Breast Cancer
Conditions
Brief summary
Because of mammography screening increasingly more women are diagnosed with centimeter or subcentimeter node-negative breast cancer (i.e., T1abN0); these tumors account for approximately 19% of all newly diagnosed breast cancers in Sweden. Although the long term relapse-free survival rates among patients with such tumors is as high as ≥90%, some reports suggest that certain patient subgroups may have rates \<75%. Firmly established prognostic and predictive factors for patients with T1abN0 tumors are, however, lacking. This is a nationwide, register-based cohort study investigating prognostic and predictive factors in women with centimeter or subcentimeter breast cancer. The study hypotheses are: 1) Established prognostic and/or predictive factors in overall breast cancer are prognostic and/or predictive factors also in centimeter or subcentimeter node-negative breast cancer; 2) The established relative reduction in risk of recurrence and death of adjuvant treatment for overall breast cancer are similar in centimeter or subcentimeter node-negative breast cancer.
Interventions
DRUGEndocrine therapy
Endocrine treatment versus no endocrine therapy (in women with hormone receptor positive1 disease).
RADIATIONRadiotherapy
Radiotherapy versus no radiotherapy.
DRUGHerceptin
Trastuzumab versus no trastuzumab (in women with HER2-positive disease).
DRUGChemotherapy
Chemotherapy versus no chemotherapy.
PROCEDUREType of breast cancer surgery
Type of surgery (partial mastectomy, mastectomy, other).
OTHERAge at diagnosis
Age at diagnosis (\<35, 35-\<50, 50-\<70, ≥70).
OTHERScreen detected tumor
Screening detected tumor (yes, no).
OTHERMenopausal status at diagnosis
Menopausal status (premenopausal, postmenopausal).
OTHERTumor size
Tumor size (≤5 mm, 6-≤10 mm).
OTHEREstrogen receptor (ER) status
ER-status (positive, negative).
OTHERTumor grade
Tumor grade (1, 2, 3).
OTHERHER2-status
HER2-status (positive, negative).
OTHERIntrinsic subgroups of breast cancer
Intrinsic subgroup proxy (Luminal A, Luminal B (HER2-negative), Luminal B (HER2-positive), HER2-positive (non-luminal), Triple negative).
OTHERNodal status
N-status (N0, N1).
Sponsors
The Swedish Society of Medicine
The Swedish Breast Cancer Association (BRO)
Swedish Breast Cancer Group
Karolinska Institutet
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
No minimum to 100 Years
Inclusion criteria
1. Female. 2. Operated for centimeter or subcentimeter breast cancer.
Exclusion criteria
1. Previous breast cancer. 2. Metastatic breast cancer at diagnosis.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Breast cancer specific death | January 1, 1977 to December 31, 2014 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Death from any cause | January 1, 1977 to July 30, 2016 | — |
| Metachronous breast cancer | January 1, 1977 to July 30, 2016 | Ipsilateral or contralateral breast cancer |
Countries
Sweden
Outcome results
None listed