Outcomes of treatment of mammary analogue secretory carcinoma of the parotid gland

Salivary Gland Secretory Carcinoma; Review of 13 Years World-Wide Experience and Meta-Analysis

OBJECTIVES

Secretory Carcinoma is a malignant salivary gland tumor, initially described in 2010. This rare tumor is associated with the translocation t(12;15) (p13;q25), resulting in the fusion gene ETV6-NTRK3. Since this tumor is quite rare, most publications describe only small cohorts of patients. We aimed to investigate the clinical, pathological, and prognostic features of this newly defined malignant entity.

DATA SOURCES

Pubmed, Google Scholar, and Web of Science databases.

REVIEW METHODS

All published articles between 2010 and 2023 were reviewed. Search terms included the terms "Mammary Analogue Secretory Carcinoma" and "Secretory Carcinoma". All articles published in English reporting on Secretory Carcinoma of salivary glands were retrieved.

RESULTS

One-hundred and 12 retrospective articles reporting a total of 674 patients were included, with 52% males and a mean age of 44.9 ± 18.9. The event rate for patients with advanced-stage disease (Stage 3/4) at presentation was 24.1% (95% CI 17.6%-31.9%, I2  = 9.2%), 14.6% for regional metastases (95% CI 10.5%-20%, I2  = 12%), and the event rate of distant metastasis was 8.4% (95% CI 5.5%-12.7%, I2  = 4.2%). Adjuvant radiotherapy was administered for 30.3% of patients (95% CI 24.1%-37.2%, I2  = 21.5%). The recurrence rate was 19% (95% CI 15.1%-23.8%, I2  = 5%). Survival outcomes showed a 17.2% death of disease rate for Secretory Carcinoma patients (95% CI 13.5%-21.8%, I2  = 7.3%).

CONCLUSIONS

Secretory Carcinoma is a rare and relatively newly defined entity arising in the parotid gland most commonly. Characterized as a low-grade tumor, the majority of patients are diagnosed at an early stage, without regional or distant disease, and the prognosis is relatively good.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1716-1724, 2024.

Prognostic factors in mammary analogue secretory carcinomas of the parotid gland: Systematic review and meta-analysis

Mammary analogue secretory carcinomas (MASCs) of the parotid gland are considered as low-grade malignancies with good clinical outcome but lacking data regarding prognostic factors. We performed meta-analysis assessing prognostic factors for disease-free survival (DFS) and overall survival (OS) in 256 patients with MASCs of the parotid gland. A total of 73 studies have met the inclusion criteria and 76.3% of patients were seen with T1 and T2 tumors and negative neck nodes. Lymph node metastasis (57.4%) and distant recurrences (46.2%) were particularly found in T4 tumors (p < 0.001). DFS at 5 and 10 years was 77.9% and 47.2% compared to 88.1% and 77.2% for OS at the same time points. Male sex, T3-T4 tumors, and recurrent disease represented independent worse prognosticators for survival outcome. Altogether, parotid gland MASCs show good long-term outcome, but T4 tumors behave significantly more aggressive and require extended treatment strategies along with close follow-ups.

Clinicopathological characteristics and outcomes of 23 patients with secretory carcinoma of major salivary glands

This retrospective study investigated the clinicopathological characteristics of secretory carcinoma of salivary glands (SCSG) in 23 patients with histopathologically confirmed SCSG between January 2010 and December 2020. In total, 13 males and 10 females (ratio, 1.3:1) aged 10 − 69 years (median, 45 years) were enrolled in this study; the average disease duration was 2.44 years (0.25–20 years). Twenty-one patients (91.3%) had SCSG in the parotid gland, and two (8.7%) in the submandibular gland. All patients had single nodules of diameters 0.8–4.8 cm (average 2.6 cm); five with lymph node metastases, and two with distant metastases. Immunohistochemically, tumors stained positive for S-100, mammaglobin, CK7, GATA3 and pan-Trk, and negative for DOG1, P63, and calponin, with Ki-67 positivity from 1 to 50%. ETV6 gene rearrangement was confirmed in 15 patients. All patients underwent oncological resection, four had radioactive particles implanted postoperatively, one received chemotherapy, and seven underwent chemoradiotherapy. Six patients had regional recurrences, two distant metastases, and one died before the last follow-up. SCSGs are typically indolent, with a low locoregional recurrence rate and excellent survival. Prognosis is correlated to clinical stage, pathological grade, and surgical procedures.

Parotid mammary analogue secretory carcinoma: A case report and review of literature

BACKGROUND

Mammary analogue secretory carcinoma (MASC) is a rare low-grade malignant salivary gland tumor. The morphological and immunohistochemical features of MASC closely resemble those of breast secretory carcinoma. The key characteristics of the lesion are a lack of pain and slow growth. There is no obvious specificity in the clinical manifestations and imaging features. The diagnosis of the disease mainly depends on the detection of the MASC-specific ETV6-NTRK3 fusion gene.

CASE SUMMARY

This report describes a rare case of a 32-year-old male patient who presented with a gradually growing lesion that was initially diagnosed as breast-like secretory carcinoma of the right parotid gland. Imaging and histological investigations were used to overcome the diagnostic difficulties. The lesion was managed with right parotidectomy, facial nerve preservation, biological patch implantation to restore the resulting defect, and postoperative radiotherapy. On postoperative follow-up, the patient reported a mild facial deformity with no complications, signs of facial paralysis, or Frey’s syndrome.

CONCLUSION

The imaging and histological diagnostic challenges for MASC are discussed.