Real-world clinical outcomes in Japanese patients with locally advanced squamous cell carcinoma of the head and neck treated with radiotherapy plus cetuximab: a prospective observational study (JROSG12-2).

BACKGROUND: Radiotherapy plus cetuximab (bioradiotherapy: BRT) is a standard option in the treatment of locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). Published data on its safety and efficacy in real-world settings is limited. Here, we conducted a prospective multi-institutional observational study to evaluate clinical outcomes of BRT in patients with LA-SCCHN. METHODS: We analyzed real-world data of all patients who underwent BRT from 2013 to 2016. The primary endpoint was 1-year progression-free survival (PFS). Secondary endpoints were 1-year locoregional PFS (LPFS), treatment completion rate (TCR), and adverse events (AEs). RESULTS: A total of 171 patients with a minimum 1-year follow-up were analyzed. Median age was 67 (36-85) years, and 37 patients (21.6%) were aged 75 years or older. 1-year PFS and LPFS were 51.5 and 56.1%, respectively. N stage (p = 0.049) was significantly associated with PFS. TCR was 77.2%. Cetuximab was definitively discontinued in 30 patients (17.5%), in 15 cases due to severe mucositis. N stage, T stage, and comorbidity were significantly associated with TCR. Major AEs of grade 3 or higher were pharyngeal mucositis (48.5%), radiation dermatitis (45.6%), and oral mucositis (40.4%). Pneumonitis was observed in 12 patients (7.0%); 6 cases (3.5%) were grades 3-4 and 2 (1.2%) were grade 5. CONCLUSION: As a result of the large number of elderly patients in clinical practice,　toxicity reduced TCR. BRT-induced pneumonitis, which is sometimes fatal, was found to be more frequent than with chemotherapy plus cetuximab.

Real-world clinical outcomes and prognostic factors in Japanese patients with recurrent or metastatic squamous cell carcinoma of head and neck treated with chemotherapy plus cetuximab: a prospective observation study (JROSG12-2).

BACKGROUND: The aims of this study are to evaluate the efficacy and safety of first-line treatment with chemotherapy plus cetuximab in real-world patients with recurrent or metastatic squamous cell carcinoma of the head and neck (RM-SCCHN) and to identify prognostic factors for overall survival (OS). METHODS: This is a prospective observation study involving 20 oncology institutions in Japan. Patients with RM-SCCHN treated with a first-line therapy consisting of cetuximab plus any chemotherapy regimen between December 2013 and February 2017 were enrolled. The primary objective of the study was 1-year OS. Secondary objectives included response rate and adverse events. RESULTS: Of 120 patients recruited, 114 patients were analyzed. Median age was 64 years. Cetuximab in combination with platinum plus 5-FU (EXTREME regimen) was chosen in 86 patients (75.4%). The median OS was 12.4 months. A point estimate of the 1-year survival rate was 51.1%. Overall response rate was 26.3%. Grade 3 or worse adverse events included neutropenia (22.8%), hypokalemia (9.6%), acneiform rash (7.0%), pneumonitis (1.8%), and infusion-related reaction (0.9%). On multivariate analysis, regional lymph node metastasis, absence of intervention by dermatologists, lack of response to therapy, skin metastasis, and non-EXTREME regimen were identified as independent unfavorable prognostic factors for OS. CONCLUSION: The combination of cetuximab plus chemotherapy was tolerable and efficacious in patients with RM-SCCHN in a real-world setting. Clinical outcomes and prognostic factors extracted from this study provide a reference of the current clinical practice as well as for the future development of novel therapy in RM-SCCHN.

Clinicopathological Features of Cervical Esophageal Cancer: Retrospective Analysis of 63 Consecutive Patients Who Underwent Surgical Resection.

