Social support and its implications in older, early-stage breast cancer patients in CALGB 49907 (Alliance A171301)

Background Studies point to a direct association between social support and better cancer outcomes. This study examined whether baseline social support is associated with better survival and fewer chemotherapy-related adverse events in older, early-stage breast cancer patients. Methods This study is a pre-planned secondary analysis of CALGB 49907/Alliance A171301, a randomized trial that compared standard adjuvant chemotherapy versus capecitabine in breast cancer patients 65 years of age or older. A subset reported on the extent of their social support with questionnaires that were completed 6 times over 2 years. Results The median age of this 331-patient cohort was 72 years (range: 65, 90); 179 (55%) were married, and 210 (65%) lived with someone. One hundred forty-five patients (46%) described a social network of 0-10 people; 110 (35%) of 11-25; and 58 (19%) of 26 or more. The Medical Outcomes Study (MOS) social support survey revealed that the median scores (range) for emotional/informational, tangible, positive social interaction, and affectionate social support were 94 (3, 100), 94 (0, 100), 96 (0, 100), and 100 (8, 100), respectively. Social support scores appeared stable over 2 years and higher (more support) than in other cancer settings. No statistically significant associations were observed between social support and survival and adverse events in multivariate analyses. However, married patients had smaller tumors, and those with arthritis reported less social support. Conclusion Although social support did not predict survival and adverse events, the exploratory but plausible inverse associations with larger tumors and arthritis suggest that social support merits further study.