So what about those published reports of clinical trials?

More chemotherapy is given for breast cancer than for any other form of cancer and there have been more published reports of clinical trials for breast cancer than for any other form of cancer.

According to the National Cancer Institute’s official cancer information website on "state of the art" chemotherapy for breast cancer, it is unclear whether single-agent chemotherapy or combination chemotherapy is preferable for first-line treatment. At this time, no data support the superiority of any particular regimen. So, it would appear that published reports of clinical trials provide precious little in the way of guidance (1).

In the total absence of guidance from published reports of clinical trials then, what basis are treatment regimens selected instead? ASCO says that this should be further based on a patient's health status and patient treatment preferences.

So what is being done?

Published in the journal Health Affairs is a joint Harvard/Michigan study entitled, "Does reimbursement influence chemotherapy treatment for cancer patients?" The authors documented a clear association between reimbursement to the oncologists for the chemotherapy of breast, lung, and colorectal cancer and the regimens which the oncologists selected for the patients. In other words, oncologists tended to base their treatment decisions on which regimen provided the greatest financial remuneration to the oncologist (2).

A March 8, 2006 New York Times article described the study. One of the more interesting aspects of the story was a comment from an executive with ASCO, Dr. Joseph S. Bailes, who disputed the study's findings, saying that cancer doctors select treatments only on the basis of clinical evidence (3).

So ASCO's Dr. Bailes maintains that drugs are chosen only on the basis of "clinical evidence."

Yet Dr. Neil Love reported a survey of breast cancer oncologists based in academic medical centers and community based, private practice medical oncologists. The former oncologists do not derive personal profit from the administration of infusion chemotherapy, the latter oncologists do derive personal profit from infusion chemotherapy, while deriving no profit from prescribing oral-dosed chemotherapy.

The results of the survey could not have been more clear-cut. For first line chemotherapy of metastatic breast cancer, 84-88% of the academic center-based oncologists (who are motivated to keep off-protocol patients out of their chemotherapy infusion rooms to reserve these rooms for on-protocol patients) prescribed an oral-dose drug (capecitabine), while only 13% prescribed infusion drugs, and none of them prescribed the expensive, highly remunerative drug docetaxel.

In contrast, among the commuity-based oncologists, only 18% prescribed the non-remunerative oral-dose drug (capecitabine), while 75% prescribed remunerative infusion drugs, and about 40% prescribed the expensive, highly remunerative drug docetaxel (4).

While the Michigan/Harvard study showed results before the new Medicare reform, the Patterns of Care study showed results that the Medicare reforms are still not working. It is still an impossible conflict of interest.

Two studies giving us a dose of reality that once a decision to give chemotherapy is taken, oncologists receiving more-generous Medicare reimbursements used more-costly treatment regimens.

Some oncologists prescribe chemotherapy drugs with equal efficacies and toxicities. I would imagine that some are influenced by the whole state of affairs, possibly without even entirely admitting it. There are so many ways for humans to rationalize their behavior.

Sources:

(1) http://www.cancer.gov/cancertopics/p...e8#Section_297

(2) http://content.healthaffairs.org/cgi...tract/25/2/437

(3) http://www.nytimes.com/2006/03/08/he...71de&ei=5 070

(4) http://patternsofcare.com/2005/1/editor.htm (figure 37, volume 2, issue 1, 2005)

*** Edited 10/18/2007 2:56:55 PM UTC by gdpawel***

As we enter the era of "personalized" medicine, it is time to take a fresh look at how we evaluate treatments for cancer patients. More emphasis should be put on matching treatment to the patient. Patients would certainly have a better chance of success had their cancer been chemo-sensitive rather than chemo-resistant, where it is more apparent that chemotherapy improves the survival of patients, and where identifying the most effective chemotherapy would be more likely to improve survival.

Findings presented at the 41st Annual Meeting of the European Society for Clinical Investigation in Uppsala, Sweden, April 18, 2007, concluded that "functional profiling" with cell culture assays is relevant for the study of both "conventional" and "targeted" anti-neoplastic drug agents (anti-tumor and anti-angiogenic activity of Iressa, Tarceva, Sutent, Nexavar, and Avastin in primary cultures of "fresh" human tumors).

Cell Culture Assays with "cell-death" endpoints can show disease-specific drug activity, are useful clinical and research tools for "conventional" and "targeted" drugs, and provide unique information complementary to that provided by "molecular" tests. There have been more than 25 peer-reviewed publications showing significant correlations between cell-death assay results and patient response and survival.

Many patients are treated not only with a "targeted" therapy drug like Tarceva, Avastin, or Iressa, but with a combination of chemotherapy drugs. Therefore, existing DNA or RNA sequences or expression of individual proteins often examine only one compenent of a much larger, interactive process. The oncologist might need to administer several chemotherapy drugs at varying doses because tumor cells express survival factors with a wide degree of individual cell variability.

There is a tactic of using biopsied cells to predict which cancer treatments will work best for the patient, by taking pieces of live "fresh" tumor tissue, applying different chemotherapy treatments to it, and examining the results to see which drug or combination of drugs does the best job killing the tumor cells. A cell culture assay test with "functional profiling," using a cell-death endpoint, can help see what treatments will not have the best opportunity of being successful (resistant) and identify drugs that have the best opportunity of being successful (sensitive).

"Funtional profiling" measures the response of the tumor cells to drug exposure. Following this exposure, they measure both cell metabolism and cell morphology. The integrated effect of the drugs on the whole cell, resulting in a cellular response to the drug, measuring the interaction of the entire genome. No matter which genes are being affected, "functional profiling" is measuring them through the surrogate of measuring if the cell is alive or dead.

For example, the epidermal growth factor receptor (EGFR) is a protein on the surface of a cell. EGFR-inhibiting drugs certainly do target specific genes, but even knowing what genes the drugs target doesn't tell you the whole story. Both Iressa and Tarceva target EGFR protein-tyrosine kinases. But all the EGFR mutation or amplificaton studies can tell us is whether or not the cells are potentially susceptible to this mechanism of attack. They don't tell you if Iressa is better or worse than Tarceva or other drugs which may target this. There are differences. The drugs have to get inside the cells in order to target anything. So, in different tumors, either Iressa or Tarceva might get in better or worse than the other. And the drugs may also be inactivated at different rates, also contributing to sensitivity versus resistance.

As an example of this testing, researchers have tested how well a pancreatic cancer patient can be treated successfully with a combination of drugs commonly used to fight lung, pancreatic, breast, and colorectal cancers. The pre-test can report prospectively to a physician specifically which chemotherapy agent would benefit a cancer patient. Drug sensitivity profiles differ significantly among cancer patients even when diagnosed with the same cancer.

The "funtional profiling" technique makes the statistically significant association between prospectively reported test results and patient survival. It can correlate test results that are obtained in the lab and reported to physicians prior to patient treatment, with significantly longer or shorter overall patient survival depending upon whether the drug was found to be effective or ineffective at killing the patient's tumor cells in the laboratory.

This could help solve the problem of knowing which patients can tolerate costly new treatments and their harmful side effects. These "smart" drugs are a really exciting element of cancer medicine, but do not work for everyone, and a test to determine the efficacy of these drugs in a patient could be the first crucial step in personalizing treatment to the individual.

Literature Citation: Eur J Clin Invest 37 (suppl. 1):60, 2007

Presentation: weisenthal.org/

*** Edited 10/18/2007 3:01:08 PM UTC by gdpawel***