Gender Difference in Symptom Presentations Among Patients With Bone Metastases in Gender-Specific and Gender-Neutral Primary Cancers

BACKGROUND: Studies have assessed gender differences on symptoms commonly experienced by cancer patients at various stages in their disease trajectory using heterogeneous cancer populations with different tumor types. The purpose of our study was to evaluate the effect of gender on symptoms among patients with bone metastases while controlling for gender-specific malignancies. METHODS: A retrospective review of patients receiving palliative radiotherapy for bone metastases was conducted on patients that completed the Brief Pain Inventory (BPI) or Edmonton Symptom Assessment System (ESAS) questionnaires from 1999 - 2004. Baseline and follow-up BPI and ESAS symptom scores were compared between males and females, with and without controlling for gender-specific tumors. RESULTS: A total of 900 patients completed baseline questionnaires: ESAS (n = 508) or BPI (n = 392). The most common tumor types were lung (26%), breast (25%) and prostate (24%). In all ESAS patients, females had significantly greater severity of tiredness, nausea, depression, anxiety and breathlessness. In the subgroup analysis when gender-specific primary cancers were removed (i.e., breast, prostate and gynecological), no significant differences in ESAS symptoms were found between genders. The BPI functional item of walking ability was significantly worse for females in both the overall and subgroup analyses. Females had worse symptoms at follow-up prior to the removal of gender-specific primaries in both ESAS and BPI. CONCLUSIONS: Gender-specific cancers may significantly bias gender studies of cancer-related symptoms when primary tumor type is not taken into account. Gender differences are best assessed in gender-neutral primaries.