Comparison of Diagnosis-Specific Survival Scores for Patients with Small-Cell Lung Cancer Irradiated for Brain Metastases

External Validation of an Extended Prognostic Assessment Model in Patients With Brain Metastases from Small-cell Lung Cancer

Background/Aim

Recently, the small-cell lung cancer (SCLC) grade model for patients with brain metastases was developed by a Japanese group. It includes sex, performance status, number of brain metastases, primary tumor control and presence of extracranial metastases. The aim of the present study was to validate this prognostic score in a European cohort of patients.

Patients and Methods

The retrospective validation study included 189 patients from two centers in Germany and Norway. Survival according to the SCLC grade score was evaluated. Additional prognostic factors were analyzed.

Results

Median survival was 7.5 months. The 3-tiered SCLC grade score based on the sum of adverse prognostic features was significantly associated with survival (p<0.001): A higher point sum resulted in shorter survival. However, in our validation cohort, age affected survival to the same degree as several parameters that were part of the score.

Conclusion

This validation study supports the international applicability of the SCLC grade model. Age, which has also been identified as a relevant prognostic factor in other previous studies (including the SCLC Graded Prognostic Assessment), may deserve consideration when trying to optimize survival prediction. Given that different studies identified different age limits, e.g., 70 or 75 years, merged databases are needed to provide definitive conclusions.

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.

Radiotherapy challenges in COVID era

The pandemic caused by the new coronavirus (SARS-CoV-2) associated with a disease named COVID-19 by the World Health Organization that began in late 2019 in Wuhan city has become a global public health problem. Only 2 months later, the new virus affected most countries of the world, the consequence being an overload of health systems, especially Intensive Care Units. Considered a category of patients at high risk of developing severe forms of the disease, cancer patients can develop a severe form of the disease, complicated by acute respiratory distress syndrome requiring mechanical ventilation. Radiotherapy, as a treatment included in the multidisciplinary management of cancer for both curative and palliative purposes, is also affected by the COVID-19 pandemic. COVID-19-positive or -suspected patients are a special category for which the decision to postpone treatment should be made based on the particularities of tumor biology and the radiobiological effect of a gap in radiation fractions delivery. Emergencies including spinal cord compressions, tumor bleeding, and brain metastases not responsive to corticosteroid treatment, should be considered a priority but the palliative treatment should be limited from one single fraction to maximum five fractions for spinal cord compression and whole brain radiotherapy. Radiotherapy for brain metastases does not bring a benefit in terms of overall survival for patients with life expectancy of days or weeks and dexamethasone treatment is the correct choice in this situation. In all settings, the approach of radiotherapy treatment must be adapted for both scenarios of an outbreak pandemic, when general measures of social distancing and protection by specific equipment of patients and radiotherapy staff are a priority, but also for a long period of coexistence with the virus with possible new “pandemic waves.”

Development of a multivariable prediction model to estimate the remaining lifespan of elderly patients with cerebral metastases from small-cell lung cancer

Background

Prognostic tools estimating survival of elderly patients with cerebral metastases from small-cell lung cancer (SCLC) improve treatment personalization. A specific tool for these patients was developed and compared to existing instruments.

Methods

One-hundred-and-forty elderly patients (≥65 years) receiving whole-brain irradiation (WBI) for cerebral metastases from SCLC were retrospectively evaluated. WBI-program, age, gender, Karnofsky performance score, number of cerebral lesions, extracerebral metastases, and interval between SCLC-diagnosis and WBI were investigated. Characteristics significantly associated with survival in the multivariate analysis were used for the tool. Scoring points were calculated by dividing 6-month survival rates (%) by 10 and added for patient scores. The tool was compared to existing diagnosis-specific instruments including updated diagnosis-specific graded prognostic assessment (DS-GPA), Rades-SCLC and WBRT-30-SCLC.

Results

In the multivariate analysis, KPS (P<0.001), number of cerebral lesions (P=0.013) and extracerebral metastases (P=0.049) were significantly associated with survival. Patient scores of 2 (n=37), 5 (n=69), 8 (n=20) and 11 (n=14) points were obtained; 6-month survival rates were 0%, 9%, 50% and 79% (P<0.001). The positive predictive value (PPV) of the worst group (2 points) to identify patients dying ≤6 months was 100%; PPVs of updated DS-GPA, Rades-SCLC and WBRT-30-SCLC were 94%, 100% and 94%. PPV of the best group (11 points) to identify patients surviving ≥6 months was 79%; PPVs of updated DS-GPA, Rades-SCLC and WBRT-30-SCLC were 86%, 79% and 100%.

Conclusions

The most precise instruments were the new tool and Rades-SCLC for identification of patients dying ≤6 months, and the WBRT-30-SCLC to identify patients surviving ≥6 months.

An easy-to-use scoring system to estimate the survival of patients irradiated for bone metastases from lung cancer

Background

The remaining lifespan of patients with metastatic lung cancer should be considered when designing a personalized treatment program. To facilitate the estimation survival in lung cancer patients with bone metastases, a specific scoring system was created.

Methods

One-hundred-and-fifty-three patients receiving fractionated radiotherapy for bone metastases without spinal cord compression from lung cancer were included in this retrospective study. Age, gender, Eastern Cooperative Oncology Group (ECOG) performance score, histology, interval from lung cancer diagnosis until irradiation of bone metastases, visceral metastases, additional bone metastases, type and number of irradiated sites, pathological fracture, upfront surgery and previous systemic treatment were evaluated for potential associations with survival. Those factors that were significant (P<0.05) or showed a trend (P≤0.10) on multivariate analysis were used to create the scoring system.

Results

On multivariate analysis, ECOG performance score was significant (risk ratio: 2.77, P<0.001), and age showed a trend (risk ratio: 1.34, P=0.10). The following scoring points were assigned: age ≤65 years =1 point, age ≥66 years =0 points, ECOG performance score of 0–1 =1 point, and ECOG performance score of ≥2 =0 points. Three prognostic groups were obtained: 0 points (n=38), 1 point (n=71) and 2 points (n=44). Six-month survival rates were 21%, 41% and 75%, 12-month survival rates 7%, 27% and 56% (P<0.001).

Conclusions

This scoring system can help estimate the remaining lifespan of lung cancer patients to be irradiated for bone metastases and will contribute to the personalization of their treatment.

Cancer Survival Data Representation for Improved Parametric and Dynamic Lifetime Analysis

Survival functions are often characterized by a median survival time or a 5-year survival. Whether or not such representation is sufficient depends on tumour development. Different tumour stages have different mean survival times after therapy. The validity of an exponential decay and the origins of deviations are substantiated. The paper shows, that representation of survival data as logarithmic functions visualizes differences better, which allows for differentiating short- and long-term dynamic lifetime. It is more instructive to represent the changing lifetime expectancy for an individual who has survived a certain time, which can be significantly different from the initial expectation just after treatment. Survival data from 15 publications on cancer are compared and re-analysed based on the well-established: (i) exponential decay (ii) piecewise constant hazard (iii) Weibull model and our proposed parametric survival models, (iv) the two-τ and (v) the sliding-τ model. The new models describe either accelerated aging or filtering out of defects with numerical parameters with a physical meaning and add information to the usually provided log-rank P-value or median survival. The statistical inhomogeneity in a group by mixing up different tumour stages, metastases and treatments is the main origin for deviations from the exponential decay.