Author:

Keywords:

survival, parotid carcinoma, salivary gland, neoplasm, prognosis, stage grouping, Science & Technology, Life Sciences & Biomedicine, Oncology, Dentistry, Oral Surgery & Medicine, parotid, carcinoma, TNM classification, survival, 1105 Dentistry, 1112 Oncology and Carcinogenesis, 1117 Public Health and Health Services, Dentistry, Oncology & Carcinogenesis, 3203 Dentistry, 3211 Oncology and carcinogenesis

Abstract:

Introduction In the last two decades, an evolution in the definition of the levels of the TNM classification and the stage grouping guidelines has been observed. These changes have been driven by empirical observations. We wanted to evaluate the prognostic effect of these changes in a patient group from a nationwide database in the Netherlands. Patients and Methods In a group of 231 patients with major salivary gland carcinoma treated by the members the Dutch Head and Neck Oncology Group with a median follow-up of 68 months and a 5 year disease specific survival of 74% (SE 3%), the stage grouping criteria of the subsequent 1987 through 2002 editions of the UICC TNM Classifications were applied , and in the same way the suggestions to relocate T4N0M0 and T3N1M0 from Stage IV to Stage III disease (Numata et al, 2000) were analysed. A system combining the proposed changes by Numata in 2000 and by the UICC in 2002 was also evaluated. Using Kaplan-Meier survival analysis for overall survival, observations were made on distribution, discrimination, and correct ordering. Results and Conclusion Suboptimal distribution and discrimination is observed when classifying patients according to the 1987-1992 UICC guidelines. Using the 1997 UICC guidelines an improved discrimination is observed, but Stage III is found to be nearly empty (only 3% of patients). Using the proposal of Numata in the patients of the Dutch Head and Neck Oncology group, a clearly better distribution and discrimination results, dealing adequately with the stage III problem in the 1997 classification. The 2002 UICC guidelines result in an upstaging of patients belonging to Stage I in earlier editions, and partly respond to the stage III problem in the 1997 classification, but still leave much to be desired as to discrimination and distribution. A combination of the changes proposed in the 2002 UICC edition and the changes proposed by Numata seems to produce a superior discrimination and distribution in our patient group and seems the way to go in the future.