Paternal smoking raises risk of acute lymphoblastic leukemia

Paternal smoking before conception or during pregnancy are both associated with increased risk of acute lymphoblastic leukemia (ALL) in offspring, and the risk is significant when daily smoking consumption is higher than a certain threshold, according to a recent meta-analysis.

Investigators based in China conducted a literature search of 4 electronic databases and retrieved more than 2000 articles from which they selected 17 studies for systematic review and meta-analysis. These studies encompassed a wide time span (1977-2011); were conducted in a variety of geographic areas; and yielded a total of 9127 childhood ALL cases. Eight of the studies reported effects of paternal smoking before conception and during pregnancy, 3 reported effects during pregnancy, and 6 reported effects for smoking before conception.

Analysis revealed a nonlinear dose-response relationship between paternal smoking both before conception and during pregnancy and the risk of ALL. Before conception, the smoking effect increased gradually along with daily smoking consumption but was not significant until it reached 16 cigarettes a day. Smoking during pregnancy showed a similar pattern, with a significant effect observed after 11 cigarettes a day (Cao Y, et al. J Pediatr Hematol Oncol. 2020;42[1]:32-40).

Thoughts from Dr. Farber

We have advised parents for years to stop smoking for the sake of their children and, for mothers, the benefits of any future babies. Now we have medical reasons to persuade fathers to stop smoking as well.