Minor salivary gland tumors of the head and neck: treatment strategies and prognosis

Treatment and outcomes of minor salivary gland cancers of the larynx and trachea: a systematic review

Objectives

Malignant minor salivary glands carcinomas (MiSGC) of the larynx and trachea are rare tumours and published evidence is sparse. We conducted a systematic review to describe shareable treatment strategies and oncological outcomes of these neoplastic entities.

Methods

Full text English manuscripts published from January 1st 2000 to December 14th 2022 were included. Data on demographics, treatments and outcomes were collected. A pooled analysis of 5-year overall survival (OS) was performed.

Results

Seventeen articles and 365 patients met the inclusion criteria. The most common subsites involved were subglottic and distal trachea. Adenoid cystic carcinoma was, by far, the most frequent histotype. The first-choice treatment strategy was surgery (86.8%), while adjuvant treatments were delivered in 57.4% of patients. Only 12.9% were treated with definitive radiotherapy with/without chemotherapy. The mean follow-up was 68.3 months. One hundred nine (34.9%) deaths were recorded and 62.4% were cancer-related. Five-year OS ranged from 20% to 100% and, at pooled analysis, it was 83% (range, 78-87%).

Conclusions

In case of MiSGC of the larynx and trachea, surgery remains the mainstay of treatment. Adjuvant treatments are frequently delivered. Survival estimates are good overall, but highly heterogeneous.

Effect of histopathological grade on treatment and survival in base of tongue adenocarcinoma

OBJECTIVES

The purpose of this study was to investigate survival differences between low-grade and high-grade base of tongue (BOT) adenocarcinoma by examining demographics, tumor characteristics, and treatment modalities.

METHODS

The National Cancer Database was queried for patients with BOT adenocarcinoma between 2004 and 2017. Univariate and multivariate analyses were performed for all cases of BOT adenocarcinoma. Subsequent analysis focused on low-grade (grade 1 and grade 2) and high-grade (grade 3 and grade 4) BOT adenocarcinoma.

RESULTS

A total of 286 patients with BOT adenocarcinoma were included in the main cohort and divided into low grade (n = 137) and high grade (n = 66). The 5-year overall survival for all patients, low-grade, and high-grade was 67%, 85%, and 58%, respectively. Prognostic factors associated with decreased survival for the main cohort include advanced age (hazard ratio [HR]: 1.04; 95% confidence interval [CI]: 1.02-1.06), non-white race (HR: 1.79; 95% CI: 1.04-3.25), public insurance (HR: 1.79; 95% CI: 1.02-3.14) and high-grade 3,4 (HR: 2.63; 95% CI: 1.51-4.56). The prognostic factor associated with increased survival for the main cohort was surgery (HR: 0.59; 95% CI: 0.36-0.96). Radiotherapy was associated with improved overall survival for high-grade BOT adenocarcinoma (HR: 0.09; 95% CI: 0.02-0.49) but not for low-grade BOT adenocarcinoma (HR: 0.93; 95% CI: 0.38-2.32).

CONCLUSIONS

This investigation is the largest to date analyzing the association of treatment modalities with overall survival in BOT adenocarcinoma. Surgery remains standard of treatment, particularly in low-grade cases, with radiotherapy offering additional survival benefit for high-grade BOT adenocarcinoma.

The impact of age on the outcome of patients treated with radiotherapy for mucoepidermoid carcinoma (MEC) of the salivary glands in the head and neck: A 15-year single-center experience

INTRODUCTION

Data regarding treatment and survival outcome of patients with mucoepidermoid carcinoma of the head and neck are limited to case reports and case series. As a consequence of lacking evidence, treatment guidelines do not exist. We aimed to analyze the effect of modern radiotherapy in form of intensity modulated radiotherapy (IMRT) either with simultaneously integrated boost or carbon ion boost on local control and survival for a relatively large patient collective.

MATERIALS AND METHODS

Patient records of 62 consecutive patients treated with postoperative (n = 53, 85%) or definitive (n = 9, 15%) radiotherapy between 2004 and 2019 were analyzed retrospectively. Kaplan-Meier estimates for overall survival (OS), distant progression-free survival (PFS), local control (LC) and locoregional control (LRC) were statistically calculated and prognostic factors were identified using the log-rank test. Toxicity was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE).

RESULTS

The median follow-up was 47 months (range, 4-188 months). The 3-year OS, DPFS, LC and LRC, estimated by Kaplan-Meier curves, were 82%, 87%, 89% and 92%, the estimated 5-year OS, DPFS, LC and LRC were 78%, 87%, 84% and 88%, respectively. In univariate analysis, age >56 years (vs. age ≤56 years) was identified as the only independent negative prognostic factor for decreased OS (HR = 1.078; 95%-CI = 1.029-1.130; p = 0.001), DPFS (HR = 1.055; 95%-CI = 1.000-1.114; p = 0.051) and LC (HR = 1.087; 95%-CI = 1.022-1.157; p = 0.008). Treatment was well tolerated without any grade ≥4 toxicity. Acute and late grade 3 toxicities were rare with 16% acute (n = 10) and 13% late toxicities (n = 8).

CONCLUSION

Radiotherapy with intensity modulated radiotherapy including either simultaneously integrated photon boost or active raster-scanning carbon ion boost for mucoepidermoid carcinomas of the head and neck resulted in excellent survival outcome and locoregional control with moderate toxicity. However, patients older than 56 years seem to have a disadvantage in all calculated endpoints (OS, DPFS, LRC) due to frequent local and distant relapses.

