Real-World Data Show SCLC Outcomes Remain Grim

People with small cell lung cancer (SCLC) still face an unsatisfactory prognosis, according to a new report that looked retrospectively at the real-world outcomes of more than 750 cases.

The authors of the study, which appeared in BMJ Open, say their findings provide important data points as the number of available therapies for the disease continues to expand.

They explained that there are several characteristics of SCLC that contribute to its high mortality rate. It typically affects people between aged 60 to 70 years; frequently metastasizes to the brain, liver, and bone; and often becomes advanced before symptoms are noticeable.

“Its rapid growth, combined with widespread metastasis early in the disease course, results in a 5-year mortality of 90% or more, which makes SCLC the most lethal lung cancer subtype,” the authors wrote.

They said the “optimal” first-line therapy for people with limited disease is concurrent chemotherapy and radiation, followed by prophylactic cranial irradiation in responsive patients. For those with extensive disease, platinum-based chemotherapy with or without consolidation irradiation has historically been the standard first-line treatment. However, the authors said new immunotherapy options are now available for inclusion in treatment regimens and appear to show promise.

Second-line therapy in SCLC typically depends on how quickly a patient relapses, the authors said. Patients who experience an early relapse are typically given chemotherapy with topotecan (Hycamtin), while those who relapse more than 6 months following their first-line treatment are typically treated with the same regimen used in first-line therapy.

Third-line therapy is uncommon given the disease’s rapid progression, the investigators added, but when given, it typically involves therapy with programmed cell death ligand-1 inhibitoers.

The newest therapy for SCLC is lurbinectedin (Zepzelca), which the FDA approved in 2020 for adults with metastatic SCLC that progresses while on or after platinum-based chemotherapy.

Given the new options and potential for shifting therapeutic habits, the study authors said they wanted to better understand the “baseline” of real-world treatment patterns and clinical outcomes in people with limited or extensive disease in 3 countries: France, Italy, and the United Kingdom. They asked 39 physicians to retrospectively analyze the medical records of adult patients treated between 2013 and 2015 (for first-line therapy) or 2016 (for second-line therapy).

A total of 231 patients with limited disease undergoing first-line therapy, 308 patients with extensive disease undergoing first-line therapy, and 225 patients in second-line treatment with relapsed or refractory disease were included in the analysis. Similar totals of patients in first- therapy received chemotherapy with radiotherapy (76.2%) and chemotherapy alone (79.6%).

Patients in first-line therapy with limited disease had a median overall survival (OS) of 17.34 months from the start of therapy and a median progression-free survival (PFS) of 11.6 months, the authors said. Among patients with extensive disease receiving first-line therapy, the median OS was 8.8 months and the median PFS was 6.1 months. In patients receiving second-line therapy, the median OS was 6.6 months—although the investigators said it was longer in patients whose initial diagnosis was for limited disease than in those whose original diagnosis was extensive disease.

Although the authors said the mortality data from the study are grim, they added that these data will also serve to show how new therapies are hopefully able to improve outcomes over time.

“Given the poor outcomes observed with chemotherapy regimens in this patient population, the introduction of novel therapies reflects an important step-change in the treatment paradigm for patients with SCLC,” they concluded. “Future research should explore the effectiveness of these new treatments in the real world.”

Reference

Blackhall F, Girard N, Livartowski A, et al. Treatment patterns and outcomes among patients with small-cell lung cancer (SCLC) in Europe: a retrospective cohort study. BMJ Open. Published online February 6, 2023. doi:10.1136/bmjopen-2021-052556