Complete remission in metastatic breast cancer: expecting the unexpected-results of a cross-sectional study

BACKGROUND

Complete response (CR) in metastatic breast cancer (MBC) is rare. This study aims at analyzing the characteristics and outcome of MBC patients achieving CR.

METHODS

We performed a cross-sectional analysis of clinical data from a consecutive series of MBC patients admitted at the Division of Medical Oncology of Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, achieving CR following treatment for systemic disease and with at least 2 years of follow-up.

RESULTS

Seventy-six MBC patients with CR were identified during a calendar year. 47 patients (61.8%) achieved CR more than once, for a total of 123 cases. Median age at MBC diagnosis was 56 years (range 30-76). 52 patients (68.4%) presented with recurrent disease, 24 (31.6%) with de novo metastatic disease. The majority of patients (80.3%) had hormone receptor (HR) positive and 26 (34.2%) had HER2 overexpressing MBC. 54 patients (71.1%) had only one site of metastatic disease. 33 patients (43.4%) received a local approach as part of their treatment and 67 (54.5%) achieved CR during maintenance therapy. CRs were durable, as after a median follow-up of 8.3 years (interquartile range 5.8-11.0 years) 42 patients (55.3%) were alive with no evidence of disease.

CONCLUSIONS

Durable CRs can occur after systemic therapy alone or after combined systemic and local treatments. Most cases presented CR in the presence of limited disease spreading, not necessarily on first-line therapy. Our study highlights the crucial role of multidisciplinary approach to MBC and the benefit of maintenance treatment.

Iterative and prolonged remission in metastatic breast cancer using pegylated irinotecan: a case report

Introduction

Pegylated irinotecan NKTR-102 is a topoisomerase I inhibitor-polymer conjugate. This new formulation of irinotecan has been evaluated in a phase II clinical trial and is showing remarkable activity. To the best of our knowledge, this is the first case report of an impressive iterative response to pegylated irinotecan NKTR-102 in metastatic breast cancer.

Case presentation

We report the case of a 49-year-old Caucasian woman diagnosed with metastatic luminal A breast cancer with initial bone followed by liver and bone marrow metastases, treated with three lines of hormonal therapy, targeted therapy and six lines of chemotherapy. She showed no major response to conventional treatment, whereas, the tumor shrinkage under pegylated irinotecan NKTR-102 was impressive, durable and iterative.

Conclusions

Reintroduction of an active drug is a valid approach as illustrated by our case. The results of the current phase III trials of pegylated irinotecan NKTR-102 are eagerly awaited.

Prolonged complete remission of metastatic HER2-positive breast cancer after continuous trastuzumab treatment: a case report and review of the literature

Metastatic breast cancer is considered an incurable disease. Targeted treatments against the human epidermal growth factor receptor 2 (HER2), however, significantly improve survival in patients with metastatic HER2-positive breast cancer. Some patients may respond with prolonged complete remission. Evidence on safety of long-term trastuzumab and risk of relapse after trastuzumab cessation is limited. We present a case of an 81-year-old patient with HER2-amplified metastatic breast cancer (MBC) in the liver. Following taxane-based chemotherapy in combination with trastuzumab after local treatment resulted in a complete radiological remission after 21 months of trastuzumab maintenance therapy. The patient remains in complete remission 6 years later and continues to receive trastuzumab as maintenance therapy. Prolonged remission in cases with complete response under trastuzumab-based regimens for metastatic HER2-positive breast cancer can be observed in some patients. Reviewing the few available cases published in the literature, these patients share some common characteristics: hormone receptor negative disease and metastases to the liver. There is no evidence that trastuzumab maintenance treatment can be safely interrupted after a certain time period.