Small Cell Carcinoma in the Head and Neck

High-grade neuroendocrine head and neck cancer: Case series and review of the literature

BACKGROUND

High-grade neuroendocrine cancers (NEC) of the head and neck (HN) are rare and aggressive, accounting for ≤1 % of all HN cancers, with a 5-year overall survival (OS) of ≤20 %. This case series examines clinical characteristics, treatments, and outcomes of patients diagnosed at a regional UK HN cancer centre over the last 23 years.

METHODS

A retrospective review of medical records was conducted for all patients diagnosed with NEC HN from 1st January 2000 until 1st March 2023 at Velindre Cancer Centre.

RESULTS

During the study period, 19 cases of NEC HN were identified, primarily affecting males (n = 15, 79 %). Median age of 67 years (range: 44-86). At diagnosis, 32 % of patients (n = 6) were smokers. The most common primary tumour sites were larynx (n = 5, 26.3 %) and sinonasal (n = 5, 26.3 %). Most patients presented with advanced loco-regional disease or distant metastasis, with stage IVA (n = 6, 32 %) and stage IVC (n = 6, 32 %) being the most common. The key pathology marker was synaptophysin, present in 100 % of the tested patients (n = 15). In the study, of the 12 patients with non-metastatic disease, 10 received a combination of treatments that included radiotherapy (RT). Some of these patients also received chemotherapy (CT) at the same time as their radiotherapy. Surgery alone was used in two patients with stage II disease. Seven subjects had complete responses, and one achieved a partial response. Among the seven metastatic patients, three received CT, and one underwent palliative RT, all achieving a partial response. In all cases, the CT used was carboplatin and etoposide. After a median follow-up of 11 months (range: 1-96), the median OS was 27 months for the overall population, 51 months for those treated radically, and three months for metastatic patients with palliative treatment. The 1-year OS for all patients was 54.3 %, the 2-year OS was 46.5 %, and the 5-year OS was 23.3 %. Among patients treated radically, these rates were 65.3 %, 52.2 %, and 26.1 %, respectively. For patients treated palliatively, the 1-year OS was 33.3 %.

CONCLUSION

This case series contributes preliminary observations on the characteristics and management of non-metastatic NEC HN, suggesting potential benefits from multimodality treatment strategies. Given the small cohort size, these observations should be interpreted cautiously and seen as a foundation for further research.

High-Grade Sinonasal Small Cell Neuroendocrine Carcinoma in a Patient With Xeroderma Pigmentosum: A Case Report

Neuroendocrine tumors are rare and highly heterogeneous neoplasms with a wide spectrum of histological differentiation, functional, and biological features. Small cell neuroendocrine carcinomas (SNECs) of the sinonasal tract are particularly rare. Pathological features of SNECs of the nasal cavity and paranasal sinuses, which are aggressive tumors, are similar to those of anaplastic small cell carcinomas of the lung. We present a case of high-grade sinonasal SNECs in a patient with Xeroderma pigmentosum complementation group C (XPC) gene-positive xeroderma, which, to our knowledge, is the first case reported worldwide.

Therapeutic challenges in small cell carcinoma of the larynx

Primary small cell neuroendocrine carcinoma (SCNC) of the larynx is a rare subtype of laryngeal cancer, accounting for less than 1% of all laryngeal tumours. It most commonly affects smokers in their fifth to sixth decade of life and is characterised by a high incidence of advanced disease at presentation and an aggressive clinical course. Here we present a case of SCNC of the larynx, presenting initially with dysphonia, and an associated literature review collating current knowledge regarding therapeutic approaches. After review of 260 cases in the literature we determined a disease-specific survival of 33.1%. Combined chemoradiotherapy is currently the recommended first-line treatment option.

