BREAST CANCER Flashcards
(45 cards)
Histopathology
- infiltrating ductal carcinoma (>70%)
- invasive lobular carcinoma (5-10%)
- inflammatory (orange, worst prognosis)
- DCIS (ductal carcinoma in situ)
- LCIS (lobular carcinoma in situ)
- Medullary
Important anatomical landmarks (no bony structures)
- Xiphoid process
- Sternal angle
- Tail of Spence
- Nipple
- Areola
Epidemiology
- the most common malignant disease in women
- 1/9 chance of developing it in lifetime
- more frequent in left breast
- more frequent in the upper-outer (triangle of Spence)
- 10% of cases are bilateral
- <1% affect men
Etiology
- F 100 : 1 M
- BRCA1 and BRCA2
- Age 60-79 yrs x2, medial age onset 55 yrs
- Family history of breast ca, 1st line relatives
- Nulliparity
- Early menarche
- Late Menopause
- Oophorectomy < 50yrs
- Diet high in fats, alcohol
- Previous cancer in one breast
- Early exposure to Radiation
Detection/Diagnosis tools
- Breast self examination
- Clinical Breast examination
- Mammography screening (although controversial)
- US (Ultrasound) which differentiates between cystic or solid tumors
- Thermotherapy (with high false +) uses infrared to detect high blood circulation
- MRI (for silicone implants)
- Fine Needle biopsy (small gauge)
- Core Needle biopsy (large gauge)
- Incisional biopsy
- Excisional biopsy
American Cancer Society (ACS) and Canadian Cancer Society (CCS) mammography recommendations
American Cancer Society (ACS) starting at 40 years old
Canadian Cancer Society (CCS) starting at 50 years old
Clinical presentation
- Breast mass
- nipple discharge
- skin changes in color and texture
- alteration breast contour
- lymphadenopathy (enlargement of axillary LNs)
- small lesions found on mammography
- distant METS
Lymphatic drainage
- Axillary LNs (70%)
- Internal mammary LNs (30%)
- Supraclavicular LNs (METS)
Sentinel Node Biopsy
Radioactive dye (Blue dye) used to stain lymph node involvement directly injected inside the tumor. This procedure reports the first nodal involvement and the requirement of a LN dissection.
Prognostic factors
- LN involvement (# of Axillary LN is the most significant prognostic factor)
- Tumor extent
- Histopathology
- ER/PR status
- HER2 protein receptors
Lymphatic channels
- Superficial (draining to skin covering breast)
- Deep (draining to internal breast tissues)
Hormonal Therapy for Breast cancer by using Tamoxifen.
Breast cancer cells can have receptors for Estrogen or Progesterone (ER/PR), therefore it’s possible to block these receptors nourishing cancer cells by using Tamoxifen (Nolvadex). Tamoxifen blocks the binding of Estrogen or Progesterone into the ER and PR. This blocks breast cell growth because the tumor cells usually nourish on these two hormones.
Tamoxifen is used in pre-menopausal women. It is important to understand Estrogen can be produced by 2 mechanism systems: produced by the ovaries or the adrenal glands (androgen to estrogen conversion). Tamoxifen can only be used for pre-menopausal women because it can block the receptors for estrogen but cannot block the androgen to estrogen conversion by adrenal glands.Whereas post-menopausal women do not produce estrogen by the ovaries anymore, Arymidex, would have to be used to cancel the nourishment of tumor cells on androgen to estrogen conversion.
How is HER2 gene protein a prognostic factor for Breast cancer?
Each healthy breast cell has two copies of HER2 gene for normal cell function
Breast cancer cells have too many copies of HER2 gene, therefore associated with higher aggressiveness of tumor, making it to grow faster!
5 year-survival rates
- Generally 89%
- If Regional spread 77%
- Distant METS 21%
First treatment of choice
-Surgery (Radical,modified mastectomy,lumpectomy)
Radical mastectomy:
Removal of breast, overlying skin, all axillary lymph nodes, pectoralis major and minor muscles
Popular in the 70s but brought high complication rates
Women had weak arm. shoulder stiffness, lymphedema (arm swelling)
Modified mastectomy:
Removal of breast, overlying skin, SOME axillary lymph nodes, pectoralis minor muscle removed, leave pectoralis major intact!!!
Reduces arm swelling and increases arm strength
Lumpectomy:
Excisional biopsy of tumor + margins of small masses (early stages)
Role of Chemotherapy
To treat the microscopic cells around the system and lymphatics as a systemic treatment.
Usually chemotherapy is given POST-OPERATIVE, especially for advanced stages like stages 2 - 4.
Common chemotherapy agents
- 5 FU
- Adriamycin (doxorubicin), heart toxicity
- Vinblastine
- Methotrexate
- Cytoxan (cyclophosphamide)
Ovarian ablation
Ovaries produce estrogen in pre-menopausal women (at least much more than post-menopausal women). Therefore, an oophorectomy is performed to treat the ER/PR + women. An LHRH (lutenizing hormone releasing hormone) agonist inhibits the pituitary gland to stop ordering for the production of estrogen by the ovaries. Ex. ZOLADEX (used actually in breast and prostate cancer.
Hormonal Therapy for Breast cancer by using Arimidex.
Compared to Tamoxifen which can be used in pre or post menopausal women, Arimidex can only be used in POST-MENOPAUSAL women.
Arimidex inhibits the conversion of androgen (produced by adrenal glands) into estrogen. Because post-menopausal do not produce estrogen by their ovaries (usually removed or non-producing), the only pathway left is the androgen-estrogen pathway. In order to inhibit that conversion (usually activated by an enzyme) Arimidex can be used.
Giving Arimidex to a pre-menopausal woman would not help in preventing ER/PR+ tumor cells from nourishing of estrogen because although Arimidex can block the conversion, her ovaries will be still producing estrogen normally.
Side effects of using Tamoxifen
- Increased risk of developing uterine cancer!
- Hot flashes
- Vaginal dryness
- Weight gain
Side effects of using Arimidex
- bone and joint pain
- osteoporosis
- decrease in bone density
Herceptin treatment for Breast cancer.
Herceptin (Trastuzumab) interferes with the HER2/neu receptor and in two days stop cancer cells to continue growing! This type of treatment is expensive 100 000$/year but can be effective in late stages of breast cancer.
Requires the patient to be Her2 +, meaning the receptor gene is present therefore we have a treatment available for it
role of Radiotherapy in treating Breast cancer
- Conservative breast cancer management!
- Therefore, a lumpectomy is done instead of a mastectomy. An ipsilateral axillary node dissection is performed if node involvement is positive after a sentinel node biopsy.
- After the dissection surgery 2-4 POST OPERATIVE recovery, Radiotherapy is given.
typical dose prescription for Breast cancer
- 50 Gy / 25 fx
- used when >26 cm separation on the breast
- when Mcgill technique is used
- when the heart is in the field and is an OAR (left breast)
- 42.4 Gy / 16 fx (hypofractionation) o 42.56 /16 fx
- used when need to accelerate waiting list
- used commonly for smaller breast <26 cm
