Low-Dose Metronomic Chemotherapy in Metastatic Breast Cancer: A Retrospective Analysis of 40 Patients ()
ABSTRACT
Purpose:
Low-dose metronomic chemotherapy is an emergent treatment schedule in which low
doses of cytotoxic agents are given orally continuously, with no or short
drug-free intervals. In general, it provides
better tolerance, especially in patients who have been previously exposed to
other oncologic treatments, with a favorable cost-effectiveness profile. It is
well known that all these low-dose schedules have a favorable safety profile
and may provide an adequate tumor control in patients with metastatic breast
cancer. However, there are no data in literature reporting the patient’s
tolerance and response to subsequent lines of chemotherapy after receiving
metronomic regimens. Methods: We retrospectively analyzed 40 patients with
metastatic breast cancer treated with low doses of Cyclophosphamide and/or
Methotrexate and/or Capecitabine in a single center from June 2009 to April
2014. The following data were collected: age, hormone and epidermal growth
factor receptor 2 (HER-2) status, number of lines of chemotherapy prior to and
after low-dose metronomic treatment, duration of metronomic treatment, toxicity
reason for treatment discontinuation. Duration of low-dose metronomic
chemotherapy was also correlated with the variables analyzed and treatment
outcomes. Results: The median time on metronomic chemotherapy was 5.4 months.
The most frequent drugs administered were cyclophosphamide, methotrexate and
capecitabine alone. Asthenia, myelotoxicity, gastrintestinal symptoms and handfoot
syndrome were the most commonly recorded treatment related toxicity. Twenty six
(65%) patients had the opportunity to receive a classic chemotherapy regimen
following metronomic regimen interruption. Although patients who developed
toxicity to low-dose metronomic chemotherapy remained less time (<6 months)
in subsequent chemotherapy, there was no statistically significant difference
among those who received more lines of chemotherapy. Discussion: This is the
first report in the literature describing the efficacy of low-dose metronomic
regimens and the tolerance to subsequent lines of treatments following a period
of metronomic chemotherapy. Most of our patients were able to tolerate
conventional chemotherapy regimens administered in full doses. Several patients
received as many as three lines of additional chemotherapy for periods that
exceeded 6 months of treatment, which suggests that the use of prolonged metronomic
treatment does not affect
a patient’s ability to tolerate subsequent therapy.
Share and Cite:
Souto, M. , Shimada, A. , Chaul, C. , Abrahão, M. and Katz, A. (2016) Low-Dose Metronomic Chemotherapy in Metastatic Breast Cancer: A Retrospective Analysis of 40 Patients.
Journal of Cancer Therapy,
7, 480-486. doi:
10.4236/jct.2016.77050.