Cancer Treatment Enters a New Era

Medical oncologists, the doctors specializing in chemotherapy administration, are able to say to their patients, “Cancer treatment now is different than it was 20 years ago, 5 years ago, or even one year ago.” Of course, surgery and radiation remain critical elements of fighting many cancers; this article focuses on developments in drug therapy, especially on improved supportive care and new anti-cancer drugs.

For decades, the backbone of cancer drug therapy has been “cytotoxic” chemotherapies, mostly given by vein. Typically, cytotoxic chemotherapy interferes with cancer cell division (cell growth by self-replication). Unfortunately, cytotoxic drugs also affect normal cells undergoing cell division, which leads to the commonly known chemotherapy side effects of mouth sores, fatigue, and immune system suppression. Nausea occurs as the body's mechanisms are triggered to “eject” these noxious chemicals. Cytotoxic agents remain a key component in the anticancer arsenal, and the development of novel cytotoxic drugs remains at the forefront of cancer research. However, better supportive care (prevention of nausea, fatigue and infection) and incorporating new “targeted” anti-cancer drugs are bringing us into a new era of cancer treatment.

“Supportive care” refers to the amelioration of the symptoms of cancer and side effects of treatment. Natural blood stimulants are now cloned and produced in biologic factories. These recombinant hematopoietic growth factors include erythropoietin, G-CSF, and GM-CSF. When administered with chemotherapy, fatigue and risk of infection are markedly reduced through stimulation of red blood cell and white blood cell production. Potent new anti-nausea drugs (aimed at molecular pathways mediated by serotonin and substance-P) completely prevent nausea in most patients receiving chemotherapy. Research continues in the effort to further improve other areas of supportive care, such as pain control (“palliative care”). Even preservation of fertility in young patients and prevention of hair loss are being addressed by current research efforts.

Known as “targeted” therapies, newer drugs directed at specific cancers or specific abnormalities unique to the cancerous cell are also changing the way cancer is treated. Typically, these targeted agents lack the toxicity associated with less discriminating conventional cytotoxic chemotherapy. Among these targeted agents are monoclonal antibodies, engineered in the lab, and directed at specific targets on certain cancers. For example, rituximab binds to CD- 20, a molecule present on the cell surface of over 90% of non-Hodgkin's Lymphoma, and thus harness the body's own immune system to better attack the cancer cells. Similarly, trastuzumab helps fight breast cancer by binding to the Her-2 molecule, present on the surface of many breast cancers. In another twist, monoclonal antibodies have been chemically coupled with radioactive molecules or poisonous toxins in an effort to better deliver the radiation/toxin directly to the cancer cell and better spare normal cells (the so call “magic bullet” approach). Other targeted therapies interfere with growth promoting molecular pathways that are revved up in cancer cells. Examples include cetuximab and erlotinib, drugs that inhibit the activity of epidermal growth factor receptor (EGFR-1); they are used primarily in lung, head and neck, and colon cancers. Sutinib and sorafenib inhibit multiple growth promoting molecules and are being used in treatment of kidney cancer and studied in a variety of tumor types. This is only a partial list of these new targeted therapies, but illustrates the fruitful research ongoing to generate not just new drugs, but new ways to treat cancer. Summit Cancer Care participates in many clinical trials using such novel agents to treat cancer.

The impact of these innovative treatments is to improve tolerance and improve effectiveness of drug therapy for cancer. No doubt, there remains considerable room for further progress. Through clinical trials, like those offered to patients at Summit Cancer Care, the hope is to continue moving forward in the fight.

About the Author

Barry Luskey joined Summit Cancer Care in 2000, bringing with him a wealth of experience in both scientific research and clinical care. A graduate of Stanford University in Stanford, Calif., and the University of Texas Southwestern Medical School in Dallas, Dr. Luskey completed fellowships in hematology and oncology at Brigham and Women's Hospital at Harvard Medical School in Boston, Mass. During fellowship, Dr. Luskey pursued basic research in gene therapy at the Howard Hughes Medical Institute at Children's Hospital in Boston. For the next decade, Dr. Luskey was an attending physician at Baylor University Medical Center in Dallas and in private practice with the nation's largest oncology partnership, Texas Oncology. During this time, he continued clinical research endeavors focusing primarily on the care of hematologic malignancies. Board certified in Internal Medicine, Medical Oncology and Hematology, Dr. Luskey is a member of the American Society of Hematology, the American College of Physicians, the American Society of Clinical Oncology, the Georgia Society of Clinical Oncology and the Georgia Medical Society. He is currently on staff at the Curtis & Elizabeth Anderson Cancer Institute at Savannah's Memorial Health University Medical Center and the Nancy N. and J.C. Lewis Cancer & Research Pavilion at St. Joseph's/Candler Health System and attends the medical oncology and hematology clinics at Memorial where he teaches resident physicians in training.