The best possible treatment - individualized for each patient


FAQ - Quick Facts         Specimen Information


Increasingly, cancer physicians are turning away from the traditional one-size-fits-all approach to chemotherapy drug selection.  It has become apparent to physicians and researchers worldwide that better results can be achieved if cancer treatments are personalized, based upon specific biologic factors.  These factors occur at the cellular level and are unique to each patient. 

Weisenthal Cancer Group provides a valuable treatment planning tool called Personalized Cytometric Profiling.  Personalized Cytometric Profiling consists of several laboratory tests performed upon your own living cancer cells.   The tests pinpoint for you and your physician which of the many available anti-cancer drugs and drug combinations - including new molecularly targeted, immunologic, and anti-vascular agents - are effective at killing your cancer cells and which agents are not effective.  The most effective drug regimen can be selected for you and you alone. 

Clinical experience with cytometric profiling includes dozens of published studies, confirming that drugs found active in our tests are associated with higher rates of clinical response, longer remission times, superior overall survival times, and more cancer cures. 

Another important benefit of personalized cytometric profiling is that ineffective cancer drugs can be identified and avoided.  This spares you needless exposure to harmful side effects from drugs that can’t possibly help you.  Importantly, valuable time is not wasted while your treatment team chases one blindly-chosen drug regimen after another.   Unnecessary costs from expensive but ineffective treatments are also avoided.

Cytometric Profiling versus Gene Testing

If you research personalized cancer treatment approaches you will also find information relating to “gene testing.”  This is also known as “molecular testing,” “target profiling,” or other by names. 

People often ask, “How does this differ from Cytometric Profiling?” and, of course, “Which approach is better?”  The answer is that both approaches have something useful to offer.  However, we and many others believe that cytometric profiling - our method - has far broader capabilities than gene testing.  Here is why:

Gene testing attempts to link expression of certain gene mutations within the nucleus of a cancer cell to a theoretical potential for drug activity.  In gene testing no chemotherapy drugs are actually tested.  Other biological mechanisms of the cancer cell are also ignored.

In Cytometric Profiling, millions of your own, living cancer cells are exposed to the widest possible range of actual chemotherapy drugs.  The true cell killing ability of each drug is observed and measured. This shows which drugs are effective and which drugs are not effective.   Cytometric profiling (our method) can test many more specific drugs in more different classes of drugs than gene testing.  This includes molecularly-targeted drugs, immunologic drugs, standard chemotherapy drugs, and anti-angiogenic drugs.

Here are other differences:

  1. Different drugs within the same general class of drugs - that is, drugs that are thought to work by the same mechanism of action - are known to produce widely varying patient outcomes.  And yet gene testing looks only at the presumed mechanism of action and not at the individual drug itself, much less at each patient’s own cancer cells in the presence of each drug.  Therefore, gene testing cannot possibly detect differences in activity among different drugs within the same class of drugs.  In contrast, Cytometric Profiling accurately measures widely varying levels of cell killing ability among drugs that otherwise would have been deemed ‘equivalent.”  It does this in a very logical and straightforward manner - by testing each patient’s living cancer cells against each, individual drug.  

  2. Cytometric profiling measures the net effect of all gene and protein interactions occurring within the cancer cell.  It also accounts for important signaling that occurs between cancer cells.   Millions of these are known to occur but most are not yet identified or fully-understood.  However, it is still possible to account for these known and unknown chemical interactions by observing the behavior of the entire cancer cell when actually exposed to different chemotherapy drugs.  Gene testing cannot do this.

  3. As stated earlier, gene testing, identifies mutations which are thought to make the cancer cell susceptible to treatment with certain types of anti-cancer drugs. However, this overlooks many practical and theoretical considerations.  Among these are many types of chemical interactions occurring within the cell and among other cancer cells, as noted in the preceding paragraph   There are also mechanisms within the cancer cell that can exclude drugs entirely or that pump drugs out of the cancer cell before they can work.  Gene testing has no way of accounting for these.  Cytometric profiling tests the cancer cell as it actually functions and so these mechanisms are accounted for accurately.

  4. Cytometric Profiling can test new gene-targeted agents - and it does so in a way that is more direct than gene testing.  Click here to see why that is important.

  5. Cytometric profiling also has the proven ability to identify synergy that frequently occurs in rationally-selected drug combinations.  Drugs which are only moderately active as single agents sometimes become extremely effective when combined with certain other agents.  Cytometric profiling can pinpoint these drug combinations - gene testing cannot. 

  6. Gene testing cannot show if you are likely to benefit from treatments involving promising new immunologic/biologic agents.  Cytometric profiling can.

  7. Finally, Dr. Weisenthal and the Weisenthal Cancer Group apply the only technology capable of assessing the effectiveness of new anti-vascular agents (such as Avastin© and others) in mixed-cell micro-clusters.  No gene test can do this.  This critically-important anti-vascular drug profiling technology was originated by Larry Weisenthal, M.D., Ph.D. and is exclusive to Weisenthal Cancer Group.  (To read more about it, click here.) 

For the reasons outlined above many physicians who use our tests to design treatments for their patients view molecular testing as an adjunct to cytometric cancer cell profiling but do not necessarily accept it as an equivalent method on its own. 

