Clinicopathological, Prognostic and Molecular Profile of Salivary Gland Intraductal Carcinoma: A Systematic Review

This study aimed to conduct a systematic review summarizing the clinicopathological, prognostic, and molecular features of salivary gland intraductal carcinoma (SGIC).

This study followed the PRISMA 2020 guidelines and was registered in the PROSPERO database. It included case reports, case series studies, and cohort studies of SGIC indexed in the PubMed, Web of Science, Scopus, and Embase databases published between 1983 and 2024. Collected variables underwent descriptive analysis, association analysis using Fisher's tests, and Kaplan-Meier analysis. The quality assessment of the included studies was conducted using the Joanna Briggs Institute tools.

This systematic review yielded 59 studies, comprising 186 SGIC cases. Most of cases involved the parotid gland of male patients around 60 years old. Lesions predominantly exhibited noninvasive growth, an intercalated duct phenotype, and minimal pleomorphism. Most of the patients did not develop recurrent or metastatic disease, indicating a good prognosis. However, male sex, invasive lesions, adjuvant treatments, high-grade lesions, as well as lymph node or distant metastasis negatively affected the survival rates. Overall SGIC cases showed S100, mammaglobin, SOX10, AR, CK7, p63, calponin, CK14, SMA, and p40 positivity and a low Ki67 index. Common molecular alterations included NCOA4-RET, TRIM33-RET, and TRIM27-RET fusions, and HRAS, PIK3CA, and BRAF V600E mutations.

SGIC is a histopathologically and molecularly heterogeneous lesion with an overall excellent prognosis. The presence of invasive lesions, as well as lymph node or distant metastasis, has emerged as one of the most critical prognostic factors in SGIC patients.