minor_salivary_port.jpg (11363 bytes) Cancer of the minor salivary gland is uncommon, the palate is the most common site of minor salivary gland tumors. Approximately 35% to 40% of submandibular tumors, 50% of palate tumors, and 95% to 100% of sublingual gland tumors are malignant. The prognosis is more favorable when the tumors are in the major salivary glands, particularly the parotid; less favorable when in the submandibular gland; and least favorable when in the sublingual or a minor salivary gland.

see results of treatment with radiation for minor salivary glands
see review here

radiation field for treatment of adenoid cystic cancer of the hard palate.

 the NCCN commonly recommends postOp irradiation (go here)
Surgery alone may be used to treat early-stage hard palate lesions without evidence of positive margins, perineural spread, or bone invasion, especially in young patients. Soft palate lesions may be treated with irradiation alone, as may early hard palate lesions, even if limited bone involvement is present. Although surgery is generally given first consideration, for early lesions, in which this modality would cause significant functional or cosmetic morbidity, irradiation alone may be used as an alternative. The radiation therapy technique for treating minor salivary gland tumors depends on the area involved and is similar to the treatment for squamous cell carcinomas in these areas, with two significant exceptions. For adenoid cystic carcinomas, which have a high propensity for perineural invasion and local spread for considerable distances, coverage of major nerve trunks to the base of skull is emphasized, especially for palate lesions. Also, because the incidence of lymph node metastases is generally lower than that for squamous cell carcinomas of similar size, the radiation therapy fields are rarely extended to cover such areas if there are no palpable lymph node metastases. When a named branch of a cranial nerve is involved by adenoid cystic carcinoma, the nerve pathways to the base of the skull should be electively treated. When only focal perineural invasion of small unnamed nerves is present, treatment of the base of the skull depends on the site. For tumors of the palate or paranasal sinuses, the base of the skull is included because of its proximity to the tumor bed. For patients receiving postoperative irradiation after surgical resection, a dose of 60 Gy is given for negative margins and 66 Gy for microscopically positive margins. For gross residual disease after surgery or for lesions treated with irradiation alone, a total dose of 70 Gy is used at 2 Gy per fraction.
see recent literature on the use of radiation for minor salivary gland cancers

Management of adenoid cystic carcinoma of minor salivary glands. Triantafillidou K  J Oral Maxillofac Surg. 2006 Jul;64(7):1114-20.

PURPOSE: Adenoid cystic carcinoma (ACC) is a rare malignant tumor originating from the salivary glands. The characteristic clinicopathologic features of this tumor are perineural spread, local recurrences, and distant metastases. Radical surgery combined with radiotherapy, as mentioned in the literature, is the best method of treatment. This clinical review article is intended to analyze the outcome of management of a group of 22 ACC patients, who were treated in our clinic. METHODS: Between 1985 and 2000, 22 patients with ACC of minor salivary glands were treated in the Clinic of Oral and Maxillofacial Surgery of the "G. Papanikolaou" General Hospital, in Thessaloniki. The age range was 22 to 87 years. The distribution of the primary sites was buccal mucosa (3), floor of the mouth (1), hard palate (3), soft palate (2), junction of hard and soft palate (7), and hard or soft palate with spread in the paranasal sinus etc (6). All the patients were treated radically with surgery. The surgery was combined with radiotherapy in 17 patients. A total dose of 60 Gy in a 30- to 40-day period was given, using conventional 2 Gy fractions per day. Immunohistochemical assay of the expression of the Ki-67 antigen was performed on a subset of 15 cases. RESULTS: The mean follow-up range was 4 to 14 years. From the 22 patients, 15 (68.18%) were alive for more than 5 years and 6 (27.7%) had died from the disease. Eight patients were free of the disease for more than 5 years (ranging from 7 to 14), 4 patients were free of the disease for 5 years, and 3 patients were free of the disease for 4 years. One patient lived more than 10 years and died from another cause. Local recurrence was developed in 2 patients. One recurrence occurred within the first year after the treatment and the second local recurrence occurred 13 years after the initial treatment. Lymph node metastases occurred in 2 patients, 3 years and 7 years after completing the treatment. Distant metastases (lung) occurred in 2 patients, 2 years and 6 years after completing the treatment. The Mann-Whitney statistical analysis was used for comparing the Ki-67 values in correlation with prognosis and location of ACCs. The Ki-67 value was significantly higher in tumors from patients with treatment failure than in nonfailures (P < .001). The Ki-67 expression was also higher in large tumors characterized by wide topical spread (P < .005). CONCLUSIONS: The most proper method of treatment for ACC seems to be radical resection combined with radiotherapy. The treatment failure is associated with positive margins of the excised surgical specimen and named nerve involvement. The immunohistochemical study of Ki-67 e

