Treatment Patterns and Outcomes of Women with Symptomatic and Asymptomatic Breast Cancer Brain Metastases: A Single-Center Retrospective Study

BACKGROUND

Breast cancer is the most common cancer among women worldwide and the second leading cause of brain metastases (BrM). We assessed the treatment patterns and outcomes of women treated for breast cancer BrM at our institution in the modern era of stereotactic radiosurgery (SRS).

MATERIALS AND METHODS

We conducted a retrospective analysis of women (≥18 years of age) with metastatic breast cancer who were treated with surgery, whole brain radiotherapy (WBRT), or SRS to the brain at the Sunnybrook Odette Cancer Centre, Toronto, Canada, between 2008 and 2018. Patients with a history of other malignancies and those with an uncertain date of diagnosis of BrM were excluded. Descriptive statistics were generated and survival analyses were performed with subgroup analyses by breast cancer subtype.

RESULTS

Among 683 eligible patients, 153 (22.4%) had triple-negative breast cancer, 188 (27.5%) had HER2+, 246 (36.0%) had hormone receptor (HR)+/HER2-, and 61 (13.3%) had breast cancer of an unknown subtype. The majority of patients received first-line WBRT (n = 459, 67.2%) or SRS (n = 126, 18.4%). The median brain-specific progression-free survival and median overall survival (OS) were 4.1 months (interquartile range [IQR] 1.0-9.6 months) and 5.1 months (IQR 2.0-11.7 months) in the overall patent population, respectively. Age >60 years, presence of neurological symptoms at BrM diagnosis, first-line WBRT, and HER2- subtype were independently prognostic for shorter OS.

CONCLUSION

Despite the use of SRS, outcomes among patients with breast cancer BrM remain poor. Strategies for early detection of BrM and central nervous system-active systemic therapies warrant further investigation.

IMPLICATIONS FOR PRACTICE

Although triple-negative breast cancer and HER2+ breast cancer have a predilection for metastasis to the central nervous system (CNS), patients with hormone receptor-positive/HER2- breast cancer represent a high proportion of patients with breast cancer brain metastases (BrM). Hence, clinical trials should include patients with BrM and evaluate CNS-specific activity of novel systemic therapies when feasible, irrespective of breast cancer subtype. In addition, given that symptomatic BrM are associated with shorter survival, this study suggests that screening programs for the early detection and treatment of breast cancer BrM warrant further investigation in an era of minimally toxic stereotactic radiosurgery.

Incidence of Brain Metastases in Nonmetastatic and Metastatic Breast Cancer: Is There a Role for Screening?

BACKGROUND

Current National Comprehensive Cancer Network and American Society of Clinical Oncology guidelines recommend against screening breast cancer patients for asymptomatic brain metastases. Because brain metastases are a major cause of morbidity and mortality from breast cancer, we undertook a literature review to ascertain whether there might be a role for brain metastases screening in high-risk patient subgroups.

MATERIALS AND METHODS

A literature search was conducted on the OvidSP platform in the MedLine database, using MeSH terms and subject headings related to breast cancer, brain metastases, and incidence. The search was conducted without language or publication restrictions, and included articles indexed from January 1, 2006 to June 10, 2018. Experimental and observational studies that reported the incidence of brain metastases in patients with nonmetastatic or metastatic breast cancer were included.

RESULTS

One hundred seventy studies were identified, with 33 included in the final analysis. Among nonmetastatic breast cancer patients, incidence of brain metastases as site of first recurrence per year of median follow-up ranged from 0.1% to 3.2%. Although incidence of brain metastases was much higher among the metastatic breast cancer population overall, it was particularly high among metastatic HER2-overexpressing (HER2⁺) and triple-negative populations, ranging between 22% and 36% for the former, and 15%-37% for the latter in the absence of screening.

CONCLUSION

In patients with nonmetastatic breast cancer, screening for asymptomatic brain metastases cannot currently be justified. However, due to the high incidence of brain metastases among patients with metastatic HER2⁺ and triple-negative breast cancer, studies to determine the value of screening for brain metastases should be undertaken in these subgroups.

Clinical manifestations and location of brain metastases as prognostic markers

BACKGROUND

Brain metastases (BM) are a frequent complication of cancer and are regularly seen in clinical practice. New treatment modalities are improving survival after diagnosis of BM. However, symptoms are rarely reported and their significance is not well established. The aim of the present study was to investigate neurologic indicators as prognostic markers in patients with brain metastases.

