IADR Abstract Archives
Multiple Primary Tumors in Oral Cancer:Patient Characteristics and Survival Patterns
Objectives: To evaluate the clinicopathological characteristics of oral cancer patients who developed MPTs and to examine the survival rates of oral cancer patients with and without MPTs.
Methods: We retrospectively studied the data of 3166 patients diagnosed with primary oral cancer using the Alberta Cancer Registry database between 2005 and 2017.
Results: A total of 532 patients developed MPTs with an overall incidence of 16.8%. Among them, 75% were diagnosed with one MPT, 20% with two MPTs and 5% were diagnosed with more than two MPTs. The average time interval of development of MPT was 5.33±5.66 years. The mean (SD) age at first diagnosis was 61.01 (12.3) years. MPTs were most prevalent in those with primary tongue tumors (n=124) and presented at earlier tumor and nodal stages than single primary carcinomas. The most common secondary tumor sites were lung (16.3%) and tongue (10.4%). The mean duration from diagnosis to treatment was higher for MPT patients (123.52 vs. 107.88 days, p=0.009). A significant association was found with Chronic Obstructive Pulmonary Disease (COPD) and diabetes mellitus (p<0.05). Most patients who developed MPT received only surgical treatment (28.4%, p=0.00) for their primary tumor. Survival analysis showed that MPT patients survived longer (7.15+/- 0.372 years, 95% CI: 6.42- 7.88) as compared to non-MPT patients (1.56+/- 0.07 years, 95% CI: 1.41-1.70). However, the mortality rate was 20% higher in MPT patients (61.8% vs. 41.7%). Multivariate Cox-regression analyses indicated that patients diagnosed after 2010 had poorer disease specific survival regardless of tumor subsite. Furthermore, N stage and type of treatment (surgery and radiotherapy alone) were identified as independent prognostic factors.
Conclusions: Differences were found in the clinical characteristics between patients with single oral cancer and multiple primary tumors. Early diagnosis as well as close long-term follow-ups are necessary for patients with multiple primary oral carcinomas.
Methods: We retrospectively studied the data of 3166 patients diagnosed with primary oral cancer using the Alberta Cancer Registry database between 2005 and 2017.
Results: A total of 532 patients developed MPTs with an overall incidence of 16.8%. Among them, 75% were diagnosed with one MPT, 20% with two MPTs and 5% were diagnosed with more than two MPTs. The average time interval of development of MPT was 5.33±5.66 years. The mean (SD) age at first diagnosis was 61.01 (12.3) years. MPTs were most prevalent in those with primary tongue tumors (n=124) and presented at earlier tumor and nodal stages than single primary carcinomas. The most common secondary tumor sites were lung (16.3%) and tongue (10.4%). The mean duration from diagnosis to treatment was higher for MPT patients (123.52 vs. 107.88 days, p=0.009). A significant association was found with Chronic Obstructive Pulmonary Disease (COPD) and diabetes mellitus (p<0.05). Most patients who developed MPT received only surgical treatment (28.4%, p=0.00) for their primary tumor. Survival analysis showed that MPT patients survived longer (7.15+/- 0.372 years, 95% CI: 6.42- 7.88) as compared to non-MPT patients (1.56+/- 0.07 years, 95% CI: 1.41-1.70). However, the mortality rate was 20% higher in MPT patients (61.8% vs. 41.7%). Multivariate Cox-regression analyses indicated that patients diagnosed after 2010 had poorer disease specific survival regardless of tumor subsite. Furthermore, N stage and type of treatment (surgery and radiotherapy alone) were identified as independent prognostic factors.
Conclusions: Differences were found in the clinical characteristics between patients with single oral cancer and multiple primary tumors. Early diagnosis as well as close long-term follow-ups are necessary for patients with multiple primary oral carcinomas.