CONDENSED ABSTRACT

Modern radiotherapy with intensity modulated radiotherapy including either a simultaneously integrated photon boost or carbon ion boost for mucoepidermoid carcinoma results in excellent survival outcome and locoregional control with moderate toxicity. The 5-year OS, DPFS, LC and LRC, estimated by Kaplan-Meier curves, were 89%, 75%, 84% and 80%, respectively. Patients older than 56 years seem to have a disadvantage in all calculated endpoints (OS, DPFS, LRC).

Adenoid cystic carcinoma of the larynx in a 70-year-old patient: A case report

Adenoid cystic carcinoma (ACC) is a relatively rare tumor that accounts for <1% of all head and neck malignancies. Laryngeal localization of ACC, which is most commonly hypoglottic, is relatively rare, occurring in 0.07-0.25% of all laryngeal tumors. ACC is characterized as a slow-growing tumor with a high recurrence rate, which often causes dyspnea and hoarseness. ACC exhibits a propensity for perineural invasion and thus, patients may experience pain as a late symptom of the disease. Distant metastasis occurs in 35-50% of cases and the lungs are the most common site of metastasis. Tumors are usually diagnosed by physical examination with fiberoscopy and computed tomography of the neck and chest, due to the high rate of lung metastases. The standard therapy for ACC is surgery followed by radiotherapy. In this study, a 70-year-old patient presented with laryngeal ACC, who underwent total laryngectomy with bilateral neck dissection and adjuvant radiotherapy, is presented. Follow-up examination performed 2 years after surgery revealed no evidence of locoregional recurrence or distant metastases. Previously published literature regarding ACC of the larynx was also reviewed.

Minor Salivary Gland Carcinoma of the Oropharynx: A Population-Based Analysis of 1426 Patients

Objective We sought to describe the patient, tumor, and survival characteristics of minor salivary gland carcinoma (MSGC) of the oropharynx using a large, population-based database. Study Design Cross-sectional analysis of the National Cancer Institute's SEER database (Surveillance, Epidemiology. and End Results). Subjects and Methods We reviewed the SEER database for all cases of MSGC of the oropharynx from 1988 to 2013. Relevant demographic, clinicopathologic, and survival variables were extracted and analyzed. Cox multivariate regression was performed to identify prognostic factors. Results We identified 1426 cases of MSGC of the oropharynx (mean age, 58 years; 51% female). The soft palate (39.2%) and base of tongue (38.6%) were the most commonly involved sites. The most common histologic subtypes were mucoepidermoid carcinoma (32.1%), adenocarcinoma (25.9%), and adenoid cystic carcinoma (23.3%). Five- and 10-year rates of disease-specific survival were 75.1% and 61.6%, respectively. Independent prognostic factors included tumor grade, T stage, N stage, and age >70 years. Conclusions This study represents the largest multivariate survival analysis of MSGC of the oropharynx to date. Independent prognosticators include tumor grade, T stage, N stage, and age.

Transoral endoscopic head and neck surgery (eHNS) for minor salivary gland tumors of the oropharynx

Background

Transoral endoscopic head and neck surgery (eHNS), including transoral laser microsurgery (TLM) and transoral robotic surgery (TORS), provides access to subsites in the head and neck that have traditionally been difficult to approach. Minor salivary gland tumors, while relatively uncommon, are frequently malignant and can occur at sites in the oropharynx accessible by transoral eHNS. Presented here is the largest review to date of patients with minor salivary gland tumors of the oropharynx managed with transoral eHNS as primary or salvage therapy.

Methods

A retrospective chart review was performed, including data from 20 patients with minor salivary gland tumors of the oropharynx managed with transoral eHNS at 2 tertiary, academic medical centers. Details of tumor pathology, margin analysis, adjuvant therapy, and an assessment of oncologic outcome were included.

Results

The base of tongue was the most common tumor site (75%). Adenoid cystic carcinoma (ACC) accounted for most cases (35%), and negative margins were obtained in most (95%) through an endoscopic-only approach. Overall, 50% of patients received post-operative radiation therapy. Postoperative complications were limited, with one patient (5%) returning to the OR for control of post-operative oropharyngeal bleeding. On average follow-up of 36 months, 90% of patients were alive with no evidence of recurrence.

Conclusion

In this experience, transoral eHNS provided a safe and consistent surgical approach to management of minor salivary gland malignancies, with low complication rates and good locoregional control. Thus, transoral eHNS may play a valuable role in the multi-disciplinary management of these malignancies.

Trial registration number

None/not applicable

Electronic supplementary material

The online version of this article (doi:10.1186/s41199-017-0024-2) contains supplementary material, which is available to authorized users.

Surgical treatment of salivary malignant tumors

Salivary gland malignant tumors (SGMT) are of key interest for head and neck surgeons since surgery with adjuvant radiotherapy is considered the treatment of choice in most of the cases. Some factors, namely rarity, high histologic heterogeneity, and possible occurrence in all the head and neck subsites, contribute to make this topic very controversial; some unclear aspects pertain surgical treatment. When dealing with major salivary gland malignant tumors (MaSGMT), the most debated issues remain the extent of surgery and management of facial nerve. In minor salivary gland malignant tumors (MiSGMT), conversely, surgical planning is influenced by the specific pattern of growth of the different neoplasms as well as the site of origin of the lesion. Finally, two additional issues, the treatment of the neck (therapeutic or elective) and reconstructive strategy after ablative surgery, are of pivotal importance in management of both MaSGMT and MiSGMT. In this review, we discuss the most relevant and controversial issues concerning surgery of SGMT.

