Nivolumab, an immune checkpoint inhibitor, was approved for the treatment of “recurrent or metastatic head and neck cancer” in March 2017 in Japan. This approval was based on the results of a global phase 3 clinical trial, the CheckMate 141 trial, in patients with recurrent or metastatic squamous cell carcinoma of the head and neck. In the 4 years after its approval, multiple Japanese research institutions have reported real-world data of nivolumab, elucidating the further treatment outcomes of nivolumab. In this article, we review published literature reporting real-world outcomes of nivolumab, focusing on: （1） long-term follow-up, （2） patients with primary sites who were excluded from the CheckMate 141 trial, and （3） salvage chemotherapy following nivolumab treatment.

View full abstract

Lenvatinib is a molecular targeted drug indicated for unresectable radioiodine refractory thyroid cancer, but predictors of therapeutic prognosis have not been established.
In this study, we retrospectively reviewed histopathological features and clinical factors in 30 cases of unresectable thyroid cancer treated with lenvatinib at Nagoya City University Hospital and related facilities, and analyzed the effects on survival.
The median follow-up was 20 months, the 1-year overall survival rate was 71.2％, and the 1-year progression-free survival rate was 63.0％. The histological types were papillary carcinoma in 17 cases, undifferentiated carcinoma in 5 cases, follicular carcinoma in 3 cases, medullary carcinoma in 2 cases, poorly differentiated carcinoma in 2 cases, and squamous cell carcinoma in 1 case. The progression-free survival rate was significantly better in cases in which tumor shrinkage was observed at 8 weeks after administration, cases with differentiated carcinoma, cases in which the neutrophil-lymphocyte ratio （NLR） was ≤ 3, and cases in which the Glasgow prognostic score （GPS） was 0. It is suggested that NLR and GPS may be new predictors of prognosis.

View full abstract

Although the incidence of para-hyoid lymph nodes is not very high, ranging from 1.6％ to 8.0％, the salvage rate is remarkably low at 30％ when found as recurrence. In our own study of 315 cases of tongue cancer, the metastasis rate of the para-hyoid lymph nodes was 2.8％, the salvage rate was 14％ when found as recurrence, and the 2-year survival rate was 27.8％. Our technique requires only 5-10 minutes of surgery, with minimal blood loss and no complications, and it is thus considered acceptable to add elective para-hyoid lymph node dissection at the time of neck dissection for its control. However, the anatomical location of the metastasis was unclear, and the extent of the dissection was not clear. Therefore, we reviewed 9 cases from our own experience and 36 cases from 22 papers, and found that metastasis around the lingual vein on the hyoglossus muscle was common. In this article, we describe the specific surgical method of para-hyoid lymph node dissection based on the clinical site of metastasis, and present a case in which metastasis was actually found after elective dissection.

View full abstract

Various functional disorders are presented after surgery for oral cancer due to changes in anatomical structure and muscle weakness. In particular, maxillary bone deficiency may induce masticatory, swallowing, and articulatory disorders associated with the communication between the oral cavity and paranasal sinuses. Jaw dentures have been conventionally used for such cases, with various degrees of functional recovery depending on the condition of the oral cavity.
In this study, we assessed the masticatory, swallowing, and articulatory functions of 20 maxillary defect patients （mean age: 69.1 years; 11 males and 9 females） who had a maxillary prosthesis fabricated and were assessable between 2014 and 2021. In the functional assessments, the degrees of functional recovery differed depending on various factors such as remaining teeth and defect status.
Maxillary prostheses can contribute to postoperative functional recovery, while multisensory assessments including subjective and objective assessments are required. It is necessary to study functional assessments for uniform use in various cases.

View full abstract

We examined 23 prefrail （vulnerable） patients among patients with late-stage elderly oral cancer treated in our department. The 5-year overall survival rate was 41.9%, and when classified according to treatment approach, the survival rate was higher in the group that received absolute curative treatment （standard treatment）. Univariate analysis of each factor affecting prognosis showed significant differences in G8 score （p=0.047） and stage （p=0.022）, and treatment approach （p=0.052） also tended to affect prognosis. In the results of multivariate analysis, only therapeutic approach was extracted as a factor that significantly affected prognosis （p=0.034）.
In addition, decision tree analysis showed that the G8 score was divided into 14 points or more and less than 14 points, suggesting that it may be a predictor of prognosis.
Prefrail （vulnerable） is a conceptual category in which it is difficult to apply standard treatment, but it is thought that aiming for standard treatment without easily reducing the treatment intensity will lead to improvement in prognosis. In addition, it is considered useful to use the G8 screening tool as a patient evaluation method.

View full abstract

Epithelial-myoepithelial carcinoma is pathologically characterized by a biphasic structure consisting of ductal epithelial cells and myoepithelial cells and has a wide variety of histological presentations. Furthermore, the disease has been reported to undergo high-grade transformation and is often difficult to diagnose. It has recently been reported that HRAS mutations are detected in 20–80％ of epithelial-myoepithelial carcinoma cases. Herein, we describe a case of suspected epithelial-myoepithelial carcinoma thought to have undergone histopathological high-grade transformation in which an HRAS mutation was detected in genetic testing. The patient was 64 years old and was referred to our department due to a rapidly growing mass anterior to the right ear and facial nerve palsy. After examination, a diagnosis of high-grade parotid cancer （cT4aN0M0 stage ⅣA） was made. Extended right total parotidectomy was performed under general anesthesia. The tumor exhibited a biphasic structure with severe atypia and an HRAS gene mutation was found following Sanger sequencing, which suggested epithelial-myoepithelial carcinoma that had undergone high-grade transformation.

View full abstract

We report a rare case of intravascular solitary fibrous tumor （SFT） from the internal jugular vein to the sigmoid sinus, which has been followed over nine years. A 51-year-old woman was referred to our hospital, presenting with fullness of the right ear and swelling of the right neck. On imaging study, a tumor occupying from the right supraclavicular to the skull base, through the jugular foramen was found. The biopsy specimen of the intravascular tumor of the right jugular vein was initially diagnosed as epithelioid hemangioendothelioma （EHE）. The tumor increased in size at first, and after two courses of S-1 therapy （Tegafur, a prodrug of 5-fluorouracil, and 5-chloro-2-4-dihydroxypyridine）, the intravascular tumor in the right jugular vein had disappeared, whereas the lesion at the skull base remained stationary. This remaining lesion had gradually enlarged over the next 3–4 years, causing Ⅶ–Ⅻ cranial nerve paralysis. Radiation therapy was administered, and arytenoid adduction and nerve-muscle pedicle flap implantation were performed for laryngeal paralysis. Over 5-year follow-up observation after irradiation, the remaining lesion at the skull base gradually diminished each year. Afterward, the histopathological findings of the biopsy specimen were reviewed and a revised diagnosis of intravascular SFT was made. Intravascular SFT is extremely rare, and the effects of chemotherapy or radiotherapy for a malignant soft tissue tumor are controversial, however, S-1 therapy and radiation therapy were successful in this case.

View full abstract