Patients with advanced non-small cell lung cancer (NSCLC) who receive treatment live longer than those who remain untreated, but the proportion of NSCLC patients with advanced disease who don’t receive treatment has been rising in the United States.
The findings were revealed in the study “Increasing Rates Of No Treatment In Advanced-Stage Non–Small Cell Lung Cancer Patients: A Propensity-Matched Analysis,” and published in the Journal of Thoracic Oncology.
Lung cancer is the No. 1 cause of cancer-related deaths in the U.S., with an estimated 158,080 people expected to die from the disease in in 2016, according to the American Lung Association. Despite new treatments and an increase in clinical trial enrollment, only 17 percent of patients with advanced NSCLC (stages 3 and 4) live longer than five years after being diagnosed.
Also, although treatment guidelines have been established for each stage of NSCLC, there is still a substantial proportion of patients that do not receive treatment at all.
“Overall, the proportion of untreated patients with NSCLC varies by stage, ranging from 7% to 45%, but in subsets of older, medically inoperable patients, the untreated population can reach as high as 90%,” Elizabeth A. David, MD, from the University of California Davis Medical Center, and colleagues wrote in the study.
“We hypothesized that patients who are older, poorly educated, without health insurance, and with a higher disease stage would have a higher likelihood of being untreated, but we also hypothesized that there are a substantial number of untreated patients who are statistically similar to patients who undergo treatment.”
Using data from the National Cancer Datadase from 1998 to 2012, researchers analyzed several parameters in patients with primary NSCLC, including gender, disease stage, type of treatment (radiation, chemotherapy, or surgery), annual income, education, and year of diagnosis.
The analysis showed that 21 percent of patients (190,539) had received no treatment and that the more advanced the disease stage, the higher the proportion of untreated patients.
In fact, during the study period, the proportion of untreated patients with stage 1 and 2 NSCLC decreased by 0.66% and 0.23%, respectively. But the proportion of untreated patients with stage 3A and 4 disease increased by 0.21% and 0.4%, respectively.
Across all disease stages, untreated patients were likely to be older and have Medicare instead of private insurance. Results also showed that these patients had significantly shorter overall survival (OS), regardless of age. While treated patients at stage 3A and 4 lived a median of 16.5 months and 9.3 months, respectively, untreated patients lived 6.1 months and 2.0 months, respectively, after diagnosis.
Shorter OS was found to be correlated with several factors, including older age, female gender, nonwhite race, no insurance, low income, low education, earlier year of diagnosis, and higher disease stage.
However, a significant number of untreated patients were matched with treated patients in both stage 3A or 4 in several parameters, suggesting that other factors may be influencing their decision for not receiving treatment.
“It is unrealistic to expect that all patients with lung cancer will be candidates for and choose to undergo treatment for NSCLC, especially those with advanced stage NSCLC,” the researchers wrote. “However, as novel therapies offering improved survival have been introduced, there have also been improvements in supportive care and side effect management that have also improved patient tolerance of standard cytotoxic therapies such as chemotherapy, radiotherapy, and even surgery.”
The researchers said the results were unexpected and that further studies are required to identify additional factors influencing treatment decisions in advanced NSCLC patients, including proximity to treatment, regional treatment variations, and existence of regional treatment resources. In addition, clinicians should carefully assess the benefits and risks of treatment with their patients before they choose to forgo treatment.