ChemoFit™ – What is it?
ChemoFit™ is the latest chemoresistance/chemosensitivity assay now being
offered for the first time in Canada. The ChemoFit™ test is conducted on a fresh
tumour sample, which is transported to ORT Inc. in New York. The patient’s
oncologist can suggest which chemo drugs they are interested in testing.
The tumour specimen is disaggregated into a Single Cell Suspension (SCS),
and exposed to chemo drugs at physiologically achievable concentrations
for up to 72 hours in a controlled environment. The drug-exposed SCS is then
exposed to stains that define cell life vs. cell death, and percentage cell kill is
determined. The drug treated SCS are compared to drug untreated SCS.
A report is generated for the oncologist indicating the effectiveness of each
chemo drug or combination (% of cells killed is reported).
Is there any data supporting the use of tumour assays?
Data supporting the use of tumour assays is emerging steadily and
is very encouraging. Studies show that cancer patients administered
chemotherapy after in vitro evaluation, respond more favourably to the
treatment with resultant decreased toxicity.
Cortazar P, Johnson, B.E., Review of the Efficacy of Individualized Chemotherapy Selected by in-vitro
Drug Sensitivity Testing for Patients With Cancer, Journal of Clinical Oncology, 17(15):1625-31, May 1999
Strauss E., Pre-testing Tumours, Scientific American, 280(2):19,22, Feb 1999
Simonsen, M., Growth is Forecast for Tumour Markers, Oncogene Assay Market, American
Health Consultants, 1(4):1-6, 1998
Meta-analysis studies further indicate that there is a more favourable response
in patients treated with regimens based on in-vitro assay results.
Cortazar, A., Johnson, M., Meta-analysis Studies in Patients Treated With Regimens Based on in-vitro Assay
Results Than Those That Are Not, Journal of Clinical Oncology, 1999
In addition, patient survival has been shown to correlate with administering assay-guided therapy.
Mehta, R. et al., Breast Cancer Survival and in vitro Tumour Response in the Extreme Drug Resistance Assay,
Breast Cancer Research and Treatment, 66:225-237, 2001
Loizzi, V., et al., Survival Outcomes in Patients With Recurrent Ovarian Cancer Who Were Treated With
Chemoresistance Assay Guided Therapy, American Journal of Obstetrics and Gynecology, 189(5):1301-7, 2003
What makes ChemoFit the ideal tumour assay?
- results are available within 72 hours
- tumor cells are exposed to drug concentrations that are physiologically achievable
- tumor cells are exposed to single drugs as well as combinations of drugs
- on-protocol drugs, off-protocol drugs, novel drugs “in the pipeline” and “orphan”
drugs can be evaluated
- DCA can be evaluated with and without chemo
- cell growth inhibition is not evaluated due to inaccuracies of this method
- the end point is cell death, regardless of pathway (apoptosis alone as an end-point
is not a sufficient indicator of cell-death)
- all causes of cell death are measured to maximize accuracy (drugs that target cell cycle parameters, signal transduction pathways etc. can be evaluated).
- no subjective pathological interpretation is required
- the cells analyzed are non-clonogenic, giving a better representation of the
heterogenic cell mass within the tumour (yielding a better indication of the
- several different drug concentrations are evaluated to minimize false
positives and false negatives
Who would be an ideal patient for ChemoFit?
ChemoFit is recommended to guide chemotherapy for solid tumors like ovarian,
lung, breast, colon, prostate, cervical, endometrial, pancreatic cancers and sarcomas.
ChemoFit can be used for selecting first line and second line chemotherapy,
whether the aim of chemotherapy is cure, or palliation.
Our physician will evaluate the suitability of ChemoFit for each patient, taking into
account the stage of cancer, the ease of obtaining a tumour sample, and the potential
benefit and risks. Note that the patient must not have had chemo or radiation within
3 weeks of specimen collection.
What should I do if my patient requests ChemoFit?
Please ask your patient to call Care Imaging
905-712-9500 to organize the test.
You will be asked to provide a list of chemo drugs or drug combinations that you would
like the tumour tested against. After the test is performed, a report will be sent to you
(within 7-10 days of specimen collection).