Human Tumor Assay Journal Home

Human Tumor Assay Journal is resource for physicians, cancer researchers, patients, and others interested in the field of Individualized Tumor Response Testing (ITRT), which, broadly defined, means testing “living” cancer cells and tissues in cell culture or organ culture to determine the “response” of the cells (or tissues) to putative anticancer drugs.  This information is most typically used to make treatment decisions involving drug selection for use in cancer chemotherapy.

ITRT is also known as “personalized chemotherapy selection,” “cytometric cancer profiling,” “chemosensitivity testing,” “chemoresistance testing,” “chemoresponse testing,” “drug resistance testing,” “cell culture drug resistance testing” (CCDRT), “cell culture drug response testing,” “functional profiling,” and by a variety of proprietary names used by commercial laboratories.

Larry Weisenthal, MD,PhD
Huntington Beach, CA, USA

9 thoughts on “Human Tumor Assay Journal Home

  1. brent

    I am interested in the status of culturing tumor cells to refine chemo from an
    investment/legal perspective. I have a few questions:
    1. I do not see any entries on this site since 2010. Is the site still active?
    2. Larry states that no money is to be made by labs that could or would
    perform the lab work. On what basis is this statement made.
    3. Has the FDA moved to regulate such labs to date and if not what seems
    to be the likely outcome on this question?
    4. How is it possible that patients who want these tests could not pay to make
    them available?
    5. In several cases I have witnessed friends fighting dancer and engaging in chemo and I have ask how the selection of chemo agents is made. Most recently the response was they just try some and hope they work.
    I am only a little scientist and much business and law educated. But I can understand this. I recently took a microbiology class in in lab did a Kirby Bauer Assay — the infectious disease equivalent to what is proposed here for cancer.
    My understanding is that the Kirby Bauer testing a culture against different
    antibiotics dates back to the 40s or 50s.
    6. Sorry this a bit long winded but I may have even more as follow up.

  2. lweisenthal

    Hi Brent.

    First, as you are the first commenter in a very long while, thanks for your comments and questions, which I shall answer in turn.

    Your question # 1. The site is still active, as I continue to pay the host fee. The reason that there haven’t been any recent posts is that I decided that I was at the stage of my career that I could either spend my remaining time ranting and raging, or I could focus on actually getting something done.

    I think that I’ve made a very major scientific discovery. It was a classic case of a chance observation favoring a prepared mind. It defies concise summary. It’s very important for cancer, but even more important for cardiovascular disease. Here’s a bibliography, to date:

    Bibliography relevant to AngioRx/Microvascular Viability assay (MVVA) 

    1. Weisenthal, L. M. Patel,N., Rueff-Weisenthal, C. (2008). “Cell culture detection of microvascular cell death in clinical specimens of human neoplasms and peripheral blood.” J Intern Med 264(3): 275-287

    2. Weisenthal, L., Lee,DJ, and Patel,N. (2008). Antivascular activity of lapatinib and bevacizumab in primary microcluster cultures of breast cancer and other human neoplasms. ASCO 2008 Breast Cancer Symposium. Washington, D.C.: Abstract # 166. Slide presentation

    3. Weisenthal, L. M. (2010). Antitumor and anti-microvascular effects of sorafenib in fresh human tumor culture in comparison with other putative tyrosine kinase inhibitors.  J Clin Oncol 28, 2010 (suppl; abstr e13617) 

    4.Weisenthal, L., H. Liu, Rueff-Weisenthal, C. (2010). “Death of human tumor endothelial cells in vitro through a probable calcium-associated mechanism induced by bevacizumab and detected via a novel method.” Nature Precedings 28 May 2010.

    5. Weisenthal, Larry . Endothelial Massive Calcium Accumulation Death (MCAD): Mechanism, Target, and Predictive Biomarker for Anti-Angiogenic Therapy. 13th international symposium on anti-angiogenic therapy: recent advances  and future directions in basic and clinical cancer research. LaJolla, CA. February 2011 Available from Nature Precedings

    6. Weisenthal, L, Williamson, S, Ryan, K, Brunshwiler, C, and Rueff-Weisenthal, C. Massive calcium uptake in human endothelial cells, submitted for publication. 

    7.Bevacizumab-induced tumor calcifications can be elicited in glioblastoma microspheroid culture and represent massive calcium uptake death (MCAD) of tumor endothelial cells. Larry Weisenthal, Summer Williamson, Cindy Brunschwiler, and Constance Rueff-Weisenthal, 14th International Anti-Angiogenesis Symposium, LaJolla CA, Feb 2012. Available from Nature Precedings

    Two additional, yet-to-be published patent applications are pending.

