Young women with breast cancer in their family background who need treatment for the disease themselves need not worry that it will be any less successful for them as for women without a family history, suggests a study comparing sporadic versus hereditary breast cancer.
The large study published in the British Journal of Surgery offers a hopeful conclusion - that young patients "presenting to breast surgical clinics with a positive family history can be reassured that this is not a significant independent risk factor for breast cancer outcome."
The findings are from a large prospective cohort study - so had a strong scientific design for finding links between disease factors and outcomes - and involved 2,850 women under age 41 years who were diagnosed with breast cancer and treated in the UK.
Ramsey Cutress, an associate professor in breast surgery at the University of Southampton and University Hospital Southampton Foundation Trust in the UK, did the analysis with colleagues on data from the so-called POSH study (prospective outcomes in sporadic vs. hereditary breast cancer).
No significant differences in rates of cancer returning after treatment were seen for women with a family history of breast cancer compared with those without.
Cutress sums up how this study means young women with experience of breast cancer in their family now have cause to be less worried:
"Successful treatment for breast cancer is just as likely in young patients with a family history of breast cancer, as in those without a family history.
Patients with a family history of breast cancer can therefore be reassured that their family history alone does not mean that their outcome will be worse."
The 2,850 women analyzed were those from 3,095 recruited to the POSH study who could yield data on whether or not there was a history in their family of breast cancer.
Two thirds of the patients reported no history, while a third reported breast/ovarian cancer in at least one first- or second-degree relative.
Such family relationships include parent or sibling for first-degree relatives, and uncle, aunt, grandparent and so on for second-degree.
Different cancer characteristics but similar chances of staying disease-free
The results for cancer characteristics showed that women with a family history were more likely than those without to have higher-grade tumors (to have grade 3 tumors - 63.3% versus 58.9%), and their tumors were more likely (28.8% versus 24.7%) to be negative for HER2 (human epidermal growth factor receptor 2) than in the women without heredity.
The hereditary element of breast cancer cause in women with a family history is complex - background genetic etiology is "likely to be accounted for by a wide spectrum of genes and modes of inheritance," say the authors. However, they cite a simpler fact in reviewing previous evidence:
"Approximately 25% of breast cancers in developed countries are thought to be related to hereditary factors and these usually present at a younger age than sporadic breast tumors."
The study findings add some clarity for these younger women with family history thinking about the potential outcomes of their disease.
The similar outlook for them as for those without close relatives being diagnosed comes from the following percentage results.
The estimated distant disease-free intervals (DDFI) - measured as the time from the date of diagnosis of invasive breast cancer to distant relapse or death from breast cancer - were, for a 5-year period:
- 74.9% for the group without family history
- 77.4% for women positive for family history.
The respective 8-year DDFI rates were 68.7% and 72%.
These comparable rates meant "no significant differences in distant disease-free intervals for patients with versus those without a family history," the authors report.
These results for the whole cohort of women remained true when they were stratified to different groups by estrogen receptor (ER) status.