Articles on cancer as a chronic condition often include an account of a patient's journey from diagnosis to present day. The patient describes a range of emotions--from disbelief, to helplessness, to outright panic--upon hearing the word "cancer," which has often been equated with a death sentence. A poor prognosis adds insult to injury, as the patient attempts to grasp the reality of a future laid out in terms of 5-year survival rates. Life then becomes focused solely on the fight ahead, as the patient and his or her loved ones deal not only with the disease and its life-and-death implications but also with the adverse effects of treatment. As one treatment fails, another becomes available, and hope and empowerment give way to helplessness and despair, and again to hope.
The account ends not with a cure or with death but with a "new normal" the patient hadn't expected: namely, the realization that his or her cancer, while not curable, has become a chronic condition to be managed and controlled.
While this may not be the case for all cancers, the scenario described above represents a growing subset of patients whose disease has become largely manageable over the long term. Indeed, the past 10 to 20 years has witnessed a very real acceleration in the advances that are rendering many forms of cancer as chronic conditions manageable with continuing surveillance and/or treatment. This is allowing patients to live months or years longer than was the case only a generation ago.
To the patient, this "new normal" is nothing less than life changing. But what does it mean to the oncologist and to the practice of oncology today and in the future?The New Normal Explained
While no one would argue that a cure remains the ultimate goal for oncologists and their patients, "there's no question that long-term control of cancer is becoming a reality," said Edward Partridge, MD, National Volunteer President for the American Cancer Society and director of the UAB Comprehensive Cancer Center in Birmingham, Alabama. This is true especially for solid metastatic colorectal, breast, and head and neck cancers, and, to some extent, lung and ovarian tumors, he said.
Those wanting to understand how this upward trend in survivorship and the resulting conversion to chronic status affect the practice of oncology must first comprehend the reasons for the phenomenon, which are both varied and interrelated. Thanks to a growing number of clinical trials, patients with metastatic disease have access to more therapeutic options than ever before, with secondand third-line treatments now available for cancers where only single therapy was offered a few years ago. This has broadened the field of effective agents available to a wider patient population, while providing individual patients with more opportunities to achieve disease control after standard treatments fail. Described as the hitchhiker model,1
this phenomenon essentially buys time for the patient, who lives longer by undergoing 1 treatment until its effectiveness wanes and then moving on to another. (See "The Hitchhiker Model at Work" sidebar.) The hope is that the patient will live long enough to benefit from the approval of another effective treatment, enrollment in a promising trial, or even a cure.
The hitchhiker model also can be seen at work in the new and more effective agents that make their way from research into clinical practice. The advent of these agents can be attributed directly to a rapidly expanding knowledge of cancer's molecular roots.1
Targeted therapies, such as the tyrosine kinase inhibitors, serve as an excellent example and are now playing a critical role in the management of many cancers. Because these agents, which interfere with specific molecular pathways to cancer, are less toxic and better tolerated than traditional chemotherapeutic agents, they can be administered for longer durations, allowing patients to reap the benefits of newer and more effective treatment modalities that come down the pipeline. Similarly, the proteasome inhibitor bortezomib, approved in 2003, has produced complete remission in some patients with multiple myeloma, once again buying the time needed to take advantage of additional treatment options as they become available.
With these ongoing advances and their improved symptom control, a patient's life can be extended for a number of years without achieving a complete cure. "With intermittent or ongoing treatment, patients can live with either persistent or stable disease, or can undergo new and potentially more effective treatment upon relapse--turning malignancy into a chronic process," said Partridge.The Oncologist's-Eye View: A Welcome Problem