Tan KS, et al. - A total of 263,894 cases were involved to quantify the variations between relative and cause-specific survival when reporting net survival of patients with non-small cell lung cancer. Across all strata, cause-specific survival estimates were greater than relative survival estimates. However the variations were negligible at 1-year postdiagnosis, they rose with increasing years of follow-up, up to 9.3 pp at 10 years. Variations in survival estimates between the methods also rose by advancing age groups but declined dramatically for those aged ≥ 75. Thus, relative survival and cause-specific survival were concluded as non-interchangeable. Moreover, the type of survival estimate used in cancer studies should be particularized, especially for long-term survival.