Summary report on the graded prognostic assessment: an accurate and facile diagnosis-specific tool to estimate survival for patients with brain metastases

Combined primary tumor and extracranial metastasis status as constituent factor of prognostic indices for predicting the overall survival in patients with brain metastases

We retrospectively analyzed the prognostic factors on overall survival (OS) in patients with brain metastasis (BM) and evaluated the role of combined primary tumor and extracranial metastasis (ECM) status as a constituent factor for prognostic index. This study involved 897 patients with BMs who underwent radiotherapy between April 2003 and December 2009. Among the clinical parameters, multivariate analysis showed that age, Karnofsky performance status (KPS), combined primary tumor and ECM status, number of BMs, and treatment group were significant prognostic factors for OS (P < 0.05). To compare the discriminatory ability of 5 prognostic indices, i.e., recursive partitioning analysis (RPA), basic score for BMs (BSBM), score index for radiosurgery (SIR), graded prognostic assessment (GPA), and modified GPA including the combined primary tumor and ECM status (mGPA), the Akaike information criteria (AIC) were calculated. The mGPA showed the lowest AIC value, followed by RPA, GPA, SIR, and BSBM, in that order. It is implicated that modified score of pre-existing factors (i.e., age and KPS) and addition of the combined primary tumor and ECM status to the prognostic index can improve its discriminatory ability and the combined primary tumor and ECM status may be useful as one of constituent factors for prognostic index.

Optimal management of brain metastases from breast cancer. Issues and considerations

The incidence of brain metastases (BM) in breast cancer patients has increased over the last decade, presumably due to advances in systemic treatment. Today, breast cancer is the second most common cause of BM among all solid malignancies, second only to lung cancer; furthermore, it is the most common cause of leptomeningeal carcinomatosis. The HER2-positive subtype was consistently shown to have a higher risk for BM as compared with HER2-negative disease. More recently, however, it was shown that a similar incidence exists in triple-negative tumours. Local treatment options, radiotherapy and neurosurgical resection, remain the mainstay of therapy for BM. While some studies have suggested a direct effect of conventional chemotherapy on BM, the main beneficial aspect of systemic treatment is rather due to control of non-CNS systemic disease. Importantly, in patients with HER2-positive breast cancer receiving HER2-targeted therapy after local treatment for BM, superior survival outcomes were reported. Leptomeningeal carcinomatosis has a dismal prognosis. Survival with whole brain radiotherapy alone remains short and the potential additional benefit of intrathecal chemotherapy is still disputed. According to case reports, intrathecal administration of trastuzumab appears to be a promising strategy in patients with HER2-positive leptomeningeal carcinomatosis. In conclusion, while the outcome of breast cancer patients with BM has improved especially in the HER2-positive subtype, the prognosis for the majority of patients remains poor. Therefore, development of novel systemic treatment options offering activity within the brain is urgently warranted. Novel insights into the pathobiology of BM formation may offer the possibility for targeted drug prophylaxis of CNS involvement in high-risk patients.

Population-based outcomes after brain radiotherapy in patients with brain metastases from breast cancer in the Pre-Trastuzumab and Trastuzumab eras

PURPOSE

To evaluate the survival of patients with human epidermal growth factor receptor 2 (HER2) positive and negative metastatic breast cancer irradiated for brain metastases before and after the availability of trastuzumab (T).

MATERIALS AND METHODS

Women diagnosed with brain metastasis from breast cancer in two eras between 2000 and 2007 (T-era, n = 441) and 1986 to 1992 (PreT-era, n = 307), treated with whole brain radiotherapy (RT) were identified. In the T-era, HER2 testing was part of routine clinical practice, and in the preT-era 128/307 (42%) cases had HER2 testing performed retrospectively on tissue microarrays. Overall survival (OS) was estimated using the Kaplan-Meier method and comparisons between eras used log-rank tests.

