RESUMEN
Background: Extensive-stage small-cell lung cancer (ES-SCLC) is an incurable cancer with poor prognosis in which characteristics predictive of long-term survival are debated. The utility of agents such as immune checkpoint inhibitors highlights the importance of identifying key characteristics and treatment strategies that contribute to long-term survival and could help guide therapeutic decisions. Objective: This real-world analysis examines the characteristics, treatment patterns, and clinical outcomes of patients receiving chemotherapy without immunotherapy for ES-SCLC in Manitoba, Canada. Methods: A retrospective cohort study assessed patient characteristics, treatment, and survival duration (short: <6 months; medium: 6-24 months; long: >24 months) using the Manitoba Cancer Registry and CancerCare Manitoba records. Eligible patients were aged >18 years with cytologically confirmed ES-SCLC diagnosed between January 1, 2004, and December 31, 2018, and received cytotoxic chemotherapy (CT). The one-, two-, and five-year probabilities of overall survival (OS) were assessed relative to patient, disease, and treatment characteristics using Kaplan-Meier methods and Cox proportional hazards models. Results: This analysis included 537 patients. Cisplatin was used in 56.1% of patients, 45.6% received thoracic radiotherapy (RT), and few received prophylactic cranial irradiation (PCI). In the overall cohort, one-, two- and five-year OS rates were 26%, 8%, and 3%, respectively. For patients with Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0, OS rates at one, two, and five years were 43%, 17%, and 10%, respectively, vs. 27%, 8%, and 2% for those with ECOG PS 1-2, and 16%, 3%, and 3% for those with ECOG PS 3-4. In long-term survivors, ECOG PS scores were lower and abnormal laboratory test results were less frequent. Overall, 74.4% of long-term survivors received thoracic RT and 53.5% received PCI. Known poor prognostic factors - including brain/liver metastases, high lactate dehydrogenase (LDH), abnormal sodium, and low hemoglobin levels - were less common but still seen in long-term survivors. Conclusion: Although rare, patients with ES-SCLC may experience long-term survival with CT ± thoracic RT ± PCI. Factors predicting long-term survival include traditional prognostic factors such as ECOG PS, LDH level, and receipt of thoracic RT or PCI. These findings support current treatment algorithms for ES-SCLC and provide baseline survival estimates to assess the real-world impact of adding immune checkpoint inhibitors in the future.
RESUMEN
Background: Although therapy for limited-stage small-cell lung cancer (LS-SCLC) is administered with curative intent, most patients relapse and eventually die of recurrent disease. Chemotherapy (CT) with concurrent radiotherapy (RT) remains the standard of care for LS-SCLC; however, this could evolve in the near future. Therefore, understanding the current prognostic factors associated with survival is essential. Objective: This real-world analysis examines factors associated with long-term survival in patients with LS-SCLC treated with CT in Manitoba, Canada. Methods: A retrospective cohort study was conducted using Manitoba Cancer Registry and CancerCare Manitoba records. Eligible patients were aged >18 years and had cytologically confirmed LS-SCLC diagnosed between January 1, 2004, and December 31, 2018, for which they received CT ± RT. Baseline patient, disease, and treatment characteristics and survival duration, characterized as short (<6 months), medium (6-24 months), and long term (>24 months), were extracted. Overall survival (OS) was estimated at one, two, and five years and assessed using Kaplan-Meier methods and Cox proportional hazards models. Results: Over the 15-year study period, 304 patients met the eligibility criteria. Long-term survivors comprised 39.1% of the cohort; at diagnosis, this subgroup was younger, more likely to have Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0, and have normal lactate dehydrogenase, sodium, and hemoglobin levels. OS estimates for the entire cohort at one, two, and five years were 66%, 38%, and 18%, respectively. In the ECOG PS 0 subgroup, OS estimates at one, two, and five years were 85%, 52%, and 24%, respectively; OS estimates were 60%, 35%, and 17%, respectively, for ECOG PS 1-2 and were 47%, 23%, and 10%, respectively, for ECOG PS 3-4. OS was significantly higher among patients with normal serum sodium and hemoglobin levels than those with abnormal levels. Univariable hazard regression models found that ECOG PS, age at diagnosis, receipt of prophylactic cranial irradiation (PCI), and thoracic RT were associated with survival. On multivariable hazard regression, ECOG PS and receipt of PCI were associated with survival. Conclusion: Survival for greater than two years in patients with LS-SCLC treated with CT ± RT was associated with ECOG PS and receipt of PCI.
RESUMEN
The prognosis for extensive-stage small cell lung cancer (ES-SCLC) is poor. Real-world evidence can highlight the unmet clinical need within this population. We conducted a population-based cohort study of ES-SCLC patients diagnosed in a large Canadian province (2010-2018) using electronic medical records and administrative claims data. In all, 1941 ES-SCLC patients were included, of which 476 (25%) were recurrent cases. Median age at diagnosis was 70 years (range: 39-94) and 50.2% were men. Of the 1941 ES-SCLC patients, 29.5% received chemotherapy and radiotherapy, 17.0% chemotherapy alone, 8.7% radiotherapy alone, and 44.8% received best supportive care. Chemotherapy was initiated by 46.5%, 8.5%, and 1.4% of first-, second-, and third-line patients, with lower uptake for recurrent cases. Median survival from first-, second-, and third-line chemotherapy was 7.82 months (95% CI: 7.50-8.22), 5.72 months (95% CI: 4.90-6.87), and 3.83 months (95% CI: 2.99-4.60). Among patients who received first-line therapy, the 2-year and 5-year survival was 7.3% (95% CI: 5.7-9.2) and 2.9% (95% CI: 1.8-4.5). In conclusion, initiation of first-line treatment in ES-SCLC was low with significant attrition in subsequent lines. These results underscore the need for effective front-line treatments and highlight the potential for novel therapies to improve patient outcomes.