Carbon ion therapy (C12) for high-grade malignant salivary gland tumors (MSGTs) of the head and neck: do non-ACCs profit from dose escalation?

Purpose

To evaluate the use of high-dose radiotherapy using carbon ions (C12) on non-adenoid cystic malignant salivary gland tumors (MSGT).

Patients and methods

Between 2009 and 2013, patients with biopsy-proven non-ACC MSGT histologies of the head and neck received a combined regimen of IMRT plus C12 boost. Treatment toxicity (CTC v3), response (RECIST 1.1), control and survival rates were retrospectively analyzed.

Results

40 patients with pathologically confirmed non-ACC MSGT (T4: 45 %; N+: 40 %; gross residual: 58 %; mucoepidermoid carcinoma (MEC): 45 %; adenocarcinoma: 20 %) were treated with a median of 74 GyE (80 Gy BED). Chemoradiation was given in 5 patients with MEC. Grade III acute toxicity was observed in up to 15 % (mucositis, dermatitis, dysphagia), no higher-grade late toxicity occurred to date. At a follow-up of 25.5 months, LC, and PFS at 2 and 3 years are 81.5 % (LC) and 66.8 % (PFS), OS at 2 and 3 years is 83.6 % and 72.8 %. Most frequent site of disease progression was distant metastasis. Histologic subtype correlated with LC and PFS. Resection status (gross vs microscopic disease) had no significant effect on LC, PFS, or OS.

Conclusion

The treatment is well tolerated, no higher grade late effects were observed. Considering the negative pre-selection, LC, PFS and OS are promising. While histology and site of origin significantly influenced control and survival rates, resection status did not, potentially due to the effect of dose escalation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0657-z) contains supplementary material, which is available to authorized users.

Adenoid cystic carcinoma of the minor salivary glands: a retrospective series of 29 cases and review of the literature

OBJECTIVE

Approximately 78% of minor salivary gland tumors are malignant, of which adenoid cystic carcinoma (ACC) represents 15% in our series. ACC is an uncommon tumor characterized by slow growth and a high potential for recurrence. This series of 29 consecutive patients examines clincopathologic features, management, and survival outcomes.

MATERIALS AND METHODS

This study is a retrospective chart review of 29 patients with ACC of the minor salivary glands in a period of 23 years (1989 and 2012).

RESULTS

The mean age was 61.2 years (16-89 years), with no gender predilection. The majority occurred in the palate/maxilla (66%) and initial presentation was stage IV. Mean follow-up was 42.6 months. Recurrence rate was 10% local, 14% distant over the observation period.

CONCLUSIONS

The palate/maxilla is the preferred location for occurrence, and initial presentation at stage IV is common. Postoperative radiation remains a common strategy to prevent local recurrence in lesions with adverse features.

Adenoid cystic carcinoma of the larynx: A report of two cases

Laryngeal adenoid cystic carcinoma (ACC) is extremely rare, worldwide. From January 1994 to January 2014, all cases of laryngeal ACC that were diagnosed in the four largest hospitals in Hainan province, were reviewed. Only two such cases were identified. The first patient had a tumor in the subglottic region and the second patient, in the glottic region. The patient with subglottic ACC, who had experienced ongoing symptoms for 3 years, had previously been diagnosed with asthma, at a local hospital. Both presented at an advanced stage. The patient with subglottic disease received a total laryngectomy with a positive surgical margin, was treated with adjuvant radiotherapy, and later succumbed to a pleural effusion as a result of pulmonary metastases. The patient with glottic disease received a partial laryngectomy and declined adjuvant radiotherapy. Subsequently, she developed recurrent disease and passed away following an episode of asphyxia at 14 months post-surgery. Each of these cases had a poor prognosis at presentation. For patients with locoregionally advanced laryngeal ACC, more effective management strategies are required.

Glottic-Subglottic adenoid cystic carcinoma. A case report and review of the literature

BACKGROUND

Malignant tumours of minor salivary glands are uncommon, representing only 2-4% of all head and neck cancers. In the larynx, minor salivary gland tumours rarely occur and constitute less than 1% of laryngeal neoplasm. Most of the minor salivary gland tumours arise in the subglottis; however, they can also occur in the supraglottis, in the false vocal cords, aryepiglottic folds and caudal portion of the epiglottis. The most common type of malignant minor salivary gland tumour is adenoid cystic carcinoma.

METHODS

We present a unusual case of adenoid cystic carcinoma of glottic-subglottic region in a 61-year-old woman. Follow-up endoscopy and laryngeal magnetic resonance imaging (MRI) at three years after treatment showed no recurrence of the tumour.

RESULTS

The diagnosis of glottic-subglottic adenoid cystic carcinoma should be considered in patients who are characterized by dyspnea, cough and stridor, but do not respond to pharmacologic approach.

CONCLUSIONS

Adenoid cystic carcinoma is usually a very slow growing cancer, invested by an apparently normal laryngeal mucosa, so that it can show no clear symptoms for a long time. For these reasons the increasing number of diagnostic mistakes or late diagnosis that may be fatal in some cases.

