Page 48 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

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Chapter 3
smaller institutional series. A recurrence was defined as a histological or cytological diagnosis of a PA after previous PA surgery in the same site. A MT was defined as a histological diagnosis of a carcinoma arising in or in the same location as a previous PA. A systematic literature search was undertaken in Pubmed, Embase (Ovid) and Scopus. Studies published in the English literature during the 40- year period between 1978 and 2017 that reported on treatment and outcome of series of ≥20 RPAs were identified, not limited to the parotid (Fig. 1: PRISM flow diagram). Search terms were “Adenoma, Pleomorphic”[Mesh] OR Pleomorphic Adenoma* [tiab] OR (mixed salivary [tiab] AND gland tumor* [tiab])) AND (“Neoplasm Recurrence, Local”[Mesh] OR recurren* [ti] OR residual [ti] OR relaps* [ti] OR return* [ti] OR recrudescence* [ti]. The content of the articles was evaluated in duplo systematically by completing a predesigned form including the following aspects: study details, epidemiology (incidence, gender, age at diagnosis of primary PA and RPA), treatment of PA and RPA (surgery/radiotherapy), pathology (multinodularity of specimen) and outcome (recurrence rate/ MT rate/ facial nerve function). Case files in the national series were available for patients who had RPA and subsequently developed MT, under the strict national database privacy regulations. Their clinical details and outcome data were retrieved and evaluated in conjunction with the pathology data.
Results
The Dutch and Danish studies reported on 3,506 (1992-2012, with 5-year intervals, major and minor salivary glands) and 5,497 (1990-2010, parotid only) cases of primary PAs, respectively, and their subsequent 125 and 151 RPAs [1,2]. The literature search identified 622 articles which were reduced to 76 after review. Of these, 28 (including the two national series) met the inclusion criteria for this study, but two Danish series described patients from the same national population (Table 1 [1-28]) [1,24]. The 25 institutional articles reported on case series of 20- 126 RPA patients (total N= 1,187) treated between 1950-2016 in 23 single and two dual center reports. Six series reported only treatment details of 1st occurrence of RPA, whereas the others reported mixed series of 1st and subsequent RPAs. The two recent studies of the Danish and Dutch national pathology databases focused on primary tumor incidence, recurrence, malignant transformation