For chemotherapy patients, things are changing in a good way and it’s because of a new individualized approach called “personalized medicine.”
The traditional method of classifying and treating cancer is rapidly becoming outdated. This is due to the convergence of new technology and the completion of the human genome sequence. What was once a relatively subjective process that depended mostly on a pathologist’s visual examination of tissue under a microscope is now achieved by using microarray technology to analyze the most minuscule data available - the thousands of proteins inside the genes that are within the cell. The result: a genetic fingerprint that can be compared to similar samples with known outcomes to treatment.
How this changes the lives of cancer patients is profound on many levels. Replacing the “one-size-fits-all” approach to cancer treatment with a molecular profile and predictable treatment options means that patients will only be treated by drugs that have an excellent chance of working. Also, if a profile indicates that one treatment is more effective than another, the doctor can recommend treatments more intelligently, with greater predictability. Furthermore, profiling is now pointing out patients whose cancer is more likely to recur, in which case the patient may want to consider more aggressive treatments.
This form of gene expression profiling is already revolutionizing treatment standards for several cancers, including cancers of the breast, lung, larynx, skin, liver, bladder, kidney, stomach, thyroid, prostate and ovary and lymphoma. These highly sensitive and very specific profiles arm oncologists and researchers with greater intelligence than they have ever had before and the application of that intelligence is still in its infancy.
For breast cancer, standard treatment calls for surgery, radiation and chemotherapy – based on the grade, stage and estrogen receptor / HER2 gene status. The concern about the standard treatment approach, although highly curative, is the over treatment of patients with chemotherapy. Profiling studies uncovered vital new information about estrogen receptor (ER) positive tumors: there are several subcategories of ER-positive breast cancer with different survival profiles and different reactions to chemotherapy. A large percentage of profiles (83 percent) remained cancer free without chemotherapy, meaning it would be unnecessary to treat those breast cancer patients with chemotherapy. A small percentage showed a distinct benefit to chemotherapy as a necessary step in survival. And, for about 14 percent of the profiles, chemotherapy made absolutely no difference at all; the patients did not survive regardless of treatment.
As technology continues to evolve and open new doors in biomedical research, we will become better at unlocking the mysteries of DNA. And, consequently, we will be able to paint for each patient her or his own individual roadmap to survival.
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References:
http://www.hsph.harvard.edu/research/aedin-culhane/files/Brennan_05.pdf
For Ovarian Cancer: http://www.clearityfoundation.org/