Sinonasal Neuroendocrine Carcinoma: A Case report

Neuroendocrine carcinoma are rare tumor which begin in specialized cells called neuroendocrine cells. It can occur anywhere in the body. Most neuroendocrine tumors occur in the lungs, appendix, small intestine, rectum and pancreas. We reported a case of sinonasal neuroendocrine carcinoma in a 65 year old lady who had presented with a history of right nasal obstruction, bloody nasal discharge, and recurrent epistaxis. On examination, a red, friable, polypoid mass with a tendency to bleed was seen in the right nasal cavity. Computed tomography revealed there was a enhancing expansile necrotic mass in right nasal cavity abutting the medial nasal wall. There was presence of mucosal thickening with inspissated secretion in all sinuses except left maxillary sinus. The patient underwent endoscopic removal of the tumour. Biopsy revealed poorly differentiated carcinoma of right nasal cavity. Immunohistochemistry revealed small cell neuroendocrine carcinoma. After that, the patient had postoperative external radiation treatment with a 6600 cGy dosage administered over 33 fractions. The patient had routine follow-up at the radiation oncology and otolaryngology outpatient departments throughout a 12-month period. During the postoperative month-to-month follow-up, there was no evidence of a local tumour recurrence in the endoscopy.

Primary Small Cell Neuroendocrine Carcinoma of nasopharynx with metastatic cervical lymph nodes: an exceedingly rare entity with review of literature

Small cell neuroendocrine carcinoma of nasopharynx is extremely rare and displays aggressive nature with a poor prognosis. Neuroendocrine tumours rarely arise from the head and neck region and pose a diagnostic and management challenge. In English literature, only 16 cases of primary small cell neuroendocrine carcinoma of nasopharynx have been reported so far; and to the best of our knowledge, this is the seventeenth case and second in the younger age group. Here, we report the case of an adolescent male patient who presented with nasal blockage, repeated episodes of epistaxis and neck swellings. After proper diagnostic workup, the diagnosis of small cell neuroendocrine carcinoma of nasopharynx was made. The patient was treated with chemotherapy, followed by radiotherapy. Imaging investigation executed after the end of the treatment exhibited complete remission of the disease. The patient is kept under active surveillance with no signs of relapse at present.

Clinical Behavior, Mutational Profile and T-Cell Repertoire of High-Grade Neuroendocrine Tumors of the Head and Neck

Neuroendocrine carcinomas (NECs) of the head and neck (HN) account for <1% of HN cancers (HNCs), with a 5-year overall survival (OS) <20%. This is a retrospective study of HN NECs diagnosed at our institution between 2005 and 2022. Immunohistochemistry and next-generation sequencing (NGS) were used to evaluate neuroendocrine markers, tumor mutational burden (TMB), mutational profiles and T-cell receptor repertoires. Eleven patients with high-grade HN NECs were identified (male:female ratio 6:5; median age 61 (Min-Max: 31-86)): nasoethmoidal (3), parotid gland (3), submaxillary gland (1), larynx (3) and base of tongue (1). Among n = 8 stage II/IVA/B, all received (chemo)radiotherapy with/without prior surgery or induction chemotherapy, with complete response in 7/8 (87.5%). Among n = 6 recurrent/metastatic patients, three received anti-PD1 (nivolumab (2), pembrolizumab (1)): two achieved partial responses lasting 24 and 10 months. After a median follow-up of 30 and 23.5 months since diagnosis and since recurrent/metastatic, median OS was not reached. Median TMB (n = 7) was 6.72 Mut/Mb. The most common pathogenic variants were TP53, HNF1A, SMARCB1, CDKN2A, PIK3CA, RB1 and MYC. There were 224 median TCR clones (n = 5 pts). In one patient, TCR clones increased from 59 to 1446 after nivolumab. HN NECs may achieve long-lasting survival with multimodality treatment. They harbor moderate-high TMBs and large TCR repertoires, which may explain responses to anti-PD1 agents in two patients and justify the study of immunotherapy in this disease.

A primary small cell neuroendocrine carcinoma (SCNC) of the oral cavity (cheek mucosa): Description of a case report

BACKGROUND

Small cell neuroendocrine carcinoma (SCNC) of the oral cavity is a poorly differentiated, high-grade and very aggressive tumor with a poor prognosis.

