Resection of Parapharyngeal Space Tumors Located in the Prestyloid Compartment: Efficacy of the Cervical Approach.

BACKGROUND: Parapharyngeal space tumors are rare. Among them, tumors in the prestyloid compartment are particularly suitable for surgery; however, there are no detailed reports of such surgery and their features remain unknown. METHODS: We conducted a retrospective cohort study. For 67 surgical cases of benign tumors in this compartment, we examined the patient and tumor characteristics, fine-needle aspiration cytology (FNAC), and intraoperative details such as surgical approach, use of complete excision, and postoperative complications. RESULTS: Pleomorphic adenomas (PAs) comprised 73.1% of the lesions. The diagnostic accuracy of FNAC to differentiate benign and malignant tumors was 97.7%. Of the treated lesions, 94.0% were removed via the cervical approach alone, including all PAs. The remaining 6.0% were resected via the cervical-parotid approach. The median operative time and bleeding volume were 89 min and 50 mL, respectively. Operative time using the cervical approach was significantly shorter (p = 0.021). All cases could be treated via complete surgical excision. Postoperative complications occurred in 32.8% of patients, with transient slight facial palsy being the most common. No fatal complications occurred and 92.5% of patients had no sequelae. There was no significant association between complications and surgical approach. CONCLUSION: Based on diagnosis by FNAC, with a high accuracy rate, most benign prestyloid tumors, especially PAs, were resected using the cervical approach alone, with a shorter operative time and without severe complications.

Clinicopathological significance of androgen receptor, HER2, Ki-67 and EGFR expressions in salivary duct carcinoma.

BACKGROUND: Salivary duct carcinoma (SDC) is a highly aggressive disease which often metastasizes to distant sites, and there is no established standard therapy for this systemic disease. Given that SDC is biologically similar to breast and prostate cancer, anti-androgenic receptor (AR) and anti-human epidermal growth factor receptor 2 (HER2) therapies have the potential to exert effects, not only on patients with breast and prostate cancer but also on those with SDC. METHODS: The expression levels of HER2, epidermal growth factor receptor (EGFR), Ki-67, and AR were assessed in 32 patients with SDC, and their correlations with overall survival (OS) and disease-free survival (DFS) were analyzed retrospectively. SDC was classified into five subtypes using a method similar to that used for breast cancer. RESULTS: Anti-AR, HER2, and EGFR were positive in 23 (71.9 %), 14 (43.8 %), and 26 (81.3 %) cases, respectively. One or more of these 3 factors were positive in 30 (93.8 %) cases. The Ki-67 labeling index was greater than 15 % in all cases. While molecular status did not correlate with OS, EGFR and AR positivity were significantly associated with DFS in univariate analysis. Multivariate analysis revealed that EGFR was the only independent predictor of DFS. CONCLUSIONS: The statuses of some molecules are useful to predict DFS in patients with SDC. Ki-67 overexpression suggests that cytotoxic agents are effective for SDC. Since the majority of SDCs express AR, HER2, and/or EGFR, assessing and targeting these molecules are promising strategies to improve the prognosis of unresectable, metastatic or recurrent SDC, and a classification system according to the molecular expression status may be useful to select appropriate therapy.

A Case of Photoimmunotherapy for Nasopharyngeal Carcinoma Requiring Emergency Tracheostomy.

