Head and neck cancer: Study identifies factors associated with increased risk of death among two-year survivors

"A conditional survival rate is the probability of surviving after having already lived for a certain length of time," the authors write as background information in the study. "This concept is important in the care of patients with head and neck cancer because it underlies the intuition of head and neck oncologists that mortality and recurrence rates are lower for patients further out from diagnoses."

Trisha L. Thompson, B.S., and colleagues from the University of Iowa Hospital and Clinics, Iowa City, conducted an observational study of 276 patients who survived two years after a diagnosis of upper aerodigestive carcinoma, and were diagnosed between September 2001 and September 2008. Data were collected using standard surveys and short-item queries. Of the 276 participants included in the analysis, 59.9 percent were previous users of tobacco, while 11.4 percent were current users, two years after diagnosis. Additionally, two years after diagnosis, 86 percent of survivors were eating a full diet and 80.5 percent reported having no pain.

The five-year traditional observed survival rate was 61.1 percent for all patients compared with the conditional rate of 90.8 percent for two-year survivors. The five-year traditional disease-specific rate was 69.8 percent for all patients, compared with the conditional rate of 94.8 percent for two-year survivors. Older age and advanced stage were associated with poorer survival, whether death was due to the cancer or from all causes. Patients with pain or poor overall quality of life were more likely to die from all causes, whereas those still smoking two years after diagnoses were more likely to die from their cancer.

The authors found that the likelihood of death was four times lower for patients reporting high overall quality of life than for those reporting low quality of life, and two times higher for those who reported the presence of pain, compared to participants who did not. Additionally, those who continued to use tobacco had a likelihood of death from cancer four times higher than those who had quit or had never used tobacco.

"In addition to older age and advanced stage, which are known to have a negative effect on survival, the presence of pain and continued tobacco use should flag patients who might need longer and more intense follow-up care to improve their observed and disease-specific survival rates," the authors conclude. "This information is useful for clinicians in the development of management plans for patients who are transitioning from treatment into survivorship."