WASHINGTON--Colorectal cancers in patients younger than age 40 are reputed to behave more aggressively than similar lesions in persons over 40, resulting in poorer survival. Younger patients have also been reported to present with a higher tumor stage.
A new study suggests that delay in seeking treatment among younger patients, rather than a delay in diagnosis after help is sought, may account for much of the difference in prognosis.
At their poster presentation during Digestive Disease Week 1997, G. Wilcox, MD, and colleagues, of Baylor College of Medicine and Methodist Hospital, Houston, described their study, which began with a review of the tumor registry files of Methodist Hospital, Houston, between 1984 and 1995.
The researchers found 34 patients diagnosed with colorectal carcinoma at 40 years of age or younger. Kaplan-Meier survival analysis was performed on 27 patients from this group and 27 patients who had been diagnosed with colorectal cancer between ages 45 and 55. The two groups were matched for gender, histologic subtype, stage, grade and treatment.
Colorectal cancer in younger persons is often poorly differentiated and includes a higher proportion of signet ring cell types. These two conditions may contribute to the less favorable prognosis in this subset of patients. However, in this study, five-year survival in younger and older patients was identical when the two groups were matched for tumor stage, histologic subtype, and treatment.
The study found that younger patients characteristically delay longer than older patients before seeking medical attention. Eleven of 33 younger patients (33%), compared with one of 29 older patients (3%), sought medical attention one year or more after the onset of symptoms (most frequently, pain and bleeding from the rectum).
Delay in diagnosis of six months or more after initial presentation was about the same in both groups: five of 31 younger patients and three of 32 older patients.
Positive family history was more likely to be obtained in younger patients (10/30, 30%) than in older patients (1/24, 4%).
"The study showed a significant difference between older and younger people in the time elapsed between initial symptoms and seeking medical attention, which may explain the reported poorer prognosis," Dr. Wilcox said. "However, younger and older people with colorectal cancer have similar prognosis when matched for stage, grade, and treatment."
The researchers urged that younger persons be educated to seek immediate medical attention for gastrointestinal symptoms, especially if they have a positive family history for the disease.