Int J Radiat Oncol Biol Phys 2001 Nov 15;51(4):952-8

Postoperative radiotherapy for malignant tumors of the submandibular gland.

Storey MR, Garden AS, Morrison WH, Eicher SA, Schechter NR, Ang KK

Department of Radiation Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, TX, USA

Cancers originating from the submandibular gland are uncommon and can represent a broad spectrum of disease. They represent approximately 15–20% of malignant tumors of major salivary glands. Surgery is generally accepted as the primary treatment for submandibular gland cancers. However, the locoregional control rate is less than 50% in patients with adverse features if no adjuvant treatment is delivered. These features include extraglandular extension, positive margin, locally recurrent disease after a previous surgical procedure, perineural invasion, and the presence of advanced nodal disease. At the University of Texas M. D. Anderson Cancer Center (MDACC), we have selectively irradiated patients with high-risk features.This retrospective study assessed the outcome and patterns of failure for patients with malignant submandibular tumors treated with surgery and postoperative radiation.Methods and Materials: Between 1965 and 1995, 83 patients aged 11-83 years old received postoperative radiotherapy after resection of submandibular gland carcinomas. The most common radiation technique was an appositional field to the submandibular gland bed using electrons either alone or mixed with photons. Primary tumor bed doses ranged from 50 to 69 Gy (median, 60 Gy). Regional lymph nodes (ipsilateral Levels I-IV) were irradiated in 66 patients to a median dose of 50 Gy. Follow-up time ranged from 5 to 321 months (median, 82 months).Results: Actuarial locoregional control rates were 90%, 88%, and 88% at 2, 5, and 10 years, respectively. The corresponding disease-free survival rates were 76%, 60%, and 53%, because 27 of 74 patients (36%) who attained locoregional control developed distant metastases. Adenocarcinoma, high-grade histology, and treatment during the earlier years of the study were associated with worse locoregional control and disease-free survival. The median survival times for patients with and without locoregional control were 183 months and 19 months, respectively. Actuarial 2-, 5-, and 10-year survival rates were 84%, 71%, and 55%, respectively. Late complications occurred in 8 patients (osteoradionecrosis, 5 patients).Conclusions: High-risk cancers of the submandibular gland have a historic control rate of approximately 50% when treated with surgery alone. In the current series, locoregional control rates for high-risk patients with submandibular gland cancers treated with surgery and postoperative radiotherapy were excellent, with an actuarial locoregional control rate of 88% at 10 years.

Cancer 1994 May 15;73(10):2563-9

Postoperative radiation therapy for malignant tumors of minor salivary glands. Outcome and patterns of failure.

Garden AS, Weber RS, Ang KK, Morrison WH, Matre J, Peters LJ

Department of Radiotherapy, University of Texas, M.D. Anderson Cancer, Houston 77030.

