Lower incidence of esophagitis in elderly NSCLC patients undergoing definitive radiation
Elderly non-small cell lung cancer (NSCLC) patients undergoing definitive radiation have a lower incidence of esophagitis compared to younger patients and tolerate aggressive standard treatment regimens.
Lung cancer is the leading cause of cancer deaths worldwide, causing more deaths than breast, colon, and prostate cancers combined. NSCLC is the most common type of lung cancer, accounting for roughly 85% of lung cancers. A large proportion of patients with lung cancer are elderly, over the age of 65, and are often poorly represented in clinical trials, undertreated, or don't receive aggressive standard treatment due to concerns about their ability to tolerate aggressive treatment regimens. While elderly patients are not different than younger patients in their willingness to accept aggressive treatment, even elderly patients with good performance status and lack of comorbidities are less likely than younger patients to be offered aggressive treatments on the basis of age. Radiotherapy is the standard treatment regimen for locally advanced NSCLC, but can lead to esophagitis and radiation pneumonitis, which are potentially life-altering toxicities of thoracic radiation.
A group of researchers in the United States conducted a study to evaluate elderly patients undergoing definitive lung radiation to assess how the elderly tolerate treatment compared to younger patients. Patients undergoing definitive radiation for lung cancer with or without chemotherapy from 2004-2013 were identified from a prospective institutional database in which patients of all ages were eligible for inclusion (UM cohort). Patients were excluded if they were treated with stereotactic body radiation therapy (SBRT) or if complete dosimetric information was not available for review. Logistic regression modeling was performed to assess the impact of age on esophagitis grade ≥3 or ≥2 and pneumonitis grade ≥3 or ≥2, adjusting for esophageal and lung dose, chemotherapy utilization, smoking status, and performance status. The analysis was validated in a large cohort of 691 patients from the Michigan Radiation Oncology Quality Consortium (MROQC) registry, an independent state-wide prospective database.
The results of the study published in the Journal of Thoracic Oncology, the official journal of the International Association for the Study of Lung Cancer (IASLC), reported that there were 179 patients extracted from the UM cohort, of which, after exclusions, 125 patients with lung cancer were included in the analysis. The median age in the UM cohort was 66, with 34% of the patients older than 70. Among the 125 patients in the UM cohort, 49 (39%) experienced grade ≥2 and 14 (11%) experienced grade ≥3 esophagitis. Of the 125 patients, 82 patients were <70 years old and 48% experienced grade ≥2 and 16% experienced grade ≥3 esophagitis. Conversely, among the 43 patients age ≥70, these rates were 23% (grade ≥2) and 2% (grade ≥3). Multivariate regression modelling of the UM cohort revealed a significant inverse correlation between age and rate of esophagitis for both grade levels. The same association was noted in the MROQC cohort, which validated these results. There was no significant association between age and pneumonitis.
The authors comment that, "Our study demonstrates significantly decreased incidence of radiation esophagitis in elderly patients. This finding remained significant even after adjusting for esophageal dose, concurrent chemotherapy, history of smoking, and performance status. In patients who are never smokers with good performance status, who received high doses of radiation to the esophagus with concurrent chemotherapy, the probability of esophagitis for a 70 year old is approximately one-third that of an identical 50 year old patient. Pattern of care studies suggest that the elderly are being undertreated for various malignancies including lung cancer, independent of other variables including performance status. Our study undermines this practice and supports standard definitive treatment for the elderly with good performance status."
More information: Journal of Thoracic Oncology, DOI: 10.1016/j.jtho.2016.11.2227 , www.jto.org/article/S1556-0864(16)33535-3/pdf