Breast leptomeningeal disease: a review of current practices and updates on management.

PURPOSE: Leptomeningeal disease (LMD) is an advanced metastatic disease presentation portending a poor prognosis with minimal treatment options. The advent and widespread use of new systemic therapies for metastatic breast cancer has improved systemic disease control and extended survival; however, as patients live longer, the rates of breast cancer LMD are increasing. METHODS: In this review, a group of medical oncologists, radiation oncologists, radiologists, breast surgeons, and neurosurgeons specializing in treatment of breast cancer reviewed the available published literature and compiled a comprehensive review on the current state of breast cancer LMD. RESULTS: We discuss the pathogenesis, epidemiology, diagnosis, treatment options (including systemic, intrathecal, surgical, and radiotherapy treatment modalities), and treatment response evaluation specific to breast cancer patients. Furthermore, we discuss the controversies within this unique clinical setting and identify potential clinical opportunities to improve upon the diagnosis, treatment, and treatment response evaluation in the management of breast LMD. CONCLUSIONS: We recognize the shortcomings in our current understanding of the disease and explore the future role of genomic/molecular disease characterization, technological innovations, and ongoing clinical trials attempting to improve the prognosis for this advanced disease state.

Clinical outcomes of breast leptomeningeal disease treated with intrathecal trastuzumab, intrathecal chemotherapy, or whole brain radiation therapy.

PURPOSE: Leptomeningeal disease is a rare presentation of advanced metastatic breast cancer. The purpose of this study was to evaluate craniospinal progression between intrathecal (IT) trastuzumab, IT chemotherapy, and whole brain radiation therapy (WBRT) in leptomeningeal disease. METHODS: A total of 56 patients were identified with breast cancer leptomeningeal disease at our institution treated with IT trastuzumab (n = 18; 32%), single-agent IT chemotherapy (methotrexate n = 14 or thiotepa n = 1; 27%), or WBRT alone (n = 23; 41%). Patients were treated beginning November 2012 and followed until November 2018. RESULTS: Median time from breast cancer diagnosis to development of leptomeningeal disease was 4.3 years. There were no significant differences noted between IT trastuzumab, IT chemotherapy, or WBRT groups in age (p = 0.4), Karnofsky Performance Status (KPS) (p = 0.07), or receipt of systemic therapy at time of leptomeningeal disease treatment (p = 0.47). Median follow-up of patients from leptomeningeal diagnosis was 5 months (range 0.2-81.1 months). Significant differences were noted in Kaplan-Meier (KM) craniospinal progression-free survival (CS-PFS) with 6-month rates of 44%, 18%, and 26% (p = 0.04) between IT trastuzumab, IT chemotherapy, and WBRT, respectively. Craniospinal control > 10 months was achieved in four patients treated with IT trastuzumab. Twelve-month KM OS rates were 54%, 10%, and 19% (p = 0.01) between IT trastuzumab, IT chemotherapy, and WBRT groups, respectively. IT therapy was adequately tolerated with three patients undergoing treatment-related hospitalizations. CONCLUSIONS: In our institutional series, significant differences were noted in CS-PFS and OS by treatment modality. IT trastuzumab should be considered in the management HER2+ breast leptomeningeal disease.

Intrathecal trastuzumab in the management of HER2+ breast leptomeningeal disease: a single institution experience.

