cadence to pads
Look at this thread on the forum - this question has been asked before:
The short answer is no. You can use a tool like CAMCAD provided you can get the BRD file into the five ASCII files required by CAMCAD. You can hire a company that specializes in file conversions. Or you can export an ODB++ or Gerber set and reverse engineer from a CAM Editor like CAM350.
If you know someone with Alitum Designer, they can import the Allegro file. You can then import the Altium Designer file into PADS using the Mentor translator.