Elsevier

Lung Cancer

Volume 63, Issue 1, January 2009, Pages 140-145
Lung Cancer

Non-small cell lung cancer and silent brain metastasis: Survival and prognostic factors

https://doi.org/10.1016/j.lungcan.2008.04.013Get rights and content

Summary

The detection of silent brain metastasis is becoming increasingly common in patients with non-small cell lung cancer (NSCLC). The aim of this study was to evaluate clinical course, prognostic significance, and treatment efficacy in patients with asymptomatic brain metastasis. A retrospective study of patients with cytologically and histologically diagnosed NSCLC and brain metastasis detected by cranial computed tomography or magnetic resonance imaging was performed. We compared 12 neurologically asymptomatic patients to 69 symptomatic patients and analyzed overall survival, clinical course, and prognostic factors (age, sex, performance status, histologic type, TNM stage, number and size of brain metastases, clinical neurologic status, and treatment of primary tumor and brain metastasis). The strongest favorable prognostic factor was active treatment of both the primary tumor (surgery, chemotherapy and/or thoracic radiotherapy) and brain metastasis (neurosurgery and/or whole brain radiotherapy). Neurologically asymptomatic patients had significantly longer survival times than did symptomatic patients (median survival of 7.5 and 4 months, respectively). Control of clinical neurologic status during follow-up was achieved in a greater proportion of asymptomatic patients (80%) than symptomatic patients (40%). We conclude that it is important to detect brain metastasis in patients with NSCLC before neurologic signs or symptoms develop, as early detection improves prognosis and provides patients with the opportunity of receiving timely and more effective treatment.

Introduction

With the increasingly widespread use of cranial computed tomography (CT) and cranial magnetic resonance imaging (MRI) to stage patients with non-small cell lung cancer (NSCLC), it is common to detect small metastases, even in neurologically asymptomatic patients [1], [2], [3], [4], [5].

The overall survival of patients with brain metastases is generally poor, ranging from about 3 to 6 months [6], [7], [8], [9], although certain patients may benefit from active treatment and survive longer. Performance status, age <65 years, absence of extracranial metastasis and a primary tumor that can be controlled with treatment, and a single surgically accessible metastasis are well-known predictors of a good prognosis [6], [7], [10], [11]. There is little information available about the prognostic significance of asymptomatic brain metastasis [12], even though the detection of such metastasis commonly affects treatment decisions.

The present study aimed to determine clinical course, prognostic significance, and treatment efficacy in patients with asymptomatic brain metastasis and to compare the results with those in patients with metastasis who were diagnosed following the development of neurologic signs or symptoms.

Section snippets

Patients and methods

We performed a retrospective analysis of patients with NSCLC and brain metastasis detected by cranial CT, cranial MRI, or both. The records of patients diagnosed between 1 January 1996 and 31 June 2007 were reviewed to include those with a cytohistologic diagnosis of NSCLC and brain metastasis detected by cranial CT or MRI during initial staging or follow-up. Patients were classified as neurologically symptomatic or asymptomatic at the time of detection. Brain metastasis was classified as

Results

Of the 476 patients diagnosed with lung cancer between 1 January 1996 and 31 June 2007 who had at least 1 cranial CT or MRI study, 81 had histologically proven NSCLC and radiologically diagnosed brain metastasis. Twelve of these patients were neurologically asymptomatic and 69 were symptomatic. Table 1 shows the characteristics of the patients from each group. Asymptomatic patients had better performance status than symptomatic ones (p = 0.048) as well as a higher rate of synchronous brain

Discussion

Although the negative predictive value of negative findings for signs of brain metastasis in clinical evaluation is high [13], a number of recent studies involving the use of cranial MRI in neurologically asymptomatic patients with NSCLC have shown that silent brain metastasis is more common than previously thought, especially in patients with adenocarcinoma [2], [3], [4], [5]. This could be because cranial MRI performs better than CT in detecting very small lesions [6], [8], [10], [11], [14].

Conflict of interest

None.

Acknowledgments

This study has been partially financed by a grant from the Respiratory Society of Extremadura (SEAR). M.E. Kerans and A. Murray assisted with the English expression in certain versions of the manuscript.

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