The best possible treatment - individualized for each patient


  1. “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.”                                    

  2. “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.”

- Medical Oncologist, California

  1. “I have had patients who came 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.”

  2. “The value of this testing is acute in the initial and subsequent management of many cancers.”

- Medical Oncologist, New York

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

- Patient, Ovarian Cancer 

  1. "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

  1. “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




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. 


The two main approaches to personalized cancer therapy are cytometric profiling - the method used by Weisenthal Cancer Group - and gene testing.  Which approach is better?  The answer is that while both approaches have something useful to offer, cytometric profiling - our method - has far broader capabilities than gene testing.

Gene testing (also called molecular testing or target profiling) attempts to link expression of certain genes 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.

This is the opposite of Cytometric Profiling, in which millions of your own, living cancer cells are exposed to the widest possible range of 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.   The most promising therapy can be selected and ineffective, expensive, time-wasting treatments can be avoided.

  1. Cytometric profiling (our method) can test many more specific drugs in more different classes of drugs than gene or molecular testing.  This includes molecularly-targeted drugs, immunologic drugs, standard chemotherapy drugs, and anti-angiogenic drugs.

  2. In addition, cytometric profiling clearly identifies widely varying patterns of activity of different anti-cancer drugs within the same broad class of drugs.  Oncologists often see differences in patient response to different drugs which are thought to work by the same general mechanism.  In contrast, gene testing looks only at the mechanism and not at the drug or at the cell in the presence of the drug and so it cannot detect differences in drug activity. 

  3. Unlike gene testing, 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 - as opposed to relying on the presence of only a few presumed markers in cells that are never exposed to drugs, as in gene testing. 

  4. Ironically, our method tests even the new gene-targeted agents in a way that is more direct than gene testing.  Click here to see why that's important.

  5. Importantly, we actually expose your own, living cancer cells to a wide range of drugs and drug combinations.  This reveals the net effect of the many crucial biological factors and important chemical interactions occurring within and among living cancer cells - YOUR cancer cells - when they exposed to each anti-cancer drug and drug combination under consideration.  

  6. In contrast, in gene testing, your tumor cells are never exposed to any of the available anti-cancer drugs.  Instead, molecular testing looks only for certain gene mutations within the cancer cell that are thought to imply a potential for susceptibility to treatment with a certain type of drug.

  7. 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. 

  8. Gene testing cannot show if you are likely to benefit from treatments involving promising new immunologic/biologic agents.  Our method can.

  9. 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.) 

Therefore, while molecular testing might be used as an adjunct to cytometric cancer cell profiling (our method) it cannot be viewed as an acceptable equivalent method on its own. 

It is likely that most physicians are not fully-aware of the many differences that exist between molecular and cytometric testing 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.