Breast Cancer

Introduction  As old as 1600 BC  Emerges from inner lining of milk ducts  Or the lobules that supply milk  Types:  DCIS  LCIS

Genetic, Behaviour, Infectious?  Non-Functional BRAC1 & BRAC2 Genes  Age, Menstrual cycle, Drinking alcohol, Late or few Births, Smoking, Hormone replacement therapy & Having dense breast

Pathology  Develops from epithelial cell lining  Invasive, stromal like adenocarcinoma  Mammography for DCIS  Biopsy is used to detect LCIS(non-palpable lesion, multifocal or bilateral)  Paget’s disease(characteristic malignant)

Molecular Basis  BRCA1 and BRCA2  Additional genes  ATM  P53  PTEN  CDH1  Characteristics  Have specific function in body  Their abnormal presence causes certain diseases  Risk of breast cancer is increased

Diagnosis Physical examination:  First step in breast cancer diagnosis  Examination of any lump, change in the size or texture of breast and lymph node in the armpit Diagnostics mammogram:  X-ray of the breast  Screening mammograms in asymptomatic women  Diagnostic mammograms in women having breast cancer MRI (magnetic resonance imaging):  Uses radio waves and strong magnets  The pattern observed is translated to image  More expensive still used more as compared to mammogram  Too much sensitive

Ultrasound (sonography):  Sound waves are used  Echo produced is converted to image Biopsy:  Only way to tell actual presence of breast cancer  Effected tissue is taken and pathologically tested Scintymammography:  New method and still under study  Radioactive tracer attached to breast cells through veins  Detected by special camera Tomosynthesis (3D mammography):  Similar to 2D mammogram  More radiation required and 3D image is formed

Two types of tests: 1. Oncotype DX:  Helps in depicting the recurrence score  Based on this score further treatment is decided  Helpful in those who are stage 1 or stage 2 estrogen positive receptor 2. Mammaprint:  Helps in determining the recurrence score in specific part of body  Both estrogen positive and negative can be detected

Prevention  Prophylactic Mastectomy or prophylactic oophorectomy  Tamoxifen and Raloxifene  Aromatase Inhibitors

Treatment  Surgical Methods- Mastectomy, sentinel node biopsy  Brachytherapy  Drug Therapy  Chemotherapeutic Drugs- Cyclophosphamide, Epirubicin, Flourouracil, Methotrexate, Doxorubicin, Docetaxel  Hormonal Therapy- SERMs, Aromatase Inhibitors  Targeted Therapy- Herceptin, Lapatinib

Biotechnology Applications  To understand the molecular basis, development of diagnostics and treatment.  Biomarkers  Defining gene and protein patterns  Human Growth Hormone  Biomolecules- Herceptin and Tamoxifen  Molecular Profiling- Real Time PCR & Microarray