OBJECTIVE: The objectives of this retrospective study were to elucidate the clinicopathological features and recent surgical results of cervical esophageal cancer. SUMMARY BACKGROUND DATA: Cervical esophageal cancer has been reported to have a dismal prognosis. Accurate knowledge of the clinical characteristics of cervical esophageal cancer is warranted to establish appropriate therapeutic strategies. METHODS: The clinicopathological features and treatment results of 63 consecutive patients with cervical esophageal cancer (Ce group) who underwent surgical resection from 1980 to 2013 were analyzed and compared with 977 patients with thoracic or abdominal esophageal cancer (T/A group) who underwent surgical resection during that time. RESULTS: Among the patients who received curative resection, the 5-year overall and disease-specific survival rates of the Ce patients were significantly better than those of the T/A patients (overall: 77.3% vs 46.5%, respectively, P = 0.0067; disease-specific: 81.9% vs 55.8%, respectively, P = 0.0135). Although total pharyngo-laryngo-esophagectomy procedures were less frequently performed in the recent period, the rate of curative surgical procedures was markedly higher in the recent period (2000-1013) than that in the early period (1980-1999) (44.4% vs 88.9%, P = 0.0001). The 5-year overall survival rate in the recent period (71.5%) was significantly better than that in the early period (40.7%, P = 0.0342). CONCLUSIONS: Curative resection for cervical esophageal cancer contributes to favorable outcomes compared with other esophageal cancers. Recent surgical results for cervical esophageal cancer have improved, and include an increased rate of curative resection and decreased rate of extensive surgery.

Single-cycle induction chemotherapy for resectable advanced hypopharyngeal cancer.

BACKGROUND: The role of induction chemotherapy (IC) in the treatment of resectable advanced head and neck squamous cell carcinoma has not been elucidated, and the most effective IC regimen for chemoselection is still unknown. At our institute we have not used the triple combination of docetaxel, cisplatin, fluorouracil (TPF) for chemoselection, but rather the double combination of docetaxel + cisplatin (TP). The aim of this study is to report the outcome of patients with advanced hypopharyngeal cancer treated by single cycle of IC with TP followed by chemoradiation (CRT) or surgery. METHODS: A total of 29 patients with resectable advanced hypopharyngeal cancer who were treated with a single cycle of IC were entered into the study. Responders were treated by CRT while nonresponders underwent surgery. Outcomes were analyzed using the Kaplan-Meier method. RESULTS: A single cycle of IC with TP achieved response in 21 of the 29 patients. The major side effect was neutropenia which could be managed without delaying the sequential treatment. The 2-year overall survival and disease-specific survival were both 74.0% (stage III 100%, stage IVA 69.1%). The cumulative 2-year laryngeal preservation rate was 100% for stage III and 53.6% for stage IVA. CONCLUSION: A single cycle of IC with the combination of docetaxel + cisplatin may be sufficient to select advanced hypopharyngeal cancer patients with radio-sensitivity. IC intended for organ preservation strategies should be low toxic. Our strategy may be a useful for providing the benefits of IC and the opportunity for curative surgery without delay.

[A Case of Pneumocystis Pneumonia after Cetuximab-based Bioradiotherapy].

Reports of drug-induced interstitial pneumonia caused by Cetuximab have been increasing. Pneumocystis pneumonia is important as a differential diagnosis of drug-induced interstitial pneumonia. We report herein on a 64-year-old man with pneumocystis pneumonia after cetuximab-based bioradiotherapy for laryngeal cancer. After radiotherapy, the patient developed multi-drug resistant pneumonia. Chest CT imaging revealed diffuse ground-glass opacities in the lung field. He was diagnosed as having pneumocystis pneumonia based on the bronchoalveolar lavage (BAL) findings, and then his symptoms improved after treatment with Trimethoprim/Sulfamethoxazole. It is important to assess the risk factor for pneumocystis pneumonia for early its detection and treatment.

Surgical resection of hypopharynx and cervical esophageal cancer with a history of esophagectomy for thoracic esophageal cancer.

