SAN FRANCISCO-While treatment and survival rates for early stage non-small cell lung cancer have improved considerably over the past 10 years in the U.S., rates for African-Americans and Native Americans have not kept pace with Caucasians, according to a findings presented at the 2017 Multidisciplinary Thoracic Cancers Symposium (Abstract 9).
Advancements in surgery and radiotherapy, such as stereotactic body radiation therapy (SBRT), have improved short- and long-term outcomes for stage I patients, and an estimated 25 percent of patients can be successfully treated if diagnosed early.
However, rates for African-Americans and Native Americans continue to lag behind those of Caucasians and others, said Andrew M. Farach, MD, senior author of the study and Radiation Oncologist at Houston Methodist Hospital, Houston.
"Despite advancements in surgery and radiation in the last decade, both African-Americans and Native Americans continue to have higher rates of overall and cancer-specific mortality from early-stage NSCLC compared to Caucasians," he told a press conference. "Our study is the first to confirm that, even with widespread growth in the availability and adoption of advanced therapies, disparities in treatment and survival persist for early-stage NSCLC."
Farach noted poorer outcomes in African-American and Native American populations could be due to more adverse risk factors, including older age of diagnosis, male gender, T2 stage, and a general tendency to receive no treatment or forego surgery.
He said the findings underscore the need to actively address racial disparities to ensure that treatment options for underserved populations include new cancer therapies as they become available.
Methods, Findings
Farach and his colleagues examined records in the NCI's Surveillance, Epidemiology, and End Results (SEER) between 2004 and 2012, and identified 62,312 eligible patients for the study. Patients without definitive records for local therapy were not included.
The patients were then grouped by race/national origin into one of five cohorts: Caucasians (86.6%), African-Americans (8.0%), Asian/Pacific Islanders (5.0%), Native Americans (0.3%), and patients with unknown racial classification (0.02%).
Patients received one of four types of primary treatment for stage I NSCLC, including surgery only (67%), radiation only (19%), both surgery and radiation (3%), or no treatment/observation only (12%).
The data showed African-Americans and Native Americans were less likely to receive surgery than typical stage I NSCLC patients (55.9% and 57.6% vs. 66.7% overall).
Two-year overall survival (OS) for Caucasians was 70 percent, African-Americans was 65 percent, 60 percent for Native Americans, and 76 percent for Asian/Pacific Islanders. Cancer-specific survival rates at 2 years were 84 percent for Asian/Pacific Islanders, 79 percent for Caucasians, 76 percent for African-Americans, 73 percent for Native Americans, and 91 percent for unknown racial classification. Median CSS for Native Americans and African-Americans was less than that of the typical stage I NSCLC patient, 49 months and 80 months, respectively, versus 107 months, according to the analysis.
Although the median CSS for African-American patients was more than 2 years shorter than the general population, the difference lost statistical significance after controlling for gender, patient, disease, and treatment factors, the researchers found, noting that treatment type directly influenced the likelihood of surviving early-stage lung cancer.
Patients who received definitive treatment, with surgery or SBRT, had improved survival rates, regardless of race, age, or gender. Compared to observation alone, the hazard ration for surgery was 0.44, 0.70 for radiation, and 0.48 for surgery with radiation.
"Unfortunately, our findings are not particularly surprising. Multiple studies have documented racial disparities in the management and outcome of different cancers. As physicians, it becomes our responsibility to understand and address these inequalities," said Farach.
In addition to improving access to care, other steps to better such patients include investigating the biology of lung cancer in understudied groups and taking more time to educate and build trust with each patient, he noted.
Clinical Implications
African-Americans continue to be the dominant population with newly diagnosed lung cancer, followed by Caucasians, American Indian/Alaskan Native, Asian/Pacific Islanders, and Hispanics, noted panel moderator Pranshu Mohindra, MD, Assistant Professor of Radiation Oncology at the University of Maryland School of Medicine, Baltimore.
He told Oncology Times that mortality rates have followed similar trends, pointing to a recently published study that showed significant disparities in clinical trial enrollment within African-Americans and other minorities (J Clin Oncol 2016;4:3992-3999).
"Even for a very favorable subgroup of patients with early-stage lung cancer, wherein long-term survival is feasible, the researcher found variable utilization of treatment modalities within different races which affected outcomes," he said.
"Clinicians should be aware of this existing racial disparity and especially try to explore social work support options for African-Americans and other minority patients so they are able to make full use of the available treatment options."
He also said patients should discuss various logistic challenges that may prevent them receiving cancer treatments with their oncologists, pointing to support services available either through the research institution's social work department or the American Cancer Society that could help improve their utilization.
Mohindra said the study, like previous SEER studies, brings to light that racial disparities are likely multifactorial. Ongoing research is needed to further explore various factors contributing to underutilization of treatment modalities in various subpopulation, he concluded.
Kurt Samson is a contributing writer.