Quitting smoking after a cancer diagnosis is associated with high-risk neutrophil-to-lymphocyte ratio among tobacco use-related cancer survivors.

Quitting smoking could potentially minimize the risk of a high neutrophil-to-lymphocyte ratio (NLR) among tobacco use-related (TUR) cancer survivors. A total of 1263 TUR cancer survivors aged 20 to 85 years old were investigated using data from the National Health and Nutritional Examination Survey 1999-2018. The primary outcome was the NLR, which was defined as having two levels: high-risk (≥ 3) and low-risk (< 3). The association between smoking cessation time and a high-risk NLR level was analyzed using weighted logistic regression models. Overall, the current smoking rate of TUR cancer survivors was found to be 21.7%. Older age (75 years above), gender and respiratory-related cancers are covariables associated with high risk of NLR levels for individual who identified as Non-Hispanic White (NHW). Non-Hispanic Black (NHB) (n = 27) who quit smoking after a cancer diagnosis were associated with the highest risk of a high NLR (OR 4.83, 95% CI 1.40-16.61, p = 0.01) compared to NHB nonsmokers (n = 139). These findings suggest that the risk of a high NLR level is strongly associated with the time of smoking cessation in NHB TUR cancer survivors. As a result, NHB TUR cancer survivors should quit smoking as soon as possible because the benefits of quitting smoking were observed over the 5 year period following smoking cessation.