I just turned 52, and was diagnosed last march with 2 cm tumor on right side of tongue, with 1 lymph node on that side. My lymph node was closer to 2 cm in size. The doctors at the CCC recommended a very aggressive course, consisting of a bilateral neck dissection, radiation and chemo.
Note that I did not have surgery to remove the tumor. Given the small size, they felt they could eliminate it completely with radiation. This proved to be true, and I am cancer free at this point.
There are no hard and fast rules. I wanted the most aggressive treatment possible, as once it is in a lymph node, the staging goes up. Neck dissection showed minor involvement of 1 other node on the right, so I was glad I did it.
I was lucky, in that I continued to work throughout treatment, and had realtively minor impacts from the treatment. Today I am bothered by dry mouth, neck stiffness, but that is a small price to pay.
We all have to make these treatment decisions individually, but for me, I did not want to take any shortcuts, as I cannot be sure that I have another crack at this deal.
Good luck, whatever you decide. Come here with questions, as we have collectively seen most, if not all, of the issues you could face.