The development of a prognostic score for patients with parotid carcinoma

BACKGROUND. Understanding of prognostic factors in parotid carcinoma has gr own considerably. In particular, clinical tumor staging and histologic clas sification have been found to be prognostically important. Univariate and m ultivariate analyses have indicated that other variables, such as age, pain , skin invasion, and facial nerve impairment, are important predictors as w ell. In an actual patient, some of these factors are present and others are absent. However, a clinical tool incorporating this information, resulting in an individualized prognosis based on the combined effects of present ad verse prognostic factors, has never been devised. METHODS. Of a cohort of 168 patients, 151 were evaluated to assess the prog nostic Value of clinical and pathologic factors in a multivariate proportio nal hazards analysis. Follow-up ranged from 1 to 278 months (median, 37 mon ths). The end point was tumor recurrence. Identified prognostic factors and their hazard ratios were combined into prognostic scores. RESULTS. Clinical T classification, clinical N classification, pain, age at diagnosis, skin invasion, facial nerve dysfunction, perineural growth, and positive surgical margins acted as major factors predicting recurrence. A prognostic score (PS), generated by the weighted combination of the factors present in the individual patient, placed the patient in one of four subgr oups with markedly different prognoses. In the subgroups based on the preop erative prognostic score, 5-year recurrence free percentages ranged from 92 % (in the group PS1=1) to 23% (in PS1=4). In the subgroups based on the pos toperative prognostic score, which took into account the histologic details of the resected specimen, 5-year recurrence free percentages ranged from 9 5% (in the group PS2=1) to 42% (in PS2=4). CONCLUSIONS. The proposed subgrouping, which is based on the combined effec ts of key prognostic preoperative and postoperative factors, provides a pra ctical prognostic grouping system for the clinician treating patients with parotid carcinoma. (C) 1999 American Cancer Society.