Most preparations of chewing tobacco are smoke or fire cured. The process still introduces many of the byproducts that are created during the combustion of dried organic material.

The most prominent example of chewing tobacco that isn't smoke cured would be Scandinavian-style snus. There's pretty compelling evidence that snus is not associated with oral cancer[1], or at the very least the risk is substantially lower than traditional chewing tobacco.

[1] https://onlinelibrary.wiley.com/doi/full/10.1046/j.1360-0443...