In the treatment of major salivary gland cancers, the addition of adjuvant postoperative radiation therapy for patients with high risk features has been shown to reduce the incidence of local failure. This retrospective study was done to determine the effectiveness of this approach for minor salivary gland cancers, to document patterns of failure, and to define prognostic variables for treatment outcome. METHODS. Between 1961 and 1990, 160 patients received postoperative radiation at the University of Texas M. D. Anderson Cancer Center (UTMDACC) after gross total removal of their tumors. These operations ranged from excisional biopsies to craniofacial resections with orbital exenterations depending on the original site and size of the tumor. The primary tumor site was in the oral cavity-oropharynx in 111 patients and in the nasal cavity or paranasal sinuses in 46 patients. The most prevalent histologic type was adenoid cystic carcinoma (71%). Microscopic positive margins were present in 64 (40%) patients. Half of the patients had pathologic evidence of perineural invasion. Radiation therapy techniques varied, depending on the site and extent of disease and the era of treatment. Doses ranged from 50 to 75 Gy (median, 60 Gy; mean 59.2 Gy). Follow-up for surviving patients ranged from 24 to 270 months (median, 110 months). RESULTS. Fifty-seven (36%) patients experienced disease relapse. Nineteen (12%) patients had a local recurrence: 6 within 5 years of treatment, 8 between 5 and 10 years, and 5 after 10 years. Regional failures occurred in 3 of 13 patients with initially node-positive disease but were uncommon (less than 5%) in patients with node-negative disease, regardless of elective neck treatments. Distant metastases developed in 43 patients, mostly (79%) within 5 years of treatment. Actuarial overall survival rates at 5, 10, and 15 years were 81%, 65%, and 43%, respectively. Complications occurred in 51 patients and were of three predominate types: hearing loss (26 patients), ocular injury (15 patients), and bone exposure/necrosis (12 patients). Improved techniques, including better immobilization, customized beam shaping, and treating multiple fields per day, have substantially reduced the risk of serious complications during the past decade. CONCLUSIONS. Postoperative radiation therapy is effective in preventing local recurrence in most patients with minor salivary gland tumors after gross total excision. When local failure occurs, it tends to be a late event. For most patients, the authors recommend a postoperative dose of 60 Gy in 30 fractions to the operative bed; if there is named nerve invasion, the path of the nerve is treated electively to its ganglion.

Int J Radiat Oncol Biol Phys 1996 Jun 1;35(3):443-54

Management of minor salivary gland carcinomas.

Parsons JT, Mendenhall WM, Stringer SP, Cassisi NJ, Million RR

Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, USA.

PURPOSE: To assess the role of radiotherapy alone or in combination with surgery in the treatment of patients with malignant minor salivary gland carcinomas. METHODS AND MATERIALS: Between October 1964 and November 1992, 95 patients with minor salivary gland carcinomas of the head and neck received radiotherapy with curative intent. Eighty-seven patients were previously untreated, and 8 were treated for postsurgical recurrence. Fifty-one patients were treated with radiotherapy alone, and 44 were treated by surgical resection plus radiotherapy. Patients were staged according to the 1983 American Joint Committee on Cancer (AJCC) staging criteria for squamous cell carcinomas. RESULTS: The 20-year actuarial rate of local control was 57% with no significant difference according to histologic type. When tumor stage was taken into consideration, there were no significant differences in local control according to tumor site. The 12-year actuarial probability of distant metastases was 40% (19% as the only site of failure). In multivariate analyses, local control was significantly affected only by tumor stage and treatment type (combined therapy better than radiotherapy alone); tumor stage was a significant predictor of cause-specific survival and freedom from relapse. Freedom-from-relapse rates were higher for patients who received combined treatment (p = 0.068). CONCLUSIONS: Treatment of minor salivary gland carcinomas is usually by combined surgery and radiotherapy, but there are situations where surgery alone or radiotherapy alone may be used. The ability to control these tumors with radiotherapy alone is not widely recognized. In the present series, the tumor was locally controlled in 20 patients with previously untreated primary lesions after radiotherapy alone (2.5 to 21 years) and in 4 other patients who were treated by radiotherapy alone for postsurgical recurrent tumor (3.5 to 14 years after radiotherapy). Contrary to the widely held belief that local recurrence after radiotherapy eventually develops in all patients with adenoid cystic carcinoma, local control has been maintained in 13 patients after radiotherapy alone; 5 of the 13 patients have been observed for 10 to 17 years.