CASE DESCRIPTION

A 64-year-old, Caucasian, smoker man consulted for an ulcero-necrotic, exophytic, lesion of the right retromolar trigone. Haed&neck CT scan showed a right tonsillar tumor lesion. The ¹⁸F-PET scan confirmed the presence of a right, highly hypermetabolic tonsillar lesion and two homolateral, cervical lymph nodes. Histology and immunohistochemistry were consisted with the diagnosis of a primary SCNC of the oral cavity. As the tumor was locally advanced and unresectable, the patient underwent a definitive radio-chemotherapy with a cisplatin/etoposide combined regimen (4 cycles). The treatment was well tolerated and led to a complete tumor response.

CONCLUSION

The particularity of this case relies on the rarity of the oral SCNC, its difficult and challenging diagnosis, and the complexity of its management that is not validated by large clinical trials, data being extrapolated from small cell lung cancer. In our case, the patient presenting a locally advanced tumor was treated by a combined radio-chemiotherapy leading to a complete tumor regression. The patient's follow up is too short to assess the real benefit of this treatment on overall survival.

Small-Cell Carcinoma of Nasopharynx: A Case Report of Unusual Localization

Neuroendocrine tumors are a spectrum of rare and highly heterogeneous neoplasms with distinct functional and biological behavior in relation to location, tumor size, and histological differentiation. Neuroendocrine tumors arise from the neuroendocrine cells of the diffuse neuroendocrine system located in almost every organ. Neuroendocrine tumors in the head and neck district are usually reported in sinonasal cavities and larynx. We present the case of a nasopharyngeal small-cell neuroendocrine carcinoma, which, as far as we know, is the 16th case reported in literature.

Head and neck small-cell carcinoma: A multicenter study of 39 cases from 10 institutions

Objective

Basal information of head and neck small-cell carcinoma (HNSmCC) including epidemiology, primary site, treatment, and prognosis remains sparse due to its rarity. We report here a multicenter retrospective study on the diagnosis, treatment, and outcomes of patients with HNSmCC.

Materials and methods

This study involved 47 patients with HNSmCC from 10 participating institutions. Eight patients were excluded for whom no pathological specimens were available (n = 2) and for discrepant central pathological judgements (n = 6). The remaining 39 patients were processed for data analysis.

Results

As pretreatment examinations, computed tomography (CT) was performed for the brain (n = 8), neck (n = 39), and chest (n = 32), magnetic resonance imaging (MRI) for the brain (n = 4) and neck (n = 23), positron emission tomography-CT (PET-CT) in 23 patients, bone scintigraphy in 4, neck ultrasonography in 9, and tumor markers in 25. Primary sites were oral cavity (n = 1), nasal cavity/paranasal sinuses (n = 16), nasopharynx (n = 2), oropharynx (n = 4), hypopharynx (n = 2), larynx (n = 6), salivary gland (n = 3), thyroid (n = 2), and others (n = 3). Stages were II/III/IV-A/IV-B/IV-C/Not determined = 3/5/16/6/5/4; stage IV comprised 69%. No patient had brain metastases. First-line treatments were divided into 3 groups: the chemoradiotherapy (CRT) group (n = 27), non-CRT group (n = 8), and best supportive care group (n = 4). The CRT group included concurrent CRT (CCRT) (n = 17), chemotherapy (Chemo) followed by radiotherapy (RT) (n = 5), and surgery (Surg) followed by CCRT (n = 5). The non-CRT group included Surg followed by RT (n = 2), Surg followed by Chemo (n = 1), RT alone (n = 2), and Chemo alone (n = 3). The 1-year/2-year overall survival (OS) of all 39 patients was 65.3/53.3%. The 1-year OS of the CRT group (77.6%) was significantly better compared with the non-CRT group (31.3%). There were no significant differences in adverse events between the CCRT group (n = 22) and the Chemo without concurrent RT group (n = 9).