RESULTS

In the preT- and T-era cohorts, the rate of HER2 positivity was 40% (176/441) and 26% (33/128) (p < 0.001). The median time from diagnosis to brain RT was longer in the preT-era (3.3 years versus 2.3 years, p < 0.001). Survival after brain RT was improved in the T-era compared to the preT-era (1-year OS 26% versus 12%, p < 0.001). The 1-year OS rate for HER2 negative patients was 20% in both eras (p = 0.97). Among HER2 positive patients, the 1-year OS in the preT-era was 5% compared to 40% in the T-era (p < 0.001).

CONCLUSIONS

Distinct from patients with HER2 negative disease in whom no difference in survival after brain RT was observed over time, patients with HER2 positive brain metastases experienced significantly improved survival subsequent to the availability of trastuzumab.

Current advances in understanding and managing secondary brain metastasis

Metastatic brain tumors are the number one cause of intracranial neoplasms in adults and are associated with higher morbidity and mortality. The frequency of metastatic brain tumors is increasing because of improved survival in cancer patients. The molecular mechanism of brain metastasis is complex and not completely known. Vasogenic edema produced by tumor-derived VEGF is responsible for clinical symptoms. Dexamethasone remains the mainstay of medical management with not completely known mechanisms of action. Surgery and radiation are the main treatment modalities for metastatic brain tumors. Systemic chemotherapy has a very limited role in treatment of these tumors. Leptomeningeal metastasis is associated with extremely poor outcome.

Gamma knife stereotactic radiosurgery for renal cell carcinoma and melanoma brain metastases-comparison of dose response

BACKGROUND

Metastatic melanoma appears to have inferior local control (LC) than renal cell carcinoma (RCC) after stereotactic radiosurgery (SRS) to the brain.

OBJECTIVE

To retrospectively examine RCC vs. melanoma LC dose response.

METHODS

Follow-up data were available for 88 patients (RCC=38; melanoma=50) with 235 tumors (RCC=92; melanoma=143) treated with Gamma Knife SRS between Dec. 2005 to Aug. 2012. LC was compared among RCC vs. melanoma and then at each margin dose (≤18Gy, 20Gy, 22Gy, and 24Gy). Patient survival and toxicity were analyzed. Median follow-up was 9.8 months (RCC) and 5.4 months (melanoma).

RESULTS

Patient characteristics were similar between RCC vs. melanoma with respect to gender, age, KPS, GPA, lesions per patient, and tumor volume. For all margin doses, LC at 6 months was 98.6% (RCC) vs. 79.2% (melanoma). When broken down by margin dose, at ≤18 Gy (P<0.0001) and 20 Gy (P=0.02), RCC had better LC compared to melanoma. At 22 Gy, LC were similar between the two histologies (P=0.19). At 24 Gy, melanoma had better LC than RCC (P=0.02). Tumor volumes were similar between RCC vs. melanoma at each margin dose (P>0.05). Small melanoma tumors (<4ml) exhibited LC dose dependence. Median survival was 16.1 months (RCC) and 9.6 months (melanoma). Toxicity was not significantly different between the two histologies and margin doses.

CONCLUSIONS

RCC has significantly better LC than melanoma after SRS. Higher doses could be used for melanoma tumors <4ml to improve melanoma LC.

Multidisciplinary approach to brain metastasis from melanoma; local therapies for central nervous system metastases

The overall treatment paradigm for melanoma brain metastases continues to evolve and reflects the relative radioresistance of this histology, as well as the effect of emerging systemic therapies with central nervous system (CNS) activity. Local therapies, including surgery, whole brain radiotherapy (WBRT), and stereotactic radiosurgery (SRS), play an important role in the multidisciplinary management of melanoma brain metastases. Treatment selection for local therapies must consider many factors: (1) size, number, and location of lesions, (2) presence or absence of neurological symptoms, (3) extracranial disease status, expected survival, age, and performance status, (4) prior treatment history, (5) expected treatment toxicities, and (6) predicted response to systemic therapies. The choice of treatment modalities for brain metastases is among the most controversial areas in oncology. There has been a trend toward reduced use of WBRT and increased reliance on SRS and surgery for melanoma brain metastases. Although no prospective randomized data exist comparing local therapies for melanoma brain metastases, several large retrospective studies suggest aggressive local treatment with modalities including surgery and SRS are associated with favorable outcomes in select patients. Multidisciplinary collaboration is required to facilitate a treatment plan that balances reduction in risk of neurological death and symptomatic progression against the risk of treatment-related toxicity.