Sinonasal tract and nasopharyngeal adenoid cystic carcinoma: a clinicopathologic and immunophenotypic study of 86 cases

Primary sinonasal tract and nasopharyngeal adenoid cystic carcinomas (STACC) are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. Eighty-six cases of STACC included 45 females and 41 males, aged 12-91 years (mean 54.4 years). Patients presented most frequently with obstructive symptoms (n = 54), followed by epistaxis (n = 23), auditory symptoms (n = 12), nerve symptoms (n = 11), nasal discharge (n = 11), and/or visual symptoms (n = 10), present for a mean of 18.2 months. The tumors involved the nasal cavity alone (n = 25), nasopharynx alone (n = 13), maxillary sinus alone (n = 4), or a combination of the nasal cavity and paranasal sinuses (n = 44), with a mean size of 3.7 cm. Patients presented equally between low and high stage disease: stage I and II (n = 42) or stage III and IV (n = 44) disease. Histologically, the tumors were invasive (bone: n = 66; neural: n = 47; lymphovascular: n = 33), composed of a variety of growth patterns, including cribriform (n = 33), tubular (n = 16), and solid (n = 9), although frequently a combination of these patterns was seen within a single tumor. Pleomorphism was mild with an intermediate N:C ratio in cells containing hyperchromatic nuclei. Reduplicated basement membrane and glycosaminoglycan material was commonly seen. Necrosis (n = 16) and atypical mitotic figures (n = 11) were infrequently present. Pleomorphic adenoma was present in 9 cases; de-differentiation was seen in two patients. Immunohistochemical studies showed positive reactions for pan-cytokeratin, CK7, CK5/6, CAM5.2, and EMA, with myoepithelial reactivity with SMA, p63, calponin, S100 protein and SMMHC. CD117, CEA, GFAP and p16 were variably present. CK20 and HR HPV were negative. STACC needs to be considered in the differential diagnosis of most sinonasal malignancies, particularly poorly differentiated carcinoma, olfactory neuroblastoma and pleomorphic adenoma. Surgery (n = 82), often accompanied by radiation therapy (n = 36), was generally employed. A majority of patients developed a recurrence (n = 52) 2-144 months after initial presentation. Overall mean follow-up was 19.4 years (range 0.4-37.5 years): 46 patients died with disease (mean 6.4 years); 5 were alive with disease (mean 5.4 years), and 35 patients were either alive or had died of unrelated causes (mean 16.3 years). ACC of the SNT is uncommon. Recurrences are common. The following parameters, when present, suggest an increased incidence of either recurrence or dying with disease: mixed site of involvement, high stage disease (stage IV), skull base involvement, tumor recurrence, a solid histology, perineural invasion, bone invasion, and lymphovascular invasion.

Postoperative 125I brachytherapy delivered by digital model obturators for recurrent or locally advanced maxillary cancers

OBJECTIVES/HYPOTHESIS

We aimed to evaluate the feasibility and effectiveness of postoperative (125) I brachytherapy delivered by use of digital model obturators for recurrent or locally advanced maxillary cancers.

STUDY DESIGN

Retrospective study.

METHODS

From 2006 to 2008, 12 patients (seven females; median age, 65 years; range, 22-86 years) with recurrent or locally advanced maxillary cancers showing positive margins after surgery underwent (125) I brachytherapy by use of digital model obturators and interstitial implants. The radioactivity was 18.5 to 33.3 MBq per seed, and the prescription dose was 80 to 160 Gy. Functional outcome of patients was evaluated by the Performance Status Scale (PSS) for head and neck cancer before and after brachytherapy.

RESULTS

The (125) I seeds and dosages were well distributed in the radiation fields, and all patients had higher PSS scores after than before treatment with obturators. During a median follow-up of 53 months (range, 28-62 months), local control at 3 and 5 years was 83.3% and 66.7%, respectively, with a mean local control time of 53.5 ± 3.79 months. Overall survival at 3 and 5 years was 91.7% and 71.4%, respectively, with a mean survival time of 56.6 ± 2.99 months. Two patients died due to local recurrence, and one patient died due to lung metastasis. No patient had severe complications during follow-up.

CONCLUSIONS

(125) I brachytherapy delivered by digital model obturator is effective in treating maxillary cancers with positive margins after maxillectomy for advanced or recurrent cancer. The method may improve the quality of life of patients with maxillary defects. Laryngoscope, 2012.

Unique presentation of adenoid cystic carcinoma in postcricoid region: a case report and review of the literature

Malignant tumors of minor salivary glands are uncommon, representing only 2-4% of all head and neck malignancies. In the larynx, minor salivary gland tumors rarely occur and constitute less than 1% of laryngeal tumors. Most of the minor salivary gland tumors arise in the subglottis; however, they can also occur in the supraglottis in the false vocal cords, aryepiglottic folds, and caudal aspect of the epiglottis. The most common type of malignant minor salivary gland tumor is adenoid cystic carcinoma. In the last 20 years, only 40 cases of adenoid cystic carcinoma arising in variable locations of the larynx have been reported in the English language literature. We present a case of adenoid cystic carcinoma of the larynx arising in the inter-arytenoid and postcricoid region in a 54-year-old woman. To our knowledge, this is the first case of adenoid cystic carcinoma arising in this particular region of the larynx.