BACKGROUND: Cancer of the hypopharynx and cervical esophagus (PhCe cancer) frequently develops synchronously or metachronously with esophageal cancer. The surgical approach is usually difficult, especially in metachronous PhCe cancer after esophagectomy. The purpose of this study was to clarify the treatment outcomes of patients with metachronous PhCe cancer with a history of esophagectomy. METHODS: The subjects evaluated in this study were 14 patients with metachronous PhCe cancer who underwent pharyngo-laryngo-esophagectomy after subtotal esophagectomy and gastric tube pull-up for primary esophageal cancer. RESULTS: Definitive chemoradiotherapy (CRT; radiation dose >50 Gy) was performed for primary laryngeal (n = 1), pharyngeal (n = 2), esophageal (n = 1), and recurrent esophageal cancer (n = 2). For seven patients with metachronous PhCe cancer, induction CRT (radiation dose <40 Gy) was performed. In all 14 patients, pharyngo-laryngo-esophagectomy was followed by free jejunal graft interposition with reconstruction of the jejunal vessels. Although postoperative complications developed in four patients, no perioperative death or necrosis of the reconstructed free jejunum occurred. The 2- and 5-year overall survival rates were 84 and 50 %, respectively. CONCLUSIONS: Pharyngo-laryngo-esophagectomy with free jejunal transfer is considered to be safe for metachronous PhCe cancer, even in patients with a history of CRT and esophagectomy.

Technical improvement of total pharyngo-laryngo-esophagectomy for esophageal cancer and head and neck cancer.

PURPOSE: Total pharyngo-laryngo-esophagectomy (PLE) is highly invasive, and the subsequent reconstruction is difficult. The purpose of this study was to clarify the techniques that can decrease the surgical stress and allow for safe reconstruction after this operation. METHODS: The surgical method and clinical outcomes of total PLE were reviewed in 12 patients with either cervicothoracic esophageal cancer or double cancer of the esophagus and pharynx. Microscopic venous anastomosis was principally performed, and arterial anastomosis was added, if needed. RESULTS: A narrow gastric tube was used in ten patients, including two patients who underwent free jejunal interposition, while the colon was used as the main reconstructed organ in two other patients. Staged operations were performed in three high-risk patients. All six patients treated after 2010 were able to undergo thoracoscopic and/or laparoscopic surgery. No critical postoperative complications developed, although minor anastomotic leakage developed in two patients who were successfully treated conservatively. CONCLUSION: When performing PLE, it is important to decrease the surgical stress and ensure a reliable reconstruction by adopting techniques that are appropriate for each case, such as thoracoscopic and laparoscopic surgery, staged operations, microvascular anastomosis, and muscular flaps.

Prevalence of human papillomavirus in oropharyngeal cancer: a multicenter study in Japan.

BACKGROUND: The incidence rates of oropharyngeal squamous cell carcinoma (OPSCC) have risen steadily in the USA and in northern Europe. These increases are thought to be a consequence of persistent infection with high-risk human papillomavirus (HPV) in OPSCC patients. HPV is an emerging etiologic factor in OPSCC. In Japan, the incidence of OPSCC has significantly increased over the last three decades. However, the population of HPV-positive OPSCC patients is currently unknown. We examined the nationwide trends with regard to HPV incidence in OPSCC patients at 21 specific sites, and examined the relationship between the presence of HPV and survival in OPSCC patients in Japan. METHODS: Tumor samples were obtained from patients with OPSCC prior to treatment, and HPV infection was investigated by polymerase chain reaction (PCR). Hybrid Capture 2 (HC2) was also adopted for swab examination on the surface of fresh tumors. RESULTS: HPV was detected by PCR in 79 (50.3%) out of 157 OPSCC patients. The clinical features of HPV-positive OPSCC were low differentiation, a tendency to involve the lateral wall, and high nodal staging. The sensitivity and specificity of HC2 were 93.7 and 96.2%, respectively, indicating its utility as a screening test. HPV-positive patients had significantly better overall survival and disease-free survival than HPV-negative patients.