EGFR mutations are associated with favorable intracranial response and progression-free survival following brain irradiation in non-small cell lung cancer patients with brain metastases

BACKGROUND

The presence of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) is associated with increased radiosensitivity in vitro. However, the results from clinical studies regarding the radiosensitivity in NSCLC with mutant EGFR are inconclusive. We retrospectively analyzed our NSCLC patients who had been regularly followed up by imaging studies after irradiation for brain metastases, and investigated the impact of EGFR mutations on radiotherapy (RT).

METHODS

Forty-three patients with brain metastases treated with RT, together with EGFR mutation status, demographics, smoking history, performance status, recursive partitioning analysis (RPA) class, tumor characteristics, and treatment modalities, were included. Radiological images were taken at 1 to 3 months after RT, and 3 to 6 months thereafter. Radiographic response was evaluated by RECIST criteria version 1.1 according to the intracranial images before and after RT. Log-rank test and Cox regression model were used to correlate EGFR mutation status and other clinical features with intracranial radiological progression-free survival (RPFS) and overall survival (OS).

RESULTS

The median follow-up duration was 15 months. Patients with mutant EGFR had higher response rates to brain RT than those with wild-type EGFR (80% vs. 46%; p = 0.037). Logistic regression analysis showed that EGFR mutation status is the only predictor for treatment response (p = 0.032). The median intracranial RPFS was 18 months (95% CI = 8.33-27.68 months). In Cox regression analysis, mutant EGFR (p = 0.025) and lower RPA class (p = 0.026) were associated with longer intracranial RPFS. EGFR mutation status (p = 0.061) and performance status (p = 0.076) had a trend to predict OS.

CONCLUSIONS

Mutant EGFR in NSCLC patients is an independent prognostic factor for better treatment response and longer intracranial RPFS following RT for brain metastases.

Diagnosis-specific graded prognostic assessment score is valid in patients with brain metastases treated in routine clinical practice in two European countries

Background

Assessment of cancer- and host-related prognostic factors has a long tradition in patients with brain metastases. In continuation of large-scale studies performed by the Radiation Therapy Oncology Group (RTOG) in the United States, the 4-tiered diagnosis-specific graded prognostic assessment (DS-GPA) score has been developed. It stratifies patients with common primary tumours metastasizing to the brain (malignant melanoma, lung, breast, kidney and gastrointestinal cancers) into subgroups with different prognoses. However, many patients in the DS-GPA study were treated with surgical resection or radiosurgery (SRS). The present multi-institutional analysis examined for the first time whether DS-GPA is a valid score in European patients managed in routine clinical practice.

Material/Methods

This was a retrospective analysis of 412 patients with primary malignant melanoma, lung, breast, kidney or gastrointestinal cancers. Survival was evaluated in uni- and multivariate tests.

Results

DS-GPA significantly predicted survival and outperformed initial GPA, a score that is not diagnosis-specific. Median survival by DS-GPA strata (all 412 patients) was 2.7, 3.6, 7.0 and 11.3 months in the 4 groups with 0–1, 1.5–2, 2.5–3 and 3.5–4 points, respectively. The previously published survival data (median 7.2 months for all patients) could not be replicated in this cohort (median 3.6 months).

Conclusions

DS-GPA is a valid prognostic score that might improve shared decision making as well as patient stratification in prospective clinical trials.

