There was a summary paper from a National Cancer Institute study, presented at the American Society of Clinical Oncologists (ASCO) Annual Conference in 1998, which looked at thirteen different studies that searched into "in vitro" (chemosensitivity assay) drug sensitivity testing for patients with cancer. It was noted that with the many different cancers represented in these studies, chemotherapy response rates went up from 3 to 66% (using standard chemotherapy drugs and procedures) and from 21 to 81% (using "in vitro" testing for the most responsive drug) and patient survival increased from 4.5 to 11.2 months (using standared procedures) and from 6.2 to 38.5 months (using "in vitro" testing).
Dr Ian Cree, Director, Translational Oncology Research Centre, Queen Alexandra Hospital, Portsmouth UK performed the very first prospective, randomized clinical trial of physician's choice chemotherapy versus ATP assay-directed chemotherapy in non-surgically debulked, platinum-resistant ovarian cancer and presented it at the May, 2005 American Society of Clinical Oncologists (ASCO) meeting in Orlando, Florida.
The results were highly suggestive of an effect due to the assay, and the most successful drug regimens used were nearly all developed using the assay. UK results in cancer are always lower than in the US for a variety of reasons. Part of this is probably lead time bias, but data on surgical debulking may be part of the explanation. Patients in the US get a whole lot more surgery along the way than in Europe.
As a result of this, the Gynecologic Oncology Group (GOG) has decided to move forward with a study in platinum-resistant ovarian cancer, utilizing a different assay called EDR, to direct chemotherapy. However, this assay is specifically designed to identify 'inactive' rather than 'active' drugs. In this light, the EDR assay has the advantage of telling you who will 'not respond' but cannot in any way change the negative outcome by selecting an 'active' alternative. At least it's a start!
There are other medical oncologists in the US, headed up by Drs Larry Weisenthal and Robert Nagourney, that are making proposals for a separate study, a front-line randomized trial with head to head comparison of several assays (EDR, ATP, DISC, MTT, as well as Caspase 3/7). These assays correlate very well with each other on direct comparisons of different methods. Different methods of assay results should be applied in choosing a particular drug regimen to be used in treating an individual patient's cancer.