Using Nomograms Wisely: Predicting Sentinel Node Positivity in Melanoma.

BACKGROUND: Four externally validated sentinel node biopsy (SNB) prediction nomograms exist for malignant melanoma that each incorporate different clinical and histopathologic variables, which can result in substantially different risk estimations for the same patient. We demonstrate this variability by using hypothetical melanoma cases. METHODS: We compared the MSKCC and MIA calculators. Using a random number generator, 300 hypothetical thin melanoma "patients" were created with varying age, tumor thickness, Clark level, location on the body, ulceration, melanoma subtype, mitosis, and lymphovascular invasion (LVI). The chi-square test was used to detect statistically significant differences in risk estimations between nomograms. Multivariate linear regression was used to determine the most relevant contributing pathologic features in cases where the predictions diverged by > 10%. RESULTS: Of 300 randomly generated cases, 164 were deleted as their clinical scenarios were unlikely. The MSKCC nomogram generally calculated a lower risk than the MIA (p < 0.001). The highest risk score attained for any "patient" using MSKCC calculator was 15% achieved in one of 136 patients (0.7%), whereas using the MIA nomogram, 58 of 136 patients (43%, p < 0.001) had predicted risk >15%. Regression analysis on patients with >10% difference between nomograms revealed LVI (26, p < 0.001), mitosis (14, p < 0.001), and melanoma subtype (8, p < 0.001) were the factors with high coefficients within MIA that were not present in MSKCC. CONCLUSIONS: Nomograms are useful tools when predicting SNB risk but provide risk outputs that are quite sensitive to included predictors.

Factors Affecting Complete Oral Rehabilitation in Patients With Vascularized Free Fibula Flap Mandibular Reconstruction: A 10-Year Retrospective Study.

The fibula is the preferred bone flap for mandibular reconstructions due to its many advantages, including the possibility to insert dental implants. All patients who received a mandibular reconstruction with a vascularized free fibula flap at the Uppsala University Hospital between 2009 and 2019 were retrospectively examined regarding the proportion of implant insertion and factors that affected implant outcome. Forty-one patients had 42 fibula flap reconstructions. Eleven patients (27%) received dental implants and 8 (20%) completed dental rehabilitation. Patient death and cancer recurrence were the main reasons for not receiving implants. The survival rates of implants placed in irradiated and nonirradiated fibulas were 15% and 76%, respectively. Less than 20% of reconstructed patients received an implant-supported prosthesis. Implants placed in an irradiated fibula should be considered at high risk for implant loss.

Feasibility of a cross-face reconstruction of the mental nerve-A cadaveric simulation study with histomorphometric analysis.

INTRODUCTION: The inevitable sacrifice of the inferior alveolar nerve during oncologic resections results in substantial sensory impairment, impacting crucial functions such as speech, saliva retention, and mastication. This study investigated the feasibility of sensory restoration through cross-face reconstruction of the mental nerve via a contralateral mental nerve branch. METHODS: The cross-face reconstruction procedure was simulated in five formalin-fixed cadavers in both sides to evaluate the anatomic fundamentals and the nerve gap between the mental nerve main trunk and transferred contralateral mental nerve branch. Furthermore, a histomorphometric analysis was performed to assess the cross-sectional area and axon counts. RESULTS: The mean gap distance between the main mental nerve trunk and transferred contralateral branch was 15.3 mm. End-to-end coaptation was achieved in nine out of ten simulations. The mean cross-sectional area was 0.996 mm2 at the main mental nerve trunk and 0.253 mm2 at the coaptation site of the nerve branch. The mean donor-to-recipient axon ratio was found to be 0.3:1. CONCLUSION: The cadaveric simulation demonstrates the feasibility of a cross-face reconstruction of the mental nerve with only minimal gapping. Advantages of the proposed technique include the use of shorter nerve grafts, to minimize donor site morbidity and enable fast reinnervation. This technique may offer a promising method to enhance the quality of life in patients by increasing survival rates and life expectancy.

Effect of radiotherapy on expression of hyaluronan and EGFR and presence of mast cells in squamous cell carcinoma of the head and neck.

Head and neck squamous cell carcinoma is a common form of cancer, and despite improvements in treatment during the last decades, survival rates have not significantly increased. There is therefore a need to better understand how these tumours and the adjacent tissues react to radiotherapy, the most common type of treatment for this group of tumours. In order to improve this understanding, the expression of hyaluronan (HA) and epidermal growth factor receptor (EGFR) and the presence of mast cells were mapped before and after radiotherapy using immunohistochemistry. The results showed HA and EGFR to have similar expression patterns in tumour tissue and histologically normal squamous epithelium prior to radiotherapy. Following radiotherapy, EGFR increased in histologically normal epithelium. An increased number of mast cells were also observed as a result of radiotherapy. No expression of EGFR was observed in the connective tissue either prior to or following radiotherapy.