Extent of peritumoral brain edema correlates with prognosis, tumoral growth pattern, HIF1a expression and angiogenic activity in patients with single brain metastases

To analyze the prognostic value of the extent of peritumoral brain edema in patients operated for single brain metastases (BM), we retrospectively evaluated pre-operative magnetic resonance images in a discovery cohort of 129 patients and a validation cohort of 118 patients, who underwent neurosurgical resection of a single BM in two different hospitals. We recorded clinical parameters and immunohistochemically assessed the Ki67 index, the microvascularization patterns and the expression of hypoxia-induced factor 1 alpha (HIF1a) in the BM tissue specimens retrieved at neurosurgery. Statistical analysis including uni- and multivariate survival analyses were performed. Baseline characteristics were well balanced between the discovery and validation cohorts. In univariate analysis, we found a significant association of favorable overall survival time with young patient age, high Karnofsky performance score, low graded prognostic assessment (GPA) class, absence of extracranial metastases, adjuvant treatment with whole brain radiotherapy and, surprisingly, large brain edema. In multivariate analysis, only GPA and extent of brain edema remained independent prognostic parameters. The prognostic impact of the extent of brain edema was consistent in the two patient cohorts. Furthermore, we found a significant correlation of small brain edema with brain-invasive tumor growth pattern as assessed intraoperatively by the neurosurgeon, low neo-angiogenic activity and low expression of HIF1a. Extent of brain edema independently correlates with prognosis in patients operated for single BM. In conclusion, patients with small peritumoral edema have shorter survival times and their tumors are characterized by a more brain-invasive growth, lower HIF1a expression and less angiogenic activity.

Brain-only metastatic breast cancer is a distinct clinical entity characterised by favourable median overall survival time and a high rate of long-term survivors

BACKGROUND

The clinical course of breast cancer patients with brain metastases (BM) as only metastatic site (brain-only metastatic breast cancer (BO-MBC)) has been insufficiently explored.

METHODS

All breast cancer patients with BM treated at our institution between 1990 and 2011 were identified. For each patient, full information on follow-up and administered therapies was mandatory for inclusion. Oestrogen receptor, progesterone receptor and Her2 status were determined according to standard protocols. Statistical analyses including computation of survival probabilities was performed.

RESULTS

In total, 222 female patients (26% luminal; 47% Her2; 27% triple negative) with BM of MBC were included in this study. In all, 38/222 (17%) BM patients did not develop extracranial metastases (ECM) during their disease course and were classified as BO-MBC. Brain-only-MBC was not associated with breast cancer subtype or number of BM. The median overall survival of BO-MBC patients was 11 months (range 0-69) and was significantly longer than in patients with BM and ECM (6 months, range 0-104; P=0.007). In all, 7/38 (18%) BO-MBC patients had long-term survival of >3 years after diagnosis of BM and long-term survival was significantly more common in BO-MBC patients as compared with BM patients with ECM (P<0.001).

CONCLUSIONS

Brain-only metastatic behaviour occurs in around 17% of breast cancer with BM and is not associated with breast cancer subtype. Exploitation of all multimodal treatment options is warranted in BO-MBC patients, as these patients have favourable prognosis and long-term survival is not uncommon.

Trial design on prophylaxis and treatment of brain metastases: lessons learned from the EORTC Brain Metastases Strategic Meeting 2012

Brain metastases (BM) occur in a significant proportion of cancer patients and are associated with considerable morbidity and poor prognosis. The trial design in BM patients is particularly challenging, as many disease and patient variables, statistical issues, and the selection of appropriate end-points have to be taken into account. During a meeting organised on behalf of the European Organisation for Research and Treatment of Cancer (EORTC), methodological aspects of trial design in BM were discussed. This paper summarises the issues and potential trial strategies discussed during this meeting and may provide some guidance for the design of trials in BM patients.

Temozolomide and unusual indications: review of literature

Temozolomide (TMZ) was first known to be useful as a radiosensitiser in both primary brain tumours like glioblastoma multiforme and oligodendroglioma. Later, TMZ proved its efficacy in the treatment of melanoma. Multiple publications have demonstrated the benefit of TMZ in terms of efficacy and tolerance (used as mono-therapy or as adjuvant chemotherapy) compared to the "gold standard" treatment of this kind of tumours. Furthermore, several recent clinical trials have shown the particular importance of TMZ in other types of cancer. This publication deals with the use of TMZ in cancers which are not formal indications for TMZ (excluding glioblastoma multiforme, oligodendroglioma and melanoma). It also includes a necessary review of recent literature about the role of TMZ in the treatment of brain metastases, lymphomas, refractory leukaemia, neuroendocrine tumours, pituitary tumours, Ewing's sarcoma, primitive neuroectodermal tumours, lung cancer and other tumours.

