This section provides an overview of the diagnostics, prognostics and treatment of early breast cancer; it covers:
- Staging and risk assessment of early breast cancer
Risk categories for early breast cancer have been comprehensively defined, but it should be noted that nodal status remains the more important feature for defining risk category1:
Risk category
Low risk Node-negative AND all of the following features:
- pT ≤2 cm, AND
- Grade 1, AND
- Absence of peritumoural vascular invasion, AND
- HER2/neu gene neither overexpressed nor amplified, AND
- Age ≥35 years
Intermediate risk Node-negative AND at least one of the following features:
- pT >2 cm, OR
- Grade 2-3, OR
- Presence of peritumoural vascular invasion, OR
- HER2/neu gene overexpressed or amplified, OR
- Age <35 years
High risk Node-positive (1-3 involved nodes) AND HER2/neu gene either overexpressed or amplified, OR
Node-positive (4 or more involved nodes)pT, pathological tumour size (ie, size of the invasive component).
TNM classification
The American Joint Committee on Cancer (AJCC) staging system can be used to group patients in terms of prognosis. Therapeutic decisions are made in part according to these staging categories. However these decisions are made primarily based on tumour size, lymph node status, oestrogen receptor and progesterone receptor levels in the tumour tissue, human epidermal growth factor receptor 2 (HER2/neu) status, menopausal status and the general health of the patient. The AJCC has chosen to use the TNM classification to define breast cancer.2
Categorising breast tumours
The first factor in categorising breast tumours is the extent of the primary tumour. Grades for tumours (T) include2:
- TX: primary breast tumour cannot be assessed
- T0: no evidence of primary breast tumour
- Tis: carcinoma in situ (non-invasive)
- T1-T4: increasing size and/or local involvement of regional lymph nodes
- T1: tumour 2 cm or less in greatest diameter
- T2: tumour more than 2 cm but not more than 5 cm
- T3: tumour more than 5 cm in greatest diameter
- T4: tumour of any size with direct extension to chest wall or skin
The second factor is whether the cancer also involves lymph nodes (nodal involvement). Grades for nodal involvement (N) include2:
- NX: regional lymph nodes cannot be assessed
- N0: no regional lymph node spread
- N1-N3: increasing involvement of regional lymph nodes
The third factor is whether the cancer has metastasised. Grades for metastases (M) include2:
- M0: no evidence of metastatic spread
- M1: evidence of metastatic spread
Once the TNM status has been determined, this information is used to assign an overall numerical stage2:
Hover over the image to see a larger view
Usually early stages include 0, I, II, and IIIA, although some IIIB and IIIC can be operable.2,3
Adapted from the National Cancer Institute. Stage Information for Breast Cancer. http://www.cancer.gov/cancertopics/pdq/treatment/breast/HealthProfessional/page32
- Early breast cancer treatment
The standard treatment for early, hormone-sensitive breast cancer is surgery and radiotherapy.1,4 This is generally followed by adjuvant endocrine therapy, with chemotherapy given in selected cases.1,4
Current expert consensus advocates the inclusion of adjuvant endocrine therapy in almost all patients whose tumours show evidence of endocrine responsiveness, which is defined as the presence of any detectable oestrogen receptor.1
The approved indications for Arimidex in Early Breast Cancer are as follows5:
- Adjuvant treatment of hormone receptor-positive early invasive breast cancer in postmenopausal women.
- Adjuvant treatment of hormone receptor-positive early invasive breast cancer in postmenopausal women who have received 2 to 3 years of adjuvant tamoxifen.
As there may be local variations in the approved label, please consult the local ARIMIDEX prescribing information before use.
References
- Goldhirsch A. Meeting Highlights: International Expert Consensus on the Primary Therapy of Early Breast Cancer. Ann Oncol 2005; 16:1569–83.
- National Cancer Institute. Stage Information for Breast Cancer. http://www.cancer.gov/cancertopics/pdq/treatment/breast/HealthProfessional/page3. Accessed on 27 October 2010.
- National Clinical Practice Guidelines in Oncology. Breast Cancer. Version 3.0. 2010. http://www.nccn.org/professionals/physician_gls/PDF/breast.pdf. Accessed on 27 October 2010.
- Howell A. The future of fulvestrant ("Faslodex"). Cancer Treat Rev 2005; 31(suppl 2): S26–33.
- ARIMIDEX UK SmPC. Last updated 7th Oct 2011. http://www.medicines.org.uk/emc/medicine/3845/SPC/Arimidex+1mg+Film-Coated+Tablet/
As there may be local variations in the approved label, please consult the local ARIMIDEX prescribing information before use.