Conclusion

Neck and chest CT, neck MRI, and PET-CT would be necessary and sufficient examinations in the diagnostic set up for HNSmCC. CCRT may be recommended as the first-line treatment. The 1-year/2-year OS was 65.3%/53.3%. This study would provide basal data for a proposing the diagnostic and treatment algorithms for HNSmCC.

Systematic review of neuroendocrine carcinomas of the oropharynx

Data describing features and management of oropharyngeal neuroendocrine carcinomas (NEC) remain sparse. A systematic review was performed. Patients were stratified by treatment modality and examined for disease progression and survival outcomes. Ninety-four patients from 50 publications were included. Average age at diagnosis was 59.7 years (range 14-83). 73.4% were male. Most studies did not document HPV status. Forty patients (85.1%) were p16 positive, and 34 (85.0%) were HPV-ISH positive. Overall survival was 75.4% at 1 year, and 40.0% at 2 years. Of patients with locoregional disease, 33.8% developed distant metastasis. 12.5% of patients developed locoregional recurrence. Patients who developed distant metastases had worse overall survival (p = 0.0004). No significant difference was found between treatment modalities. Human papilloma virus may be associated with oropharyngeal NEC. Current treatments provide locoregional control, but distant metastases are common and confer low overall survival.

Small cell neuroendocrine carcinoma of buccal mucosa: Innocuous but invasive

Small cell neuroendocrine carcinoma (SNEC) was first described in the 19^th century which is usually seen in association with lung cancer and is very rare in the oral cavity. Here, we report one such case in a 39-year-old male patient who presented with swelling on the left middle third of the face for 6 months. This is the 12^th SNEC of oral cavity case so far reported in the English literature and the third case to be present on buccal mucosa. It presented as a nodular swelling over the buccal mucosa and was clinically diagnosed as a traumatic fibroma. The histopathological sections showed diffuse sheets of round cells with granular chromatin. Immunohistochemical findings helped us arrive at a final diagnosis. SNECs are highly proliferative tumors characterized by early and widespread metastases through the vascular channels. Hence, the diagnosis and appropriate management of these lesions is important to decrease the morbidity and mortality rate.

Clinical Characteristics and Prognosis of Small Cell Carcinoma in the Nasopharynx: A Population-Based Study

Background

Nasopharyngeal small cell carcinoma (SmCC) is a rare histological type of nasopharyngeal cancer, and its prognosis remains poor. This study aimed to determine the clinical characteristics and survival prognostic factors of nasopharyngeal SmCC.

Methods

Detailed clinicopathologic and therapeutic characteristics of a patient diagnosed with nasopharyngeal SmCC were determined. Nasopharyngeal SmCC cases reported previously were reviewed and summarized. Furthermore, a retrospective analysis was performed on data from the Surveillance, Epidemiology, and End Results (SEER) Program database. Kaplan–Meier analysis was conducted to compare survival within groups. Univariate and multivariate analyses were performed to investigate prognostic factors.

Results

A nasopharyngeal SmCC patient treated with chemoradiotherapy who achieved 46 months long-term survival was reported. In reviewing 16 reported cases with epidemiologic and therapeutic details, we found most of nasopharyngeal SmCC patients were diagnosed with advanced grades and received chemoradiotherapy. In total, 13,993 cases of nasopharyngeal cancer were extracted from the SEER database, from which 57 nasopharyngeal SmCC cases were eventually screened out. The mean age of the patients was 55.70 years, and 64.9% of these cases were either grade III or IV; the median overall survival (OS) was 18 months. Statistically significant differences were observed in the OS values of groups categorized by age (P = .025) or radiotherapy (P = .037). Age (<70 years) and radiotherapy were identified as independent survival and prognostic factors.

Conclusion

Patients with nasopharyngeal SmCC are usually diagnosed with advanced grades and have poor prognoses; nevertheless, they can benefit from radiotherapy with prolonged overall survival.