PURPOSE: Leptomeningeal disease is a rare and devastating presentation of advanced stage metastatic breast cancer with historically poor overall survival. We assessed the safety and feasibility of intrathecal (IT) trastuzumab in HER2+ leptomeningeal disease. METHODS: A total of 13 patients were treated at our institution with IT trastuzumab beginning November 2012 and followed until November 2017. Outcomes including craniospinal progression as well as overall survival (OS) following initiation of IT trastuzumab were assessed from review of the clinical chart and radiologic examinations. RESULTS: The median age of patients was 48 (range 29-75). Median time from breast cancer diagnosis to development of brain metastases was 87.7 months with a median of 4.6 months from brain metastases diagnosis to the development of leptomeningeal disease. Previous whole brain radiotherapy was received by the majority of patients (92%) and prior surgery for brain metastases was performed in 23%. Median duration of IT trastuzumab treatment was 6.4 months. Median time from IT trastuzumab start to craniospinal progression was 5.7 months with 6- and 12-month Kaplan-Meier rates of 41 and 21%, respectively. Sustained responses > 6 months were achieved in 4 patients. Median survival from the start of IT trastuzumab was 10.6 months with 6- and 12-month OS rates of 68 and 47%, respectively. IT trastuzumab was well tolerated with one patient developing ventriculitis, which resolved with IV antibiotics. CONCLUSIONS: IT trastuzumab was well tolerated with prolongation of OS over historical controls. IT trastuzumab should be considered for management of HER2+ leptomeningeal disease patients.

Therapies beyond Physiological Barriers and Drug Resistance: A Pilot Study and Review of the Literature Investigating If Intrathecal Trastuzumab and New Treatment Options Can Improve Oncologic Outcomes in Leptomeningeal Metastases from HER2-Positive Breast Cancer.

Leptomeningeal metastases (LM) are a rare but rapidly fatal complication defined by the spread of tumor cells within the leptomeninges and the subarachnoid space, found in approximately 10% of patients with HER2-positive breast cancers. This pilot study evaluated the efficacy of local treatment with intrathecal Trastuzumab (IT) added to systemic treatment. The oncologic outcome of 14 patients with HER2-positive LM is reported. Seven received IT, and seven received standard of care (SOC). The mean number of IT cycles administered was 12.14 ± 4.00. The response rate to CNS after IT treatment + SOC was 71.4%, and three patients (42.8%) obtained durable responses lasting more than 12 months. The median progression-free survival (mPFS) after LM diagnosis was six months, and the median overall survival (mOS) was ten months. The mean values of the PFS in favor of IT therapy (10.6 mo vs. 6.6 mo) and OS (13.7 vs. 9.3 mo) suggest a non-negligible investigation direction in the sense of exploiting intrathecal administration as a possible treatment modality in these patients. Adverse events reported were local pain related to intrathecal administration and one case of arachnoiditis, hematoma, and CSF fistulae. Intrathecal administration of Trastuzumab, alongside systemic treatment and radiotherapy, might improve oncologic outcomes in LM HER2-positive breast cancer with manageable toxicity.

Treatment of Leptomeningeal Carcinomatosis Following Treatment of Cerebellar Metastasis of HER2+ (Human Epidermal Growth Factor Receptor 2 Positive) Breast Cancer: Case Report and Review of Literature.

Leptomeningeal carcinomatosis (LC) after metastasis of breast cancer is a rare occurrence with potentially devastating complications. Treatment options are limited, and there is a lack of literature on this topic. We report the case of a 38-year-old woman with estrogen/progesterone receptor negative (ER/PR-), human epidermal growth factor receptor 2 positive (HER2+) invasive ductal carcinoma of the left breast who underwent bilateral mastectomies with axillary lymph node dissection and chemotherapy treatment. The patient returned 11 months later with persistent headaches. Imaging and resection found cerebellar metastasis of the breast carcinoma. The brain metastasis was treated with further chemotherapy and stereotactic radiosurgery. Follow-up imaging showed the development of small lesions outside the radiation site. Metabolic studies were performed to determine if the new lesions were due to tumor recurrence or radiation necrosis, but the studies were inconclusive as to the etiology of these lesions. The patient later developed LC that was successfully treated with full resolution of the disease using intrathecal trastuzumab. There are currently no consensuses on treatment guidelines for treating LC. Here, we demonstrate successful treatment of LC from an ER/PR-, HER2+ breast carcinoma with intrathecal trastuzumab.

A successful compartmental approach for the treatment of breast cancer brain metastases.