Surgical strategies for esophageal cancer associated with head and neck cancer.

Esophageal cancer is frequently associated with squamous cell carcinoma in the head and neck. Both cigarette smoking and alcohol consumption are risk factors for multiple cancers of the head and neck, as well as the esophagus. Routine screening and close follow-up for second cancers are important in patients with esophageal cancer or head and neck cancer. For this purpose, endoscopy with Lugol's staining, as well as narrow-band imaging combined with magnifying endoscopy, is a powerful tool for the early detection of esophageal cancer. Multimodal therapy is essential for patients with double cancers. When considering surgical treatment, the curability of both cancers must be carefully evaluated. If both tumors are potentially curable, each lesion should be treated individually. In patients with metachronous double cancers, the prior treatment of the first primary carcinoma often affects the treatment of the second cancer. Close cooperation among medical staff members is essential for complicated surgeries for double cancers. Techniques that are appropriate for each case must be adopted, such as careful dissection, staged operations, muscular flaps and microvascular anastomosis.

Removal of a Metallic Stent after 9 Years of Placement That Caused Tracheal Stenosis: A Rare Case Report.

Introduction: Metallic stents are widely used to prevent airway obstruction for tracheal stenosis caused by malignant diseases. Although their efficacy has been recognized, there is no established evidence surrounding their long-term safety. We report a case of airway stenosis caused by a metallic tracheal stent. Removal of the stent to secure the airway was difficult and extremely complicated. Case Presentation: A 50-year-old male suffering from dyspnea caused by malignant lymphoma (diffuse large B-cell lymphoma) of the thyroid gland was treated with a metallic tracheal stent. After remission of the lymphoma, stenosis of the stent lumen developed gradually, and the patient complained of dyspnea. Tracheostomy could not be performed due to the metallic stent. Since the patient was unable to intubate, the stent was removed under general anesthesia with partial percutaneous cardiopulmonary support 9 years after the stent placement. Conclusion: Otolaryngologists should be aware of the possibility of severe stenosis following the long-term placement of a metallic tracheal stent.

Efficacy of anti-PD-1 monotherapy for recurrent or metastatic olfactory neuroblastoma.

Background: Olfactory neuroblastoma (ONB) is a rare malignant tumor of the head and neck. Due to its rarity, standard systemic therapy for this condition has yet to be established. In particular, the use of immune checkpoint inhibitors (ICIs) for the recurrent or metastatic (R/M) ONB population remains unclear. Methods: We retrospectively evaluated 11 patients with R/M ONB who received any systemic chemotherapy at two Japanese institutions (National Cancer Center Hospital East and Kyushu Medical Center) between January 2002 and March 2022 and analyzed outcomes by use of anti-PD-1 antibody (nivolumab or pembrolizumab) monotherapy. Results: Of the 11 patients, 6 received ICI (ICI-containing treatment group) and the remaining 5 were treated with systemic therapy but not including ICI (ICI-non-containing treatment group). Overall survival (OS) was significantly longer in the ICI-containing group (median OS: not reached vs. 6.4 months, log-rank p-value: 0.035). The fraction of ICI systemic therapy in the entire treatment period of this group reached 85.9%. Four patients (66.7%) in the ICI-containing treatment group experienced immune-related adverse events (irAE), with grades of 1/2. No irAE of grade 3 or more was seen, and no patient required interruption or discontinuation of treatment due to toxicity. Conclusion: ICI monotherapy appears to be effective and to contribute to prolonged survival in R/M ONB.

Clinical decision pathway and management of locally advanced head and neck squamous cell carcinoma: A multidisciplinary consensus in Asia-Pacific.

