Prognostic Value of Brain Metastasis-Free Interval in Patients with Breast Cancer Brain Metastases

The clinical, molecular, and therapeutic implications of time from primary diagnosis to brain metastasis in lung and breast cancer patients

PURPOSE

Lung cancer (LC) and breast cancer (BC) are the most common causes of brain metastases (BMs). Time from primary diagnosis to BM (TPDBM) refers to the time interval between initial LC or BC diagnosis and development of BM. This research aims to identify clinical, molecular, and therapeutic risk factors associated with shorter TPDBM.

METHODS

We retrospectively reviewed all diagnosed LC and BC patients with BM at Harbin Medical University Cancer Hospital from 2016 to 2020. A total of 570 patients with LC brain metastasis (LCBM) and 173 patients with breast cancer brain metastasis (BCBM) patients who met the inclusion criteria were enrolled for further analysis. BM free survival time curves were generated using Kaplan-Meier analyses. Univariate and multivariate Cox regression analyses were applied to identify risk factors associated with earlier development of BM in LC and BC, respectively.

RESULTS

The median TPDBM was 5.3 months in LC and 44.4 months in BC. In multivariate analysis, clinical stage IV and M1 stage were independent risk factors for early development of LCBM. LC patients who received chemotherapy, targeted therapy, pulmonary radiotherapy, and pulmonary surgery had longer TPDBM. For BC patients, age ≥ 50 years, Ki67 ≥ 0.3, HER2 positive or triple-negative breast cancer subtype, advanced N stage, and no mastectomy were correlated with shorter TPDBM.

CONCLUSIONS

This single-institutional study helps identify patients who have a high risk of developing BM early. For these patients, early detection and intervention could have clinical benefits.

Predictors of Survival in Patients with Metastatic Brain Tumors: Experience from a Low-to-Middle-Income Country

Objective The interplay of static factors and their effect on metastatic brain tumor survival, especially in low-to-middle-income countries (LMICs), has been rarely studied. To audit our experience, and explore novel survival predictors, we performed a retrospective analysis of brain metastases (BM) patients at Shaukat Khanum Memorial Cancer Hospital (SKMCH), Pakistan.

Materials and Methods A retrospective review was conducted of consecutive patients who presented with BM between September 2014 and September 2019 at SKMCH. Patients with incomplete records were excluded.

Statistical Analysis SPSS (v.25 IBM, Armonk, New York, United States) was used to collect and analyze data via Cox-Regression and Kaplan–Meier curves.

Results One-hundred patients (mean age 45.89 years) with confirmed BM were studied. Breast cancer was the commonest primary tumor. Median overall survival (OS) was 6.7 months, while the median progression-free survival (PFS) was 6 months. Age (p = 0.001), gender (p = 0.002), Eastern Cooperative Oncology Group (p < 0.05), anatomical site (p = 0.002), herniation (p < 0.05), midline shift (p = 0.002), treatment strategies (p < 0.05), and postoperative complications (p < 0.05) significantly impacted OS, with significantly poor prognosis seen with extremes of age, male gender (hazard ratio [HR]: 2.0; 95% confidence interval [CI]: 1.3–3.1; p = 0.003), leptomeningeal lesions (HR: 5.7; 95% CI: 1.1–29.7; p = 0.037), and patients presenting with uncal herniation (HR: 3.5; 95% CI: 1.9–6.3; p < 0.05). Frontal lobe lesions had a significantly better OS (HR: 0.5; 95% CI: 0.2–1.0; p = 0.049) and PFS (HR: 0.08; 95% CI: 0.02–0.42; p = 0.003).

Conclusion BM has grim prognoses, with comparable survival indices between developed countries and LMICs. Early identification of both primary malignancy and metastatic lesions, followed by judicious management, is likely to significantly improve survival.

Breast cancer subtype predicts clinical outcomes after stereotactic radiation for brain metastases

PURPOSE

We investigated the prognostic ability of tumor subtype for patients with breast cancer brain metastases (BCBM) treated with stereotactic radiation (SRT).

