Long-term results of the International Adjuvant Lung Cancer Trial (IALT) evaluating adjuvant cisplatin-based chemotherapy in resected non-small cell lung cancer (NSCLC)
7507 Background: Based on 4 to 5-year follow-up data in recent randomized trials, adjuvant cisplatin-based chemotherapy is now generally recommended after complete surgical resection for patients with non-small-cell lung cancer. We evaluated the results of the IALT study, initially reported with a 4.7 year follow-up (ASCO 2003), with three additional years of follow-up. Methods: Patients with completely resected NSCLC were randomly assigned to three or four cycles of cisplatin-based chemotherapy or to observation. The dose of cisplatin (total 300–400 mg/m2), the drug to be combined with cisplatin (etoposide or vinorelbine or vindesine or vinblastin) and the use of adjuvant radiotherapy were predefined at each center. Cox models were used to evaluate treatment effect according to follow-up duration. Results: Between February 1995 and December 2000, there were 1,867 patients included. Median follow-up was 7.5 years at the cut-off date of September 1, 2005. The survival status was known for 1,807 patients. Results showed a beneficial effect of adjuvant chemotherapy on overall survival (HR: 0.91; 95% CI: 0.81–1.02, p= 0.10) and on disease-free survival (HR: 0.88; 95% CI: 0.78–0.98, p= 0.02). However, there was a significant difference between the results of overall survival before and after 5 years (HR: 0.86; CI: 0.76–0.97, p = 0.01 versus HR: 1.45; CI: 1.02–2.07, p =0.04); p-value for interaction was 0.006. Disease-free survival benefit was also different according to the follow-up duration (p-value for interaction: 0.04; global, first 5 years, HR=0.85, p=0.006; after five year, HR=1.33, p=0.16). The analysis of non-lung cancer deaths for the whole period showed a HR of 1.34 (CI: 0.99–1.81; p=0.06). Conclusions: These results confirm the efficacy of chemotherapy for the first 5 years after surgery. The difference in results between less than and more than 5 years of follow-up may suggest possible late adjuvant chemotherapy-related over-mortality. This potential effect underscores the need for the long-term follow-up of adjuvant lung cancer trials in order to evaluate results in terms of treatment benefits and long-term hazards. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration GlaxoSmithKline