The best possible treatment - individualized for each patient




Here are answers to some of the questions we hear quite a lot.  For your convenience, the questions are numbered and presented in the order in which they appear in the following list.  To find the answer to a question that interests you, simply scroll down the page to locate your question and answer.  If there is something you were wondering about that doesn’t appear here, please give a us call and we’ll be glad to answer it for you.

  1. 1.What is Personalized Cytometric Profiling?

  2. 2.How is personalized cytometric profiling performed?

  3. 3.Who is responsible for evaluating and reporting the results of my profiling studies?

  4. 4.What will Dr. Weisenthal’s tests tell me?        

  5. 5.Will personalized cytometric profiling cure my cancer?

  6. 6.Are drugs tested as single agents or in combination?

  7. 7.Who can have personalized cytometric profiling?

  8. 8.What are some likely sources of cancer cells in my body for profiling?

  9. 9.Isn’t there a testing method that just uses a blood sample for solid tumor profiling?

  10. 10.How do I know if I qualify?

  11. 11.How many drugs can you test?

  12. 12.How do I arrange for personalized cytometric profiling?

  13. 13.How much do Dr. Weisenthal’s services cost?

  14. 14.Will healthcare insurance cover the costs of my tests?

  15. 15.Are Dr. Weisenthal’s services available to persons living outside of the U.S.?


  1. 1.What is Personalized Cytometric Profiling?

Thousands of individual processes and chemical interactions occurring within a cancer cell determine whether or not the cell will or will not respond to treatment with a chemotherapy drug.  Personalized cytometric profiling assesses the combined effect of all of these processes as they occur in real time within your living cancer cells. 

  1. 2. How is Personalized Cytometric Profiling performed?

A biopsy sample containing living cancer cells is removed from your body thorough a surgery or other biopsy procedure.  In our laboratory, the cancer cells are extracted from the sample, taking great care not to harm them.  Your living cancer cells are distributed among several 96-well polystyrene microtiter plates.  Each well will contain about 10,000 of your cancer cells.  A very broad range of anti-cancer drugs is selected by Dr. Weisenthal for testing against your cancer cells.  A different anti-cancer drug or drug combination is added to each well.  Your cells are held in carefully-controlled temperature and CO2 incubator conditions during a 96 hour exposure period.  The cells are not "grown" or multiplied as in older methods as this could produce inaccurate test results.  The testing process is not intended to precisely replicate what occurs in the human body - that would be impossible.  Instead, the drug exposure conditions and drug concentrations were meticulously calibrated over many years of assay development to achieve the highest possible rate of correlation between what happens in the laboratory and what happens in the patient. 

Once the cells have finished their exposure period the cell killing effect of each drug upon the cancer cells is measured using at least three and as many as five three different laboratory technologies.  Multiple tests are used for increased accuracy and to obtain the maximum amount of information about your cancer cells   Each technology evaluates tumor cell killing in a manner which is complementary to that of the other technologies which Dr. Weisenthal selects for you.  The choice of technologies used for your comprehensive analysis is based upon your cancer type, the specific drugs being tested for you, and factors specific to your individual biopsy specimen. 

Each, separate drug activity measurement is then analyzed by Dr. Weisenthal, who examines and interprets dozens of microscope slides upon which your cells, which have been stained and counterstained, are mounted.  Dr. Weisenthal then integrates data from each of the different tests which were carried-out for you and performs computer comparisons of your various test results with an extensive, multi-parametric index database.  This is a critical step which converts otherwise crude cell killing data into information which is meaningful, highly specific to you, and clinically-useful for you and your physician.  Dr. Weisenthal compiled his database laboriously over a twenty year period.  It is far more detailed than databases used by any other laboratory in the world.  The aim is to achieve the highest levels of accuracy and clinical relevance.  For more information on the importance of Dr. Weisenthal’s index database, please click here.

  1. 3.Who is responsible for evaluating and reporting the results of my profiling studies?

Results of all of the tests are personally and individually evaluated by Larry Weisenthal, M.D., Ph.D..  Dr. Weisenthal is a physician - a board certified Medical Oncologist (cancer physician) who formerly worked at the National Cancer Institute.  In addition to his medical degree, Dr. Weisenthal also holds a Ph.D. in pharmacology.  Dr. Weisenthal microscopically examines your tumor cells before and after testing, along with data produced by the three different technologies used on your behalf.  Then, within the context of your clinical situation and treatment history, he interprets data produced by your profiling analysis by mathematical comparison with an extensive index database.  Based upon his knowledge of the drugs and of your cancer type and clinical situation, along with your individual test results, Dr. Weisenthal determines which drug or combinations of drugs have the best chance of providing benefit to you.  For each test, Dr. Weisenthal devotes more than 8 hours of concentrated, individualized effort.  This is in addition to several hours spent by an experienced laboratory technologist to prepare your specimen for testing.  This is done meticulously, under Dr. Weisenthal’s direct , actively-involved supervision, to produce the best possible testing environment and the most accurate, most useful test results.

