Influence of young age at diagnosis and family history of breast or ovarian cancer on breast cancer outcomes in a population-based cohort study.
OBJECTIVE
The objective of this study was to examine the association of: (i) diagnosis at age </=35, (ii) first-degree family history of breast or ovarian cancer (BOC) and (iii) a research based definition of genetic risk, with tumor characteristics, treatment and survival in breast cancer (BC).


METHODS
Consenting female participants in the population-based Ontario Familial Breast Cancer Registry diagnosed with primary invasive BC between 1996 and 1998 were followed prospectively until 2005.


RESULTS
Among 967 women, 105 were </=35 years old at diagnosis and 686 were classified as genetic risk cases, including 349 with a first-degree family history. Individuals diagnosed at age </=35 were more likely to self-detect tumors, to present with inflammatory BC, to have invasive ductal carcinoma of no special type, high T stage, and tumors with lymphovascular invasion (LVI), high grade and negative estrogen receptors. Younger women were more likely to receive chemotherapy and less likely to receive hormonal therapy. Diagnosis </=35 years old was associated with significantly reduced distant recurrence free survival, an effect that did not persist after adjustment for tumor and treatment related variables. Poor outcomes were restricted to younger women with hormone responsive BC. Family history was associated with increased rates of mammographic detection of BC, lower tumor stage and less frequent inflammatory BC, but had no association with BC outcomes.


CONCLUSIONS
Women diagnosed with BC at age </=35 have more aggressive tumors; these adverse tumor characteristics, rather than age, lead to poor outcomes. Family history was not associated with survival.
Figueiredo
Jane C
JC
Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 60 Murray Street, Box 18, Toronto, Ontario, Canada, M5T 3L9.
Ennis
Marguerite
M
Knight
Julia A
JA
McLaughlin
John R
JR
Hood
Nicky
N
O'Malley
Frances
F
Andrulis
Irene L
IL
Goodwin
Pamela J
PJ
D000328:Adult; D017668:Age of Onset; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D008957:Models, Genetic; D009864:Ontario; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D012042:Registries; D012306:Risk; D016896:Treatment Outcome