Tumor subsites and risk of osteoradionecrosis of the jaw in patients with oral cavity cancer: a national-based cohort study.

PURPOSE: The association between the tumor subsites of the oral cavity and the risk of osteoradionecrosis of the jaw (ORNJ) remains unclear. We study the correlation between oral cavity tumor subsites and the risk of ORNJ in a nationwide population-based database. METHODS: We enrolled 16,701 adult patients with oral cavity cancers who were treated with radiotherapy between 2000 and 2013. The subsites of the oral tumor, treatments of oral cavity cancers, and the timing of tooth extraction were examined for their association with ORNJ in oral cancer patients. RESULTS: 903 patients (5.40%) developed ORNJ. Of the relevant variables, pre-RT mandible surgery, tooth extraction either before or after RT, and tumor sites were associated with the risk of ORNJ. The adjusted HRs for ORNJ in the mouth floor, gums, retromolar, and buccal cancer were 2.056 (1.490-2.837), 1.909 (1.552-2.349), 1.683 (1.105-2.562), and 1.303 (1.111-1.528), respectively, compared with the risk of tongue cancer. There was no significant difference in the risk of ORNJ between the pre-RT extraction group, the during-RT extraction group, and the post-RT extraction (less than 6 months) group; the post-RT extraction (more than 6 months) group had a significantly higher risk of ORNJ. CONCLUSIONS: This study demonstrated that oral cavity tumor subsite is an independent risk factor of ORNJ after RT. Post-RT extraction (less than 6 months) group did not carry a significantly higher risk of ORNJ compared with pre-RT extraction group or during RT extraction group.

Preradiation tooth extraction and jaw osteoradionecrosis: Nationwide population-based retrospective study in Taiwan.

OBJECTIVE: Radiotherapy (RT) for head and neck cancer (HNC) within 7 days of tooth extraction is contraindicated because it may increase the risk of osteoradionecrosis of the jaw (ORNJ). However, delayed RT could compromise survival in patients with HNC. By using a national healthcare database, we reviewed the contraindications and analysed other risk factors for ORNJ. DESIGN: A retrospective cohort study. SETTING: By using Taiwan's National Health Insurance Research Database, 5,062 HNC patients with at least one tooth extraction 1-21 days before the first RT day (index day) and without any extractions during or after RT from 2000 to 2013 were included. The patients were divided into two groups according to the time of tooth extraction before the index day: 1-7 days and 8-21 days. PARTICIPANTS: Taiwanese patients with head and neck cancer. MAIN OUTCOMES MEASURE: Univariate and multivariate Cox proportional hazard regression models were used to evaluate the risk factors of ORNJ. RESULTS: The overall incidence of ORNJ in the included patients was 1.03% (mean follow-up duration, 4.07 ± 3.01 years; range, 1.00-13.99 years). Tooth extraction within 7 days before RT was not associated with increased ORNJ risk (hazard ratio [HR] =0.734; P = .312). Significant risk factors for ORNJ included oral cancer (adjusted HR = 3.961), tumour excision surgery within 3 months before RT (adjusted HR = 3.488) and mandibulectomy within 3 months before RT (adjusted HR = 5.985; all P < .001). CONCLUSION: In a mean follow-up of 4 years, tooth extraction within 7 days before RT for HNC treatment did not increase the ORNJ risk compared with tooth extraction 7-21 days before RT.

Effects of continuity of care on the postradiotherapy survival of working-age patients with oral cavity cancer: A nationwide population-based cohort study in Taiwan.

OBJECTIVES: Cancer of the oral cavity, a well-known global health concern, remains one of most common causes of cancer mortality. Continuity of care (COC), a measurement of the extent to which an individual patient receives care from a given provider over a specified period of time, can help cancer survivors process their experiences of dealing with the illness and recuperation; however, limited research has focused on the survival rate of working-age patients with oral cancer. METHODS: A total of 14,240 working-age patients (20 0.38) and non-high COC (COCI ≤ 0.38) groups. After propensity-score matching, the mortality risk in the low and intermediate COC groups was also found to be significantly higher than that in the high COC group (aHR = 1.178, 95% CI = 1.074-1.292, p < 0.001 and aHR = 1.189, 95% CI = 1.107-1.277, p = 0.001, respectively). CONCLUSIONS: In Taiwan, COC and prior dental treatment before RT significantly affected the survival rate of working-age patients with oral cancer. This result merits policymakers' attention.