A new instrument for estimation of survival in elderly patients irradiated for metastatic spinal cord compression from breast cancer

Background: Elderly patients become more important in oncology. In this group, personalized treatment approaches taking into account survival prognoses and comorbidities play a major role. Predictive instruments are necessary to estimate the survival of elderly cancer patients. The importance of separate instruments for different tumor entities has been recognized. In this study, an instrument was generated to estimate the survival of elderly patients developing metastatic spinal cord compression (MSCC) from breast cancer. Methods: In 218 elderly patients (age ≥65 years) irradiated for MSCC from breast cancer, nine factors were evaluated for survival: fractionation regimen, age, time from breast cancer diagnosis to RT of MSCC, visceral metastases, other bone metastases, time developing motor deficits, pre-radiotherapy ambulatory status, number of involved vertebrae, and Eastern Cooperative Oncology Group (ECOG) performance score. Factors significantly associated with survival in the Cox regression analysis were included in the prognostic instrument. Scores for each factor were calculated by dividing the 6-months survival rates by 10. The sums of these scores represented the patients' scores. Results: On multivariate analyses, visceral metastases (p < 0.001), time developing motor deficits (p < 0.001), ambulatory status (p < 0.001), number of involved vertebrae (p = 0.032), and ECOG performance score (p < 0.001) were significant and included in the prognostic instrument. Based on the patients' scores, three groups were designed: 18-27 points, 28-39 points and 40-42 points. Six-months survival rates were 4, 62 and 100 %, respectively (p < 0.001). Conclusions: This new instrument contributes to personalized treatment in elderly patients with MSCC from breast cancer by predicting an individual patient's survival prognosis.