    Now, the NCI made the command decision in the late 1980s that there was absolutely no possibility of ever getting cell culture-based assays to work. Think of this. Can you imagine practicing medicine or doing drug development for diseases like bacterial infections, multi-drug resistant tuberculosis, or HIV/AIDS without the benefit of culture-based tests performed on the exact offending organism in question? The challenges associated with tests based on fresh tumor cell cultures were simply of a bioengineering nature — yet the NCI stopped funding work in this area and specifically dis-invited funding proposals to do this. Try to find publications after 1990 from American universities or NCI-designated cancer centers relating to work in this area. It’s the greatest lost opportunity in all of clinical cancer research.

    Look at the program for the upcoming, huge meeting jointly sponsored by the NCI, ASCO, and the EORTC on cancer biomarkers for individualizing therapy and for drug development research.

    There are NO sessions at all devoted to predictive/prognostic tests based on cell culture technologies. This is the year 2012 and no one in the NCI or cancer research establishment thinks that there is any point at all in supporting work in this area. It’s absolutely crazy. It’s nuts.

    I decided that ranting and raging about this incredibly short-sighted folly was a strategy doomed to failure. One of my favorite quotations, in all of scientific inquiry, is one from Martin Apple of UCSF, in the late 1960s, to wit: “any experiment which has failed 1,000 times should be viewed with suspicion.”

    Ranting and raging doesn’t work. What the establishment demands is a prospective, randomized trial, between cell culture assay-directed chemotherapy and physician’s choice chemotherapy. In a future autobiography (purely a thought experiment), I’ll detail the efforts that I and others in this field have made to actually do these things. For now, I’ll only report the most recent effort.

    A year or so ago, such a clinical trial was proposed by Dave Alberts, Director of the University of Arizona Cancer Center. In my mind, Dave is absolutely the only person in mainstream clinical cancer research who has the mental clarity and vision to realize that it’s inevitable that, one day, someone will figure out a way to get cell culture assays (analogous to bacterial Kirby Bauer assays) to work, and that these assays have the potential to add enormously to the efficacy of both cancer treatment and drug development.

    Anyway, Dave invited me and Robert Nagourney to come up with a proposal for a clinical trial in second line ovarian cancer, through the Gynecologic Oncology Group (GOG). I proposed a three arm clinical trial. (1.) Physician’s choice chemotherapy. (2.) Cell culture assay directed chemotherapy. (3.) “Molecular” (or “molecular target”) directed chemotherapy. I wrote a study outline. Dave made some helpful suggestions and we submitted it to the GOG for evaluation.
    Then we had a classic untoward event.

    On December 7, 2011, I was an invited speaker at the Farrah Fawcett Symposium on Chemosensitivity Testing and Circulating Tumor Cells. One of the other speakers was Matt Sargent, MS, MBA of Caris Lifesciences, a private company which does so-called “molecular” profiling, based on immunohistochemistry, FISH, RT-PCR, and molecular microarrays. During a break, Matt came up to me and said some nice things about me and my work. I told him about the GOG trial which we were working on. Matt asked me if Caris could be the lab to do the “molecular” directed arm of the three arm clinical trial. I told Matt that, in principle, that would be just fine, but that he’d need to speak to the GOG about it.

    Three weeks later, it was leaked to me by an informant whom I won’t name that Caris had gone to the GOG and proposed a TWO arm clinical trial (physician’s choice vs. molecular), cutting out the cell culture arm. Furthermore, Caris offered the GOG $3.2 million to do the clinical trial. I am not a corporation and I have only my personal resources (my average adjusted gross income over the past 10 years has been on the order of $150K, which is about what it was last year); so I don’t have the resources to pay the GOG anything; all I can do is to provide “free” assays.

    I wanted an explanation from Matt Sargent. I called him a half dozen times, and he never once took my call and never once returned my call. I then wrote a personal U.S. mail-delivered letter to Dan Von Hoff, the clinical scientist behind the Caris clinical trials. Dan wrote back a terse reply, saying that “I can’t help you.”

    Anyway, Dave Alberts suggested that I obtain a grant to pay for the trial; so we are dutifully preparing a grant request to support the trial. Obviously, this is a trial which will take years to get off the ground and more years to perform, and I only hope that I’m still alive when it’s finally published.

    I’ll post the proposed protocol for this trial and other related information over the next few days, but I do want to respond in a timely fashion to your questions; so I’m posting this response right now.

    Question 2: In order to perform these cell culture tests properly, it requires an enormous amount of work. It is very labor intensive and it is intellect intensive. It’s truly a medical service, more than a laboratory service. I’ll try to expand upon this, in the future. But, even were it a laboratory service, there’s no real money to be made in laboratory businesses, compared to pharmaceutical businesses. Labs such as Quest make a profit, but not on the order of magnitude of pharmaceutical companies. It’s a nice small business for a partnership group of oncologists and pathologists, but it’s not a good business for an MBA CEO and a bunch of other MBAs and PhDs, supported by an oncologist and pathologist.