Introduction: Photoimmunotherapy (PIT) is a treatment wherein intravenous cetuximab sarotalocan sodium is administered followed by laser light irradiation. This treatment exhibits a specific antitumor effect if in tumors expressing the epidermal growth factor receptor, regardless of the carcinoma [Mitsunaga et al.: Nat Med. 2011;17(12):1685-91, Sato et al.: ACS Cent Sci. 2018;4(11):1559-69, Nakajima et al.: Cancer Sci. 2018;109(9):2889-96]. The current indications are unresectable, locally advanced, or locally recurrent head and neck cancer. If standard treatments, such as radiotherapy and chemotherapy, are available, they are given priority. However, a significant concern in PIT is the occurrence of airway emergencies related to pharyngeal edema. Prophylactic tracheostomy is often performed in cases of PIT involving the root of the tongue, hypopharynx, or larynx. Case Presentation: In this study, we administered transoral PIT to a patient diagnosed with radiation-induced nasopharyngeal carcinoma (squamous cell carcinoma (SCC) cT1N0M0 stage I). Although previous case reports and our own experiences did not report airway emergencies following PIT for nasopharyngeal carcinoma, a unique case occurred in our study [Omura et al.: Auris Nasus Larynx. 2023;50(4):641-5, Kushihashi et al.: Int J Otolaryngol Head Neck Surg. 2022;11(5, Sep):258-65]. The patient experienced poor oxygenation and a decreased level of consciousness early in the morning following the laser irradiation. Nasal endoscopy revealed airway narrowing due to upper airway edema, and intubation was challenging. Consequently, we performed emergency bedside tracheostomy and the patient's condition improved. Conclusion: Therefore, it is crucial to note that airway emergencies can be life-threatening and should be diligently monitored as a potential complication of PIT.

Role of Hematological Markers in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma Treated With Pembrolizumab.

BACKGROUND/AIM: The predictive role of hematological markers in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) treated with pembrolizumab remains unclear. PATIENTS AND METHODS: We conducted a multicenter retrospective cohort study to investigate the predictive impact of the pre-treatment hematological markers neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), CRP-albumin-lymphocyte (CALLY) index, and the modified Glasgow prognostic score (mGPS) on overall survival (OS) and progression-free survival (PFS) in patients with R/M SCCHN treated with pembrolizumab. From December 2019 to February 2022, 119 and 28 patients were treated with pembrolizumab alone and pembrolizumab plus chemotherapy, respectively. The optimal cut-off point of dichotomized hematological markers was calculated using the area under the receiver operating characteristic curve. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) were estimated using Cox proportional hazard models with adjustment for potential confounders. RESULTS: In the pembrolizumab monotherapy group, patients with higher NLR, PLR, and mGPS and a lower CALLY index showed significantly shorter OS after adjustment for potential confounders. In addition, all hematological markers examined in this study tended to be associated with clinical response, such as overall response rate or disease control rate (DCR); in particular, a lower CALLY index and higher mGPS were significantly associated with poor DCR. In the pembrolizumab with chemotherapy group, these hematological markers had a similar association with OS but not with clinical response. CONCLUSION: Pre-treatment NLR, PLR, CALLY index, and mGPS might be predictive markers of survival in patients with R/M SCCHN treated with pembrolizumab.

Efficacy of a new instrument for dural defect repair in anterior skull base reconstruction: a technical note.

BACKGROUND: The anterior skull base is a deep and narrow area, which makes dural repair technically challenging. The goal of this study was to demonstrate the efficacy of a new instrument for anterior skull base dural repair. METHODS: Ten patients underwent surgery via the transbasal approach, combined with either a transfacial or a transnasal endoscopic resection. The dural repair was performed prior to tumor resection, and the new instrument was used to suture the fascia lata in an underlay fashion. The repaired dural defect was then covered with a pericranial flap. RESULTS: The follow-up period ranged from 2 to 18 months, with an average follow-up time of 8.7 months. During this period, none of the patients experienced cerebrospinal fluid leakage, meningitis, tension pneumocephalus, abscess formation, or flap necrosis. CONCLUSIONS: Our findings suggest that the use of this instrument combined with the technique of suturing the fascia lata in an underlay fashion and covering it with a pericranial flap, may be an effective alternative approach to anterior skull base reconstruction.

[A site of origin histopathological study on parapharyngeal space tumors. A review of 76 cases].

