Development and validation of a prognostic model for non-lung cancer death in elderly patients treated with stereotactic body radiotherapy for non-small cell lung cancer

Abstract

This study sought to develop and validate a prognostic model for non-lung cancer death (NLCD) in elderly patients with non-small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Patients aged ≥65 diagnosed with NSCLC (Tis-4N0M0), tumor diameter ≤5 cm and SBRT between 1998 and 2015 were retrospectively registered from two independent institutions. One institution was used for model development (arm D, 353 patients) and the other for validation (arm V, 401 patients). To identify risk factors for NLCD, multiple regression analysis on age, sex, performance status (PS), body mass index (BMI), Charlson comorbidity index (CCI), tumor diameter, histology and T-stage was performed on arm D. A score calculated using the regression coefficient was assigned to each factor and three risk groups were defined based on total score. Scores of 1.0 (BMI ≤18.4), 1.5 (age ≥ 5), 1.5 (PS ≥2), 2.5 (CCI 1 or 2) and 3 (CCI ≥3) were assigned, and risk groups were designated as low (total ≤ 3), intermediate (3.5 or 4) and high (≥4.5). The cumulative incidences of NLCD at 5 years in the low, intermediate and high-risk groups were 6.8, 23 and 40% in arm D, and 23, 19 and 44% in arm V, respectively. The AUC index at 5 years was 0.705 (arm D) and 0.632 (arm V). The proposed scoring system showed usefulness in predicting a high risk of NLCD in elderly patients treated with SBRT for NSCLC.

Predicting 2-year survival in stage I-III non-small cell lung cancer: the development and validation of a scoring system from an Australian cohort

“…However, only patient and tumour-related factors were retained in this multivariate model, precluding its use in treatment decision-making. Another model developed in Japan only included patient-related variables (age, performance status, body mass index and Charlson comorbidity index) to predict non-lung cancer death in an elderly cohort receiving definitive SABR [ 27 ]. In contrast to these models, we deliberately chose to include a potentially curable population of patients with stage I-III NSCLC who were managed heterogeneously in order to develop a prediction model which can help decision-making in the real world.…”

“…The patient-related determinants most commonly included in NSCLC models are age, sex and performance status. While a poorer prognosis has been associated with older age [ 27 ] and male sex [ 8 ] overall findings have been inconclusive. In line with previous models, our study found no significant associations between age and sex on the survival outcomes of the study population [ 28 , 29 ].…”

“…In contrast, performance status has been associated with NSCLC survival in patients receiving curative radiotherapy [ 23 , 26 , 28 , 30 ] and was retained in our final model. However, a recognised limitation of performance status as a predictive variable is its subjectivity and inter-observer variability [ 27 ].…”

Stereotactic body radiotherapy compared with video‐assisted thoracic surgery after propensity‐score matching in elderly patients with pathologically‐proven early‐stage non‐small cell lung cancer

“…Despite minimally invasive surgical techniques, elderly patients undergoing guideline‐recommended lung resection have a significantly higher operative mortality rate than younger patients (6.9% vs. 3.7%) 24–26 . Several reports have shown that SBRT is a safe and feasible treatment for elderly patients regarding treatment complications and oncological outcomes 18,27–38 . The use of SBRT as an alternative treatment modality for elderly patients has increased owing to the availability and development of various stereotactic radiotherapy techniques and equipment.…”

“…[24][25][26] Several reports have shown that SBRT is a safe and feasible treatment for elderly patients regarding treatment complications and oncological outcomes. 18,[27][28][29][30][31][32][33][34][35][36][37][38] The use of SBRT as an alternative treatment modality for elderly patients has increased owing to the availability and development of various stereotactic radiotherapy techniques and equipment.…”