It is likely that most physicians are not fully-aware of the many differences that exist between gene testing and cytometric profiling and how these differences dramatically affect the accuracy and usefulness of the information provided by the different tests.  He or she may not be familiar with the extensive body of medical literature that supports the use of cytometric profiling.  That is why we encourage physicians and patients to contact us.  We welcome the opportunity to answer questions and discuss objective data from dozens of published clinical studies that show our laboratory tests are accurate and that our test results are clinically useful.  



In the only head-to-head study of gene testing (molecular profiling) versus cytometric profiling to date, cytometric profiling was found to be highly relevant - 90% concordance with treatment outcome - while gene testing was found to be considerably less relevant (0%, 25%, or 75%, depending upon which genes were studied).  This rigorous, independently-conducted study was published in a peer-reviewed medical journal.  For more information about this study and its findings - and about gene testing versus personalized cytometric profiling, please click here.


In over 100 separate, published clinical studies, personalized cancer cytometrics, using cell death-based assays, accurately and reproducibly measured drug-induced cell death and correlated with individual patient chemotherapy response and survival.  Overall, the studies found that drugs which successfully killed patients’ tumor cells in prospectively reported cytometric profiling tests were 7.5 times more likely to improve clinical response rates and prolong the lives of cancer patients than drugs identified in advance by the tests as ineffective for those patients. 


Thousands of patients around the world have benefitted from personalized therapy selection provided by Dr. Weisenthal, an NCI-trained medical oncologist and extensively-published cytometric profiling pioneer.  Dr. Weisenthal is widely-acknowledged as the world’s leading expert in this field. He personally leads his team in each patient’s cytometric profiling study - from beginning to end.  His methods are rigorous and the extent of his analysis far exceeds that which occurs at other labs. 

Specimen processing, disaggregation, and concentration, drug panel selection, drug concentrations, cell incubation environments, cell exposure times, assay take-down and slide preparation, data analysis, and assay reporting are all performed precisely and with uncompromising attention to detail. 

Each patient receives the benefit of parallel testing in 3 to 5 separate cytometric profiling technologies for greater test accuracy.  All laboratory results are benchmarked though statistical analysis involving the most specifically-detailed cytometric profiling database in existence. 

Dr. Weisenthal personally examines and interprets each microscope slide, analyzes and calculates all test data, and recommends the personalized treatment plan which offers each patient the highest probability for success.  Typically, he devotes over eight hours to each patient’s cytometric profiling analysis. 

In a new era of personalized medicine, cytometric profiling is a superior approach.  Nobody performs it more comprehensively, more personally, and with greater experience and expertise than Dr. Weisenthal.   


To learn more, please phone our laboratory for a friendly, no-obligation discussion with Connie Rueff, M.T., Laboratory Manager.  All callers are accorded patience, compassion, and complete confidentiality.  (714) 596-2100.               

This website is owned and administered solely by the Weisenthal Cancer Group, which provides a laboratory testing method called Personalized Cancer Cytometric Profiling.  Weisenthal Cancer Group accepts no financial support from any drug company, medical equipment manufacturer, insurance carrier, professional organization, or hospital group.  We do not administer treatments nor do we derive any benefit, financial or otherwise, from recommending any specific treatment.  Our treatment recommendations are free from outside influence, obligation, research interest, or institutional bias. 

“I have had patients who ca
me from the most prestigious cancer centers in America on hospice care who had their disease eradicated by using the drugs suggested by Dr. Weisenthal’s chemosensitivity and chemoresistance testing.  The value of this testing is acute in the initial and subsequent management of many cancers.”

William R. Grace, M.D.

Grace Oncology

New York, NY

  1. “An integrated approach to cancer management includes laboratory tools that make it possible to tailor treatments precisely.  Dr. Weisenthal’s cytometric profiling  studies help me to ensure that each patient receives personalized therapy targeted to his or her specific clinical situation.“

Mark Rosenberg, M.D.

Rosenberg Integrative Cancer Treatment and Research Institute

Boca Raton, FL

“In my perfect world, *every* person with cancer who is a candidate for chemotherapy, biologic targeted agents, or immunotherapy would receive cytometric profiling first.  Period.  Because it’s so clinically reliable, and far better than any other technology available when it comes to predicting therapeutic response.  I have consistently been greatly impressed by the results patients get when their therapy is guided by your profiling, even in heavily pre-treated, refractory settings.”

  1. Mark C. Bricca, ND, LAc

  2. Bodhicitta Healing Arts

  3. 10800 Cherry Ridge RD

  4. Sebastopol, CA 95472

“I just wanted to let you know that the chemo regimen you recommended was EXTREMELY effective with me.”

Patient, Ovarian Cancer 

"We cannot thank you enough.  First of all, for the passion you have for your work and the life you breathe back into cancer victims.  You are such a blessing.  Thank you from all of our little group for...your kindness, and your treasured knowledge.”

Patient, Pancreatic Cancer

“You performed an assay on my cancer 2.5 years ago. I'm healthy today and I did the treatment recommended by the assay…your assay predicted [effectiveness of a new drug combination] a few years before the clinical research was in place!”

Patient, Breast Cancer