METHODS

This is a retrospective review of 181 patients who underwent SRT to 664 BCBM from 2004 to 2019. Patients were stratified by subtype: hormone receptor (HR)-positive, HER2-negative (HR+/HER2-), HR-positive, HER2-positive (HR+/HER2+), HR-negative, HER2-positive (HR-/HER2+), and triple negative (TN). The Kaplan-Meier method was used to calculate overall survival (OS), local control (LC), and distant intracranial control (DIC) from the date of SRT. Multivariate analysis (MVA) was conducted using the Cox proportional hazards model.

RESULTS

Median follow up from SRT was 11.4 months. Of the 181 patients, 47 (26%) were HR+/HER2+, 30 (17%) were HR-/HER2+, 60 (33%) were HR+/HER2-, and 44 (24%) were TN. Of the 664 BCBMs, 534 (80%) received single fraction stereotactic radiosurgery (SRS) with a median dose of 21 Gy (range 12-24 Gy), and 130 (20%) received fractionated stereotactic radiation therapy (FSRT), with a median dose of 25 Gy (range 12.5-35 Gy) delivered in 3 to 5 fractions. One-year LC was 90%. Two-year DIC was 35%, 23%, 27%, and 16% (log rank, p = 0.0003) and 2-year OS was 54%, 47%, 24%, and 12% (log rank, p < 0.0001) for HR+/HER2+, HR-/HER2+, HR+/HER2-, and TN subtypes, respectively. On MVA, the TN subtype predicted for inferior DIC (HR 1.62, 95% CI 1.00-2.60, p = 0.049). The modified breast-Graded Prognostic Assessment (GPA) significantly predicted DIC and OS (both p < 0.001).

CONCLUSIONS

Subtype is prognostic for OS and DIC for patients with BCBM treated with SRT.

Endocrine therapy for the treatment of leptomeningeal carcinomatosis in luminal breast cancer: a comprehensive review

Leptomeningeal disease (LMD) represents a devastating complication of advanced breast cancer (ABC), with survival of <5 months with multimodal treatment. The role of endocrine therapy (ET), due to its favorable toxicity profile and first-line indication in luminal ABC, appears promising in the setting of LMD, where symptom stabilization and quality-of-life preservation are the main goals; however, evidenced-based data are lacking. We conducted a thorough review of published evidence, aiming to investigate the role of ET in LMD treatment in luminal ABC. Twenty-one of 342 articles, evaluating 1302 patients, met inclusion criteria. ET use was rarely reported. New targeted agents show CNS activity. Research is lacking on the role of ET and targeted agents in BC-LMD treatment.

Prescription of memantine during non-stereotactic, brain-directed radiation among patients with brain metastases: a population-based study

PURPOSE

Whole brain radiation therapy (WBRT) remains an important component of treatment for patients with multiple brain metastases (BrM) but is associated with significant neurotoxicity and memory impairment. Although RTOG 0614 demonstrated that administration of memantine to patients receiving WBRT may reduce radiation-associated cognitive decline, prior literature has suggested that radiation oncologists are hesitant to prescribe memantine. We sought to assess the frequency of memantine prescription in patients managed with non-stereotactic, brain-directed radiation for BrM.

METHODS

Patients > 65 years old with newly diagnosed BrM between 2007 and 2016 receiving non-stereotactic, brain-directed radiation (including WBRT) were identified using the SEER-Medicare database. Receipt of memantine with non-stereotactic, brain-directed radiation was defined as any Part D claim for memantine 30 days before or after initiation of non-stereotactic, brain-directed radiation. Clinical and demographic variables among patients who did and did not receive memantine were compared.

RESULTS

Between 2007 and 2016, we identified 6220 patients with BrM receiving non-stereotactic, brain-directed radiation. Only 2.20% of patients (n = 137) received memantine with radiation. Rates were 1.10% versus 5.14% in the period preceding (2007-2013) and following (2014-2016) the publication of RTOG 0614, respectively. Overall utilization of memantine remained low across several clinical, demographic, and prognostic variables.

CONCLUSION

Despite phase 3 evidence supporting memantine utilization among patients receiving WBRT, our population-based study indicates that rates of memantine prescription are strikingly low, although memantine utilization seems to be increasing since publication of RTOG 0614. Further investigation is needed to identify provider and practice-related barriers preventing incorporation of memantine into management paradigms.