MicroBio 160 1st Edition Lecture 12Outline of Last Lecture I. Risk Factors II. Anatomy of the BreastIII. SymptomsIV. Detecting Breast Cancer V. Mammogram ImagesVI. CalcificationsVII. Breast DensityVIII. Invasive Diagnostics: BiopsyIX. Non-invasive Breast CancerX. Invasive Breast CancerXI. Estrogen Target TissueXII. Breast MutationsXIII. Human Epidermal Growth Factor Receptor-2 (HER 2)XIV. Cumulative RiskOutline of Current Lecture I. Breast Cancer Staging II. Sentinel Lymph Node BiopsyIII. Sentinel Lymph Node DetectionIV. Surgery for Breast Cancer V. Radiation Therapy vs. Brachytherapy:VI. Hormone Therapy VII. Tamoxifen, the first SERM:VIII. Raloxifene, an alternative SERM:IX. How your body makes Estrogen after MenopauseCurrent LectureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Breast Cancer Stage and Survival: 5-10 year survival ratesStaging Breast Cancer: TNMStage Tumor Size Axillary Lymph nodes MetastasisNoninvasive O Tiny cluster of cancer cells in a breast duct (in situ); no invasive cancer seenNo spread NoneInvasive I Up to 2cm No spread NoneInvasive II a) Smaller than 2cm b) Between 2 and 5cmc) Larger than 5cma) Has spread to axillary lymph nodesb) May or may not have spread to the axillary lymph nodesc) No spreadNoneInvasive III a) Any size b) Larger than 5cmc) Any size but cells have spread to skin or chest wall d) Any sizea) Has spread to the axillary lymph nodes so that the nodesbecome attached to each otherb) Has spread to the axillary lymph nodesc) May or may not have spread to the axillary lymph nodes d) Has spread to the lymph nodes along breastbone or above or below collarbone None Metastatic IV Any size May or may not have spread to the axillary lymph nodes Has spread to other organs ofthe bodySentinel Lymph Node Biopsy:Lymph Node Status Chances of Surviving 5 YearsChances of Surviving 10 yearsChances Surviving Years without RecurrenceNo career in any node Better than 90% Better than 80% Better than 70%Cancer in one to three nodesAbout 60 to 70% About 40 to 50% About 25 to 40%Cancer in four or more nodesAbout 40 to 50% About 25 to 40% About 15 to 35%Injecting dye into tumor to identify sentinel nodes: In your lymphatic system there are one way valves—when you inject it will spread out from the tumor- Whatever is the first one moving out from the radius of the tumor, anyone after that are the secondary lymph nodes Sentinel Lymph Node Detection: - Before going to the operating room, the surgeon injects a small dose of low-level radioactive tracer called technetium-99 into the breast in the region of the patient’s tumor- Technetium-99 contains less radiation than a standard x-ray, CT scan or bone scan and is a relatively safe substance. – Half-life is less than 6 hourso A blue dye is also injected to help virtually track the location of the sentinel node during surgery—the surgeon then uses a hand held counter to detect the radioactive tracer and locate the sentinel nodeSurgery for Breast Cancer:- Lumpectomy: You take out the lump and some of the surrounding tissue—when a pathologist looks at the tissue they want to have clean margins—free of cancer - Wide excision- Quadrectomy- Mastectomy: They go all the way up to the armpit and remove the entire breastso Simple Mastectomy o Radical Mastectomy (Very invasive): Removes the breast, tissue in the shoulderRadiation Therapy vs. Brachytherapy:- Mammosite RTS: Inside the breast inside the cavity where the tumor used to be, they plant a balloon—that balloon has a catheter—the balloon will remain in place for the duration of the radiation treatments- Radioactive material placed in body in the area near cancer cells (internal radiation therapy, implant radiation, or brachytherapy)o Benefits: radiation dose targets lumpectomy cavity; minimizes normal tissue exposureHormone Therapy:Why is hormone receptor status important in breast cancer treatment?- 75% of breast cancers are estrogen-receptor-positive (“ER-positive” or “ER+”)- 65% of ER+ breast cancers are also progesterone receptor positive (“PR positive” or “PR+”)- Approximately 25% of breast cancer patients have tumors that are HER2+- We can block HER2 receptors with Herceptin- We can block estrogen receptors with SERMs Tamoxifen, the first SERM:- 1992 NCI study involving 13,000 healthy women at high risk for breast cancer based on their family or medical history - Half were given tamoxifen, while other half were given a placebo - After 5 years, group receiving tamoxifen had a lower rate of breast cancerBoth shared same risk of getting breast cancer; however Tamoxifen reduces risk- Increases uterine cancer risk and blood clot risk Raloxifene, an alternative SERM:- Raloxifene is another anti-estrogen SERM medication - Approved by the FDA in 1997 for preventing osteoporosis in postmenopausal women- Reduces risk of breast cancer without stimulation of uterine cell division exhibited by Tamoxifen- Women taking Raloxifene had 36% fewer uterine cancers and 29% fewer blood clots than women taking TamoxifenHow your body makes Estrogen after Menopause: if you are post-menopausal, most of your estrogen is produced in two steps:1. Your adrenal gland (two small glands that sit on top of your kidneys) make a hormone called androgen—androgens are mostly male hormone but women have them too2. Then a special protein found in muscle and fat cells throughout your body makes an enzyme called aromatase, which changes androgen into
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