Palliative Effect of Chemotherapy: Objective Tumor Response Is Associated With Symptom Improvement in Patients With Metastatic Breast Cancer

Abstract

PURPOSE: Because one of the goals of chemotherapy for metastatic breast cancer is to provide symptom palliation, we were interested in identifying the relationship between tumor shrinkage and improvement in disease-related symptoms. PATIENTS AND METHODS: Three hundred patients enrolled onto a randomized trial of metastatic breast cancer formed the basis of our study. The nine most common baseline symptoms were identified and followed. Changes from baseline (improvement, stable, worsening) were defined using patient responses to a quality-of-life (QoL) questionnaire (the European Organization for Research and Treatment of Cancer EORTC QLQ-C30) as well as using graded toxicity data collected on case report forms (CRFs). The association between symptom improvement and tumor response was assessed using a linear trend test via a logistic regression model. RESULTS: The most commonly reported baseline symptoms were cancer pain in 38% (CRF data) and 81% of patients (QoL data) and tiredness in 26% (CRF data) and 89% (QoL data) of patients. Three symptoms—cancer pain, shortness of breath, and abnormal mood—showed a significant relationship between improvement and objective response, using both CRF and QoL assessments. Constipation, anorexia, and nausea showed a similar trend when QoL data were used but not when CRF information was used. The converse was seen for lethargy. There was no correlation between symptom change and response for cough and insomnia. CONCLUSION: For some symptoms, we found a significant association between symptom improvement and objective tumor regression. In these cases, symptom improvement was greatest in those patients who had complete or partial responses, followed by those with stable disease and then those with progressive disease. Further work in this area will be useful in determining the surrogate value of objective tumor response in identifying the efficacy of palliative chemotherapy.