FRIDAY, May 13, 2011 (HealthDay News) -- Doctors rely on a patient's knowledge of his or her family medical history in assessing cancer risk, but these recollections are not always dependable.
A new study published online May 11 in the Journal of the National Cancer Institute reveals that patients' accuracy in reporting the cancer diagnoses of their relatives was low to moderate.
Researchers surveyed about 1,000 people about cancer diagnoses in nearly 21,000 first-degree relatives (parents, siblings and children) as well as second-degree relatives (grandparents, aunts, uncles, nieces and nephews).
Researchers then confirmed the cancer histories of about 2,600 of those relatives for four of the most common adult malignancies -- breast, colorectal, prostate and lung -- using medical records, state cancer registries, death certificates and interviews with the relatives or their proxies.
About 61 percent of patients were accurate about their family history of breast cancer; 60 percent recalled family lung cancer history correctly; 27 percent were right about their relatives' history of colorectal cancer and 32 percent knew who in their family had been diagnosed with prostate cancer.
In contrast, patient reports on relatives who didn't get cancer were highly accurate.
Not surprisingly, knowledge of the cancer histories of first-degree relatives were more accurate than for second-degree relatives.
The researchers concluded that the accuracy of family cancer history reporting must be improved. "If we want to be able to appropriately integrate family history into personalized clinical care, studying systematic ways to enhance family history ascertainment should be a research priority," said the study's authors in a news release.
The U.S. National Cancer Institute has more on the role family history plays in cancer diagnoses.