OBJECTIVES: To develop consensus on patient characteristics and disease-related factors considered in deciding treatment approaches for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) based on real-world treatment patterns in 4 territories in Asia-Pacific. METHODS: A three-round modified Delphi involving a multidisciplinary panel of HN surgeons, medical oncologists, and radiation oncologists was used. Of 41 panelists recruited, responses of 26 from Australia, Japan, Singapore, and Taiwan were analyzed. All panelists had ≥five years' experience managing LA-HNSCC patients and treated ≥15 patients with LA-HNSCC annually. RESULTS: All statements on definitions of LA-HNSCC, treatment intolerance and cisplatin dosing reached consensus. 4 of 7 statements on unresectability, 2 of 4 on adjuvant chemoradiotherapy, 7 of 13 on induction chemotherapy, 1 of 8 on absolute contraindications and 7 of 11 on relative contraindications to high-dose cisplatin did not reach consensus. In all territories except Taiwan, high-dose cisplatin was preferred in definitive and adjuvant settings for patients with no contraindications to cisplatin; weekly cisplatin (40 mg/m2) preferred for patients with relative contraindications to high-dose cisplatin. For Taiwan, the main treatment option was weekly cisplatin. For patients with absolute contraindications to cisplatin, carboplatin ± 5-fluorouracil or radiotherapy alone were preferred alternatives in both definitive and adjuvant settings. CONCLUSION: This multidisciplinary consensus provides insights into management of LA-HNSCC in Asia-Pacific based on patient- and disease-related factors that guide selection of treatment modality and systemic treatment. Despite strong consensus on use of cisplatin-based regimens, areas of non-consensus showed that variability in practice exists where there is limited evidence.

Surgical resection for esophageal cancer synchronously or metachronously associated with head and neck cancer.

BACKGROUND: Esophageal cancer is frequently associated with head and neck cancer, and esophagectomy is usually difficult in such a case. The purpose of this study was to clarify the clinical significance of esophagectomy for patients with esophageal cancer associated either synchronously or metachronously with head and neck cancer. METHODS: The clinical outcomes of surgical resections for esophageal cancer were compared between 26 patients with head and neck cancer (double cancer group) and 176 without head and neck cancer (control group). RESULTS: Staged operations were performed in 5 patients in the double cancer group, while microvascular anastomosis as well as a muscle flap was added for 3 and 4 patients, respectively. The mortality and morbidity of the double cancer group were 0 and 35 %, respectively, which were not significantly different from those of the control group (3 and 31 %, respectively). There were no significant differences in overall survival in the double cancer and control groups, which had 5-year survival rates of 59 and 49 %, respectively. CONCLUSIONS: Esophagectomy can be an effective treatment when techniques are adopted that are appropriate for each case, such as staged operations, muscular flaps, and microvascular anastomosis, even in patients with double cancers of the esophagus and the head and neck.

HER2 and EGFR gene copy number alterations are predominant in high-grade salivary mucoepidermoid carcinoma irrespective of MAML2 fusion status.

AIMS: In this study, we aimed to investigate the molecular mechanisms underlying the development of mucoepidermoid carcinoma (MEC). METHODS AND RESULTS: In 31 cases, we examined the MAML2 fusion status using reverse transcriptase-polymerase chain reaction, and HER2 and EGFR status using immunohistochemistry and chromogenic in-situ hybridization. MAML2 fusions were detected in 15 (57.7%) of 26 MECs analysed, including 11 of 16 (68.8%) low-grade, two of four (50%) intermediate-grade and two of six (33.3%) high-grade MECs. HER2 gene amplification and an increased EGFR gene copy number (with balanced chromosome 7 high-polysomy) were each detected in four of 28 (14.3%) MECs analysed. Irrespective of MAML2 fusion status, all seven high-grade MECs had an increased gene copy number of either HER2 or EGFR, in a mutually exclusive manner, whereas such abnormalities were extremely rare in low- and intermediate-grade MEC. CONCLUSIONS: These results suggest that HER2 or EGFR gene abnormality could play an important role in the development of high-grade MEC, and also in the progression from MAML2 fusion-positive low-/intermediate-grade to high-grade in a subset of MEC. Furthermore, we suggest that high-grade MEC comprises a heterogeneous group of tumours in terms of molecular pathogenesis, in particular MAML2 fusion status.