    It’s all relative. Given that the establishment demands prospective, randomized trials to prove the superiority of cell culture assay directed treatment, it puts the laboratory business in competition with the pharmaceutical business for patients forf clinical trials. There aren’t sufficient cancer patients to support the needed clinical trials for pharmaceutical development, and the pharmaceutical companies can offer much more in the way of support than can start up laboratory companies.

    Question #3: The FDA formally considered whether it should regulate laboratories doing cell culture testing in 1999. The verbatim transcript of their conclusion was presented at a national Medicare technology evaluation meeting and is up on another of my websites. I’ll provide a link later. Bottom line is that the FDA declared, in 1999, that so-called “home brew” laboratory tests in this area did not fall under the FDA’s regulatory jurisdiction. So the laboratories which provide this service are regulated through the CLIA mechanism and by the individual states, but not by the FDA.

    Now, this may or may not change in the future, as a result of the huge interest in so-called “molecular” testing. Genentech (and presumably other pharmaceutical companies) don’t want outside labs being the gatekeepers for their drugs. So Genentech formally asked the FDA to regulate labs which perform “molecular” tests to predict clinical outcomes of drug therapy of cancer. Whether the FDA will ultimately choose to do so is an unanswered question. The FDA definitely does regulate test “kits” however, as it considers test “kits” to be medical devices. There is a precedent, related to cell culture testing, for which I’ll provide a link in the future.

    Question 4. We, ourselves, opted out of Medicare on July 1, 2008, at a time when Medicare was paying for our services. The Medicare reimbursement was just too meager to allow us to offer our services. So all Medicare beneficiaries who would like to avail themselves of our services are notified in advance that Medicare won’t pay and that they are personally responsible for all charges. This obviously reduces our referrals, but we really had no choice. So, yes, it is possible to do this on a patient pay model. I wish that I could provide free assays to desperately ill cancer patients who could benefit from our services. Alas, I can’t. All I can do is to try to do the Holy Grail clinical trial to convince the world that these tests are valuable and cost effective, and therefore worth being paid for — adequately — by Medicare and insurance companies. But this is years down the road.

    5. I totally agree with you. You’ve motivated me to write more about this. I’ll try to do so in the near future.

    6. Ask as many questions as you wish and make as many comments as you wish.

    – Larry Weisenthal

  3. brent

    Thanks for you reply. I have some follow up questions but would prefer to
    continue the discussion off line. I think you have access to my email.
    If you don’t mind please send me an address where I could send some
    follow up questions and comments.

  4. brent

    Greg, no discussion has taken place off line.
    Larry, some of your links are broken or inoperative. For example No. 4 and
    No. 5. The patent references are some how erroneous i.e.. there are too many digits.
    You stated,
    “In order to perform these cell culture tests properly, it requires an enormous amount of work. It is very labor intensive and it is intellect intensive. It’s truly a medical service, more than a laboratory service. I’ll try to expand upon this, in the future.”
    Would you mind explaining and quantifying: specifically how much labor in
    hours and cost does one assay take? What do you mean by: “medical” v.
    “lab work”? Is it possible you have merged the two? If a lab ran an assay if
    that is the proper term, and gave the results to a treating physician would that not be useful and would it not be “lab work”? Why would willing patients and
    willing treating physicians need to wait for the clinical trials?
    I think all of my dead friends would have ordered up an assay provided it makes rational sense. Maybe I am missing something, What are the most convincing
    rational arguments against: 1. growing a culture from the surgically extracted
    tumor; 2. testing the growth against different chemo recipes; using that information combined with the experience and knowledge of the treating

  5. admin

    Hi brent:

    I fixed the links. Sorry and thanks for informing me that they didn’t work.

    I’ll reply to the other questions in the near future.

    – Larry Weisenthal/Huntington Beach CA

  6. Larry Weisenthal

    From Brent:

    Would you mind explaining and quantifying: specifically how much labor in hours and cost does one assay take?

    If one devotes a nearly full time effort to something for 33 years, it is possible to make progress.

    The challenge is not trivial. We get all sorts of specimens, from nice, sterile, viable sugar-cubed size pieces of tumor tissue from a sterile site to mucinous, contaminated low viability specimens from inside the colon lumen to several liters of bloody fluid to fried liver (from electrocautery biopsies of liver tumors) to small needle biopsies to bone marrow and blood specimens. For solid tumors, we prefer to test three dimensional clusters. It can take a lot of work to glean viable tumor cells and get a quantitative yield and separate tumor cells from normal and dead cells and get rid of mucin and what I call “brain matrix” (from specimens of glioblastoma) and then to isolate the viable cell clusters from the discohesive, single cells, and so on. It just goes on and on. Two specimens are seldom alike.

    Not infrequently, patients have had fairly major, invasive surgery primarily to get tumor for testing. Failure (an inevaluable assay) is not an option.

