Expansion of the LabBM Score: Is the LabPS the Best Tool Predicting Survival in Patients With Brain Metastases?

The LabPS score: Inexpensive, Fast, and Site-agnostic Survival Prediction

OBJECTIVES

To provide a widely applicable, blood-biomarker-based and performance-status-based prognostic model, which predicts the survival of patients undergoing palliative non-brain radiotherapy. This model has already been examined in a cohort of patients treated for brain metastases and performed well.

METHODS

This was a retrospective single-institution analysis of 375 patients, managed with non-ablative radiotherapy to extracranial targets, such as bone, lung, or lymph nodes. Survival was stratified by LabPS score, a model including serum hemoglobin, platelets, albumin, C-reactive protein, lactate dehydrogenase, and performance status. Zero, 0.5, or 1 point was assigned and the final point sum calculated. A higher point sum indicates shorter survival.

RESULTS

The LabPS score predicted overall survival very well (median 0.6 to 26.5 mo, 3-month rate 0% to 100%, 1-year rate 0% to 89%), P =0.0001. However, the group with the poorest prognosis (4.5 points) was very small. Most patients with comparably short survival or radiotherapy administered in the last month of life had a lower point sum. Additional prognostic factors, such as liver metastases, opioid analgesic use, and/or corticosteroid medication, were identified.

CONCLUSIONS

If busy clinicians prefer a general prognostic model rather than a panel of separate diagnosis-specific/target-specific scores, they may consider validating the LabPS score in their own practice. In resource-constrained settings, inexpensive standard blood tests may be preferable over imaging-derived prognostic information. Just like other available scores, the LabPS cannot identify all patients with very short survival.

Personalized treatment of brain metastases: Evolving survival prediction models may benefit from evaluation of serum tumor markers (narrative review)

Treatment of a limited number of brain metastases (oligometastases) might include complex and sometimes invasive approaches, e.g. neurosurgical resection followed by post-operative stereotactic radiotherapy, and thus, correct identification of patients who are appropriate candidates is crucial. Both, staging procedures that visualize the true number of metastastic lesions and prognostic assessments that identify patients with limited survival, who should be managed with less complex, palliative approaches, are necessary before proceeding with local treatment that aims at eradication of all oligometastases. Some of the prognostic models, e.g. the LabBM score (laboratory parameters in patients with brain metastases), include blood biomarkers believed to represent surrogate markers of disease extent. In a recent study, patients with oligometastases and a LabBM score of 0 (no abnormal biomarkers) had an actuarial 5-year survival rate of 27% after neurosurgical resection and 39% after stereotactic radiotherapy. Other studies have tied serum tumor markers such as carcinoembryonic antigen (CEA) to survival outcomes. Even if head-to-head comparisons and large-scale definitive analyses are lacking, the available data suggest that attempts to integrate tumor marker levels in blood biomarker-based survival prediction models are warranted.

External Validation of the Graded Prognostic Assessment in Patients with Brain Metastases from Small Cell Lung Cancer

BACKGROUND

Recently, graded prognostic assessment (GPA) for small cell lung cancer (SCLC) patients with brain metastases has been developed. This includes age, performance status, number of brain metastases and presence of extracranial metastases. The aim of the present study was to validate this four-tiered prognostic score in a European cohort of patients.

METHODS

The retrospective validation study included 180 patients from two centers in Germany and Norway.

RESULTS

Median survival from radiological diagnosis of brain metastases was 7 months. The GPA point sum as continuous variable (0-4 points) was significantly associated with survival (p < 0.001). However, no significant survival difference was observed between patients in the two strata with better survival (3.5-4 and 2.5-3 points, respectively). Long-term survival in the poor prognosis group (0-1 points) was better than expected.

CONCLUSION

This study supports the prognostic impact of all four parameters contributing to the GPA. The original way of grouping the parameters and breaking the final strata did not give optimal results in this cohort. Therefore, additional validation databases from different countries should be created and evaluated.

30-day mortality in patients treated for brain metastases: extracranial causes dominate

Background

Established prognostic models, such as the diagnosis-specific graded prognostic assessment, were not designed to specifically address very short survival. Therefore, a brain metastases-specific 30-day mortality model may be relevant. We hypothesized that in-depth evaluation of a carefully defined cohort with short survival, arbitrarily defined as a maximum of 3 months, may provide signals and insights, which facilitate the development of a 30-day mortality model.

Methods

Retrospective analysis (2011–2021) of patients treated for brain metastases with different approaches. Risk factors for 30-day mortality from radiosurgery or other primary treatment were evaluated.

Results

The cause of death was unrelated to brain metastases in 61%. Treatment-related death (grade 5 toxicity) did not occur. Completely unexpected death was not observed, e.g. accident, suicide or sudden cardiac death. Logistic regression analysis showed 9 factors associated with 30-day mortality (each assigned 3–6 points) and a point sum was calculated for each patient. The point sum ranged from 0 (no risk factors for death within 30 days present) to 30. The results can be grouped into 3 or 4 risk categories. Eighty-three percent of patients in the highest risk group (> 16 points) died within 30 days, and none survived for more than 2 months. However, many cases of 30-day mortality (more than half) occurred in intermediate risk categories.

Conclusion

Extracranial tumor progression was the prevailing cause of 30-day mortality and few, if any deaths could be considered relatively unexpected when looking at the complete oncological picture. We were able to develop a multifactorial prediction model. However, the model’s performance was not fully satisfactory and it is not routinely applicable at this point in time, because external validation is needed to confirm our hypothesis-generating findings.

Comprehensive summary and retrospective evaluation of prognostic scores for patients with newly diagnosed brain metastases treated with upfront radiosurgery in a modern patient collective

BACKGROUND

Numerous prognostic scores (PS) for patients with brain metastases (BM) have been developed. Recently, PS based on laboratory parameters were introduced to better predict overall survival (OS). A comprehensive comparison of the wide range of scores in a modern patient collective is still missing.

MATERIALS AND METHODS

Twelve PS considering clinical parameters only at the time of BM diagnosis were calculated for 470 patients receiving upfront SRS between January 2014 and March 2020. In a subcohort of 310 patients where a full laboratory dataset was available five additional prognostic scores were compared. Restricted mean survival time (RMST), partial likelihood and c-index were calculated as metrics for performance evaluation. Univariable and multivariable analysis were used to identify prognostic factors for OS.

RESULTS

The median OS of the whole cohort was 15.8 months (95% C.I.: 13.4-20.1). All prognostic scores performed well in separating patients into different prognostic groups. RPA achieved the highest c-index, whereas GGS achieved highest partial likelihood with evaluation in the total cohort. With incorporation of the laboratory scores the recently suggested EC-GPA achieved highest c-index and highest partial likelihood. A prognostic score solely based on the assessment of performance status achieved considerable high performance as either 3- or 4-tiered score. Multivariable analysis revealed performance status, systemic disease status and laboratory parameters to be significantly associated with OS among variates included in prognostic scores.

CONCLUSION

Although recent PS incorporating laboratory parameters show convincing performance in predicting overall survival, older scores relying on clinical parameters only are still valid and appealing as they are easier to calculate, and as overall performance is almost equal. Moreover, a score just based on performance status is not significantly inferior and should at least be assessed for informed decision making.