Minimally invasive total pharyng-laryngo-esophagectomy and reconstruction with gastric tube: report of three cases.

Total pharyngo-laryngo-esophagectomy (TPLE) is indicated for either cervical esophageal cancer or synchronous double cancer of the thoracic esophagus and head and neck and this operation is extremely invasive. We adopted minimally invasive surgery for three patients who underwent this operation: VATS (video-assisted thoracoscopic surgery) esophagectomy was undergone in left semi-prone position and laparoscopic approach was also applied to reconstruction with gastric tube. After pharyngo-laryngectomy and gastric tube pull-up through post-mediastinal route, cervical anastomosis was performed. Free jejunal interposition was added in a case, while microvascular venous anastomosis between short gastric vein and cervical vein in another two cases. All patients recovered well without any postoperative complications. This is the first report, which describes minimally invasive TPLE using both VATS and laparoscopic technique in addition with plastic surgery.

An invasive presentation of parotid lymphadenoma: A first reported case.

Lymphadenoma, a rare benign tumor recognized in the WHO salivary gland tumor classification of 2005, poses diagnostic and treatment challenges due to its rarity and distinct histopathological characteristics. We report a unique case of lymphadenoma in a 45-year-old male patient who presented with a hard, painless tumor in the right parotid gland that had been present since he was 15 years old. Distinctively, MRI and CT imaging revealed signs of infiltration into the surrounding muscle tissues, challenging the traditional notion of lymphadenomas as tumors with clear boundaries. The histopathological examination identified the characteristic epithelial and lymphoid cell proliferation, suggestive of a lymphadenoma. However, the possibility of sebaceous differentiation due to faintly pale cells within the epithelial component was inconclusive. The tumor's invasive nature and the high risk of facial nerve paralysis associated with surgical resection led to the patient's decision against treatment. Findings from this case underline the need for caution in diagnosing lymphadenoma, given its potential to show invasive images and the risks associated with a malignant diagnosis based solely on these images. Furthermore, the observations from this case present new insights into the FDG-PET findings of lymphadenoma, contributing to the overall understanding of this rare tumor's clinical implications. Future studies are warranted to provide more clarity on this condition.

HER-2/neu gene amplification in carcinoma ex pleomorphic adenoma in relation to progression and prognosis: a chromogenic in-situ hybridization study.

AIMS: The aim of this study was to investigate the potential role of HER-2/neu in the stepwise progression of carcinoma ex pleomorphic adenoma (CXPA) and to evaluate its prognostic significance in CXPA. METHODS AND RESULTS: We examined HER2 overexpression and HER2 amplification by immunohistochemistry and chromogenic in-situ hybridization in 31 cases of CXPA with ductal differentiation (eight intraductal, five intracapsular, and 18 extracapsular) and seven cases of atypical pleomorphic adenoma (PA). HER2 overexpression and HER2 amplification were found in 17 (54.8%) and 12 (38.7%) of the 31 CXPA cases, respectively. HER2 amplification was more prevalent in extracapsular CXPAs (9/18 cases; 50%) than intracapsular CXPAs (1/5 cases; 20%), intraductal CXPAs (2/8 cases; 25%), or atypical PAs (0/7 case; 0%). The status of HER2 amplification was essentially retained from the intraductal to the extracapsular component in individual extracapsular CXPAs. In addition, HER2 amplification was significantly associated with a worse prognosis (shorter disease-free survival time and shorter overall survival time) among extracapsular CXPAs (each P < 0.05). CONCLUSIONS: These results suggest that HER2 may play an important role in the progression of CXPA, and that HER2 amplification may be an additional prognostic indicator of CXPA.

