Breast Cancer – MD Nexus

Epidemiology

Epidemiology
- Breast cancer commonly metastasizes to the lungs
- Lung is only site of metastasis in 21% of cases
Physiology
- Hematogenous Dissemination to lungs: most common mechanism of spread to lungs
- Lymphatic Dissemination: also occurs
- Direct Invasion of Lungs: occurs in some cases from mediastinal lymphadenopathy
Clinical
- Lung Nodules (see Lung Nodule or Mass, [[Lung Nodule or Mass]])
  - 3 mm-6 cm (of various size) smooth or slightly lobulated nodules
  - Lower-lobe predilection
  - Calcification is rare
  - May cavitate
  - Usually absent hilar and mediastinal lymphadenopathy
- Pleural Metastases with Pleural Effusion (see Pleural Metastases, [[Pleural Metastases]] and Pleural Effusion-Exudate, [[Pleural Effusion-Exudate]])
- Endobronchial Metastases (see Lung Metastases-Endobronchial, [[Lung Metastases-Endobronchial]])
  - Most common tumor to metastasize to the airway (accounts in 36% of endobronchial mets, by autopsy studies)
  - Occurs more commonly in post-menopausal cases
  - May occur up to 33 years later
  - Rarely, breast cancer may also directly invade trachea from mediastinal mets
- Lymphangitic Metastases (see Lung Metastases-Lymphangitic Carcinomatosis, [[Lung Metastases-Lymphangitic Carcinomatosis]])
- Autopsy Studies: 24% of breast cancer cases have lymphangitic lung mets
- Mechanism: mediastinal or hilar node involvement with retrograde spread to lung lymphatics

Pulmonary Metastatectomy: see above
Survival is related to aggressiveness of malignancy: Patients with <1 year disease-free interval between initial diagnosis and discovery of pulmonary mets have short survival times after surgical resection

Massive cavitation of solid pulmonary metastatic lesions in a breast cancer patient: a case report. Ann Clin Onc 2002; 3: 173-174