There are far fewer cases of cancer among frail, elderly nursing home residents (NHRs) than would be expected from data on cancer incidence in the general older population. This is the surprising conclusion of an EORTC study of new cancer events in NHRs in Belgium. «Although there are a number of reasons why the occurrence of cancer can decline in very frail patients, ours is the first study to show this prospectively,» says Professor Hans Wildiers, Head of Clinic at the Department of Medical Oncology, University Hospitals Leuven, Leuven, Belgium.
It is widely known that cancer is primarily a disease of old age. Approximately 50-60% of all new cancers and 70% of cancer mortality occur in people who are aged over 65. But knowledge about aging and cancer, and about the best treatment for older patients, is still far from adequate. « A key problem in geriatric oncology research is that the results from general cancer studies are not representative for very old and frail patients as they are rarely included in trials,» says Prof Wildiers.
Together with colleagues from Belgium, France, and The Netherlands, he decided to study the incidence of cancer events, as well as how they were diagnosed, referred and treated, in 39 nursing homes from the Armonea network in Belgium. The study covered 4262 nursing home beds, and the NHRs had a median age of 87. They were prospectively followed for a year for any new sign of cancer events, defined as suspicion or diagnosis of a new cancer or the progression of one already diagnosed.
Cancer events were found in only nine of the more than 4000 residents during that year. These included five new cancer events, and four cancer progressions. «This equates to an incidence of new cancers of 123 per 100,000 person years, whereas epidemiological data for those aged 75 and over in the general population show incidence numbers about 20 times higher. Although the latter group will include NHRs, we estimate that NHRs will only make up about 10% of the total 75+ population. Even though we know that cancer incidence reaches a peak around age 80-85 and then declines in the very old, our results are still striking,» says Prof Maryska Janssen-Heijnen, clinical epidemiologist at VieCuri Medical Centre Venlo and Maastricht University, Maastricht, The Netherlands.
The researchers say that under-reporting of cancer events in the very elderly can contribute in some way to their results. Doctors may not refer elderly nursing home patients with suspected cancers for further diagnostic tests, perhaps believing that therapy will not help because the patient is too frail. And although there are many effective therapies that can alleviate cancer-related problems, with few side effects, healthcare workers in nursing homes may be unaware of them.
«In order to avoid underreporting of new cancer events, we prospectively investigated this issue, and we focused not only on diagnosis of cancer but also on clinical suspicion of cancer. We thought that it was likely, in some cases, that such a suspicion existed, but that no further investigation was carried out because either the doctor or the patient and family did not want this to happen. Our results have shown that this was indeed the case,» says Prof Wildiers.
Out of the nine cancer events found in the study, in four no diagnostic procedure was performed, and in five no anti-cancer treatment was started. «It is impossible to know retrospectively whether the five patients who did not receive treatment would have benefited from it. However, some common cancers can easily be controlled for significant periods by ‘easy’ drugs such as anti-hormone therapy, and undertreatment should be avoided. On the other hand, two out of the four patients who received anti-cancer treatment died within one month, so it is also crucial to avoid overtreatment in the frail elderly, » Prof Wildiers says.
The results of the study are important for the organisation of healthcare in nursing homes, as well as contributing to wider knowledge of the incidence of cancer in the elderly. «There may be several biological reasons why cancers occur much less frequently in very frail people. When damage occurs to individual cells in the body, cellular aging is actually a protection mechanism against cancer. When we better understand the relation between aging and cancer, we may also find new ways to treat it in a better way.
« We believe that it is important that healthcare workers in nursing homes are aware of the treatment options available, and that they ask the advice of an oncologist when a tumour is suspected because there are sometimes easy treatments that can improve quality of life dramatically, even in very frail persons,» Prof Wildiers concludes.
The research is published in the Journal of Geriatric Oncology. It was supported financially and logistically by the Armonea network in Belgium.