    That’s just for starters. Next, we’ve got to have reliable, sensitive, specific cell death endpoints. We try to apply at least three different cell death endpoints for every specimen (of the five at our immediate disposal). This is explained on our business website: Basically, you’ve got to make sure that the signal you are measuring is really from tumor and not normal cells and different endpoints have different advantages and disadvantages, depending on the type of specimen. Also, in certain instances, one cell death endpoint is biologically more valid than another, for reasons too complicated to explain briefly. Additionally, when we get the same result with multiple endpoints, I have confidence in the results. When there is disagreement, and I don’t readily understand the reason for the disagreement, I have to be much more cautious in using this information for treatment recommendations.

    There isn’t a simple, turn-key solution. Each specimen must be individualized. The way that we do it, each specimen requires a total of 8 hours of technologist time and nearly that many hours of my own time. Other labs do it differently. More simply. More cheaply. But this is life or death information, and it deserves the same degree of professional time and attention as major extirpative or debulking surgery or radiotherapy. The tumor holds the key to the patient’s clinical outcome (and, often, survival). It’s worth the effort to get it right. So it’s a professional service, more than a simple laboratory test. I call myself a “Laboratory Oncologist,” practicing the specialty of “Laboratory Oncology.” I think that one day there will be residencies for subspecialty training in “Laboratory Oncology.” Doing this properly requires either an MD/PhD oncologist with at least a street education in pathology, or else a collaboration between an oncologist, pathologist, and PhD cell biologist.

    You ask other questions. I’ll answer them in turn, in installments.

    – Larry Weisenthal/Huntington Beach CA

  7. Greg Pawelski

    It’s been some time (again) we haven’t read anything more about the status of culturing tumor cells to refine chemotherapy treatment. With biologic therapy on the ascendancy, I understand you developed a biomarker for Avastin or any other anti-angiogenesis compound to better help choose which patients would be most likely to respond, thereby avoiding the need to treat everyone to gain a benefit in a few.

    It seems like the AURELIA study presented at the ASCO trade show confirms what you have discovered about Avastin’s use. At the 13th International Symposium on Anti-Angiogenic Therapy, you presented data showing antagonism between Avastin and cytotoxic agents. You understand the “mechanism” involved in this. But while standard, traditional cytotoxic drugs all inhibited Avastin, the new “targeted” drugs either don’t inhibit it or actually enhance it.

    While cell function analysis had found that Avastin appears to better deliver the effects of cytotoxic drugs (but not other targeted drugs), Avastin as a single agent is relatively ineffective in virtually all solid tumor types other than Renal cancer. Some scientists are not sure whether Avastin or any other anti-angiogenic agents are working primarily by pruning new blood vessels, increasing the delivery of another anti-cancer therapy, or potentially another mechanism.

    I’ve known for years about the vascular permeability factor (pruning new blood vessles) of Avatin, but according to your old colleague, Dr. Robert Nagourney, VEGF was originally known as VPF, by the scientist who developed Avastin. The short-term control of vasculature is followed by revascularization. Is this why there is the Avastin rebound (regrowth) effect?

    This piths my curiosity because revascularization is what’s needed with radiation-induced necrosis (which my wife was inflicted with from whole brain radiation). Revascularization is what HBOT does to the radiation-induced necrosis. It is revascularization that Avastin helps with in radiation-induced necrosis. This explains the miniscule response rates with single-agent Avastin, but yet a profound effect when used with cytotoxic drugs?

    And I also understand that the recent investigations leading to whether blocking the recycling system (autophagy) might be useful to support anticancer therapies, they are basically rediscovering something you reported 20 years ago (JNCI, 83:37-42, 1991).

    I (and I think a lot of others) would like to know more about your clinical investigations with cell function analysis. Should make for interesting reading. Thanks!

  8. Greg Pawelski

    Immunotherapy was one of those hot-to-trot subjects at this past ASCO trade show in Chicago. My understanding is that immunotherapy was a prematurely abandoned treatment option as far back as the 1960’s. In fact, I believe tumor immunology was probably the hottest field in cancer research back then, too.

    I understand that you even dabbled with some concept of “in situ vaccination” based upon biologic response modifiers in an assay. I read your 1991 paper. It found a striking association between the activity of biologic response modifiers which activate machrophages and the prior treatment status of patients with breast and ovarian cancers.

    Effective chemotherapy produced a massive release and processing of tumor antigens, which led to a state in which the human immune system, via in situ cancer vaccination, responded to exogenous machrophage activation signals with potent and specific anti-tumor effects.

    Because all research was prematurely abandon back then and you had to refocus gears on bringing about the latest technology on cell function analys (recently known as Personalized Cancer Cytometrics), is there any chance that you may dabble in this again? Can Functional Profiling measure these new immunologic drugs that are beginning to come out today?

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