Importance of comorbidity in head and neck cancer

Objectives/Hypothesis: Patients with head and neck cancer are staged accord ing to the morphology of the tumor with little or no attention given to the importance of the other diseases, illnesses, or conditions. These other co nditions are generally referred to as comorbidities. Although not a feature of the cancer itself, comorbidity is an important attribute of the patient with cancer. Comorbidity has direct impact on the care of patients, select ion of initial treatment, and evaluation of treatment effectiveness. The ob jective of this thesis is to demonstrate the importance of comorbidity in h ead and neck cancer. Specifically, the aims are I) to demonstrate the burde n of comorbidity among head and neck cancer patients by comparing the incid ence of none, mild, moderate, and severe comorbidity among patients with he ad and neck cancer to patients with cancers of the colorectum, lung, breast , gynecological sites, or prostate, 2) to demonstrate the independent impac t of comorbidity on overall survival, and 3) to demonstrate the importance of comorbidity in the assessment of initial treatment effectiveness. Study Design: This was a prospective cohort study of the impact of comorbidity on head and neck cancer patients presenting for treatment between January 199 5 and December 1996. Methods: In 1994, the author trained cancer registrars at an academic teaching hospital to code comorbidity from the medical reco rd of new patients using a standard comorbidity index. Standard statistical techniques, including multivariable analysis, were used to compare and con trast the burden of comorbidity for patients with different cancers. Life s urvival techniques and multivariable logistic regression analysis were used to assess the independent prognostic impact of comorbidity. Further, the t echnique of conjunctive consolidation was used to augment the TNM system wi th comorbidity information, to more completely assess the impact of differe nt initial treatments for patients with head and neck cancers. Results: The cohort consisted of 3,378 patients with cancers of the head and neck (341) , colorectum (307), lung (655), breast (483), gynecological sites (482), an d prostate (1,110). The percentage of head and neck cancer patients with mo derate to severe comorbidity was 21%; this degree of comorbidity burden was second only to patients with lung (40%) and colorectal. (25%) cancer. Ther e was a significant relationship between severity of comorbidity and overal l survival dog-rank test, chi(2) = 15.75; P < .0013). For cancers of the he ad and neck, lung, breast, and prostate the prognostic significance of como rbidity remained even after controlling for other factors, such as age and TNM stage. Conclusions: The results of this study show that comorbidity is an important feature of patients with head and neck cancer. Valid instrumen ts exist to measure and classify the overall severity of comorbidity. The s cientific evaluation of treatment and the care of patients are impeded by a rigid adherence to a staging system based solely on morphological descript ions of the cancer while ignoring suitable descriptions of the patient. The author believes that the addition of comorbidity information will improve the value of cancer statistics and the care of cancer patients.