Cancer experience in the relatives of an unselected series of breast cancer patients.
First- and second-degree relatives of an unselected series of 402 breast cancer patients have been studied for their cancer experience. In the first-degree relatives an excess of all cancers is seen [overall relative risk (RR) = 1.28, P = 0.002; males RR = 1.26, P = 0.047; females RR = 1.30, P = 0.022). There is a marked excess of sarcoma (RR = 4.26, P = 0.0064); females are at high risk of breast cancer (RR = 2.68, P < 0.0001) and males have an excess of carcinoma of the lip, oral cavity and pharynx (RR = 4.22, P = 0.0032). Second-degree relatives have a non-significant excess of all cancers (RR = 1.14, P = 0.14); females have a borderline excess of breast cancer (RR = 1.53, P = 0.08) and an excess of carcinoma of the kidney (RR = 7.46, P = 0.0012) and males have an excess of carcinoma of the trachea and lung (RR = 1.50, P = 0.032). No excess of prostate or ovarian carcinoma was seen. Relatives are at slightly higher risk if the index patient is diagnosed between the ages of 40 and 49 (first-degree RR = 1.64, P = 0.007; second-degree RR = 1.43, P = 0.02). The excess of cancers, including breast cancers, is not limited to a few high-risk families, but appears to be spread across many. These observations may be accounted for by shared environmental factors within families or a common predisposing gene with low penetrance.
Cancer Research Campaign Paediatric and Familial Cancer Research Group, Christie Hospital NHS Trust, Manchester, UK.
M D
MD
Teare
S A
SA
Wallace
M
M
Harris
A
A
Howell
J M
JM
Birch
D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology* / Q000235:genetics; D004739:England / Q000453:epidemiology; D005192:Family Health; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*; D016012:Poisson Distribution; D012042:Registries; D012307:Risk Factors; D012737:Sex Factors