Chemotherapy Use, Survival in SCLC Increased Over 20 Years

A study looking at trends from 1985 to 2005 found that overall survival has increased in Medicare patients with small-cell lung cancer (SCLC), and that treatment with chemotherapy is associated with improved survival.

“Although the proportion of cases diagnosed as SCLC has declined from approximately 20% to 13%, this subset is still a major cause of disease burden with close to 30,000 new cases annually,” wrote study authors led by Madhusmita Behera, PhD, of Emory University in Atlanta. The use of chemotherapy in real-world populations is limited by significant toxicity, they added, and whether recommended therapies are adopted has not been well studied.

The new study used the SEER database to study trends in outcome and treatment; it included 47,351 eligible patients divided into 5-year intervals, with 1985–1990 used as the baseline. Results were published online ahead of print in Cancer.

The median age in the cohort was 71 years, and 52% were male. The proportion of patients treated with chemotherapy was generally low, but increased over time, from 38% in 1985–1990 to 53% in the 2000–2005 period (P < .001). Female patients (51%), Asian patients (53%), and those who lived in rural areas (60%) were more likely to receive chemotherapy than others.

Over the full time period, the median overall survival in patients treated with chemotherapy was 9.6 months, compared with only 3.6 months in those who did not undergo chemotherapy.

The benefit that chemotherapy bestowed on survival decreased slightly over time: in the 1985–1990 period, the hazard ratio (HR) for survival for chemotherapy vs no chemotherapy was 0.587 (95% confidence interval [CI], 0.546–0.631; P < .001). In the 1991–1995 period, the HR was 0.609 (95% CI, 0.579–0.640; P < .001); in the 1996–2000 period, it was 0.638 (95% CI, 0.611–0.666; P < .001); and in the 2001–2005 period it was 0.619 (95% CI, 0.598–0.640).

There were “modest” trends toward increased survival in both the chemotherapy (P = .005) and non-chemotherapy patients (P < .001) over time.

“Because there were no newly available agents corresponding to the temporal periods, the improved outcome over time probably reflected both increased use of chemotherapy and potential improvements in supportive care over time,” the authors wrote.

They speculated that the low rates of chemotherapy in this population is likely connected to patients presenting as generally sicker than NSCLC patients, with other tobacco-related disease that could limit their suitability for treatment. “Moreover, the general nihilism associated with SCLC as an incurable cancer by medical oncologists and other physicians could also have contributed to this low rate of chemotherapy usage.”