New York: Incidents of rectal cancer among people below 40 years have been rising steadily in the past two decades and doctors are failing to diagnose it early, says
a new research.
Rectal cancer is a disease in which malignant (cancer) cells form in the tissues of the rectum -- the last six to eight inches of the large intestine which stores solid waste.
Possible signs of rectal cancer include a change in bowel habits or blood in the stool.
Although both colon and rectal cancer are thought to share the same risk factors, the incidence of colon cancer has remained steady during that period, while the incidence of
rectal cancer has grown by an average of 3.8 percent per year in the past 20 years, the scientists reported online in the journal Cancer.
"We suggest that in young people presenting with rectal bleeding or other common signs of rectal cancer, endoscopic evaluation should be considered in order to rule out a
malignancy," said Dr Joshua Meyer of the Fox Chase Cancer Centre in Philadelphia, the lead author of the study.
"This is in contrast to what is frequently done, which is to attribute these findings to hemorrhoids. More frequent endoscopic evaluation may be able to decrease the documented delay in diagnosis among young people," he explained.
By conducting a retrospective study using data from the Surveillance Epidemiology and End Results (SEER) cancer registry, Dr Meyer and his team identified 7,661 colon and
rectal cancer patients under age 40 years between 1973 and 2005.
The researchers then calculated the change in incidence over time for colon and rectal cancers, and found that overall rates of colon and of rectal cancer were low during the years of the study (1.11 and 0.42 cases per 100,000, respectively).
While colon cancer rates remained essentially flat in individuals under age 40 years in recent decades, rectal cancer rates have been increasing since 1984, they observed.
Specifically, between 1984 and 2005, the rate of rectal cancer diagnosis rose 3.8 percent per year and the increase was the same for all races and both sexes, they found.
According to the scientists, the first symptoms of the disease is rectal bleeding, which doctors often assume as the result of hemorrhoids and fail to diagnose it quickly. Other
symptoms of rectal cancer include a change in bowel habits, anaemia, weight loss and diarrhoea.
Although the scientists were unable so far to pin point what causes the disease, they said risk factors for the cancer include a family history of the disease, obesity, smoking,
heavy alcohol use, a diet high in red meat and low in vegetables, and insufficient intake of vitamin D.
Meanwhile, the authors do not advocate for a change in screening guidelines as the overall incidence of rectal cancer is relatively low.