[Clinical analysis of 31 patients with sinonasal neuroendocrine carcinoma]

Objective:To investigate the characteristics and prognostic factors of sinonasal neuroendocrine carcinoma （SNEC）. Methods:The clinical data of 31 patients with SNEC were retrospectively analyzed. Among the 31 patients, 3 cases were simply surgically removed, 4 cases were surgery + radiotherapy, 4 cases were surgery + chemotherapy, 10 cases were surgery + chemoradiotherapy, and 10 cases were simply given chemoradiotherapy without surgery. The study follow-up 8-64 months. Results:By the end of follow-up, 2 patients were lost to follow-up, 17 died, 12 survival, 8 relapsed and 5-year survival rate was 36.4％. High TNM stage, lymph node metastasis, skull base infiltration and Ki-67≥55％ were the negative prognostic factors for survival. Conclusion:SNEC is a rare aggressive tumor, with poor prognosis, high local recurrence rate, metastasis tendency, hidden disease. The comprehensive treatment of surgery combined with chemoradiotherapy is still the best treatment.

Primary small cell neuroendocrine carcinoma in the nasal cavity: A CARE-compliant case report

RATIONALE

Small cell neuroendocrine carcinoma of the nasal cavity and paranasal sinuses is a rare but aggressive neoplasm with a poor prognosis and a strong propensity for regional recurrence and distant metastasis. Diagnosis is challenging and relies on immunohistochemical study. Treatment includes surgical resection, radiation therapy, chemotherapy, or a combination of these modalities. However, the optimal therapeutic strategy is still controversial. Due to its rarity, the complexity of the histological diagnosis, and the variety of the treatment regimens, we presented a case of primary small cell neuroendocrine carcinoma in the nasal cavity with description of the clinical manifestation, pathology features, and our treatment regimen.

PATIENT CONCERNS

An 82-year-old female patient with hypertension presented with right epistaxis on and off with nasal obstruction for several days.

DIAGNOSIS

An exophytic mass over the posterior end of the right inferior turbinate was found on nasopharyngoscope. Biopsy was done and the pathology confirmed small cell carcinoma, strongly positive for cytokeratin (AE1/AE3) and insulinoma-associated protein 1 (INSM-1), scatteredly positive for chromogranin A, synaptophysin and CD56. The final diagnosis was small cell neuroendocrine carcinoma of right nasal cavity, pT1N0M0, stage I.

INTERVENTIONS

The patient underwent wide excision of right intra-nasal tumor and post-operative radiotherapy with a dose of 6600 cGy in 33 fractions.

OUTCOMES

No local recurrence or distant metastasis was noted during the 12 months of follow-up.

LESSONS

Multimodality treatment remains the most common therapeutic strategy, although no proven algorithm has been established due to the rarity of this disease. Further investigation is needed for providing evidence to standardize the treatment protocol.

Genetic and transcriptomic analyses in a rare case of human papillomavirus-related oropharyngeal squamous-cell carcinoma combined with small-cell carcinoma

Human papillomavirus (HPV)-related oropharyngeal small-cell carcinoma (OPSmCC) is a rare malignancy with aggressive behavior, whereas HPV-related oropharyngeal squamous-cell carcinoma (OPSqCC) displays a favorable prognosis. Notably, these two malignancies occasionally arise in an identical tumor. In this case study, we explored the molecular characteristics that distinguishes these two carcinomas using a rare case of HPV-related oropharyngeal carcinoma (OPC) with the combined histology of SmCC and SqCC. Immunohistochemical analysis and HPV-RNA in situ hybridization (ISH) suggested that both SmCC and SqCC were HPV-related malignancies. Targeted exome sequencing revealed that SmCC and SqCC had no significant difference in mutations of known driver genes. In contrast, RNA sequencing followed by bioinformatic analyses suggested that aberrant transcriptional programs may be responsible for the neuroendocrine differentiation of HPV-related OPC. Compared to SqCC, genes up-regulated in SmCC were functionally enriched in inflammatory and immune responses (e.g., arachidonic acid metabolism). We then developed a SmCC-like gene module (top 10 up-regulated genes) and found that OPC patients with high module activity showed poor prognosis in The Cancer Genome Atlas (TCGA) and GSE65858 cohort. Gene set enrichment analysis of the SmCC-like gene module suggested its link to MYC proto-oncogene in the TCGA data set. Taken together, these findings suggest that the SmCC-like gene module may contribute to acquisition of aggressive phenotypes and tumor heterogeneity of HPV-related OPC. The present case study is the first report of genetic and transcriptomic aberrations in HPV-related OPSmCC combined with SqCC.

