Risk of hospitalization according to chemotherapy regimen in early-stage breast cancer

Purpose: To compare the risk of hospitalization between patients with early-stage breast cancer who received different chemotherapy regimens. Patient and Methods: We identified 3,567 patients older than age 65 years from the SEER/Texas Cancer Registry-Medicare database and 9,327 patients younger than age 65 years from the MarketScan database who were diagnosed with early-stage breast cancer between 2003 and 2007. The selection was nonrandomized and nonprospectively collected. We categorized patients according to the regimens they received: docetaxel (T) and cyclophosphamide (C), doxorubicin (A) and C, TAC, AC + T, dose-dense AC + paclitaxel (P) or AC + weekly P. We compared the rates of chemotherapy-related hospitalizations that occurred within 6 months of chemotherapy initiation and used multivariable logistic regression analysis to identify the factors associated with these hospitalizations. Results: Among patients younger than age 65 years, the hospitalization rates ranged from 6.2% (dose-dense AC + P) to 10.0% (TAC), and those who received TAC and AC + T had significantly higher rates of hospitalization than did patients who received TC. Among patients older than age 65 years, these rates ranged from 12.7% (TC) to 24.2% (TAC) and the rates of hospitalization of patients who received TAC, AC + T, AC, or AC + weekly P were higher than those of patients who received TC. Conclusion: TAC and AC + T were associated with the highest risk of hospitalization in patients younger than age 65 years. Among patients older than age 65 years, all regimens (aside from dose-dense AC + P) were associated with a higher risk of hospitalization than TC. Results may be affected by selection biases where less aggressive regimens are offered to frailer patients.