Tumors of the parapharyngeal space are said to account for 0.5% of all head and neck tumors, and are thus relatively rare. We performed histopathological examination of 76 tumors of the parapharyngeal space in patients hospitalized at the International University of Health and Welfare, Mita Hospital Head and Neck Oncology and Surgery center for 6 years from July 2005 to June 2011. There were 35 men and 41 women; the patients ranged in age from 15 to 78 years with a median age of 44. We performed preoperative CT and MRI, aspiration biopsy cytology (fine needle aspiration [FNA]) and postoperative histopathology diagnosis. There were 69 benign tumors (90.8%), and 7 malignant tumors (11.8%). Among the benign tumors were 32 schwannomas (42.1%) and 28 pleomorphic adenomas (36.8%). A total of 26 tumors of prestyloid origin were pleomorphic adenomas (93.8%), and 28 tumors of poststyloid origin were schwannomas (87.5%); all 7 malignant tumors (100%) were of prestyloid origin. There were 55 patients who underwent preoperative FNA, and the proper diagnosis rate was 70.9% (39/55 case). Preoperative imaging seemed to be very useful for predicting the histopathology. Furthermore, it would be desirable for FNA to be performed preoperatively for tumors of prestyloid origin, in consideration of the likelihood of such tumors being malignant. We think that there is room for improvement in the accurate FNA diagnosis rate.

Effects of Pembrolizumab in Recurrent/Metastatic Squamous Cell Head and Neck Carcinoma: A Multicenter Retrospective Study.

BACKGROUND/AIM: Pembrolizumab exhibits anticancer efficacy in platinum-sensitive or platinum-unfit patients with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). However, no large-scale retrospective real-world data are available. This retrospective study aimed to examine the efficacy and safety of pembrolizumab in multiple facilities. PATIENTS AND METHODS: Data of 167 patients with R/M SCCHN treated with pembrolizumab between December 2019 and February 2022 were analyzed. The endpoint was overall survival (OS), progression-free survival (PFS), and immune-related adverse events (irAEs). OS and PFS were analyzed comparatively with and without irAEs, and complete response (CR) or partial response (PR), and stable disease (SD) or progressive disease (PD) were compared. RESULTS: One hundred thirty-five patients received pembrolizumab alone, whereas the others received pembrolizumab with chemotherapy. For the pembrolizumab only group, the median OS and PFS were 22.7 and 5.1 months, respectively. There were significant differences in OS and PFS between CR or PR and SD or PD (p<0.01, p<0.01, respectively). For pembrolizumab with chemotherapy, the OS was not reached and median PFS was 7.0 months. There was a significant difference in PFS between CR or PR and SD or PD (p<0.01). There was a significant difference in PFS between patients with and without irAEs (p=0.02). CONCLUSION: The real-world therapeutic effect of pembrolizumab for R/M SCCHN was comparable to that observed in the KEYNOTE048 trial. In addition, irAEs and best overall response were considered as prognostic factors.

Preoperative S-1 Therapy for Head and Neck Carcinoma During the Waiting Period Before Surgery.

BACKGROUND/AIM: In patients with squamous cell carcinoma of the head and neck (SCCHN), delayed surgery can result in poorer postoperative function and prognosis due to the growth of the tumor and extended surgery. Further, delay may even make the tumor unresectable. To prevent tumor growth during the waiting period before surgery, S-1 has been administrated preoperatively at several facilities in Japan. To date, however, the safety and efficacy of preoperative S-1 remain unclear. PATIENTS AND METHODS: We conducted a retrospective cohort study of 118 patients with SCCHN treated with S-1 before radical surgery at 2 institutions in Japan. We evaluated the safety of S-1 therapy, which was evaluated by the incidence of grade 3 or greater adverse events (AEs). The rate of achievement of non-growth of tumors was also calculated. RESULTS: Regarding safety, 125 AEs of all grades were recorded in 71 patients (60%). Of these, grade 3 AEs were detected in 3 patients (3%), and no grade 4 or 5 AEs occurred. The nongrowth rate of primary lesions and lymph node metastases was 89% and 85%, respectively. CONCLUSION: Preoperative S-1 therapy might be useful, with acceptable toxicity, on an outpatient basis in patients with SCCHN.

