{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T13:59:17Z","timestamp":1787839157636,"version":"build-2784847793"},"reference-count":19,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,11,25]],"date-time":"2024-11-25T00:00:00Z","timestamp":1732492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: The role of occult nodal metastases in patients with parotid gland cancers remains unclear; such metastases are histologically diverse and exhibit unpredictable clinical courses. Here, we evaluated the prognostic utilities of such metastases, including metastases in the intraparenchymal lymph nodes (PARs). Materials and Methods: We retrospectively reviewed the medical charts of patients who underwent surgery to treat clinically N0 primary parotid gland cancers from 2000 to 2022. The primary outcome variables were 5-year overall survival (OS) and 5-year disease-free survival (DFS). We explored the effects of occult nodal metastases, including metastases in the PARs, especially in terms of the pathological T (pT) classification. Results: Among 74 patients, 48 (64.8%) were pT1\/2 cases, and 26 (35.2%) were pT3\/4 cases. Both perineural and lymphatic invasion were negatively associated with the 5-year DFS (hazard ratio [HR] = 3.533, 95% confidence interval [CI] = 1.325\u20139.421, p = 0.012; HR = 4.028, 95% CI = 1.497\u201310.839, p = 0.006, respectively). During pathological review, PAR metastases were observed in 12 patients (16.2%), and other occult metastases were present in 8 patients (10.8%). PAR metastases reduced the 5-year DFS in pT1\/2 cases (87.2% vs. 22.2%, p = 0.001) but not in pT3\/4 cases. Conclusions: PAR metastases significantly reduced the 5-year DFS in patients with clinically N0 primary parotid gland cancer. On subgroup analysis according to pT classification, this effect was significant among patients with early pT1\/2 status but not patients with advanced pT3\/4 status.<\/jats:p>","DOI":"10.3390\/medicina60121942","type":"journal-article","created":{"date-parts":[[2024,11,25]],"date-time":"2024-11-25T06:25:19Z","timestamp":1732515919000},"page":"1942","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Prognostic Implications of Occult Nodal Metastases in Patients with Clinically N0 Primary Parotid Gland Cancer"],"prefix":"10.3390","volume":"60","author":[{"given":"Jooin","family":"Bang","sequence":"first","affiliation":[{"name":"Department of Otolaryngology-Head and Neck Surgery, Eunpyeong St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1540-8944","authenticated-orcid":false,"given":"Oh-Hyeong","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology-Head and Neck Surgery, Seoul St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5032-5853","authenticated-orcid":false,"given":"Geun-Jeon","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology-Head and Neck Surgery, Seoul St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dong-Il","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology-Head and Neck Surgery, Seoul St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sang-Yeon","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology-Head and Neck Surgery, Seoul St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"E13","DOI":"10.1177\/014556131709600319","article-title":"The rising incidence of major salivary gland cancer in the United States","volume":"96","author":"Megwalu","year":"2017","journal-title":"Ear Nose Throat J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1007\/s12105-022-01420-1","article-title":"Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Salivary Glands","volume":"16","author":"Hyrcza","year":"2022","journal-title":"Head Neck Pathol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1016\/j.ijom.2018.05.012","article-title":"A gland of diverse pathology and unpredictable behaviour: Our experience of primary submandibular gland malignancies","volume":"47","author":"Rajappa","year":"2018","journal-title":"Int. J. Oral. Maxillofac. Surg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"105076","DOI":"10.1016\/j.oraloncology.2020.105076","article-title":"The impact of nodal status in major salivary gland carcinoma: A multicenter experience and proposal of a novel N-classification","volume":"112","author":"Lombardi","year":"2021","journal-title":"Oral. Oncol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1002\/hed.10400","article-title":"Salivary gland carcinoma: Independent prognostic factors for locoregional control, distant metastases, and overall survival: Results of the Dutch head and neck oncology cooperative group","volume":"26","author":"Terhaard","year":"2004","journal-title":"Head Neck"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1016\/j.ejso.2018.11.008","article-title":"The number and ratio of positive lymph nodes are independent prognostic factors for patients with major salivary gland cancer: Results from the surveillance, epidemiology, and End Results dataset","volume":"45","author":"Qian","year":"2019","journal-title":"Eur. J. Surg. Oncol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"856","DOI":"10.1017\/S0022215120002054","article-title":"Surgical anatomy of the lymphatic drainage of the salivary glands: A systematic review","volume":"134","year":"2020","journal-title":"J. Laryngol. Otol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"286","DOI":"10.3109\/00016480903062160","article-title":"Indication for elective neck dissection for N0 carcinoma of the parotid gland: A single institution\u2019s 20-year experience","volume":"130","author":"Kawata","year":"2010","journal-title":"Acta Otolaryngol."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Niu, X., Fang, Q., and Liu, F. (2019). Role of intraparotid node metastasis in mucoepidermoid carcinoma of the parotid gland. BMC Cancer, 19.","DOI":"10.1186\/s12885-019-5637-x"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"932","DOI":"10.1016\/j.ejso.2008.02.004","article-title":"Patterns of lymph node spread and its influence on outcome in resectable parotid cancer","volume":"34","author":"Klussmann","year":"2008","journal-title":"Eur. J. Surg. Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Han, X., Wang, J., Li, Y., Xi, S., and Xiao, W. (2023). Intraparotid lymph node metastasis affects distant metastasis in parotid adenoid cystic carcinoma. Sci. Rep., 13.","DOI":"10.1038\/s41598-023-38227-1"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1111\/coa.12672","article-title":"Prediction of outcome by lymph node ratio in patients with parotid gland cancer","volume":"42","author":"Meyer","year":"2016","journal-title":"Clin. Otolaryngol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2625","DOI":"10.1002\/hed.25742","article-title":"Examined and positive lymph nodes counts and lymph nodes ratio are associated with survival in major salivary gland cancer","volume":"41","author":"Elhusseiny","year":"2019","journal-title":"Head Neck"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1659","DOI":"10.1007\/s00405-016-4407-5","article-title":"Probability and pattern of occult cervical lymph node metastases in primary parotid carcinoma","volume":"274","author":"Stodulski","year":"2017","journal-title":"Eur. Arch. Otorhinolaryngol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"856","DOI":"10.1016\/j.anl.2022.03.010","article-title":"Is elective neck dissection necessary for patients with cT3-4N0 parotid gland cancer?","volume":"49","author":"Adachi","year":"2022","journal-title":"Auris Nasus Larynx"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Terada, T., and Kawata, R. (2022). Role of Intra-Parotid Lymph Node Metastasis in Primary Parotid Carcinoma. Life, 12.","DOI":"10.3390\/life12122053"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1007\/BF02301058","article-title":"\u00dcber den Einschluss von Parotislappchen in Lymphknoten","volume":"10","author":"Neisse","year":"1898","journal-title":"Anat. Hefte"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1634","DOI":"10.1002\/hed.23507","article-title":"Clinical significance of intraparotid lymph node metastasis in primary parotid cancer","volume":"36","author":"Lim","year":"2014","journal-title":"Head Neck"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2309","DOI":"10.1002\/lary.27701","article-title":"Significance of intraparotid node metastasis in predicting local control in primary parotid cancer","volume":"129","author":"Feng","year":"2019","journal-title":"Laryngoscope"}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/60\/12\/1942\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:39:01Z","timestamp":1760114341000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/60\/12\/1942"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,25]]},"references-count":19,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2024,12]]}},"alternative-id":["medicina60121942"],"URL":"https:\/\/doi.org\/10.3390\/medicina60121942","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,25]]}}}