[Utility of Prophylactic Administration of Pegfilgrastim in Breast Cancer Chemotherapy].

Febrile neutropenia(FN)is a frequent adverse event observed in cancer patients undergoing chemotherapy that may cause life-threatening infections. However, reducing the dose of anti-cancer drugs for breast cancer in adjuvant settings to prevent FN has been reported to adversely affect patient survival. Therefore, it is important to administer therapeutic agents as per their prescheduled regimens without delays or reductions in the dosage. From April 2015 to September 2017, pegfilgrastim was administered to 24 patients with breast cancer(primary prevention in 11 patients and secondary prevention in 13 patients)to prevent FN during chemotherapy in either adjuvant or metastatic settings. We were able to reduce the incidence of FN through prophylactic administration of pegfilgrastim without encountering serious adverse events. The inclusion of pegfilgrastim is considered essential for the safe administration of chemotherapy according to a preplanned schedule. Here, we discuss the indications, efficacy, and safety of the drug.

Candidate biomarkers predictive of anthracycline and taxane efficacy against breast cancer.

BACKGROUND: Since breast cancer shows diversity in clinical behaviors, a standard therapy does not always lead to favorable outcomes. MATERIALS AND METHODS: The expression statuses of candidate markers, including topoisomerase-II alpha (TOP2A), beta-tubulin (B-tub), and tissue inhibitor of metalloprotease-1 (TIMP-1), were immunohistochemically evaluated in 70 breast cancer tissues from 68 patients with advanced breast cancers receiving chemotherapy. RESULTS: The response rates to anthracycline and taxane were 70.5% and 67.2%, respectively. Overall, 25.1% ± 29.7%, 8.32% ± 10.1%, and 16.37% ±17.5% of cancer cells in the tumors studied were positive for B-tub, TOP2A, and TIMP-1 expressions, respectively. However, positive molecule expression did not differ between patients who did and did not exhibit clinical responses to treatment. The proportion of TOP2A-positive cancer cells was significantly higher among anthracycline responders than among nonresponders in HR-negative cancer (15.4% ±17.5% vs. 2.0% ± 2.4%, respectively, P = 0.048), whereas TOP2A and TIMP-1 expression statuses did not differ in HR-positive cancer. When patients were stratified according to B-tub, TOP2A, or TIMP-1 expression statuses (B-tub ≥10% vs. <10%, TOP2A ≥5% vs. <5%, TIMP-1 ≤20% vs. >20%, respectively), the proportion of patients with ≥10% B-tub-positive cancer cells was significantly higher in taxane responders than in nonresponders (72.4% vs. 37.5%, respectively, P = 0.016). Anthracycline responders showed a trend to have a higher proportion of patients with either ≥5% TOP2A-positive cancer cells or ≤20% TIMP-1-positive cancer cells compared to nonresponders (86.7% vs. 61.5%, respectively, P = 0.066). CONCLUSION: Immunohistochemical TOP2A, TIMP-1, and B-tub expression analyses are expected to be useful for predicting tumor responses to chemotherapy.