Postoperative Complications and Swallowing Function after Jejunal and Skin Flap Reconstruction for Hypopharyngeal Carcinoma-A Multicenter Retrospective Study.

This study compared the incidence of perioperative complications and swallowing function between free jejunal flap reconstruction and cutaneous free tissue flap construction. We included 223 patients who underwent hypopharyngeal reconstruction using free flap. At discharge, +the free jejunal flap was associated with a Functional Oral Intake Scale (FOIS) score of 1-6 in 132 cases (70%) and a score of 7 in 56 cases (30%). Regarding the cutaneous free tissue flaps, FOIS scores of 1-6 were observed in 18 cases (51%), and a score of 7 was noted in 17 cases (49%). Donor site complications occurred in 12% of the patients who underwent free jejunal flap procedures and in none of the patients who underwent cutaneous free tissue flap procedures. We found that the free jejunal flap had a regular dietary intake rate in 56 patients (30%), whereas cutaneous free tissue flaps had a regular dietary intake rate in 17 patients (49%). Cutaneous free tissue flaps had a significantly higher regular dietary intake rate at discharge and a significantly lower incidence of donor site complications than free jejunal flaps. In conclusion, free-flap reconstruction may be a better method than free jejunal flap reconstruction for the treatment of hypopharyngeal cancer.

Nivolumab for Platinum-refractory and -sensitive Recurrent and Metastatic Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Nivolumab has antitumor efficacy in patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) who relapse within 6 months after platinum-based therapy; however, the efficacy of nivolumab for platinum-sensitive R/M HNSCC has not been shown. Therefore, this study compared the efficacy and safety of nivolumab for platinum-refractory and platinum-sensitive R/M HNSCC. PATIENTS AND METHODS: This was a retrospective study of patients who received nivolumab for R/M HNSCC who had been previously treated with platinum-based anticancer drugs. Patients were divided into a platinum-sensitive and a platinum-refractory group, and progression-free survival (PFS), overall survival (OS), the overall response rate (ORR) [complete response (CR) + partial response (PR)], the disease control rate (DCR) (CR + PR + stable disease), and the incidence of immune-related adverse events (irAEs) were compared between the two groups. RESULTS: We included 88 patients with squamous cell carcinoma: 60 with platinum-refractory disease and 28 with platinum-sensitive disease. The median PFS in the platinum-refractory and platinum-sensitive groups were 2.7 months and 5.3 months, respectively (p=0.03), and the median OS were 8.8 months and 17.1 months, respectively (p=0.06). There were no significant differences in the ORR, DCR, or incidence of irAEs between the two groups (p>0.99, p=0.11, and p>0.99, respectively). CONCLUSION: Nivolumab is a safe and effective treatment for platinum-sensitive R/M HNSCC.

Comparison of Dosage of Nivolumab in Efficacy and Safety for Recurrent Metastatic Squamous Cell Carcinoma.

BACKGROUND/AIM: There are no real-world comparative data of nivolumab doses of 3 mg/kg and 240 mg/body for recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). We investigated the efficacy and safety of nivolumab in treating recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) at different doses using real-world data. PATIENTS AND METHODS: R/M SCCHN patients who received nivolumab were divided into the 3 mg/kg and 240 mg/body groups and retrospectively examined for efficacy and safety. RESULTS: A total of 199 patients (3 mg/kg and 240 mg/body, 88 and 111 patients, respectively) were included. The 3 mg/kg vs. 240 mg/body groups had similar overall response rates (15% vs. 25, p=0.15), disease control rates (46% vs. 57%, p=0.15), overall survival (9.5 months vs. 10.9 months), and progression-free survival (3.7 months vs. 3.8 months, p=0.95). The incidence of immune-related adverse events was also similar in both groups. CONCLUSION: In R/M SCCHN patients, nivolumab showed similar efficacy and safety at doses of 3 mg/kg and 240 mg/body.

[Investigation of how to prevent mucositis induced by chemoradiotherapy].

