Lymphatic Tissue Engineering: A Further Step for Successful Lymphedema Treatment

Background Secondary lymphedema, caused by oncologic surgery, radiation, and chemotherapy, is one of the most relevant, nononcological complications affecting cancer survivors. Severe functional deficits can result in impairing quality of life and a societal burden related to increased treatment costs. Often, conservative treatments are not sufficient to alleviate lymphedema or to prevent stage progression of the disease, as they do not address the underlying etiology that is the disruption of lymphatic pathways. In recent years, lymphatic surgery approaches were revolutionized by advances in microsurgical technique. Currently, lymphedema can effectively be treated by procedures such as lymphovenous anastomosis (LVA) and lymph node transfer (LNT). However, not all patients have suitable lymphatic vessels, and lymph node harvesting is associated with risks. In addition, some data have revealed nonresponders to the microsurgical techniques. Methods A literature review was performed to evaluate the value of lymphatic tissue engineering for plastic surgeons and to give an overview of the achievements, challenges, and goals of the field. Results While certain challenges exist, including cell harvesting, nutrient supply, biocompatibility, and hydrostatic properties, it is possible and desirable to engineer lymph nodes and lymphatic vessels. The path toward clinical translation is considered more complex for LNTs secondary to the complex microarchitecture and pending final mechanistic clarification, while LVA is more straight forward. Conclusion Lymphatic tissue engineering has the potential to be the next step for microsurgical treatment of secondary lymphedema. Current and future researches are necessary to optimize this clinical paradigm shift for improved surgical treatment of lymphedema.

Using the Fat-Clearing Technique to Improve Lymph Node Retrieval in Colorectal Cancer

College of American Pathologists recommended that at least 12 lymph nodes should be harvested for adequate staging of colorectal carcinoma. Lymph node harvesting is routinely performed by a manual technique of inspection and palpation, which is laborious and time-consuming. The study assessed the influence of the improved fat-clearing technique on the number of lymph nodes retrieved from colorectal cancer specimens and the clinical efficacy. Seventy colorectal cancer resection specimens were examined and assessed by 4 pathology residents. Thirty-five specimens were handled with the conventional manual technique by inspection and palpation, and the other 35 specimens with the improved fat-clearing technique to retrieve lymph nodes. As a result, compared with the conventional manual technique, the numbers of lymph nodes retrieved with the improved fat-clearing technique were significantly increased from 14.7 ± 6.2 lymph nodes to 20.8 ± 9.0 lymph nodes per specimen ( P < .05). Besides, the percentage of cases with at least 12 lymph nodes retrieved increased from 80% to 91%. The result of this study pointed out that using the improved fat-clearing technique to process colorectal specimens could increase the lymph node yield effectively, and was effective, practical, and suitable for routine gross examination.

COLORECTAL CANCER AND LYMPH NODE COUNT: IS THE NUMBER RECOMMENDED FOR STAGING RETRIEVED?

Background Colorectal cancer (CRC) ranks as the third most commonly diagnosed cancer in males and the second in females. According to the TNM staging system, status of the draining lymph nodes is a key pathologic characteristic. Inadequate lymph node harvesting may result in under treatment of patients. The purpose of the present study was to evaluate the factors that influence the number of lymph nodes retrieved in colorectal cancer specimens. Methods Sixty five patients with histologically proven colorectal adenocarcinoma over a period of 18 months were included. All patients underwent surgical resection for their disease. All significant patient, tumour and treatment variables were assessed for their impact on the average total number of lymph node harvested. Further, the efficacy of the GEWF solution (glacial acetic acid, ethanol, distilled water, formaldehyde) in lymph node retrieval was also assessed. Results In this study, 43 men and 22 women with a median age of 61 years were included. The median total number of lymph nodes examined was 17. 87.6% had adequate (≥ 12) lymph nodes examined, and 12.4% had <12 nodes examined. The number of lymph nodes were found to be higher and statistically significant in under 60-year-old group (p=0.001), tumours of size > 5cm (p=0.002), tumours of the ascending colon (p=0.025) and cases operated on by super specialist surgeons (p=0.017).Factors such as gender (p=0.23),BMI (p=0.22),tumour differentiation (p=0.348) and T staging (p=0.026) had no statistically significant association with lymph node harvest. Mean LN count was significantly higher (p = 0.0001) regrossing by a senior pathologist. However a statistically significant increase in LN harvest was not seen (p=0.159) when specimens were further subjected to GEWF treatment. Conclusions This study indicates that several modifiable factors impact LN retrieval and hence gives scope for improvement. Refinement of surgical and pathological care is suggested especially in challenging cases like rectal cancer and elderly patients.

Clinical and pathologic characteristics of early-onset colorectal cancer (EoCRC).

72 Background: Although CRC incidence continues to fall in patients over 50 due to adoption of screening programs, there has been an increasing incidence in patients < 50 where screening does not occur. We investigated the clinical and pathologic characteristics of EoCRC in BC. Methods: We retrospectively analyzed 27612 patients diagnosed with CRC and referred to BC Cancer between 1990-2016. Patients < 50 were classified as early onset CRC and analyzed for baseline and disease characteristics. Results: In the 2540/27612 (9.2%) of patients < 50, patients were more likely to be female (OR 1.33, 95% CI 0.61-1.44, P < 0.0001), have left sided tumors (OR 1.50, 95% CI 1.35-2.01, P < 0.0001), have poorly differentiated tumors (OR 1.24, 95% CI 1.10-1.34, P = 0.0003), and more patients presented with metastatic disease (OR 1.26, 95% CI 1.15-1.38, P < 0.0001) compared to patients ≥50. At diagnosis, patients < 50 were more likely to have a significant complication related to the primary tumor (OR 1.18, 95% CI 1.06-1.32, P = 0.0041), specifically, greater rates of perforation (OR 1.84, 95% CI 1.47-2.31, P < 0.0001). Although high risk features used to guide adjuvant therapy decisions in patients < 50 with stage II CRC were not higher, with similar T4 prevalence, poor differentiation, lymphovascular and perineural invasion, and less inadequate lymph node harvesting (≤12) (all p > 0.05), rates of adjuvant therapy were higher (OR 2.39, 95% CI 1.91-3.00, P < 0.0001). This was also noted in stage III CRC (OR 4.11 95% CI 3.07-5.48, P < 0.0001). Age impacted overall survival, with younger patients of all stages living longer (HR 0.72, 95% CI 0.68-0.76, P < 0.0001). Similar findings were noted for stage I-III CRC (HR 0.54 0.50-0.58, P < 0.0001) and for patients once they became metastatic (HR 0.84 95% CI 0.75-0.93, P = 0.0025). To control for competing causes of death, we looked at disease specific survival, which continued to show improved outcomes for patients age < 50 in stage I-III (HR 0.88 95% CI 0.81-0.97, P = 0.0016) and stage IV (HR 0.77 95% CI 0.72-0.84, P < 0.0001) CRC. Conclusions: EoCRC patients present with unique clinical and pathologic characteristics which may impact outcome. While the population < 50 has comparable outcomes, they may undergo increased rates of treatment.