Some breast cancer patients have metastases at the initial visit, and 15% to 20% of breast cancers develop metastases to distant organs after surgery, with the most common sites being lung, bone, liver, and brain.
Pulmonary metastases
Breast cancer with lung metastases first has a significantly better outcome than those with liver and brain metastases first. Patients with lung metastases have been shown to survive up to 29 months.
Presentation
Most lung metastases have no obvious symptoms but are detected by imaging during postoperative follow-up of breast cancer. A small number of patients may present with cough, bloody sputum, chest pain, fever and dyspnea.
Diagnosis
The diagnosis of lung metastases relies on imaging tests such as chest CT, thin-layer CT, and positron emission computed tomography (PET-CT), but is sometimes differentiated from lung cancer and benign lung lesions. Puncture pathology biopsy is the gold standard for the diagnosis of lung metastases, and biopsy can obtain specific pathological types and immunohistochemical indices of metastases, which can be very helpful in guiding treatment.
Treatment
- Surgical treatment. There are no clear guidelines or norms regarding the surgical treatment of lung metastases from breast cancer. Typically, physicians may consider surgery for those who meet the following criteria.
- The primary tumor has been relatively thoroughly treated or controlled, with no local recurrence and no metastases to other organs throughout the body;
- The lung metastases are solitary, or multiple metastases are more limited and located in one lobe or one side of the lung;
- The patient’s general condition and cardiopulmonary function were good.
- Radiotherapy. Pulmonary metastases from breast cancer are relatively sensitive to radiotherapy. When there are few lesions in the lungs or the lesions are more centrally located and there are no other organ metastases, the doctor may consider radiotherapy in order to relieve symptoms such as pain, difficulty breathing, and difficulty eating caused by airway or esophageal compression.
- Systemic therapy. Because the goal of treatment for advanced breast cancer is to prolong survival and improve quality of life, doctors generally choose treatment options that are less toxic. Endocrine therapy is feasible for hormone receptor-positive patients, chemotherapy is feasible for hormone receptor-negative, hormone receptor-positive patients with visceral metastases that are resistant to endocrine therapy and symptomatic but inoperable, and targeted anti-HER-2 therapy is also considered for human epidermal growth factor receptor 2 (HER-2)-positive patients (except for those who are drug-resistant).
Hepatic metastases
The liver is the third most distant site of breast cancer metastasis after lung and bone. Compared with metastases from other sites, liver metastases have a short survival period, with a mean survival of 9 months and a 1-year survival rate of only 23.4% reported in the literature.
Presentation
As with lung metastases, most patients with liver metastases from breast cancer are asymptomatic in the early stages and are detected by imaging. In the later stage, there may be discomfort in the liver area, pain, nausea, vomiting, loss of appetite, jaundice, fever, and enlargement of the liver.
Diagnosis
The diagnosis of liver metastases relies on liver ultrasound, CT, and magnetic resonance imaging (MRI) examinations. Among them, ultrasound is the easiest to perform and inexpensive, and is mostly used for primary screening of liver metastases. For liver metastases from breast cancer, MRI is the most diagnostic imaging test in addition to pathologic biopsy.
Treatment
- Surgical treatment. Surgical treatment is often considered by physicians for patients with liver metastases from breast cancer who meet the following criteria.
- The primary tumor has been relatively thoroughly treated or controlled, with no local recurrence and no metastases to other organs throughout the body;
- The liver metastasis is an isolated nodule or confined to one liver lobe;
- The patient’s general condition and cardiopulmonary function were good.
- Systemic chemotherapy. The efficacy of liver metastases from breast cancer is poorer than other metastases and survival is relatively short.
- Hepatic artery infusion chemotherapy. It is now widely used, with a documented response rate of 41.7% and a 1-year survival rate of 46.8%. The advantage of this treatment is that it allows for higher local drug concentrations in the liver and lower systemic toxicity, making it superior to systemic chemotherapy. And, patients can be treated with long-term, intermittent chemotherapy via a chemotherapy cartridge connected to the body.
- Percutaneous radiofrequency ablation therapy. Primarily for smaller liver metastases that are not located in the hilar region of the liver with important vascular access and are away from large intrahepatic vessels.
- Other treatments. Cryotherapy, anhydrous alcohol injection, radiotherapy, and Chinese herbal medicine have also been reported, but the efficacy of these approaches for liver metastases from breast cancer is uncertain at this time.
Brain metastases
The incidence of brain metastases from breast cancer is 10% to 15%, and the rapid progression of brain metastases, lack of effective treatment modalities, and poor outcomes.
Presentation
The most common symptom in patients with brain metastases is headache. As the disease progresses, the headache worsens and lengthens in duration. Those who develop increased intracranial pressure may also present with nausea, vomiting, drowsiness, blurred vision, and syncope.
Diagnosis
The imaging method of choice for diagnosing brain metastases is MRI enhancement, and secondarily, physicians may consider enhanced CT and MRI plain.
Treatment
In the case of brain metastases from breast cancer, the physician will consider the patient’s general condition, the location of the lesion, and the control of the extracranial lesion to make a comprehensive assessment and develop a treatment plan.
Currently, surgery, stereotactic radiosurgery (SRS, a special type of radiotherapy), and whole brain radiotherapy (WBRT) are the preferred treatment options for brain metastases. Chemotherapy, targeted therapy, and endocrine therapy can also be applied. It must be emphasized that the efficacy of systemic therapy for patients with brain metastases is usually not satisfactory because many drugs cannot reach the lesions in the brain to take effect due to the existence of a barrier between the brain and systemic blood (blood-brain barrier). However, some studies have shown that whole-brain radiotherapy can open the blood-brain barrier and thus improve the efficacy of systemic therapy. In addition, doctors may choose hormone therapy to relieve symptoms in response to elevated intracranial pressure.