My fiancée had breast tumor removed last year and a genetic test was run on it by a genetic testing company. This company tests for the expression of 21 genes but will only release to my fiancée or her doctor a single "weighted score" (based on an algorythym) of the results. They will not "publish" or release the individual expressions of the 21 genes. Obviously my fiancée would like to know what genes were expressed and to what extent. To my knowledge, there were no documents from this company that were signed (other than the Lab's request to release the sample to the genetic testing company).

Is there a way to compel them to release the individual expression information to my fiancée or her doctor?

If they will not release after being asked, you will have to hire an attorney to write them for possible legal action

They may not have individual test data. It's quite possible that they put the sample in a machine, the machine tests it, runs the algorithm, and spits out the answer. A lot depends on whether the test is to determine the likelihood of a particular condition, which is dependent on multiple genes for expression, or if the testing is to confirm multiple conditions. In the first case you are much more likely to just get a weighted score, since that's what will determine the likelihood of the condition.