Colon cancer patients with a first-degree relative who also had colon cancer have a significantly better prognosis.
In a recent study, even after all risk factors were taken into consideration, they had less chance of cancer recurring and less chance of dying than people without a close family history.
However, the same thing was not true for rectal cancer.
Researchers in Sweden questioned 318 consecutive colorectal cancer patients about their family cancer history. They found 31 (10 percent) had at least one first-degree relative who also had colorectal cancer — a parent, sister or brother, or child. They then followed all of the patients for the next six years, watching for recurrences and deaths.
Two patients met the criteria for Lynch syndrome and were not included in the study.
They found a 63 percent reduction in risk for recurrence among patients who also had a family member with colorectal cancer and a 75 percent reduction in the risk of dying. This reduced risk could not be explained by other factors including the patient’s age or sex, the cancer stage, tumor differentiation or invasion of nearby blood vessels.
Helgi Birgisson and her team at Uppsala University in Sweden concluded,
Family history for colorectal cancer in a first-degree relative is an individual prognostic factor in patients with colon cancer and could not be explained by known clinico-pathological factors. The value of family history taking in patients with colon cancer is therefore not only to identify families with hereditary colorectal cancer, but also to add information to the prognosis of the patients.
Another study, published in 2008 in the Journal of the American Medical Association, found a smaller but similar association between family history and stage III colon cancer recovery. In that review of 1,087 patients with stage III colon cancer, 195 (17.9 percent) had a first-degree relative with colorectal cancer. Following them for a median of five and a half years, researchers found that disease-free survival, recurrence-free survival, and overall survival were significantly better for patients who had a close family member with colorectal cancer.
Other than the fact that patients with a family history were less likely to have had a bowel obstruction when they were first diagnosed, there were no significant differences between people with close family histories of colorectal cancer and those without them. Sex, race, age, tumor characteristics, smoking history, diet, and exercise were all similar. Microsatellite instability or DNA mismatch repair status didn’t appear to affect the lowered risk.
Overall, patients with a first-degree relative with colorectal cancer had a 28 percent reduced risk of having cancer return or dying of the disease. This improved outcome was even stronger when there was more than one close relative. Among these stage III colon cancer patients, all of whom received chemotherapy, 29 percent experienced recurrence or death compared to 38 percent of those who had no family history.
Jennifer Chan, MD, MPH, and her colleagues analyzing the CALGB 89803 clinical trial concluded,
Among patients with stage III colon cancer receiving adjuvant chemotherapy, a family history of colorectal cancer is associated with a significant reduction in cancer recurrence and death.