The range and demographics of salivary gland tumours diagnosed in a UK population

Salivary gland tumours are relatively rare and comprise a diverse range of neoplasms. The aim of this study was to determine the range and demographics of all histologically diagnosed salivary tumours in a European population. All entries for salivary gland tumours from 1974 to 2005 inclusive were retrieved and analysed for each diagnosis including number of specimens, male:female ratio and age range. These data were then analysed for the distribution of benign and malignant salivary tumours in major and minor salivary glands. 58,880 specimens were received; of these, 741 cases (1.3% of all specimens) were diagnosed as salivary gland tumours with a male to female ratio of 0.7:1. There were 481 (64.9%) benign and 260 (35.1%) malignant neoplasms, with the most common tumours being pleomorphic adenoma and mucoepidermoid carcinoma, respectively. Our study provides demographic data on a large series of salivary gland tumours in a European population. Accurate diagnosis is essential as salivary lesions have diverse clinical and prognostic outcomes. This study has confirmed that some tumours have a predilection for certain sites and that the risk of malignant disease is also greater at specific sites within the oral cavity.

The homeobox HOXB13 is expressed in human minor salivary gland

BACKGROUND

Homeobox are a family of developmental genes involved in morphogenesis and cellular differentiation. Participation of homeobox within normal and malignant tissue has been recently discussed in the literature.

OBJECTIVE

To analyze the presence of HOXB13 transcript expression in human minor salivary gland.

MATERIAL AND METHODS

Ten-micrometer sections from frozen samples were evaluated employing non-radioactive in situ hybridization technique and HOXB13 mRNA probes.

RESULTS

HOXB13 was found to be expressed in ducts and mucous acini but not in serous acini.

CONCLUSIONS

RESULTS suggest that HOXB13 transcripts are differently expressed in normal mucous and serous acini, and it may possibly reflect a different role in salivary gland carcinogenesis.

Mucoepidermoid carcinoma of the salivary glands. Review of the literature and clinicopathological analysis of 18 patients

Salivary gland carcinomas are a rare and clinically diverse group of neoplasms among which mucoepidermoid carcinomas (MEC) are reported to be the most frequently encountered. During the years 1994-2004 18 patients with MEC were treated in our Department. All patients underwent surgery with a curative intent, and in 11 of them treatment was supplemented by radiotherapy. Follow up ranged from 6 to 120 months. Twelve (66.6%) MECs originated from the major salivary glands with the majority located in the parotid. Histologically, 50% of tumors were classified as low grade, 28% as intermediate and 22% as high-grade MECs. Positive surgical margins were documented in six cases (33%) and all in tumors of high or intermediate histological grade. All these patients received adjuvant radiotherapy and one developed local recurrence. Local recurrence occurred in two more patients with histologically free margins. Both received postoperative radiotherapy. Distant metastases were documented in four patients all between 14 and 24 months after surgical treatment. An association between local recurrence and distant metastasis might be suggested since all patients with local recurrences subsequently developed distant metastases. The 5-year overall disease specific survival rate was 85%. Statistical multivariate analysis demonstrated that the factor that significantly correlated with overall survival was the histological grade of tumors (Log Rank test: p=0.013). A trend towards poorer survival was observed in patients aged over 50 years. Our results also suggested a potential benefit of postoperative radiotherapy for patients with positive margins.

p63 Immunohistochemistry in the distinction of adenoid cystic carcinoma from basaloid squamous cell carcinoma

Morphologic distinction of high-grade adenoid cystic carcinoma from basaloid squamous cell carcinoma can be difficult. Equivocal diagnoses can mislead treatment. We have investigated the possibility that immunohistochemical staining for the presence of p63, a novel epithelial stem-cell regulatory protein, could be a useful means of distinguishing these two neoplasms. Archival, routinely processed slides were subjected to citrate-based antigen retrieval, exposure to anti-p63 monoclonal 4A4, and developed with a streptavidin-biotin kit and diaminobenzidine as chromogen. p63 was detected in 100% of the adenoid cystic carcinomas (n=14) and 100% of basaloid squamous cell carcinomas (n=16). Basaloid squamous cell carcinomas consistently displayed diffuse p63 positivity, with staining of nearly 100% of tumor cells. In contrast, adenoid cystic carcinoma displayed a consistently compartmentalized pattern within tumor nests. Compartmentalization was manifested in two patterns: (1) selective staining of a single peripheral layer of p63-positive cells surrounding centrally located tumor cells that were p63-negative and (2) tumor nests consisting of multiple contiguous glandular/cribriform-like units of p63-positive cells surrounding or interspersed with p63-negative cells. p63 immunostaining constitutes a specific and accurate means of distinguishing adenoid cystic carcinoma from basaloid squamous cell carcinoma. p63 positivity in adenoid cystic carcinoma appears to be homologous to that seen in the basal and/or myoepithelial compartments of salivary gland and other epithelia, and may signify a stem-cell-like role for these peripheral cells. Diffuse p63 positivity in basaloid squamous cell carcinoma suggests dysregulation of p63-positive stem cells in poorly differentiated squamous carcinoma.

Post-operative treatment of malignant salivary gland tumours of the palate with iodine-125 brachytherapy

BACKGROUND AND PURPOSE

Malignant minor salivary gland tumours are usually small and clinically indistinguishable from benign lesions. Surgery is the treatment of choice with post-operative radiotherapy for involved margins or unfavourable histology. We assessed the results of a series of such patients treated with iodine-125 brachytherapy in the form of a temporary applicator or implant.

PATIENTS AND METHODS

There were nine patients with T1/T2 tumours of the hard and/or soft palate that had been excised. All had close or involved margins. Six were treated with a dental applicator alone, two with an applicator and additional I-125 seeds in tubes and one with an implant alone. The applicator consists of two layers of plastic made from a dental impression enclosing a predetermined number of I-125 seeds, 9-39, glued to one surface and a layer of ash metal to protect the tongue. It was inserted 1-3 months post-operatively and delivered 35-62 Gy, median 56 Gy, at 5-7 mm depth over 58-156 h, median 120 h, at 0.26-0.67 Gy/h, median 0.45 Gy/h.

