Vertical mandibular invasion of lower gingival squamous cell carcinoma (LGSCC) determines the method of resection, which significantly affects the patient's quality of life. Therefore, in mandibular invasion by LGSCC, it is extremely important to monitor progression, specifically whether invasion is limited to the cortical bone or has progressed to the bone marrow. This retrospective study aimed to identify the diagnostic and predictive parameters for mandibular invasion, particularly vertical invasion, to enable appropriate selection of the method of mandibular resection. Of the patients who underwent surgery for LGSCC between 2009 and 2017, 64 were eligible for participation in the study based on tissue microarrays (TMA) from surgical specimens. This study analyzed morphological features using computed tomography (CT), and metabolic characteristics using maximum standardized uptake value (SUVmax), peak value of SUV (SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Moreover, immunohistochemical analysis of proteins, including parathyroid hormone-related protein (PTHrP), interleukin-6 (IL-6), E-cadherin, and programmed cell death-1 ligand 1 (PD-L1), was performed. Statistical analysis was performed using univariate logistic regression analysis with the forward selection method. The present study showed that MTV (≥2.9 cm 3 ) was an independent diagnostic and predictive factor for positivity of mandibular invasion. Additionally, TLG (≥53.9 bw/cm 3 ) was an independent diagnostic and predictive factor for progression to bone marrow invasion. This study demonstrated that in addition to morphological imaging by CT, the volume-based parameters of MTV and TLG on fluorine-18 fluorodeoxyglucose positron emission tomography were important for predicting pathological mandibular invasion in patients with LGSCC. A more accurate preoperative diagnosis of vertical mandibular invasion would enable the selection of appropriate surgical procedure for mandibular resection. Abbreviations: 18 F-FDG PET = fluorine-18 fluorodeoxyglucose positron emission tomography, CT = computed tomography, H-E = hematoxylin and eosin, IHC = immunohistochemistry, IL-1 = interleukin-1, INF = infiltration factor, LGSCC = lower gingival squamous cell carcinoma, MR = magnetic resonance, MTV = metabolic tumor volume, NPV = negative predictive value, OSCC = oral squamous cell carcinoma, PD-L1 = programmed cell death-1 ligand 1, PET = positron emission tomography, PPV = positive predictive value, PTHrP = parathyroid hormone-related protein, QOL = quality of life, ROC = receiver operating characteristic, ROI = region of interest, SUV = standardized uptake value, SUVmax = maximum value of SUV, SUVpeak = peak value of SUV, TAM = tumor-associated macrophages, TIA = tumor infiltrating lymphocytes, TLG = total lesion glycolysis, TMA = tissue microarray, TME = tumor microenvironment, TNF-α = Tumour necrosis factor-α, VIF = variance inflation factor, VOI = volume of interest.

Cetuximab produces antitumor effects by inhibiting the epidermal growth factor receptor (EGFR)-mediated signal transmission route of tumor cells. However, monoclonal-antibody-administration-related infusion reactions (IRs) or anaphylaxis may appear. We report a case of cetuximab-induced anaphylaxis in a patient with mandibular gingival cancer in whom beef-specific IgE antibodies were detected. The patient was an 81-year-old woman with gingival cancer (cT2N2bM1, adenocarcinoma, NOS low grade). To reduce bone-metastasis-related neurological symptoms, radiotherapy was performed. To treat the primary lesion and metastatic cervical lesions, cetuximab monotherapy was selected. On serum IgE antibody testing, beefspecific IgE was detected, and treatment was begun, given the possibility of anaphylaxis related to cetuximab administration. Anaphylactic symptoms, such as a decrease in blood pressure, urticaria, and loss of consciousness, appeared 20 minutes after the initial administration. Rapid infusion, oxygen administration, and vasopressor administration led to the resolution of shock. Subsequently, the additional administration of cetuximab was not conducted, and palliative radiotherapy (30 Gy/10 fractions) for cervical/thoracic vertebral metastases was performed, resulting in pain relief. The patient was discharged 24 days after admission. Among IRs, IgE-mediated allergic reactions should be pathophysiologically differentiated from standard infusion reactions (SIRs) , which are associated with hypercytokinemia. The onset of IgE-mediated allergic reactions may be avoided by discontinuing administration to patients in whom IgE antibody is detected on a beef-specific IgE antibody test before treatment.