Analysis of data from 102,929 patients with stage IV lung cancer found that “prior cancer does not convey an adverse effect on clinical outcomes, regardless of prior cancer stage, type, or timing.” Based on these findings, investigators from the Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, concluded that “broader inclusion in clinical trials of advanced lung cancer patients with a history of prior cancer should be considered.”
Using the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked registry, the investigators identified patients older than age 65 years with stage IV lung cancer diagnosed between 1992 and 2009. “Prior cancer was characterized by type, stage, and timing. All-cause and lung cancer–specific survival were compared between patients with and without prior cancer using propensity score–adjusted Cox regression,” Andrew Laccetti, MD, and colleagues wrote in the Journal of the National Cancer Institute.
Overall, 14.7% of the patients had a history of cancer, 76% localized or regional stage, “so presumably cured or at least not life-limiting in the context of advanced lung cancer,” the authors noted. Most prior cancers were diagnosed 5 or fewer years before lung cancer was diagnosed. The most common prior cancer types were prostate (27.9%), gastrointestinal (15.1%), other genitourinary (14.4%), and breast (14.2%).
In propensity score–adjusted analysis, patients with prior cancer had better all-cause survival (hazard ratio [HR] = 0.93, 95% confidence interval [CI] = 0.91–0.94) and better lung cancer–specific survival (HR = 0.81, 95% CI = 0.79–0.82). “In a simulated clinical trial–eligible population (age < 75 years, no comorbidity, treated with chemotherapy), similar trends were noted. In subset analyses according to stage, type, and timing of prior cancer, no group of patients with prior cancer had inferior survival compared with patients without prior cancer,” the researchers wrote.
“Fewer than 5% of adults with cancer in the United States participate in clinical trials,” the investigators noted. Among the barriers to accrual, “clinical trial eligibility criteria present a major barrier to study enrollment and represent one of the few accrual factors directly controlled by investigators and sponsors,” the authors added. The findings that prior cancer did not adversely impact all-cause or lung cancer–specific survival and patients with prior cancer actually had slightly better survival “suggest that broader inclusion in clinical trials of advanced lung cancer patients with prior cancer could be considered without impacting study outcomes,” the researchers concluded. “Such policy modifications could lead to faster accrual, higher trial completion rates, and more generalizable results, ultimately providing better treatments to more patients sooner.” ■
Laccetti AL, et al: J Natl Cancer Inst 107:djv002, 2015.