RESULTS

The patients have been followed up for 32-158 months, median 50 months, and there were no recurrences. The applicator was well tolerated. A confluent mucositis developed which lasted 3-4 weeks. One patient developed a mucosal ulcer which healed spontaneously.

CONCLUSIONS

Brachytherapy is an effective way of delivering post-operative radiotherapy to the hard and soft palate in patients with malignant salivary gland tumours that have been incompletely excised or have unfavourable histology. Local control is excellent, treatment time is short and morbidity is minimal.

Factores pronósticos en el carcinoma adenoide quístico de glándulas salivares

OBJECTIVE

Adenoid cystic carcinoma (ACC) is a relatively rare tumor which is characterized by its long clinical history, with multiple recurrences and late distant metastasis. The aim of the present study is to show our experience in the management of this tumor and the relationship of different clinico-pathological parameters with its prognosis.

MATERIAL AND METHODS

A retrospective study was carried out between 1984 and 2004 in 28 patients with ACC of the salivary glands, analyzing the most outstanding clinico-pathological variables in this tumor related to the prognosis of the tumor and the survival.

RESULTS

The overall survival rates at 5, 10 and 15 years were 88%, 69% and 52% respectively. Ten (36%) patients presented local recurrence and 10 (36%) presented distant metastasis (four of which also have local recurrence). Although the differences were not statistically significant, the patients with solid histological subtype (p=0.17), with positive margins status (p=0.2), with perineural invasion (p=0.59), and those treated with surgery alone (p=0.19), presented a worse survival.

DISCUSSION/CONCLUSION

Our study confirms that the ACC is a tumor with a high tendency to local recurrence and development of distant metastasis, even long term, which means a close follow-up for life. Nevertheless, it also demonstrates that acceptable survival rates can be obtained with aggressive treatment.

Role for Postoperative Radiation Therapy in Adenoid Cystic Carcinoma of the Head and Neck

OBJECTIVE

Clarify the role for postoperative radiation for adenoid cystic carcinoma (ACC) of the head and neck as it relates to tumor site, T-stage, and surgical margin status.

STUDY DESIGN

Retrospective cohort study at an academic tertiary care hospital.

METHODS

A review of 129 patients with biopsy-proven ACC was performed. Previous treatment failures and nonoperative candidates were excluded, with 75 patients considered eligible for further study. Patients were grouped according to treatment modality and Kaplan-Meier estimates of overall survival, locoregional control, and distant control were compared using log-rank tests. Patients were also stratified according to tumor site, T-stage, and surgical margin status, and pair-wise comparisons of treatment outcome within each group were performed using Wald tests from Cox proportional hazards models.

RESULTS

Twenty-five patients were treated with surgery alone, and 50 were treated with surgery and postoperative radiation. There was no significant difference in outcome between treatment groups when correlated with tumor site (P =.89). However, postoperative radiation was associated with improved overall survival for advanced T-stage (T4) tumors (P =.019) and greater locoregional control for patients with microscopically positive margins (P =.018). There was no demonstrated benefit of postoperative radiation for patients with microscopically negative margins (P =.93).

CONCLUSIONS

The findings of this study suggest that advanced T-stage and positive microscopic margins are important factors in determining the necessity for postoperative radiation therapy for ACC of the head and neck and that radiation therapy may not be necessary for patients with early T-stage tumors and negative surgical margins.

Salivary gland neoplasms

Treatment and cure of salivary gland neoplasms requires surgical intervention in most cases. For parotid neoplasms, the most common surgical procedure performed is the superficial parotidectomy with facial nerve preservation. Postoperative radiation therapy is indicated in high-grade salivary gland malignancies and malignancies with increased risk of locoregional recurrence. Primary radiation, including neutron beam techniques, may play a role in certain histologic types or nonoperative candidates. Chemotherapy has yet to result in improvements in survival or quality of life in the treatment of salivary gland malignancy. Advances in radiation therapy techniques, including intensity-modulated radiation therapy, provide opportunities for reduced morbidity.

Adenoid cystic carcinoma of the base of the tongue

A retrospective review of 14 patients with adenoid cystic carcinoma of the tongue treated between 1955 and 1997 was performed. Treatment consisted of surgery (n = 2), radiotherapy (n = 2), chemotherapy (n = 1), or combination therapy (n = 9). The 2-, 5-, and 10-year absolute survival rates were 92%, 79%, and 63%, respectively. Seventy-five percent of the patients who died of cancer succumbed to distant metastases. However, long-term survival was common despite a high incidence of local and distant recurrence. The presence of positive surgical margins, the incidence of regional metastases, the incidence of perineural invasion, the initial stage of disease, and the eventual development of locoregional recurrence and distant metastases did not significantly alter the survival rate. Surgical extirpation combined with postoperative radiotherapy is advocated for the treatment of adenoid cystic carcinoma of the tongue. Given the indolent nature of this disease process, surgery should be directed toward conservation of speech and swallowing function.

Treatment of locally advanced adenoid cystic carcinoma of the head and neck with neutron radiotherapy

PURPOSE

To examine the efficacy of fast neutron radiotherapy for the treatment of locally advanced and/or recurrent adenoid cystic carcinoma of the head and neck and to identify prognostic variables associated with local-regional control and survival.

