Amplifier circuit for different frequency
I can't see exactly what your circuit is, but the part is capable of 12 MHz at a gain of 100dB. Given that, I would check your external feedback resistors versus the data sheet recommendations. Plus all the data uses a load of 100 ohms to 1K. What is your load?

Aside from that I recommend using some common techniques for higher frequencies on solderless breadboards. First cut the leads on your resistors so they can either be set vertical in two adjacent holes (or diagonal or 0.3 apart) or cut them and bend so they fit 0.4 to 0.6 spacing. Do the same for jumper wires. In other words, use the shortest possible path. Put a load on the output at the part's output pin and measure from that point.

The breadboards are not great for high frequencies. What is the surface under your breadboard? Each of the rows of holes has a single metal conductor under it. I do this kind of thing on a piece of bare copper PCB with the PCB grounded and all grounds soldered to the PCB. The rest is "up in the air" with wires soldered to the amp pins. It is better than a custom PCB. (I got it from this guy http://www.rfcafe.com/references/electrical/bob-pease-breadboard.htm   Buy the book! If it isn't worth every penny I'll buy it from you and give it to a student.)

Last, have you checked your signal source with a simple load?