Faculty Bibliography

PURPOSE: Skin metastases of breast cancer remain a therapeutic challenge. Toll-like receptor 7 agonist imiquimod is an immune response modifier and can induce immune-mediated rejection of primary skin malignancies when topically applied. Here we tested the hypothesis that topical imiquimod stimulates local antitumor immunity and induces the regression of breast cancer skin metastases. EXPERIMENTAL DESIGN: A prospective clinical trial was designed to evaluate the local tumor response rate of breast cancer skin metastases treated with topical imiquimod, applied 5 d/wk for 8 weeks. Safety and immunologic correlates were secondary objectives. RESULTS: Ten patients were enrolled and completed the study. Imiquimod treatment was well tolerated, with only grade 1 to 2 transient local and systemic side effects consistent with imiquimod's immunomodulatory effects. Two patients achieved a partial response [20%; 95% confidence interval (CI), 3%-56%]. Responders showed histologic tumor regression with evidence of an immune-mediated response, showed by changes in the tumor lymphocytic infiltrate and locally produced cytokines. CONCLUSION: Topical imiquimod is a beneficial treatment modality for breast cancer metastatic to skin/chest wall and is well tolerated. Importantly, imiquimod can promote a proimmunogenic tumor microenvironment in breast cancer. Preclinical data generated by our group suggest superior results with a combination of imiquimod and ionizing radiation and we are currently testing in patients whether the combination can further improve antitumor immune and clinical responses.

BACKGROUND: Taxanes are effective in treating metastatic breast cancer. Liposomal doxorubicin (LD) is as effective as doxorubicin but less toxic. PATIENTS AND METHODS: This phase II trial assessed the combination of LD and docetaxel (D). Between 12/2002 and 9/2005, 12 women received monthly LD (30 mg/m(2)) and weekly D (30 mg/m(2)). Cycles were continued until progression or toxicity. Primary outcome was time to progression. Secondary endpoints included response rate, time to treatment failure, duration of response, survival, and toxicity. RESULTS: Median age was 49 (31-60) years. 9 (75%) patients had estrogen receptor-positive or progesterone receptor-positive tumors. 5 (41.7%) women had her-2/neu-positive tumors. 4 women stopped participation due to toxicity, and 7 due to progression. 8 (67%) participants (95% confidence interval (CI) 51.6-94.5%) had a partial response, and 2 (16.7%) had stable disease. Median time to progression was 9.6 months (95% CI 4.7-12.2). Median time to treatment failure was 6.5 months (95% CI 4.4-10.5). Median survival was 22.1 months (95% CI 9.6-40.8). Median duration of partial response was 2.7 months (95% CI 2.4-10.5). 10 (83%) women experienced grade 3/4 toxicities: neutropenia 3 (25%), infection 3 (25%), stomatitis 5 (41.7%), nausea 2 (16.7%), vomiting 1 (8.3%), dyspnea 2 (16.7%), pericardial effusion 1 (8.3), and palmar-plantar erythrodysesthesia 1 (8.3%). CONCLUSIONS: LD and D resulted in an encouraging response and unacceptable toxicities.