  1. 4.What will Personalized Cytometric Profiling tell me?

The tests show if your cancer cells were killed by exposure to one or more of the 20 or more different anti-cancer drugs or drug combinations that might otherwise have been considered as possible treatments for your type of cancer.

  1. 5.Will Personalized Cytometric Profiling cure my cancer?

Personalized cytometric  profiling is a comprehensive laboratory analysis that can evaluate but cannot change the chemical make-up of your cancer cells.  If a drug or combination of drugs exists that is effective against your cancer cells, cytometric profiling can pinpoint that drug or those drugs for you. However, if no drug exists that is able to control your cancer, personalized cytometric  profiling cannot alter that fact.  Numerous studies have shown that cytometric profiling can show us which drugs have a higher or much higher than average likelihood of success, which drugs have a lesser chance of success, and which drugs have virtually no chance of success.  This can be an invaluable aid in treatment selection.  But the tests by themselves cannot change the fundamental nature of your illness.  The goal of personalized cytometric profiling is to afford you the best possible chance for treatment success by pinpointing specific drugs that are found in the laboratory to be the most effective at killing your own tumor cells.  At the same time, personalized cytometric  profiling saves valuable time and spares needless exposure to toxic and costly drugs which might otherwise have been chosen for you but which cannot possibly help you.  

  1. 6.Are drugs tested as single agents or in combination?

We always test each drug individually but some of the drugs are also tested in combination with an additional, carefully selected drug if there is a rational basis to support the possibility of drug synergy. 

  1. 7.Who can have Personalized Cytometric Profiling?

A patient must have living cancer cells in his or her body.  The cells must be accessible by means of surgery or other biopsy procedure.  The tests cannot be performed on dead cells or on tissues that were obtained in a past surgery or biopsy procedure.   

  1. 8.What are some likely sources of cancer cells in my body for profiling?

A solid tumor mass is the most commonly tested specimen type but malignant effusions often are usable when these are available.  For many leukemias and for some multiple myelomas and lymphomas, blood or bone marrow might contain cancer cells in numbers sufficient for testing.  For details about specimen requirements and special handling techniques please click here to jump directly to that section.

  1. 9. Isn’t there a testing method that just uses a blood sample for solid tumor profiling?

There is a laboratory in Greece - and perhaps others elsewhere, that we are not aware of - which claims the ability to test blood samples in order to identify effective treatments for patients with solid tumor types.  There are compelling scientific reasons why Dr. Weisenthal and other experts have very serious concerns about this approach.  The method consists of removing normal cells from blood samples.  This supposedly leaves only tumor cells.  The remaining cells are then cultured and passed through a flow cytometer.  A flow cytometer is a machine that detects a fluorescing marker which was added to a cell sample during processing.  In this case, the marker used is called “annexin.”  Annexin binds to the membranes of cells which have been killed through a process called apoptosis.  

Here is why that approach cannot possibly work as the laboratory claims.  First, real tumor cells always clump together when they are cultured (“culturing,” as it is used here, means inducing tumor cells to multiply outside the body).  Cells which have clumped-together CANNOT be interrogated with a flow cytometer, which works by passing cells through a laser light beam, one cell at a time.  Secondly, the lab in question prepares the sample using what is called “negative selection.”  It attempts to remove normal cells from the sample and leave behind what are hoped to be only tumor cells.  Experts in the field of cell selection state that this is impossible. No negative selection methods, known to exist today, can produce a pure tumor population - or even come close to doing so.  Persons knowledgable in this area agree that this method always leaves behind hundreds or thousands of normal cells for every one tumor cell obtained.  Hence, any readings obtained with this method would be based mainly upon normal cells and not upon tumor cells.  Data obtained with this method would be irrelevant at best.  More importantly, it is easy to see how inaccurate data such as these could drive treatment decisions which are harmful to the patient.  Dr. Weisenthal has never warned against using the services of any specific lab.  In this case, he strongly advises awaiting the emergence of data from independent investigators, showing that this method is capable of accurately assessing anti-tumor drug activity.

  1. 10.How many drugs can you test?