[Laryngeal preservation for hypopharyngeal cancer by radiotherapy with S-1 and vitamin A(TAR therapy)].

The objective of this study was to analyze the outcome of hypopharyngeal cancer patients who underwent triple combination treatment with S-1, vitamin A and radiation(TAR therapy), and to analyze the role of TAR therapy for treating locally advanced hypopharyngeal cancer patients. 146 patients(stage I: 10 cases, stage II : 22 cases, stage III : 23 cases, stage IV: 91 cases)with hypopharyngeal squamous cell carcinoma were treated with TAR therapy(S-1; orally, 65mg/m²day, twice a day; vitamin A(retinol palmitate): 50, 000 I U/day, intra-musculary on each day of radiation; radiation: 1. 5-2 Gy/day, 5 days/week). Histologic complete responders at 30-40 Gy continued TAR therapy up to 60-70 Gy. Nonresponders at 30-40 Gy underwent surgery. The overall 5-year survival and disease-specific 5-year survival rates were 50. 5%and 59%respectively. The cumulative 3-year laryngeal preservation rate for stage I was 100%, 82. 5% for stage II, 66. 6% for stage III, and 35%for stage IV. Laryngeal preservation was fair in T1/T2 patients(81%), but not satisfactory in T3/T4 patients(21. 4%). S- 1 is administered orally, and TAR therapy can be conducted in the clinic with low toxicity. However, protocols with high intensity may be necessary to improve laryngeal preservation for locally advanced(T4)hypopharyngeal cancer.

Retrospective Study of Cisplatin/Carboplatin, 5-Fluorouracil Plus Cetuximab (EXTREME) for Advanced-stage Salivary Gland Cancer.

BACKGROUND/AIM: Surgery remains the standard treatment for salivary gland carcinoma (SGC). Our study investigated the association between epidermal growth factor receptor (EGFR) status in recurrent/metastatic SGC and the effectiveness of treatment with cisplatin/carboplatin and 5-fluorouracil plus cetuximab (EXTREME). PATIENTS AND METHODS: We retrospectively collected 19 SGCs from patients treated with the EXTREME regimen. After analyzing EGFR expression and gene copy number gain, we evaluated the correlation between EGFR status and clinicopathological factors and prognosis. RESULTS: EGFR overexpression was detected in 77.8% cases, but not statistically associated with clinicopathological factors or prognosis. EGFR gene copy number gain was detected in 16.7% cases, and statistically positively correlated with lymph node metastasis (p=0.0291). The best overall response was partial response in two cases, stable disease in 15, and progressive disease in one case. The EXTREME regimen was discontinued in all cases. CONCLUSION: Our results suggest that SGCs are positive for EGFR protein expression but the response rate to the EXTREME regimen was unremarkable.

Treatment Efficacy of PD-1 Inhibitor Therapy in Patients With Recurrent and/or Metastatic Salivary Gland Carcinoma.

BACKGROUND/AIM: The efficacy of programmed cell death 1 (PD-1) inhibitor therapy for patients with recurrent and/or metastatic salivary gland carcinoma (R/M SGC) remains unclear. PATIENTS AND METHODS: We retrospectively analyzed 36 patients with R/M SGC treated with PD-1 inhibitor. The expression of programmed cell death ligand 1 (PD-L1) and mismatch repair (MMR) proteins was also analyzed. RESULTS: The objective response rate (ORR) was 11.1%. The histopathological subtypes of patients who achieved complete response or partial response were salivary duct carcinoma (SDC) in three patients and poorly differentiated carcinoma in one patient, all of whom showed a positive PD-L1 expression. The expression of MMR proteins was not associated with the efficacy of PD-1 inhibitors. CONCLUSION: Although the efficacy of PD-1 inhibitor therapy in R/M SGC is limited, certain patients may respond and achieve long-term disease control. There is a potential therapeutic effect in SDC patients with positive PD-L1 expression.