Postoperative stereotactic radiosurgery without whole-brain radiation therapy for brain metastases: potential role of preoperative tumor size

PURPOSE

Radiation therapy following resection of a brain metastasis increases the probability of disease control at the surgical site. We analyzed our experience with postoperative stereotactic radiosurgery (SRS) as an alternative to whole-brain radiotherapy (WBRT), with an emphasis on identifying factors that might predict intracranial disease control and overall survival (OS).

METHODS AND MATERIALS

We retrospectively reviewed all patients through December 2008, who, after surgical resection, underwent SRS to the tumor bed, deferring WBRT. Multiple factors were analyzed for time to intracranial recurrence (ICR), whether local recurrence (LR) at the surgical bed or "distant" recurrence (DR) in the brain, for time to WBRT, and for OS.

RESULTS

A total of 49 lesions in 47 patients were treated with postoperative SRS. With median follow-up of 9.3 months (range, 1.1-61.4 months), local control rates at the resection cavity were 85.5% at 1 year and 66.9% at 2 years. OS rates at 1 and 2 years were 52.5% and 31.7%, respectively. On univariate analysis (preoperative) tumors larger than 3.0 cm exhibited a significantly shorter time to LR. At a cutoff of 2.0 cm, larger tumors resulted in significantly shorter times not only for LR but also for DR, ICR, and salvage WBRT. While multivariate Cox regressions showed preoperative size to be significant for times to DR, ICR, and WBRT, in similar multivariate analysis for OS, only the graded prognostic assessment proved to be significant. However, the number of intracranial metastases at presentation was not significantly associated with OS nor with other outcome variables.

CONCLUSIONS

Larger tumor size was associated with shorter time to recurrence and with shorter time to salvage WBRT; however, larger tumors were not associated with decrements in OS, suggesting successful salvage. SRS to the tumor bed without WBRT is an effective treatment for resected brain metastases, achieving local control particularly for tumors up to 3.0 cm diameter.

Clinical application of RapidArc volumetric modulated arc therapy as a component in whole brain radiation therapy for poor prognostic, four or more multiple brain metastases

Purpose

To determine feasibility of RapidArc in sequential or simultaneous integrated tumor boost in whole brain radiation therapy (WBRT) for poor prognostic patients with four or more brain metastases.

Materials and Methods

Nine patients with multiple (≥4) brain metastases were analyzed. Three patients were classified as class II in recursive partitioning analysis and 6 were class III. The class III patients presented with hemiparesis, cognitive deficit, or apraxia. The ratio of tumor to whole brain volume was 0.8-7.9%. Six patients received 2-dimensional bilateral WBRT, (30 Gy/10-12 fractions), followed by sequential RapidArc tumor boost (15-30 Gy/4-10 fractions). Three patients received RapidArc WBRT with simultaneous integrated boost to tumors (48-50 Gy) in 10-20 fractions.

Results

The median biologically effective dose to metastatic tumors was 68.1 Gy₁₀ and 67.2 Gy₁₀ and the median brain volume irradiated more than 100 Gy₃ were 1.9% (24 cm³) and 0.8% (13 cm³) for each group. With less than 3 minutes of treatment time, RapidArc was easily applied to the patients with poor performance status. The follow-up period was 0.3-16.5 months. Tumor responses among the 6 patients who underwent follow-up magnetic resonance imaging were partial and stable in 3 and 3, respectively. Overall survival at 6 and 12 months were 66.7% and 41.7%, respectively. The local progression-free survival at 6 and 12 months were 100% and 62.5%, respectively.

Conclusion

RapidArc as a component in whole brain radiation therapy for poor prognostic, multiple brain metastases is an effective and safe modality with easy application.