A Case of Small Cell Carcinoma Originated from Sphenoid Sinus in Patient with Recurrent Pituitary Tumor

Small cell carcinoma (SmCC) is a type of neuroendocrine tumor commonly originating in the lung, with only about 2-4% of cases arising at extrapulmonary sites. Extrapulmonary SmCC of the head and neck has a poor prognosis and a high rate of distant metastasis. The paranasal sinus is a rare location for extrapulmonary SmCC and only a few related papers have been published to date. We report a rare case of SmCC originating from the sphenoid sinus in a patient with a recurrent pituitary tumor with a literature review.

Clinicopathological and genomic features in patients with head and neck neuroendocrine carcinoma

Neuroendocrine carcinoma (NEC) of the head and neck is a rare type of malignancy, accounting for only 0.3% of all head and neck cancers, and its clinicopathological and genomic features have not been fully characterized. We conducted a retrospective analysis of 27 patients with poorly differentiated NEC of the head and neck seen at our institution over a period of 15 years. Patient characteristics, adopted therapies, and clinical outcomes were reviewed based on the medical records. Pathological analysis and targeted sequencing of 523 cancer-related genes were performed using evaluable biopsied/resected specimens based on the clinical data. The most common tumor locations were the paranasal sinus (33%) and the oropharynx (19%). Eighty-one percent of the patients had locally advanced disease. The 3-year overall survival rates in all patients and in the 17 patients with locally advanced disease who received multimodal curative treatments were 39% and 53%, respectively. Histologically, large cell neuroendocrine carcinoma was the predominant subtype (58% of evaluable cases), and the Ki-67 labeling index ranged from 59 to 99% (median: 85%). Next-generation sequencing in 14 patients identified pathogenic/likely pathogenic variants in TP53, RB1, PIK3CA-related genes (PREX2, PIK3CA, and PTEN), NOTCH1, and SMARCA4 in six (43%), three (21%), two (14%), two (14%), and one (7%) patients, respectively. Sequencing also detected the FGFR3-TACC3 fusion gene in one patient. The median value of the total mutational burden (TMB) was 7.1/Mb, and three patients had TMB ≥ 10. Regardless of the aggressive pathological features, our data revealed favorable clinical characteristics in the patients with locally advanced disease who received curative treatment. The lower TP53 and RB1 mutation prevalence rates compared to those described for small cell lung cancer suggests the biological heterogeneity of NEC in different parts of the body. Furthermore, the FGFR3-TACC3 fusion gene and mutations in genes encoding the components of the NOTCH and PI3K/AKT/mTOR pathways found in our study may be promising targets for NEC of the head and neck.

Small Cell Carcinoma of the Head and Neck: Update on the University of Florida Experience

We updated the University of Florida experience treating head and neck small cell carcinoma. Eight patients received a median of 67.7 Gy between 1989 and 2017. The 2-year rates of local, regional, distant, and disease control were 73, 60, 33, and 13%, respectively. The 2-year overall survival rate was 38%; median survival was 1.4 years. The longest disease-free period was 9.5 years after treatment with no evidence of disease. Radiotherapy is an acceptable treatment for these patients, who tend to have poor outcomes and distant metastatic disease. Superior systemic chemotherapy may improve outcomes and decrease the likelihood of distant recurrence.

Clinicopathological characteristics, treatment and prognosis of head & neck small cell carcinoma: a SEER population-based study

Background

To investigate the clinicopathological characteristics of head and neck small cell carcinoma (H&NSmCC) and identify prognostic factors on the basis of the Surveillance, Epidemiology and End Results (SEER) database.

