White blood cells protect us from infection. However, these cells can become cancerous, leading to malignancies including leukemia, lymphoma, and myeloma. Just 50 years ago, a diagnosis of one of these blood cancers was usually a rapid death-sentence. We understood very little about how these cancers developed and there were essentially no effective treatments. Dramatic scientific breakthroughs in the past several years have significantly improved our understanding of these diseases and have opened up new treatment opportunities.
New advances in the genetic analysis of cancer cells allow physicians and scientists to pinpoint the molecular defects in a patient’s blood cancer cells. These molecular mutations let physicians better predict the likely response to treatment and personalize the treatment approach. In addition, new drugs targeting these specific mutations in blood cancer cells have been developed and are being tested in clinical trials. Some of these drugs are producing dramatic responses in patients who are resistant to conventional chemotherapy.
We are also learning about the origins of blood cancers such as leukemia and why and how some cancers relapse after initial treatment. This knowledge is also opening up new possibilities for treatments and how to monitor patients during and after therapy.
Recent breakthroughs in immunology have revealed new opportunities for the treatment of blood cancers. Antibodies that preferentially target blood cancer cells are currently used to treat many patients both as standard of care and in clinical trials. We are also learning how to harness the patient’s own immune system to treat cancers. In patients with solid tumors such as lung cancer, new drugs can prompt the patient’s immune cells to recognize and destroy the cancer. Clinical trials with these agents are on-going in blood cancers. Finally, in the last few years, we have been able to genetically modify a patient’s immune T cells so they can better recognize the blood cancer within them. These modified cells are then infused back into the patient where they seek out and attack the blood cancer. Dramatic results have been seen with this experimental therapy and studies evaluating the effectiveness and safety of these cellular therapies are on-going.
Coupled with the advances in molecular biology and new drug therapy, we are also improving our ability to support patients through their journey with cancer. Interventions to address the symptoms of cancer and the side effects of treatment such as pain, fatigue, depression and problems with memory are being intensively studied. Improvements in our support for patients and their families will be critical as it will allow them to live better as well as longer.
Thus, we have seen remarkable progress in the last 50 years in the scientific understanding of how blood cancers develop and why they return in some patients after initial treatment. This scientific progress is now being translated into improved therapies for our patients.
For more information about blood cancers, go to: llscanada.org
Dr. Aaron D. Schimmer
University Health Network, Toronto, Ontario