ABSTRACT
Dedicated software packages incorporating prognostic models are meant to aid physicians in making accurate predictions of prognosis. This study concerns 742 predictions of 5-year survival on consecutive newly diagnosed patients with head- and neck squamous cell carcinoma. The 5-year survival predictions made by the physicians are not compared with actual survival, but with a prediction made by OncologIQ, a dedicated software package. We used a linear regression and a linear mixed-effects model to look at absolute differences between both predictions and possible learning effects. Predictions made by the physicians were optimistic and inaccurate. Using the linear regression and linear mixed-effects models, the physicians' learning effect showed little improvement per successive prediction. We conclude that prognostic predictions in general are imprecise. When given feedback on the model's predicted survival, the accuracy increases, but only very modestly.
Subject(s)
Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/mortality , Computer Simulation , Decision Support Techniques , Otorhinolaryngologic Neoplasms/diagnosis , Otorhinolaryngologic Neoplasms/mortality , Software , Aged , Carcinoma, Squamous Cell/pathology , Disease-Free Survival , Feedback , Female , Humans , Linear Models , Male , Middle Aged , Neoplasm Staging , Otorhinolaryngologic Neoplasms/pathology , Patient Education as Topic , PrognosisABSTRACT
BACKGROUND: Patients with head and neck cancer are prone to develop significant comorbidity mainly because of the high incidence of tobacco and alcohol abuse, both of which are etiologic and prognostic factors. However, to the authors' knowledge little is known regarding the prognostic relevance of comorbidity in patients with salivary gland cancer. METHODS: A retrospective cohort of 666 patients with salivary gland cancer was identified within the Dutch Head and Neck Oncology Cooperative Group database. For multivariate analysis, a Cox proportional hazards model was used to study the effect of comorbidity on overall survival and disease-specific survival. RESULTS: According to the Adult Comorbidity Evaluation-27 (ACE-27) index, 394 patients (64%) had grade 0 comorbidity, 119 patients (19%) had grade 1 comorbidity, 71 patients (12%) had grade 2 comorbidity, and 29 patients (5%) had grade 3 comorbidity. In multivariate analysis for overall survival, the ACE-27 comorbidity grade was a strong independent prognostic variable. The hazards ratio (HR) of death, including all causes, was 1.5 (95% confidence interval [CI], 1.1-2.1) for patients with ACE-27 grade 1 comorbidity versus grade 0 comorbidity (P < .007). The HR was 1.7 (95% CI, 1.2-2.5) for grade 2 comorbidity (P = .003) and 2.7 (95% CI, 1.5-4.7) for grade 3 comorbidity versus grade 0 comorbidity (P = .001). In the current analysis, ACE-27 comorbidity grade was not an independent prognostic factor for disease-free survival. CONCLUSIONS: To the authors' knowledge, this is the first study concerning the prevalence and relevance of the prognostic comorbidity variable ACE-27 grade in patients with salivary gland cancer. Overall survival, but not disease-free survival, was correlated strongly with ACE-27 grade. Compared with other studies that investigated the effect of comorbidity on patients with head and neck cancer, patients with salivary gland cancer had less comorbidity. Their comorbid status appeared to be reasonably comparable to that of patients with other nonsmoking- and nonalcohol-related cancers.