Chemoradiotherapy for head and neck cancer is associated with a high incidence of severe oral mucositis; an adverse, painful event. Oral mucositis also causes nutritional deficiency by making oral feeding difficult. This may lead to prolongation of hospitalization due to complications caused by malnutrition. However, an effective way to prevent oral mucositis completely, remains to be found. In this study, we evaluated the occurrence of oral mucositis, and nutritional conditions such as hypoalbuminemia, reduction of body weight, and length of hospital stay (days) when the mouth was rinsed using rebamipide solution (R solution), or Poraprezinc-alginate sodium solution (P-A solution) (both considered to be effective for oral mucositis). A mouth rinsed with sodium azulene sulfonate (S solution) was used as a control. The mouth was rinsed out six times per day continuously during chemoradiotherapy. In the study, 31 patients were assigned to rinse their mouths using R solution, 11 patients using PA solution, and 15 patients using S solution (reduction rate of body weight in 14 patients). For the evaluation, the criteria for adverse drug reactions CTCAE (v3. 0) were used. Grade 1 and over, oral mucositis occurred in 48% of the R solution group, 36% of the P-A solution group, and 80% of the S solution group, indicating that the P-A solution group significantly prevented the occurrence of oral mucositis as opposed to the S solution group. A reduction in body weight was observed in 81% of the R solution group, 82% of the P-A solution group, and 79% of the S solution group, indicating a similar weight reduction rate among individual solution groups. Hypoalbuminemia equal to grade 2 or higher occurred in 3% of the R solution group, 18% of the P-A solution group, and 29% of the S solution group, indicating that the R group significantly prevented the occurrence of hypoalbuminemia compared to the S solution group. In addition, the length of hospital stays were 44 ± 8. 0 days for the R solution group, 52 ± 18. 8 days for the P-A solution group, and 61 ± 19. 5 days for the S solution group, indicating that the R solution group significantly shortened the length of hospital stay compared to the S solution group. These results suggested that the use of an R or P-A solution may be effective in preventing oral mucositis and impaired nutrition of those undergoing chemoradiotherapy for head and neck cancer.

Prognostic Factors of Potential Early Recurrence of Hypopharyngeal Carcinoma.

BACKGROUND/AIM: Prognostic factors of hypopharyngeal carcinoma have been reported previously. However, recurrent cases of this disease occurring within 6 months of treatment have been excluded or poorly documented in many studies. We aimed to evaluate the prognostic factors of hypopharyngeal carcinoma recurrence within 6 months. PATIENTS AND METHODS: A total of 120 patients were eligible for this retrospective study. Recurrent cases of hypopharyngeal carcinoma occurring within 6 months of treatment were evaluated and compared with non-recurrent cases. RESULTS: Recurrence within 6 months was detected in 28/50 cases. In univariate analyses, classification markers (pT≥4a and cN≥2b) were statistically significant prognostic factors for early recurrence (p=0.04 and p=0.04, respectively); however, only pT≥4a was predictive of recurrence in multivariate analyses (p=0.02). CONCLUSION: Risk stratification according to the prognostic factor pT≥4a will allow physicians to identify patients who should be followed meticulously within the first 6 months.

Weekly Cetuximab and Paclitaxel for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Head and neck cancers account for 8% of all cancer cases worldwide. However, identifying the optimal treatment for recurrent or metastatic head and neck cancer (R/MHNSCC) has been challenging. The aim of this study was to evaluate the efficacy, safety, and prognostic factors of the outcome of patients with R/MHNSCC who were treated with weekly cetuximab and paclitaxel (Cmab-PTX). PATIENTS AND METHODS: The records of R/MHNSCC patients who were treated with Cmab-PTX in our institution between June 2013 and September 2017 were collected. We analyzed Overall survival (OS), progression-free survival (PFS), prognostic factors and adverse events. RESULTS: The records of 59 patients treated with Cmab-PTX were analyzed. The median PFS was 5.7 months, and the median OS was 11.8 months. Patients who had been administered cetuximab previously had shorter PFS and OS than those who had not. CONCLUSION: Cmab-PTX may be considered as a treatment option in head and neck R/MHNSCC patients.

