September 2019 HSC Section 1 Congenital and Pediatric Problems

Reprinted by permission of Pediatr Blood Cancer. 2019; 66(3):e27543.

Received: 17 July 2018 Revised: 18 September 2018 Accepted: 17 October 2018

DOI: 10.1002/pbc.27543

Pediatric Blood & Cancer

R E V I EW

TheAmericanSocietyof PediatricHematology/Oncology

Survival and characteristics of pediatric salivary gland cancer: A systematic review and meta-analysis

Martin Zamani

Christian Grønhøj

Jakob Schmidt Jensen

Christian von Buchwald BirgitteWittenborg Charabi

Thomas Hjuler

Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark Correspondence Martin Zamani, Department of Otorhinolaryngology, Head andNeck Surgery andAudiology, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100Copenhagen, Denmark. Email: martin.zamani.01@regionh.dk

Abstract A systematic search of PubMed, EMBASE, and the Cochrane Library for studies from 2000 to 2017 including children aged 0-19 with salivary gland cancer was performed. In 19 studies, 749 children (median age of 14.2 years, female to male ratio of 1.4:1) were included; 72% had parotid tumors and 95% underwent surgery, of whom 65% had surgery alone and 24% with adjuvant radiotherapy. Low-grade and stage mucoepidermoid carcinoma were the most frequent cancer. The 5-year overall- and disease-free survival was 94% and 83%. Recurrence was observed in 20% at a median of 1.1 years from diagnosis.

K E YWO R D S meta-analysis, pediatric, salivary gland cancer, systematic review

1 BACKGROUND

2 METHODS

2.1 Database search and data extraction

Salivary gland cancer (SGC) in children accounts for only 5% of SGC in the general population, which in turn comprises 1% of all malignancies. 1 SGC typically presents in childrenwho are in the second decade of life, similar to children with benign salivary gland tumors. 1–4 In children, salivary gland tumors are more often malignant than benign. 3–7 Children with SGC most commonly present with a slowly enlarg- ing mass in the major salivary glands or oral cavity over the past 8-12 months without metastases. 4,8,9 Diagnosis is often delayed due to the asymptomatic nature and rarity of the disease, and knowledge on sali- vary gland tumors in children is sparse. 4 Considering histopathology, pediatric SGC is usually of epithe- lial origin, the most common being mucoepidermoid carcinoma (MEC), acinic cell carcinoma (AciCC), and adenoid cystic carcinoma (AdCC). 5,8 Pediatric SGC is often of lower grade in children older than 10 years and higher grade in children younger than 10 years, which leads to a worse prognosis in younger children. 5,8 This study systematically reports the distribution, treatment, and histopathology as well as outcome for children with SGC.

This systematic review was completed in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. 10 One author (MZ) systematically searched PubMed, EMBASE, and the Cochrane Library for published articles in English from January 1, 2000 to December 31, 2017. Abstracts were screened to include papers with at least 10 children aged 0-19 with SGC and avail- able tumor anatomical distribution, treatment, or histopathology data. Included papers were reviewed in full text, and studies with overlap- ping patient cohorts/cases due to identical centers and overlapping inclusion periods were excluded. PubMed was searched using a combination of MeSH terms, includ- ing “Salivary Gland Neoplasms, Parotid Gland, Submandibular Gland, Salivary Glands” and keywords such as “Malignan*, Cancer, Tumors, Tumours, and Neoplasms.” Titles and abstracts were filtered for the keywords “Juvenile, Pediatric, Paediatric, Child, Children, Adolescent*, Teen*, and Infant*” (see full search strategy in Supporting Information Methods). Data were collected from eligible studies, including study design, country, inclusion period, treatment center, number of malignant cases, age, gender, anatomical tumor site, symptoms, diagnostic tools, treatment, complications, histopathology, grade, Tumor-Node- Metastasis (TNM) stage, follow-up, recurrence, and survival. Extracted

Abbreviations: AciCC, acinic cell carcinoma; AdCC, adenoid cystic carcinoma; MEC, mucoepidermoid carcinoma; MRI, magnetic resonance imaging; PET-CT, positron emission tomography-computed tomography; SGC, salivary gland cancer

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