Primary invasive breast cancer

Last reviewed: 3 Sep 2022
Last updated: 22 Apr 2021



History and exam

Key diagnostic factors

  • breast mass
  • nipple discharge
  • axillary lymphadenopathy
More key diagnostic factors

Other diagnostic factors

  • skin thickening or discoloration
  • retraction or scaling of the nipple
Other diagnostic factors

Risk factors

  • increasing age
  • female sex
  • ethnic origin
  • positive family history
  • genetic mutations
  • endogenous estrogen exposure
  • exogenous estrogen/progestin exposure
  • alcohol consumption
  • radiation exposure
  • benign breast disease
  • increased breast density
  • mild, moderate, or marked background parenchymal enhancement (BPE) on breast MRI
  • reduced physical activity
  • poor diet
  • high socioeconomic class
  • smoking
  • obesity
  • high dibutyl-phthalate exposure
More risk factors

Diagnostic investigations

1st investigations to order

  • mammogram
More 1st investigations to order

Investigations to consider

  • breast ultrasound
  • breast MRI
  • biopsy
  • hormone receptor testing
  • HER2 testing
  • gene expression assays
  • computed tomography
  • genetic testing
  • CBC
  • LFTs
  • alkaline phosphatase
More investigations to consider

Treatment algorithm


early-stage breast cancer (stages I to IIB [T2 N1 M0])

locally advanced breast cancer (stages IIB [T3 N0 M0] to III)


disease recurrence



Krystal Cascetta, MD

Assistant Professor

Division of Hematology and Medical Oncology

Icahn School of Medicine at Mount Sinai

New York



KC declares that she has no competing interests.

Amy Tiersten, MD


Division of Hematology and Medical Oncology

Dubin Breast Center of the Tisch Cancer Institute

New York



AT is on the advisory board for Immunomedics, AstraZeneca, Novartis, Eisai, and Healthline. She receives research funding from Pfizer, Novartis, Genentech, Lilly, and AstraZeneca and does expert testimony work.


Dr Krystal Cascetta and Professor Amy Tiersten would like to gratefully acknowledge Dr Hope S. Rugo, Dr Amal Melhem-Bertrandt, Dr Gabriel N. Hortobagyi, and Dr Phuong Khanh H. Morrow, the previous contributors to this topic.


AMB, GNH, and PKHM declare that they have no competing interests. HSR receives research funding through the University of California from Novartis, Pfizer, Genentech, Macrogenics, Plexxikon, Merck, Nektar, and GSK. She has been reimbursed for travel by Novartis, Genentech, and Nektar. She has received speaker honorarium from Genomic Health.

Peer reviewers

Anees Chagpar, MD

Assistant Professor

University of Louisville




AC declares that she has no competing interests.

Gurhan Celik, MD

General Surgeon

General Surgery Department

Istanbul Training and Research Hospital




GC is an author of a number of references cited in this topic.

Edward R. Sauter, MD, PhD

Medical Officer

Breast and Gynecologic Cancer Working Group

Division of Cancer Prevention

National Cancer Institute




ERS declares that he has no competing interests.

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