Methods

Total of 789 primary cases from 1973 to 2016 were included. Univariate and multivariate analyses were performed to identify independent prognostic indicators. An H&NSmCC-specific nomogram was constructed and compared with the AJCC staging system by calculating the time-dependent area under the curve (AUC) of the receiver operating characteristic (ROC) curves.

Results

The incidence of H&NSmCC peaked during the period of 50 to 70 years old, and the most frequent location was the salivary gland. The 5-year disease specific survival (DSS) was 27%. In the multivariate survival analysis, AJCC III + IV stage [HR = 2.5, P = 0.03, I + II stage as Ref], positive N stage [HR = 1.67, P = 0.05, negative N stage as Ref], positive M stage [HR = 4.12, P = 0.000, negative M stage as Ref] and without chemotherapy [HR = 0.56, P = 0.023, received chemotherapy as Ref] were independently associated with DSS. The H&NSmCC-specific nomogram was built based on the independent prognostic indicators. The nomogram demonstrated better predictive capacity than the AJCC staging system for 5-year DSS [(AUC: 0.75 vs 0.634; Harrell’s C-index (95% CI): 0.7(0.66–0.74) vs 0.59(0.55–0.62), P < 0.05].

Conclusion

N stage, M stage, AJCC stage and chemotherapy were independent prognostic indicators included in the prognostic nomogram model, which can better predict the survival of H&NSmCC than the AJCC staging system.

Primary small cell neuroendocrine carcinoma of the right posterior tongue

Small cell neuroendocrine carcinoma (SNEC) is an extremely aggressive tumor and mainly occurs in the lung. Primary extra-pulmonary SNEC is rare. To date, only 11 primary SNECs occurring in the oral cavity have been reported in the English literature. We describe a case of primary SNEC of the right posterior tongue in a 46-year-old man. The patient had stage IVA disease and received adjuvant chemotherapy, followed by radical surgery and radiotherapy. He remained tumor-free for 20 mo before death due to gastrointestinal metastasis. The relevant literature on the 11 previously reported patients was reviewed, and the clinical features, histopathological characteristics, differential diagnosis and therapeutic strategies of this rare tumor were analyzed.

Clinicopathological Characteristics and Survival of Small Cell Carcinoma of the Salivary Gland: a Population-Based Study

Background

Small cell carcinoma (SmCC) of the salivary gland is rare, and the characteristics and survival are not well defined due to only case reports or case series being reported. The present study aimed to describe the clinicopathological characteristics and determine the factors associated with survival of this rare cancer.

Materials and methods

A population-based study was carried out to investigate clinical characteristics and prognosis of SmCC of the salivary gland using prospectively extracted data from the Surveillance, Epidemiology and End Results (SEER) database between 1988 and 2016.

Results

Totally, 198 patients with SmCC of the salivary gland were identified with an average age of 72.6±12.4 and a male to female ratio of 3.4:1. The lesions of most patients (167/198) were located in the parotid gland. The median overall survival (mOS) of all patients is 25.0 months. The 1-, 3-, 5- and 10-year survival rate was 65.7%, 40.9%, 33.0% and 22.7%, respectively. Surgery could prolong significantly the mOS by almost 17.0 months (28.0 months vs 11.0 months; P<0.01). Radiotherapy, as well as radiotherapy after surgery, could prolong the mOS (P<0.01 for both). Patients who received chemotherapy had significantly longer overall survival time than those without chemotherapy (28.0 months vs 20 months; P=0.04). The survival analysis demonstrated that old age (>72 years), lymph node (N3) and distant metastases were independent factors for poor survival, whereas radiotherapy was an independent factor for favorable survival.

Conclusion

Small cell carcinoma of the salivary gland is a rare disease, and old age, lymph node and distant metastases, and radiotherapy were significantly associated with prognosis. In order to understand this disease more thoroughly, more cases with adequate information are required.