Association between symptom experience and long-term survival in people treated for cancer.

BACKGROUND: Both symptoms and other aspects of health-related quality of life have been shown to be prognostic factors for cancer survival. Less is known about the association between distinct symptom subgroups and survival. Thus, this prospective study aimed to explore the possible association between symptom class membership during cancer treatment and long-term all-cause mortality, adjusting for known sociodemographic and clinical prognostic factors. PATIENTS AND METHODS: Between 2008 and 2011, 534 patients with cancer were included in a study assessing self-reported symptoms during cancer treatment. Symptom class membership before initiation of new treatment was investigated and four subgroups were identified on the basis of the occurrence of symptoms [i.e. 'all low' (28% of all patients), 'all high' (28%), 'high psychological' (23%), and 'low psychological' (21%)]. In the present follow-up analysis, multivariate Cox proportional hazards regression models were used to estimate the strength of a possible association between symptom class membership and all-cause mortality by comparing the 'all high' subgroup with the three other subgroups 12-15 years after study inclusion. RESULTS: When adjusted for sociodemographic and clinical variables (i.e. sex, age, cancer diagnosis, and comorbidities), belonging to the 'all high' subgroup compared with the three other subgroups was associated with significantly higher mortality (hazard ratio 1.48, 95% confidence interval 1.14-1.94). CONCLUSION: The present study identified an association between symptom experience and long-term survival. This finding suggests that symptom class membership may be an important prognostic marker for identifying patients at increased risk of all-cause mortality.