Salvage Chemotherapy After Nivolumab for Recurrent or Metastatic Head and Neck Carcinoma.

BACKGROUND/AIM: The treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) has remained challenging. The effect of salvage chemotherapy (SCT) after nivolumab has been identified recently in other cancer types. The aim of this study was to examine the efficacy of SCT after nivolumab treatment in patients with R/M HNSCC. PATIENTS AND METHODS: A retrospective study was conducted at four institutions in Japan. Fifty-six patients were enrolled in the study. RESULTS: The overall survival (OS) in SCT patients was significantly longer than that in best supportive care (BSC) patients. In the SCT patients, the median OS, median progression-free survival (PFS) and objective response rate (ORR) were 7.3 months, 2.3 months and 36%, respectively. Prognostic factor for OS and ORR was performance score (PS) and previous radiation, respectively. CONCLUSION: SCT after nivolumab is associated with better clinical outcomes in patients with R/M HNSCC compared to those receiving BSC.

A novel technique of arterial blood flow modification in intra-arterial chemoradiotherapy of maxillary sinus squamous cell carcinoma.

OBJECTIVES: Intra-arterial chemoradiotherapy via a superficial temporal artery is reportedly a useful organ-preserving treatment for maxillary sinus squamous cell carcinoma. This study aimed to determine whether blood flow modification facilitates sufficient drug delivery to the entire carcinoma via the maxillary artery alone, even for advanced tumors. MATERIALS AND METHODS: A retrospective study of 10 patients who were diagnosed with locally advanced carcinoma (4 [40%] at stage T3, 5 [50%] at T4a, and 1 [10%] at T4b) from August 2016 to July 2018, with tumor blood flow from both the maxillary and facial arteries, was conducted. Patients underwent intra-arterial chemoradiotherapy, which involved chemotherapy with weekly cisplatin administration (40 mg/m2) and radiotherapy (70 Gy/35 fr), with facial artery ligation. The success rate of blood flow modification, as well as its therapeutic effects and safety, were evaluated, with a median follow-up period of 14.4 months (range: 12.3-35 months). RESULTS: The blood flow surrounding the tumor was changed from both the maxillary and facial arteries to the maxillary artery alone in all patients. A median of 9 chemotherapy courses (range: 8-10) were administered; the median total cisplatin dose was 350 mg/m2 (range: 320-360 mg/m2). Radiotherapy of 70 Gy/35 fr was used to treat all patients. Grade 3 oral mucositis (80%) and irradiation field dermatitis (40%) were observed. In all patients, complete response was achieved, and local recurrence was not observed for at least 1 year. CONCLUSION: Simplifying the blood flow around the tumor facilitates more standardized intra-arterial chemoradiotherapy via a superficial temporal artery procedure.

Age-based efficacy and safety of nivolumab for recurrent or metastatic head and neck squamous cell carcinoma: A multicenter retrospective study.

AIM: This study retrospectively investigated the efficacy and safety of nivolumab for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) classified using age <65 years as the cutoff. METHODS: Overall, 88 patients with R/M HNSCC treated with nivolumab were classified into the young group (<65 years; n = 39) and elderly group (≥65 years; n = 49). Efficacy was evaluated using overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR). Safety was evaluated considering immune-related adverse events (irAEs). RESULTS: The median OS was 9.7 and 8.6 months in the young and elderly groups, respectively. The 1-year OS rate was 42.0% and 29.4% in the young and elderly groups, respectively. The median PFS was 3.0 and 4.2 months in the young and elderly groups, respectively. The 1-year PFS rate was 30.0% and 27.9% in the young and elderly groups, respectively. In the young group, the ORR was 10.3% and DCR was 33.3%. In the elderly group, the ORR was 18.4% and DCR was 53.1%. There were no significant differences in OS, PFS, ORR, and DCR (P = 0.36, 0.53, 0.29 and 0.06, respectively). Interstitial lung disease (ILD) as an irAE occurred in the young group at a significantly higher rate (20.5% vs 4.1%; P = 0.02). CONCLUSIONS: There were no significant differences in OS, PFS, ORR, and DCR between the young and elderly groups. DCR tended to be better in the elderly group (P = 0.06). ILD occurred at a significantly higher rate in the young group.