METHODS AND MATERIALS

One hundred fifty-nine patients with nonmetastatic, previously unirradiated, locally advanced, and/or recurrent adenoid cystic carcinoma (ACC) of the head and neck region were treated with fast neutron radiotherapy during the years 1985-1997. One hundred fifty-one patients had either unresectable disease, or gross residual disease (GRD) after an attempted surgical extirpation. Eight patients had microscopic residual disease and were analyzed separately. Sixty-two percent of patients had tumors arising in minor salivary glands, 29% in major salivary glands, and 9% in other sites such as the lacrimal glands, tracheal-bronchial tree, etc. Fifty-five percent of patients were treated for postsurgical recurrent disease and 13% of patients had lymph node involvement at the time of treatment. The median duration of follow-up was 32 months (range 3-142 months). Actuarial curves for survival, cause-specific survival, local-regional control, and the development of distant metastases are presented for times out to 11 years.

RESULTS

The 5-year actuarial local-regional tumor control rate for the 151 patients with GRD was 57%; the 5-year actuarial overall survival rate was 72%; and the 5-year actuarial cause-specific survival rate was 77%. Variables associated with decreased local-regional control in the patients with GRD as determined by multivariate analysis included base of skull involvement (p < 0.01) and biopsy only versus an attempted surgical resection prior to treatment (p = 0.03). Patients without these negative factors had an actuarial local-regional control rate of 80% at 5 years. Patients with microscopic residual disease (n = 8) had a 5-year actuarial local-regional control rate of 100%. Base of skull involvement (p < 0.001), lymph node metastases at the time of treatment (p < 0.01), biopsy only prior to neutron radiotherapy (p = 0.03), and recurrent tumors (p = 0.04) were found to be associated with a diminished cause-specific survival as ascertained by multivariate analysis. Patients with base of skull involvement and positive lymph nodes at presentation had an increased rate of the development of distant metastases at 5 years, (p < 0.01 and p < 0.001, respectively). No statistical difference in outcome was observed between major and minor salivary gland sites.

CONCLUSIONS

Fast neutron radiotherapy is an effective treatment for locally advanced ACC of the head and neck region with acceptable toxicity. Further improvements in local-regional control are not likely to impact survival until more effective systemic agents are developed to prevent and/or treat distant metastatic disease.

Postoperative irradiation of minor salivary gland malignancies of the head and neck

OBJECTIVES

(1) To review the Stanford experience with postoperative radiotherapy for minor salivary gland carcinomas of the head and neck. (2) To identify patterns of failure and prognostic factors for these tumors.

MATERIALS AND METHODS

Fifty-four patients with localized tumors were treated with curative intent at Stanford University between 1966 and 1995. The 1992 AJCC staging for squamous cell carcinomas was used to retrospectively stage these patients. Thirteen percent had stage I, 22% stage II, 26% stage III, and 39% stage IV neoplasms. Thirty-two patients (59%) had adenoid cystic carcinoma, 15 (28%) had adenocarcinoma, and seven (13%) had mucoepidermoid carcinoma. Thirty (55%) had positive surgical margins and seven (13%) had cervical lymph node involvement at diagnosis. The median follow-up for alive patients was 7.8 years (range: 25 months-28.9 years).

RESULTS

The 5- and 10-year actuarial local control rates were 91 and 88%, respectively. Advanced T-stage (T3-4), involved surgical margins, adenocarcinoma histology, and sinonasal and oropharyngeal primaries were associated with poorer local control. The 5- and 10-year actuarial freedom from distant metastasis were 86 and 81%, respectively. Advanced T-stage (T3-4), lymph node involvement at diagnosis, adenoid cystic and high-grade mucoepidermoid histology were associated with a higher risk of distant metastases. The 10-year cause-specific survival (CSS) and overall survival (OS) were 81 % and 63%, respectively. On multivariate analysis, prognostic factors affecting survival were T-stage (favoring T1-2), and N-stage (favoring NO). When T- and N-stage were combined to form the AJCC stage, the latter became the most significant factor for survival. The 10-year OS was 86% for stage I-II vs. 52% for stage III-IV tumors. Late treatment-related toxicity was low (3/54); most complications were mild and no cranial nerve damage was noted.

CONCLUSIONS

Surgical resection and carefully planned post-operative radiation therapy for minor salivary gland tumors is well tolerated and effective with high local control rates. AJCC stage was the most significant predictor for survival and should be used for staging minor salivary gland carcinomas.

A clinicopathologic study of 196 intraoral minor salivary gland tumours

We present a retrospective study of 196 patients with intraoral minor salivary gland tumours, 128 malignant and 68 benign, diagnosed from 1954 to 1993 in the A. C. Camargo Hospital, São Paulo, Brazil. Sixty-five percent of the cases occurred in the palate, followed by tongue (9.7%) and retromolar area (6.1%). Pleomorphic adenoma was the most common benign tumour, and mucoepidermoid carcinoma was predominant among the malignant tumours. Surgery was the main treatment method and postoperative radiotherapy and radiotherapy alone were used in 40 and 15 patients, respectively. Local recurrence was observed in two patients with pleomorphic adenoma and in eight patients with malignant tumours. Regional lymph node metastases occurred in four cases and distant metastases in five. Forty-six of 47 patients with benign tumours who were followed up from 1 to 7 years were alive without disease. Twenty-four of 79 patients with malignant tumours who were followed up for at least 5 years died due the tumour and 47 were alive without disease.

