Radiotherapy for nonagenarians: the value of biological versus chronological age

The number of nonagenarian cancer patients (≥ 90 years) is continuously increasing, and radiotherapy is performed in a relevant proportion of patients, as surgery and chemotherapy are often not feasible for these patients. However, the evidence regarding the feasibility and treatment outcomes after radiotherapy for this patient group is very limited.

All nonagenarian patients receiving (chemo) radiotherapy between 2009 and 2019 at the University of Freiburg - Medical Center were analyzed for patterns of care, overall survival (OS) and therapy-associated toxicities according to the Common Terminology Criteria for Adverse Events. Uni- and multivariate Cox regression analyses were conducted to assess the influence of patient- and treatment-related factors on patient outcomes.

One hundred nineteen patients with a total of 137 irradiated lesions were included in this analysis. After a median follow-up of 27 months, median OS was 10 months with a 3-year OS amounting to 11.1%. Univariate analyses demonstrated that a reduced performance status (HR = 1.56, 95% CI 1.00-2.45, p < 0.05), a higher burden of comorbidities (HR = 2.00, 95% CI 1.00-4.10, p < 0.05) and higher UICC tumor stages (HR = 2.21, 95% CI 1.14-4.26, p < 0.05) were associated with impaired survival rates. Split-course treatments (HR = 2.05, 95% CI 1.07-3.94, p < 0.05), non-completion of radiotherapy (HR = 7.17, 95% CI 3.88-13.26, p < 0.001) and palliative treatments (HR = 2.84, 95% CI 1.68-4.81, p < 0.05) were found to result in significantly reduced OS. In the multivariate analysis, split-course concepts (HR = 2.21, 95% CI 1.10-4.37, p < 0.05) and palliative treatments (HR = 3.19, 95% CI 1.77-5.75, p < 0.001) significantly deteriorated outcomes, while impaired ECOG status (HR = 1.49, 95% CI 0.91-2.43, p = 0.11) did not. The vast majority of patients reported either no (n = 40; 33.6%) or grade 1-2 acute toxicities (n = 66; 55.5%), and only very few higher-grade toxicities were observed in our study.

Radiotherapy for nonagenarian patients is generally feasible and associated with a low toxicity profile. Given the relatively poor OS rates and the importance of the quality of life for this patient group, individualized treatment regimens including hypofractionation concepts should be considered.