Radiother Oncol 1999 Aug;52(2):165-71

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

Le QT, Birdwell S, Terris DJ, Gabalski EC, Varghese A, Fee We Jr, Goffinet DR

Department of Radiation Oncology, Stanford University Hospital, CA 94305-5105, USA.

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.

Am J Otolaryngol 1989 Jul-Aug;10(4):250-6

Minor salivary gland tumors: the role of radiotherapy.

Jenkins DW, Spaulding CA, Constable WC, Cantrell RW

Division of Therapeutic Radiology and Oncology, University of Virginia Health Sciences Center, Charlottesville 22908.

Previous analyses of minor salivary gland tumors (MSGTs) have not clearly established the role of radiotherapy in their treatment. The following is a retrospective review of 44 patients treated from 1956 to 1984 with MSGT of the maxillary sinus (15 of 44), nasal cavity/ethmoid complex (six of 44), or hard palate (23 of 44). Histological findings included adenocarcinoma (18), adenoid cystic (17), high-grade mucoepidermoid (six), and mixed malignant (three). Treatment was by surgery (18 of 44), radiotherapy (eight of 44), or a combination of both (18 of 44). Patients treated with radiotherapy, either alone or combined with surgery, had disease that was inoperable, marginally resectable, or residual after surgery. Despite this handicap, 3-year local control rates for all treatment modalities were similar (surgery, 78%; radiotherapy, 63%; and combined treatment, 83%). Absolute 3-year survival rates were 94% for surgery, 63% for radiotherapy, and 78% for combined therapy, with death attributable to distant metastases a significant factor in the advanced cases treated with radiotherapy. A dose response relationship was apparent in those patients whose treatment involved radiotherapy. Clearly, MSGTs are radioresponsive lesions and radiotherapy can play an important role in their management.

J Oral Maxillofac Surg 1996 Apr;54(4):448-53

Carcinoma of the minor salivary glands: results of surgery and combined therapy.

Chou C, Zhu G, Luo M, Xue G

Department of Oral and Maxillofacial Surgery, Shanghai Tiedao University College of Medicine, China.

PURPOSE: This article reports the results of treatment of 7 histologic types of minor salivary gland carcinoma. PATIENTS AND METHODS: Of 256 cases, local excision was used in 194, extended excision in 62, excision accompanied by neck dissection in 98, and surgery with adjunctive radiation therapy or chemotherapy in 101. Forty-five of the 98 neck dissection cases had cervical node metastases. RESULTS: Survival rates were analyzed for 233 patients. The 3-year survival rate was (167 of 215) (77.67%), the 5-year survival rate was 134 of 187 (71.76%), and the 10-year survival rate was 79 of 113 (69.91%). CONCLUSIONS: These data confirm that surgery is still the mode of choice in the treatment of minor salivary gland carcinoma, but a combination with radiation therapy or chemotherapy is advisable in some patients.

Am J Clin Oncol 1993 Feb;16(1):3-8

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

Sadeghi A, Tran LM, Mark R, Sidrys J, Parker RG

VA Medical Center, West Los Angeles 90073.

Between 1961 and 1985, 117 patients with malignant tumors of the minor salivary glands of the upper aerodigestive tract were treated with curative intent at the University of California, Los Angeles (UCLA). The length of follow-up ranged from 24-225 months, with a median of 38 months. The most common site of origin was the oral cavity (65 cases), and the most common histology was adenoid cystic carcinoma (69 cases). Tumor size, histology, and site were important prognostic factors. For oral cavity lesions, small tumors were well controlled with resection alone (25 of 26) or local excision, followed by irradiation (7 of 7). For advanced tumors arising from the paranasal sinuses and pharynx, the control rates were 43% (15 of 35) and 29% (5 of 17), respectively. Ninety-three percent (27 of 29) of patients with mucoepidermoid carcinoma had no evidence of disease at last follow-up versus 55% (38 of 69) of patients with adenoid cystic carcinoma and 56% (10 of 18) of those with adenocarcinoma. It appears that resection with good margin is adequate treatment for small lesions. Large, poorly differentiated tumors require a combined approach: surgery and radiation therapy.