: There was a higher overall rate of complications for the group undergoing systematic lymphadenectomy, as well as higher rates of lymphocele and lymphedema according to the symptom score. No difference was found in overall QoL between SLN and SLN+LND groups.

Serum Cathepsin D was Elevated in Patients with Limb Lymphedema.

BACKGROUND: Lymphedema (LE) is a chronic disease that can lead to disability. Currently, the pathogenesis of LE remains unclear, and there is a lack of serum proteins applicable for diagnosis in clinical practice. This study aimed to screen and identify the differentially expressed proteins in serum samples of limb lymphedema and normal subjects and to further explore their value in the diagnosis of LE. METHODS: Nano-flow reverse phase liquid chromatography-tandem mass spectrometry (Nano RPLC-MS/MS) was used to establish the serum protein profiles of primary lymphedema (PLE), secondary lymphedema (SLE), and normal controls (NC). Differentially expressed serum proteins were screened and identified. Subsequently, enrichment analysis was performed for proteins that were upregulated in the LE group compared to the NC group. The target protein was validated by western blot (WB) and enzyme-linked immunosorbent assay (ELISA). Both the receiver operating characteristic (ROC) curve and Spearman's correlation test were employed to evaluate the diagnostic performance of the protein and its relationship with disease severity. RESULTS: A total of 362 serum proteins were identified, among which 241 proteins were differentially expressed among PLE, SLE, and NC subjects (p < 0.05, fold change > 1.2). The enriched pathway correlated with cornified envelope formation was selected for further analysis. Cathepsin D (CTSD), a target protein involved in the selected pathway, was found to be up-regulated in the serum of PLE and SLE patients compared to NC. The AUCs of CTSD were 0.849 and 0.880 for patients with PLE and SLE, respectively. There was a significant positive correlation between the levels of serum CTSD and disease severity in the PLE group. CONCLUSIONS: Proteomic analysis found that the levels of serum proteins related to cornified envelope formation were elevated in patients with limb lymphedema. Serum CTSD was highly expressed in patients with limb lymphedema and showed good diagnostic value.

A dominant-negative SOX18 mutant disrupts multiple regulatory layers essential to transcription factor activity.

Few genetically dominant mutations involved in human disease have been fully explained at the molecular level. In cases where the mutant gene encodes a transcription factor, the dominant-negative mode of action of the mutant protein is particularly poorly understood. Here, we studied the genome-wide mechanism underlying a dominant-negative form of the SOX18 transcription factor (SOX18RaOp) responsible for both the classical mouse mutant Ragged Opossum and the human genetic disorder Hypotrichosis-lymphedema-telangiectasia-renal defect syndrome. Combining three single-molecule imaging assays in living cells together with genomics and proteomics analysis, we found that SOX18RaOp disrupts the system through an accumulation of molecular interferences which impair several functional properties of the wild-type SOX18 protein, including its target gene selection process. The dominant-negative effect is further amplified by poisoning the interactome of its wild-type counterpart, which perturbs regulatory nodes such as SOX7 and MEF2C. Our findings explain in unprecedented detail the multi-layered process that underpins the molecular aetiology of dominant-negative transcription factor function.