Drug sensitivity testing -- Information for Clinicians
Ex vivo drug sensitivity testing is designed to elucidate individual
patient response to cytotoxic drugs in the heterogeneous patient population.
Twenty-five or more drugs can be tested, including new cytotoxics. We
routinely test leukaemias and lymphomas - most experience is with CLL,
AML, NHL and similar diseases - using whatever source of live tumour cells
is most readily available.
Drug sensitivity tests are carried out at Bath Cancer Research, a charitably
funded research group based at the Royal United Hospital in Bath. Research
scientist Dr Andrew Bosanquet, who has twenty-five years experience in
this field, leads the team.
Drug Sensitivity Testing Methodology
We use the TRAC assay (Tumour Response to Anti-neoplastic Compounds),
a recent development of the DiSC assay - a drug sensitivity testing methodology
that has been described in detail . Briefly, mononuclear cells are
isolated from blood, lymph node, bone marrow, fluids or tumour and cultured
with drugs for 4 days. Then cells are cytocentrifuged onto slides, stained,
apoptotic cell death is assessed morphologically, and an LC90 calculated.
For each drug, a Drug Sensitivity Index (DSI) is determined by ranking
the patient's LC90 within all the LC90 results of patients with the same
or, in rare malignancies, similar diagnoses. Results are available within
Drug Sensitivity Test Results
Your patients relative drug sensitivity and resistance for the drugs
tested will be charted. Our drug sensitivity results compare well with
subsequent patient response [2-5]. They show that patients who are treated
with assay-sensitive drugs are 4 to 8 times more likely to achieve a response
than those treated with assay-resistant drugs . Results suggest that
survival can be improved by treating with drugs that are assay-sensitive
[4,6]. Response and survival benefits are being quantified in an international
randomised, controlled clinical trial - the LRF CLL4 trial. As of June
2006, results from this trial are being presented (EHA 2006, ASH 2006).
Limitations of the TRAC assay
Incubating drugs and cells together in the lab and observing loss of live
cells integrates the effects of many drug resistance mechanisms. However,
a cytotoxicity test is obviously limited in that it cannot take into account
patient effects on cell survival in vivo such as liver metabolism, enhanced
excretion, effect of other medications, etc.
Cytotoxicity of the antibodies alemtuzumab and rituximab is observed
but they also induce cell kill by other methods that this test does not
detect: it is not known which method of cell kill is most active in vivo.
It is also not possible to determine induction of differentiation or inhibition
of angiogenesis with this methodology (i.e. we cannot test thalidomide).
For some resistant tumours there are few effective drugs available to
test. We are more likely to identify effective drugs for diseases that
are generally drug sensitive. However, drug resistance information is
valuable when deciding treatment options as it enables avoiding the morbidity
of ineffective therapy.
Obtaining a Drug Sensitivity Profile for your
We need LIVE
TUMOUR CELLS within 24 hrs (48 hrs max)
So No Freezing, No Formalin,
No Friday dispatch
To ensure good results:Send sufficient tumour cells (1 million cells required per drug tested)
Get your sample to us quickly, preferably within 24 hours of harvest
or phlebotomy. Use the GPO's 'Special Delivery' or ask us about a courier
Send tumour cells appropriately - blood into EDTA, bone marrow into
preservative free heparin, ascites "as is", lymph nodes and
solid tumours chopped and placed in culture medium e.g. RPMI 1640
Fill in the specimen request form and either
e-mail or enclose with specimen
Inappropriately dispatched specimens are the largest
cause of no TRAC assay result -
a waste of your time, our time and the patient's time.
Please take care when sending samples.
Drugs Currently available for testing
Bleomycin, carboplatin, chlorambucil, cladribine, cyclophosphamide, cytarabine,
daunorubicin, dexamethasone, doxorubicin, etoposide, fludarabine, gemcitabine,
hydroxycarbamide (mustine), idarubicin, ifosfamide, melphalan, methylprednisolone,
mitoxantrone, paclitaxel (taxol), pentostatin, prednisolone, tioguanine
(thioguanine), topotecan, vinblastine, vincristine, vinorelbine.
The testing of other drugs may be possible prior arrangement.
