Related Experiment Video
Updated: Jul 2, 2026
11:49
Single-port Non-liposuction Endoscopic Axillary Lymph Node Dissection in Breast Cancer Surgery
Published on: April 3, 2026
Lymphopenia associated with adjuvant anthracycline/ taxane regimens
Sara M Tolaney1, Julie Najita, Eric P Winer
1Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. stolaney@partners.org
Clinical Breast Cancer
|September 2, 2008
Summary
Dose-dense chemotherapy for breast cancer can lead to severe lymphopenia, increasing the risk of Pneumocystis pneumonia (PCP). This risk is particularly noted around cycle 5 of treatment, highlighting the need for careful monitoring of lymphocyte counts in patients receiving AC --> T regimens.
Area of Science:
- Oncology
- Infectious Disease
Background:
- Two cases of Pneumocystis carinii pneumonia (PCP) were observed in HIV-negative patients undergoing dose-dense chemotherapy (doxorubicin/cyclophosphamide followed by paclitaxel) for breast cancer.
- These cases represent the first reports of PCP during dose-dense chemotherapy for breast cancer, prompting an investigation into potential risk factors.
Purpose of the Study:
- To explore whether shortened chemotherapy intervals in dose-dense regimens contribute to lymphocyte depletion.
- To assess the potential increased risk of opportunistic infections, such as PCP, due to chemotherapy-induced lymphopenia.
Main Methods:
- Analysis of three patient cohorts receiving different dose-dense chemotherapy regimens (AC --> T, AC --> albumin-bound paclitaxel).
- Review of electronic medical records and prospective data collection to determine absolute lymphocyte counts (ALCs) and absolute neutrophil counts (ANCs) throughout treatment cycles.
- Identification of the nadir (lowest) ALC for each patient during the treatment course.
Main Results:
- The majority of patients in all cohorts experienced grade 3 or 4 lymphopenia (ALC < 500 or < 200 cells/mm3, respectively).
- Median nadir ALC counts were observed around cycle 5 of treatment across all cohorts.
- Specific median nadir ALCs were 400 cells/mm3 (cohort 1), 690 cells/mm3 (cohort 2), and 400 cells/mm3 (cohort 3).
Conclusions:
- Most patients receiving dose-dense AC --> T chemotherapy experience significant lymphopenia.
- Lymphocyte counts reach their lowest point around cycle 5, coinciding with the observed PCP cases.
- These findings suggest that patients on dose-dense AC --> T regimens are at risk for opportunistic infections due to profound lymphopenia.