PATIENTS AND METHODS

A prospectively acquired database from 2 referral centers was analyzed. All patients had had at least 2 neuro-oncologic consultations and magnetic resonance imaging to confirm the diagnosis. Patients were classified according to universally used prognostic scores, gender, primary tumor, localization of BM, and clinical complaints. Univariate and multivariate analysis was used to evaluate associations.

RESULTS

A total of 570 patients were included; 71% were female, and 91% had solid tumors. Median survival was 11 months (95% confidence interval 9.4-12.6). Of 1322 parenchymal lesions, 78% were supratentorial, and were most commonly in the frontal lobe. The most common symptoms were headache, vision changes, and weakness. Brain metastases in the brainstem were associated with a worse prognosis (P = 0.04). Visual complaints (P = 0.005), altered mental status, (P < 0.0001) and cranial neuropathy (P 0.001) were also associated with a poor outcome, as were poor performance status, more than 1 brain metastases, meningeal carcinomatosis, and uncontrolled primary cancer.

CONCLUSIONS

Both presenting symptoms and the location of brain metastases have prognostic significance and should be further studied, both as independent prognostic predictors and in conjunction with other factors used in prognostic scores.

The economic burden of brain metastasis among lung cancer patients in the United States

OBJECTIVE

Brain metastases among lung cancer patients can impair cognitive and functional ability, complicate care, and reduce survival. This study focuses on the economic burden of brain metastasis in lung cancer-direct healthcare costs to payers and indirect costs to patients, payers, and employers-in the US.

METHODS

Retrospective study using claims data from over 60 self-insured Fortune 500 companies across all US census regions (January 1999-March 2013). Adult, non-elderly lung cancer patients with brain metastasis were evaluated over two study periods: (1) pre-diagnosis (≤30 days prior to first observed lung cancer diagnosis to ≤30 days prior to first-observed brain metastasis diagnosis) and (2) post-diagnosis (≤30 days prior to first observed brain metastasis diagnosis to end of continuous eligibility or observation).

OUTCOME MEASURES

Healthcare costs to payers and resource utilization, salary loss to patients, disability payouts for payers, and productivity loss to employers.

RESULTS

A total of 132 patients were followed for a median of 8.4 and 6.6 months in the pre- and post-diagnosis periods, respectively. At diagnosis of brain metastasis, 21.2% of patients were on leave of absence and 6.1% on long-term disability leave. Substantial differences were observed in the pre- vs post-diagnosis periods. Specifically, patients incurred much greater healthcare utilization in the post-diagnosis period, resulting in $25,579 higher medical costs per-patient-per-6-months (PPP6M). During this period, patients missed significantly more work days, generating an incremental burden of $2853 PPP6M in salary loss for patients, $2557 PPP6M in disability payments for payers, and $4570 PPP6M in productivity loss for employers.

LIMITATIONS

Type of primary lung cancer and extent of brain metastasis could not be assessed in the data. The analysis was also limited to patients with comprehensive disability coverage.

CONCLUSIONS

Development of brain metastasis among lung cancer patients is associated with a substantial economic burden to payers, patients, and employers.

Exploring factors related to metastasis free survival in breast cancer patients using Bayesian cure models

BACKGROUND

Breast cancer is a fatal disease and the most frequently diagnosed cancer in women with an increasing pattern worldwide. The burden is mostly attributed to metastatic cancers that occur in one-third of patients and the treatments are palliative. It is of great interest to determine factors affecting time from cancer diagnosis to secondary metastasis.

MATERIALS AND METHODS

Cure rate models assume a Poisson distribution for the number of unobservable metastatic-component cells that are completely deleted from the non-metastasis patient body but some may remain and result in metastasis. Time to metastasis is defined as a function of the number of these cells and the time for each cell to develop a detectable sign of metastasis. Covariates are introduced to the model via the rate of metastatic-component cells. We used non-mixture cure rate models with Weibull and log-logistic distributions in a Bayesian setting to assess the relationship between metastasis free survival and covariates.

RESULTS

The median of metastasis free survival was 76.9 months. Various models showed that from covariates in the study, lymph node involvement ratio and being progesterone receptor positive were significant, with an adverse and a beneficial effect on metastasis free survival, respectively. The estimated fraction of patients cured from metastasis was almost 48%. The Weibull model had a slightly better performance than log-logistic.

CONCLUSIONS

Cure rate models are popular in survival studies and outperform other models under certain conditions. We explored the prognostic factors of metastatic breast cancer from a different viewpoint. In this study, metastasis sites were analyzed all together. Conducting similar studies in a larger sample of cancer patients as well as evaluating the prognostic value of covariates in metastasis to each site separately are recommended.