Treatment of advanced breast cancer
Breast cancer may occasionally present as
metastatic disease without evidence of a primary tumour (that is with an occult
primary). The diagnosis is made partly by exclusion of another site for the
primary and may be confirmed by histology of the metastatic lesions. Treatment
should be aimed at palliation of the symptoms and treating the breast cancer,
usually by endocrine manipulation.
Locally
advanced inoperable breast cancer
Locally advanced inoperable breast cancer,
including inflammatory breast cancer, is usually treated with systemic therapy
—
either chemotherapy or hormone therapy.
Occasionally
‘toilet mastectomy’ or radiotherapy is required to control a fungating
tumour, but often incision through microscopically permeated tissues makes the
outcome worse than the original.
Metastatic
carcinoma of the breast
Metastatic carcinoma of the breast will also
require some form of palliative systemic therapy to alleviate symptoms. Hormone
manipulation is often the first line because of its minimal side effects. It is
particularly useful for bony metastases. However, only about 30 per cent of
these tumours will be hormone responsive, and unfortunately even these will in
time become resistant to this treatment. First-line hormone therapy for
postmenopausal women is tamoxifen, and for premenopausal women ovarian
suppression, but where resistance to these has developed, other hormonal agents
can prove useful, with about half of the response rate seen in the first-line
therapy. Synthetic progestagens such as medroxyprogesterone acetate (‘Provera’)
aromatase inhibitors or the newer agents such as antiprogestins and pure
antioestrogens are all candidates for this role.
Cytotoxic
therapy is used, particularly in younger women or those with visceral metastases
and rapidly growing tumours. A variety of regimens is available and although
none prolongs survival, contrary to expectations quality of life and symptom
control is often better with more aggressive treatments, responses being seen in
up to 70 per cent of patients.
Local
treatment may also prove useful for some metastatic disease such as radiotherapy
for painful bony deposits and internal fixation of pathological fractures.