Prediction of outcomes for patients with brain parenchymal metastases from breast cancer (BC): a new BC-specific prognostic model and a nomogram

The purpose of this study is to validate the recently published Breast-Graded Prognostic Assessment (GPA) and propose a new prognostic model and nomogram for patients with brain parenchymal metastases (BM) from breast cancer (BC). We retrospectively investigated 171 consecutive patients who received a diagnosis of BM from BC during 2000-2008. We appraised the recently proposed Sperduto's BC-specific GPA in training cohort through Kaplan-Meier survival curve using log-rank test and area under the curve for the BC-GPA predicting overall survival at 1 year and developed a new nomogram to predict outcomes using multivariate Cox-regression analysis. By putting the Sperduto's Breast-GPA together with our nomogram, we developed a new prognostic model. We validated our new prognostic model with an independent external patient cohort from 2 institutes for the same period. On the basis of our Cox-regression analysis, therapeutic effect of trastuzumab and status of extracranial systemic disease control were incorporated into our new prognostic model in addition to Karnofsky performance status, age, and hormonal status. Our new prognostic model showed significant discrimination in median survival time, with 3.7 months for class I (n = 15), 7.8 months for class II (n = 82), 10.7 months for class III (n = 42), and 19.2 months for class IV (n = 32; P < .0001). The new prognostic model accurately predicted survival among patients with BC from BM in an external validation cohort (P < .0001). We propose a new prognostic model and a nomogram reflecting the different biological features of BC, including treatment effect and status of extracranial disease control, which was excellently validated in an independent external cohort.

Brain metastases in patients under 50 years of age: retrospective analysis

Several previous publications suggested that younger patients with brain metastases have longer survival than older patients. However, detailed studies of younger patient groups are scarce. Therefore, a multi-institutional analysis of younger patients with brain metastases was performed (defined as adults with age <50 years). Prognostic factors for survival were examined by uni- and multivariate analyses and compared to those obtained in patients with age ≥50 years. Multivariate analysis of 106 patients (median age 44 years, range 23-49 years) revealed three independent prognostic factors for survival: performance status, extracranial metastases and primary tumor control. Survival was significantly better in patients treated after the year 2000 (median 9.4 months) as compared to those treated before the year 2000 (median 5.1 months, p = 0.04). This improvement appeared to be related to an increased use of surgery or radiosurgery (SRS) and decreasing numbers of patients with uncontrolled primary tumor. Irrespective of management approach, survival beyond 5 years was uncommon (actuarial rate 6 %; 17 % in patients treated with upfront surgery or SRS). In conclusion, more intense multidisciplinary approaches aiming at control both in the brain, extracranial metastatic sites, and primary tumor site might have contributed to gradual survival improvements in recent years. Nevertheless, further efforts are necessary to improve long-term survival.

Use of the Graded Prognostic Assessment (GPA) score in patients with brain metastases from primary tumours not represented in the diagnosis-specific GPA studies

BACKGROUND AND PURPOSE

Assessment of prognostic factors might influence treatment decisions in patients with brain metastases. Based on large studies, the diagnosis-specific graded prognostic assessment (GPA) score is a useful tool. However, patients with unknown or rare primary tumours are not represented in this model. A pragmatic approach might be use of the first GPA version which is not limited to specific primary tumours.

PATIENTS AND METHODS

This retrospective analysis examines for the first time whether the GPA is a valid score in patients not eligible for the diagnosis-specific GPA. It includes 71 patients with unknown primary tumour, bladder cancer, ovarian cancer, thyroid cancer or other uncommon primaries. Survival was evaluated in uni- and multivariate tests.

RESULTS

The GPA significantly predicted survival. Moreover, improved survival was seen in patients treated with surgical resection or radiosurgery (SRS) for brain metastases. The older recursive partitioning analysis (RPA) score was significant in univariate analysis. However, the multivariate model with RPA, GPA and surgery or SRS versus none showed that only GPA and type of treatment were independent predictors of survival.

CONCLUSION

Ideally, cooperative research efforts would lead to development of diagnosis-specific scores also for patients with rare or unknown primary tumours. In the meantime, a pragmatic approach of using the general GPA score appears reasonable.