Advantages of Choosing Therapy knowing a Patients
Drug Sensitivity Profile
Response is four to eight times more likely to be achieved with assay-sensitive
Morbidity and mortality associated with ineffective drugs can
Drug resistance induced by ineffective treatment is avoided
Relative efficacy of two similar regimens is elucidated
Rational treatment choices are possible when no clearly defined
treatment protocols exist
When standard regimens fail, newer or non-standard regimens
can be considered
A therapeutic index can be obtained when normal cells are also tested
Financial savings ensue as responding patients need less supportive
Expensive new drugs can be avoided in test-resistant patients [3,4]
New therapeutic options can be rationally assessed in end-stage patients
Charges for Drug Sensitivity Tests
Specimens for research projects and clinical trials are not charged.
NEW until further notice
June 2006. Bath Cancer Research has launched two
far simpler, and therefore cheaper, drug sensitivity tests for CLL. These
will allow physicians to test the main cytotoxic drugs of interest at
diagnosis and also after the patients first regimen:
TRAC-0 suggested for untreated CLL patients
- testing five drugs at just £95.00 (Euros 150.00). Drugs tested
fludarabine, cyclophosphamide, mitoxantrone, chlorambucil, methylprednisolone.
TRAC-1 suggested for CLL patients at first
relapse - testing 10 drugs and costing £195.00 (Euros 300.00).
for further details.
Apart from any prior agreement, other NHS tests
will cost £395.00 + to test the sensitivity to 20+ cytotoxic drugs.
Private patients and those from North America -
Bath Cancer Research was inspected in April 2006 by Clinical Pathology
Accreditation (CPA), ref. no. 2769. Its status is "Conditional
Reports are generally available within 7 days of receiving a sample.
Bath Cancer Research, Wolfson Centre, Royal United Hospital, Combe Park,
Bath BA1 3NG, UK
Tel 01225 824 124. Fax 01225 824 114
Hours: 8.30-5.30 Mon-Thur, 8.30-5.00 Fri. Out of hours by prior arrangement.
The Director, Dr Andrew Bosanquet PhD MIBiol MRCPath FRSC, is available
for scientific advice and interpretation during office hours.
- Bosanquet AG, Bell PB. Enhanced ex vivo drug sensitivity testing of
chronic lymphocytic leukaemia using refined DiSC assay methodology.
Leuk Res 1996; 20: 143-153.
- Bosanquet AG. Correlations between therapeutic response of leukaemias
and in vitro drug sensitivity assay. The Lancet 1991; 23: 711-714.
- Bosanquet AG, Copplestone JA, Johnson SAN, Smith AG, Povey SJ, Gillingham
R, Oscier DG. Response to cladribine in previously treated patients
with chronic lymphocytic leukaemia identified by ex vivo assessment
of drug sensitivity by DiSC assay. Br J Haematol 1999; 106: 474-476.
- Bosanquet AG, Johnson SA, Richards SM. Prognosis for fludarabine therapy
of chronic lymphocytic leukaemia based on ex vivo drug response by DiSC
assay. Br J Haematol 1999; 106: 71-77.
- Fruehauf JP, Bosanquet AG. In vitro determination of drug response:
A discussion of clinical applications. PPO Updates 1993; 7 (December):
- Mason JM, Drummond MF, Bosanquet AG, Sheldon TA. The DiSC assay: a
cost-effective guide to treatment for chronic lymphocytic leukaemia?
Int J Tech Assess Health Care 1999; 15: 173-184.
- Catovsky D et al. MRC Chronic Lymphocytic Leukaemia Trial 4 Protocol
Document 1999. Link
- Bosanquet AG, Bell PB. Novel ex vivo analysis of nonclassical, pleiotropic
drug resistance and collateral sensitivity induced by therapy provides
a rationale for treatment strategies in CLL. Blood 1996; 87: 1962-1971.
- Bosanquet AG, Burlton AR, Bell PB. Parameters affecting the ex vivo
cytotoxic drug sensitivity of normal human cells. J Exp Ther Oncol 2002;
- Bosanquet AG, Bell PB. Ex vivo therapeutic index by drug sensitivity
assay using fresh human normal and tumour cells. J Exp Ther Oncol 2004;
- Bosanquet AG, Burlton AR, Bell PB, Harris AL. Ex vivo cytotoxic drug
evaluation by DiSC assay to expedite identification of clinical targets:
results with 8-chloro-cAMP. Br J Cancer 1997; 76: 511-518.
- Bosanquet AG, Raper SL, Durant J, Scadding SM, Richards SM, Catovsky
D. Comparison of ex vivo drug sensitivity by TRAC assay and patient
response in the UK LRF CLL4 trial. Haematologica / Hematology Journal
2006: 91 (Suppl. 1); 100 (Abstract #267). European Hematology Association,
Abstracts and pdf versions of the full paper can be obtained
for some of these publications from Selected