Very elderly patients respond just as well to surgery for colorectal cancer as their younger counterparts, a new study has found.
The findings contradict the perceived wisdom that older people should not be operated on because the risk of surgery outweighs any perceived benefits.
Colorectal cancer is the most common form of the disease to affect men and women in the Republic with about 2,000 new cases per year.
Researchers at the Centre for Colorectal Disease in St Vincent's University Hospital in Dublin, found that a strategy of early and active surgical intervention for colorectal cancer in very elderly patients has proved highly effective in curing the disease.
Prof Diarmuid O'Donoghue, a a gastroenterologist and director of the centre, said he and the research team had been "a little surprised" at the findings.
"There would not be a general perception that very elderly people can do well with such surgery," he said.
However, he pointed out that the average life expectancy for 85-year-old Irish males and females was now almost five and six years respectively, while life expectancy for 90-year-olds "is still excellent at over three and four years and increasing rapidly".
He acknowledged that anticipated quality of life following an operation was a crucial factor in assessing elderly cancer patients.
"But merely to focus on this fails to take account of the fact that a cancer 'cure' may be just as important to an 86-year-old patient as to a 56-year-old," he said.
The study, conducted over 25 years, involved more than 2,200 patients, including 90 who were more than 85 years old. The researchers said it was the largest ever attempt to answer how cancer behaves in the very elderly and the effect of interventional treatment in the very old.
Senior author of the research, gastroenterologist Dr Hugh Mulcahy, said the study had allowed them to directly compare both tumour behaviour and long-term outcome in the very elderly and younger patients.
"Our results show that cancer behaviour in our older cohorts is generally similar to that of younger patients, given that the cancers found were no more or less advanced in the older group."
The researchers found little difference in surgical rates between older and younger patients at 91 and 94 per cent respectively nor of tumour spread at the time of operation.
Although one in 10 patients over 85 years died within 40 days of surgery, the five-year relative survival rate of the elderly group was 51 per cent, compared with 53 per cent for younger patients.
Prof O'Donoghue said the research findings "justify the aggressive approach to cancer we have had [in St Vincent's hospital] . . . it justifies the approach that if patients are relatively fit, they will do relatively well with surgery".
The research findings will be presented at the American Society of Gastroenterology's Digestive Diseases Week in Washington today.
According to the researchers, their study has generated considerable interest in the US, even before its presentation.
Dr Glen Doherty, a gastroenterology specialist registrar who will be presenting the study, said that this was not surprising given the continual increase in the American very elderly population, allied to "their broad awareness of current healthcare matters and proactive stance on age- related issues".