My husband has been diagnosed with nsclc stage 4. The cancer has spread to bones in back, pelvic & femur. His doctor tested him for gene therapy & apparently he was in the 16% of people that would benefit from tarceva. Doctor said he had the mutation that tarceva would target. Does anyone know about this?

That means that you husband is likely to be EGFR + and that he have many chances to responde to Tarceva . Is a great drug, must be taken orally in a dayly basis with, in general, few side effects manageable.
Blessings
Seb