Real-World, Long-Term Outcomes of Nivolumab Therapy for Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck and Impact of the Magnitude of Best Overall Response: A Retrospective Multicenter Study of 88 Patients.

No real-world, long-term outcomes of immunotherapy with nivolumab for recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) have yet been reported. Furthermore, the prognostic impact of the best overall response (BOR) of this therapy remains unclear. We conducted a multi-institutional cohort study of the long-term efficacy and safety of this therapy and investigated prognostic factors associated with survival. Further, we evaluated the relationship between BOR and survival. Median follow-up time was 25.9 months. Median overall survival (OS) was 9.6 months, and two-year survival rate was 25.0%. Median progression-free survival (PFS) was 3.7 months, and two-year PFS rate was 19.6%. BOR was assessed as complete response (CR) in 6%, partial response (PR) in 13%, stable disease (SD) in 30%, and progressive disease (PD) in 52% of the patients. Overall response rate was 18%, and disease control rate was 48%. For immune-related adverse events (irAEs), 38 irAEs were detected in 29 patients. On multivariate analysis, the development of irAEs was significantly associated with better OS and PFS. Better BOR was significantly associated with longer OS and PFS. These findings demonstrate the long-term efficacy and safety of nivolumab therapy for R/M SCCHN in a real-world setting. The magnitude of BOR and the development of irAEs might be useful surrogate markers of survival.

Multicentre, retrospective study of the efficacy and safety of nivolumab for recurrent and metastatic salivary gland carcinoma.

Although immune-checkpoint inhibitors (ICIs) are effective against various cancers, little is known regarding their role in salivary gland carcinoma (SGC) treatment. Therefore, we evaluated the efficacy and safety of nivolumab monotherapy in patients with recurrent and/or metastatic SGC. In this multicentre retrospective study, nivolumab (240 mg) was administered every 2 weeks. The overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety were examined; the correlation between treatment outcomes and clinicopathological factors was analysed. Twenty-four patients were enrolled; the most common histopathology was salivary duct carcinoma. Eleven tumours were PD-L1-positive; no tumour was microsatellite instability-high. The ORR was 4.2%, and the median PFS and OS were 1.6 and 10.7 months, respectively. One patient continued nivolumab for 28 months without disease progression. One patient showed grade 4 increase in creatine phosphokinase levels and grade 3 myositis. Biomarker analysis revealed significantly increased OS in patients with performance status of 0; modified Glasgow prognostic score of 0; low neutrophil-to-lymphocyte ratio, lactate dehydrogenase, and C-reactive protein; and high lymphocyte-to-monocyte ratio and in patients who received systemic therapy following nivolumab. Although nivolumab's efficacy against SGC was limited, some patients achieved long-term disease control. Further studies are warranted on ICI use for SGC.

Surgical management of giant trigeminal schwannomas extending into the parapharyngeal space.

PURPOSE: Trigeminal schwannomas extending into the deep parapharyngeal space are relatively rare, and a surgical approach to such tumors has not been well established. We report four cases in which the tumors were completely removed by using a combination of three approaches. METHODS: Four patients with trigeminal schwannomas extending into the extracranial space were surgically treated using a combination of the transcervical approach, anterolateral retromaxillar pathway via gingivobuccal sulcus, and epi and interdural middle fossa approach. RESULTS: The maximum diameters of the tumors ranged from 4 to 7 cm. Three tumors extended beyond the lower end of the maxillary sinus. All tumors were completely excised. The Karnofsky performance scales after surgery were more than 90% in all patients. CONCLUSION: Although the tumors extending to the deep parapharyngeal space are difficult to completely remove via a single approach, a combined approach is useful in these huge extracranial extensions.