Shabbir M.H. Alibhai, MD, FRCP(C)
It is my pleasure to have been invited to write this editorial on the interface of oncology and aging. As a Geriatrician and a researcher in prostate cancer, this topic is near and dear to my heart. Astute readers will realize that this theme has been employed once before in Geriatrics & Aging. Clinicians will also recognize the tremendous burden that cancer in the elderly imposes--hence our decision to revisit this theme annually. In this issue we have attempted to deal with both commonly discussed tumors not focused on previously (prostate), as well as less commonly discussed malignancies (brain, lymphoma). We hope you find this issue informative.
Recently, there has been a tremendous surge in interest directed at the fields of oncology and aging, coming from a myriad of perspectives. For example, oncology training programs in the U.S. are beginning to have mandatory rotations for trainees in geriatric medicine. Whether Canadians will follow suit remains to be seen. I wish to touch further on three areas--cancer screening in the elderly, trends in treatment, and implicit values.
When we examine recommendations for cancer screening for the elderly (from such internationally respected organizations as the Canadian Task Force on Preventive Health Care), there appear to be no recommendations made (based on current evidence) to screen for any malignancy for anyone over the age of 70 to 75. Most other organizations, no matter how "evangelical", echo the CTFPHC's recommendations' principles. This is most interesting and bears further scrutiny. Why is there such consensus? Is it because cancer is uncommon in the elderly? Hardly. Is disease unlikely to be found at a curable stage? No. In general, and for most tumor types, it occurs more often than in younger patients. Is it because of the proven lack of benefit of screening? Once again, no. In most instances, there is simply a paucity of controlled clinical studies which have included patients in this age group. So what else can the CTFPHC fairly conclude? Could it be that the reasons for the recommendations (or absence thereof) have far more to do with lack of proof of efficacy than proof of lack of efficacy.
there are countless studies demonstrating that older patients are treated less aggressively than younger patients, even with similar stage and grade of disease.
The lessons we learn from the screening recommendations can be extended to the treatment of cancer in seniors. From surgical therapy for localized prostate and lung cancer to adjuvant therapy for colorectal and breast cancer, to intensive chemotherapy for leukemia and lymphoma, there are countless studies demonstrating that older patients are treated less aggressively than younger patients, even with similar stage and grade of disease. What accounts for this disparity? Closer examination of these studies reveals two main reasons: a perception of decreased life expectancy for an older cancer victim, and an increased risk of toxicity in treating the elderly. Note that lack of efficacy is rarely an issue. Clinicians (and family members) argue that older patients are more likely to die of other causes than of their underlying malignancy. Yet the work of numerous cancer scientists in various fields, including some of my own work in prostate cancer, shows that this is often not the case, especially for higher grades of neoplasm in relatively healthy older people. Furthermore, clinicians generally fare poorly when trying to estimate life expectancy, even for dying patients in a palliative care unit (as one recent study reaffirmed). On the toxicity front, numerous studies in the last few years have supported the notion that body-weight-adjusted chemotherapy is generally well-tolerated by the elderly, often to a degree comparable with younger patients. As concerns the morbidity and mortality of surgery, carefully selected older patients have only slightly higher treatment risks than younger ones--these are nowhere near the figures that some experts have been heard quoting at the bedside. Yet misperceptions flourish.
Something obvious but heretofore unspoken needs to be said. Evidence is accumulating that the attitudes of clinicians who treat cancer are ageist; this is to say they are discriminating unfairly or without due justification against individuals on the basis of age. Implicit in this ageist bias is the value that we place on life. For example, a 50-year-old man with localized high grade prostate cancer will gain 9 years of life with surgery, while a 75-year-old man will only gain 2 years; should we treat the older man? I believe that for too long we have implicitly attached our own values to the years of life gained from intervention. If this was done systematically and openly, supported by the society at large, that would be one thing. Done haphazardly and secretly, it is far from ideal. Without question, our patients, young and old, should carefully assess the quantity and quality of life, with or without treatment, before making any decision. Unfortunately, when it comes to the elderly, it has become amply clear that they are not even being given the chance to choose for themselves.