Large European study looked at people with close relatives who'd been affected
WebMD News from HealthDay
By Dennis Thompson
HealthDay Reporter
THURSDAY, July 25 (HealthDay News) -- A family history of cancer raises your overall risk of developing cancer, including types of cancer far removed from those suffered by your relatives, according to a new study of 23,000 people.
Doctors have long known that people have an increased risk of developing the same type of cancer as a close relative. In addition, some genetics studies have found that common gene mutations can increase the risk of different types of cancer -- for example, one genetic abnormality can increase risk of both breast and ovarian cancer in women.
But this review, performed by European researchers and published July 25 in the journal Annals of Oncology, found that a close family member's history of cancer appears to increase a person's risk of suffering either the same cancer or a different type of cancer.
"It looks like there clearly are associations between family members developing cancer and you developing cancer," said Dr. Dennis Kraus, director of the Center for Head and Neck Oncology at the New York Head & Neck Institute at Lenox Hill Hospital in New York City. He was not involved with the new research.
"It's a well-done study," Kraus said. "It's a huge number of patients where they had controls, and they were able to take into account lifestyle and try to remove things like smoking and drinking from the equation."
Significant associations found in the study include:
- A 1.5-fold increased risk of breast cancer in women with a history of colorectal cancer in the family.
- A 3.3-fold increased risk of oral and pharyngeal cancer among people who had a first-degree relative with cancer of the larynx (voice box).
- A four-fold increased risk of cancer of the esophagus among people with a first-degree relative who had oral or pharyngeal cancer.
- A 2.3-fold increased risk of ovarian cancer among those with a first-degree relative who had breast cancer.
- A 3.4-fold increased risk of prostate cancer if a first-degree relative had bladder cancer.
First-degree relatives are parents, brothers, sisters, sons and daughters.
"Our results point to several potential cancer syndromes that appear among close relatives and that indicate the presence of genetic factors influencing multiple cancer sites," said study co-author Dr. Eva Negri.
"These findings may help researchers and clinicians to focus on the identification of additional genetic causes of selected cancers and on optimizing screening and diagnosis, particularly in people with a family history of cancer at a young age," said Negri, head of the laboratory of epidemiologic methods at the Mario Negri Institute for Pharmacological Research in Milan, Italy.
The researchers from Italy, Switzerland and France looked at 12,000 cases of cancer occurring in 13 different parts of the body between 1991 and 2009, and matched them to control cases of 11,000 people without cancer. For both groups they collected information on any cancer in the family, as well as data on health and lifestyle factors that can influence a person's cancer risk.
source : Family History of Cancer May Raise Risk for Other Types of Tumors