Multivariate survival analysis of 128 cases of oral cavity minor salivary gland carcinomas

BACKGROUND

Minor salivary gland carcinomas are uncommon tumors of the oral cavity. The decision regarding treatment remains controversial. The main objective of this paper is to report on the survival results of 128 patients treated in a single institution.

METHODS

Tumor sites were: hard palate (62 cases), tongue (16 cases), buccal mucosa (13 cases), soft palate (12 cases), and other sites (25 cases). The most common histology was mucoepidermoid carcinoma (76 cases). Clinically metastatic lymph nodes were palpable in 21 patients. Cox regression technique was used to construct the mathematical-statistical models, aiming to predict the risks of recurrence and of death as functions of the different variables under study.

RESULTS

The 5-year overall survival rates were, respectively, 85.9% and 87.7% in the groups of patients treated by surgery or combined therapy. There were significant differences in survival rates according to N stage, bone involvement, tumor histology, sex, and type of surgery.

CONCLUSIONS

Most of the recurrences were at the site of primary tumor; neck metastases were rare at presentation and after initial treatment. Prognosis involves several factors related to stage, histology, and treatment.

Neutron therapy in malignant salivary gland tumors: results at European centers

Malignant salivary gland tumors are relatively rare and account for only 3%-4% of all head and neck cancers. Especially in adenoid cystic carcinoma, the incidence of local recurrence and distant metastases is influenced by the perineural spread of tumor. In advanced salivary gland tumors, surgery alone has a high incidence of local failure. The results of conventional radiotherapy are suboptimal in inoperable or not completely resected salivary gland tumors and in recurrent disease. The pooled data of some international series for low linear energy transfer radiation show a local control of only 28%. Especially in advanced salivary gland tumors, neutron therapy can improve local control. In Europe at least 570 patients with salivary gland tumors have been treated with neutrons alone or with combined modalities. The clinical data of different centers in Europe and the United States result in a similar local control rate of 67% in gross disease. An analysis of different European series shows on average a complication rate of 10.6% for severe radiation-related morbidity. Modern neutron machines and the use of three-dimensional treatment planning systems are now available in a few institutions and may further reduce side effects.

Neutron radiotherapy for adenoid cystic carcinoma of minor salivary glands

PURPOSE

To examine the efficacy of fast neutron radiotherapy for the treatment of patients with locally advanced, adenoid cystic carcinoma of minor salivary glands and to identify prognostic variables associated with local control, overall survival, and cause specific survival.

METHODS AND MATERIALS

Eighty-four patients having adenoid cystic carcinoma of minor salivary glands were treated with fast neutron radiotherapy during the years 1985-1994. All patients had either unresectable disease or gross disease remaining after attempted surgical extirpation. Seventeen patients had previously received conventional radiotherapy and their subsequent treatment fields and doses for neutron radiotherapy were modified for critical sites (brainstem, spinal cord, brain). Although the median doses (tumor maximum and tumor minimum) only varied by < or = 10%, treatment portals were substantially smaller in these patients because of normal tissue complication considerations. Twelve patients (13%) had distant metastases at the time of treatment and were only treated palliatively with smaller treatment portals and lower median tumor doses (< or = 80% of the doses delivered to curatively treated patients). Seventy-two patients were treated with curative intent, with nine of these having recurrent tumors after prior full-dose radiotherapy. The median duration of follow-up at the time of analysis was 31.5 months (range 3-115). Sites of disease and number of patients treated per disease site were as follows: paranasal sinus-31; oral cavity-20; oropharynx-12; nasopharynx-11; trachea-6; and other sites in the head and neck-4.

RESULTS

The 5-year actuarial local-regional tumor control rate for all patients treated with curative intent was 47%. Patients without involvement of the cavernous sinus, base of skull, or nasopharynx (51 patients) had a 5-year actuarial local-regional control rate of 59%, whereas local-regional control was significantly lower (15%) for patients with tumors involving these sites (p < 0.005). In the latter cases, normal tissue injury considerations precluded delivery of the full dose to the entire tumor. Patients with no history of prior radiotherapy (63 patients) had an actuarial local control rate of 57% at 5 years compared to 18% for those (9 patients) who had been previously irradiated with conventional photons (p = 0.018). Eliminating the dose-limiting factors of prior radiation therapy and/or high risk sites of involvement, the 5-year actuarial local-regional control rate for these 46 patients was 63%, with an actuarial cause specific survival rate of 79%. Lymph node status was a predictor of distant metastasis: 57% of node positive patients developed distant metastases by 5 years compared to 15% of patients with negative nodes (p < 0.0005), and patients who had nodal involvement developed distant metastases sooner than node negative patients (p < 0.0001). The 5-year actuarial overall survival and cause specific survival for the 72 patients treated with curative intent were 59% and 64%, respectively.

CONCLUSIONS

Fast neutron radiotherapy offers high local-regional control and survival rates for patients with locally advanced, unresectable adenoid cystic carcinomas of minor salivary glands. It should be considered as initial primary treatment for these patients, as well as for other patients in whom surgical extirpation would cause considerable morbidity.

Metastatic adenocarcinoma of a minor salivary gland in a cat

Neoplasms derived from salivary glands are uncommon in domestic animals and descriptions of neoplasms derived from minor salivary glands are quite rare. A primary neoplasm derived from a minor salivary gland is described in a 13-year-old domestic shorthair cat. The oral neoplasm was locally invasive, and had metastasized to the regional lymph nodes and hilus of the lungs.