The number of drugs we can test is determined by the number of tumor cells we can isolate from the tissue we receive.  Sometimes a very large piece of tissue contains mostly normal cells and only a small nest of viable tumor cells.  On the other hand, a smaller specimen might yield an abundance of useable cells.  We don't grow cells or try to multiply them in culture as some labs do.  This can change the behavior and genetic make-up of the cells and artificially skew your test results.  For maximum accuracy, we test your cancer cells just as they were removed from your body. 

Testing begins immediately on the day your sample arrives.  Therefore, the cells we receive from your physician are all that we will have for testing.  We request a gram or more of tissue.  For reference, that is a piece of tissue somewhere between the size of a lima bean and a radish.  Your physician can help by selecting one to two grams of firm, viable tumor tissue, by not damaging the cells with electrocautery knives, toxic inks, formalin, or other harmful items, by placing the specimen quickly in fresh transport media, by keeping the specimen cold but not frozen, and by shipping your specimen on the same day it is collected.  For more on specimen requirements, please click on the link.  To learn more about how your drugs are selected for you for testing, please click here.  

  1. 10.How do I know if I qualify?

Your doctor will know if you have accessible tumor cells.  However, you must also be well enough to receive chemotherapy.  Please feel free to phone us with your questions.  We  probably can tell from hearing about your specific illness and clinical situation if you are a good candidate for personalized cytometric  profiling. 

  1. 11.How do I arrange for Personalized Cytometric Profiling?

Phone us at (714) 596-2100 - or else ask your doctor to do so.  Government regulations require that a physician must order testing on your behalf but we certainly do invite you to phone or email us to help in making the arrangements if you would like to do so.  It should be noted that regulations also require that laboratory test results must be reported to the physician who ordered the testing and to other physicians who are designated on the assay order form. Your physician should be happy to furnish you with a copy of your test results but, legally, we cannot report test results directly to patients. 

The most important thing is for someone - whether it is you or your physician - to contact us in advance so that we can make sure that specimen transport materials reach your physician or the hospital  before your surgery or biopsy procedure.  Included in our transport package are specimen handling instructions, overnight shipping labels, specimen containers, and a special transport medium that will keep your cancer cells alive during conveyance to our laboratory.  Please be sure to call us a minimum of two days prior to your scheduled surgery date to make sure that the critical specimen transport materials reach your physician on time. 

  1. 12.How much does profiling cost?

The cost of testing can vary widely, depending upon the number of drugs and drug combinations tested for you.  Fees for personalized cytometric profiling can range from $2000 to as much $8,000.  The number of drugs to be tested is determined by what is appropriate for you in your specific clinical situation, by what additional drugs and combinations your doctor requests, and by the quantity and quality of the biopsy specimen that is furnished to our laboratory. 

  1. 13.Will healthcare insurance cover the costs of my profiling tests?

Personalized cytometric profiling will not be covered under your Medicare policy.  If you are a Medicare patient and if you do not have supplemental insurance your testing service fees will not be reimbursed.  If you have private insurance, coverage for the tests depends upon the policies of your individual carrier and upon the provisions of your specific insurance plan.  It is possible that your insurance will cover at least some portion of your testing costs, although normal co-payment and deductible amounts will apply.  However, many insurance carriers pay for only a relatively small percentage of the costs while some carriers will deny insurance claims entirely.  If this should occur, our reimbursement specialist will gladly assist you in appealing an unfavorable determination. In the past, many such appeals have been successful.  However, you will be responsible for balances not paid by your carrier.  As a courtesy, we are pleased to bill your insurance carrier directly on your behalf. 

  1. 14.Is Personalized Cytometric Profiling available to persons living outside of the U.S.?

Yes.  We routinely perform testing for patients from around the world.  Specimen requirements are the same as for patients living in the U.S..  Biopsy specimens should arrive at our laboratory no more than 48 hours after removal from the patient.  We work closely with FedEx to ensure that specimens from overseas arrive on time and we have had great success in making this happen.  It is extremely important that you contact us at least 48 hours before surgery so that we can make arrangements and also provide international declarations, shipping labels,  specimen transport medium, and other necessary materials.  Please phone us at 001-714-596-2100.


If you have questions that aren’t covered here - or if you would like to discuss those that are - please don’t hesitate to phone us.  Chances are, you’ll speak directly with Connie Rueff, M.T., who is our laboratory manager.  Connie has been at this for about 20 years now and she definitely knows what she is talking about.  Connie is friendly, patient, and always happy to speak with patients and physicians.

Give Connie a call at 714-596-2100 during normal business hours.  That would be from 9 AM until 5 PM, Monday through Friday.  Please remember that we are located in California and so we operate on Pacific time.