BACKGROUND: Brain metastases are challenging daily practice in oncology and remain a compartmental problem since most anti-cancer drugs do not cross the blood-brain barrier at relevant pharmacological concentrations. METHODS: In a young woman with HER2-overexpressing breast cancer resistant to standard treatments, at the time of brain metastases progression, a ventricular reservoir was implanted for intrathecal drug injections and detailed pharmacokinetic studies. RESULTS: A first association of intrathecal trastuzumab with intravenous cisplatin was offered to the patient. For trastuzumab, the mean cerebrospinal fluid trough concentration of 53.4 mg/L reached relevant levels, enabling the stabilization of the metastases. Adding intravenous cisplatin was not beneficial, since the cerebrospinal fluid exposure was almost undetectable under 0.08 mg/L. We then offered the patient an intrathecal combination of trastuzumab and methotrexate, because of their in vitro synergic cytotoxicity. The cerebrospinal fluid peak of methotrexate was 1037 µmol/L at 2 h, and the concentrations remained above the theoretical therapeutic concentration. After 2 months of this drug combination, we obtained an excellent response on the brain metastases. CONCLUSION: Our preliminary study supports the interest of a compartmental approach through a direct administration of drugs into the cerebrospinal fluid for the treatment of breast cancer brain metastases.

Intrathecal trastuzumab for leptomeningeal carcinomatosis in patients with human epidermal growth factor receptor 2 positive breast cancer.

There has been recent increase in incidence of leptomeningeal carcinomatosis, possibly due to widespread use of adjuvant trastuzumab and its known poor CNS penetration. Currently there are limited therapeutic options for these patients and outcome is poor. We report two cases of women with HER2 positive breast cancer who developed leptomeningeal carcinomatosis for which they were treated with intrathecal trastuzumab in combination with systemic therapy. Both patients had rapid symptomatic benefit and radiological response and remained progression free for at least seven months. Intrathecal trastuzumab can be considered a reasonable therapeutic option for these difficult to treat patients.

Sanctuary site leptomeningeal metastases in HER-2 positive breast cancer: A review in the era of trastuzumab.

The development of trastuzumab and other targeted systemic therapies has transformed the management of HER-2 positive breast cancers. However, as patients live longer and systemic therapies may not cross the blood brain barrier a rising number of patients are developing leptomeningeal metastases and brain metastases as a sanctuary site of disease. Intrathecal trastuzumab has been reported to treat these. We describe a breast cancer patient with HER-2 positive leptomeningeal disease in the spinal cord successfully treated with intrathecal trastuzumab and methotrexate, alongside systemic anti-HER-2 therapy and radiotherapy. We also review the literature to date on the efficacy and safety of intrathecal trastuzumab, and recent evidence suggesting that intrathecal trastuzumab passes via the blood brain barrier into the serum to achieve intravenous concentrations similar to that seen with systemic therapy alone. Overall, intrathecal trastuzumab appears to be a safe and often effective treatment for leptomeningeal metastases in HER-2 positive breast cancer. Ongoing phase I and II studies are required to determine optimum dosing schedules, validate CSF and CSF-to-serum pharmacokinetics, determine efficacy, and to assess the added benefits or disadvantages of prior radiotherapy and concomitant systemic therapy.

Intrathecal trastuzumab: immunotherapy improves the prognosis of leptomeningeal metastases in HER-2+ breast cancer patient.

We describe the clinical and therapeutic course of a 51-year-old woman with HER-2+ breast cancer who developed leptomeningeal (LM) and spinal cord metastases after 8 years of stable disease on combination therapy with intravenous (IV) trastuzumab. Due to progressive CNS disease, intrathecal (IT) trastuzumab was introduced to enhance HER-2+ therapy into the CSF space. A combination HER-2+ targeted approach achieved clinical remission with stable disease in our patient 46 months after she was diagnosed with LM metastases. However, spinal cord C-1 metastasis was not fully controlled with IT trastuzumab, ultimately leading to the patient's respiratory compromise. In our patient, IT trastuzumab immunotherapy improved prognosis and was an effective strategy to manage HER-2+ LM disease. Given alone or alongside other anti-HER-2+ therapeutics with sufficient CNS penetration, IT trastuzumab could extend the lifespan of patients with leptomeningeal and CNS metastases.