C

Cancer (invasive cancer): Malignant cells that have penetrated the underlying basement membrane that supports the natural cell arrangement within the tissue of origin. These invasive malignant cells have the propensity to spread to other sites. In breast cancer, this spread could be to regional lymph nodes in the axilla (armpit) or to distant organs such as lung, bone, liver, etc.

Chemotherapy: (1) Adjuvant chemotherapy. Systemic treatment given after surgery for stage I or II breast cancer (see entry) founded upon the concept that malignant breast conditions have a predisposition to spread from the early stages, even if undetectable using conventional tests. Adjuvant chemotherapy forms an important part of the multidisciplinary management of operable breast cancer. Indications for adjuvant chemotherapy are based upon the histopathology of the surgical specimen. Indications include any grade III breast cancer, grade II cancers greater than 15mm, the presence of vascular invasion, and lymph node positive disease. These indications for chemotherapy are routinely offered to women up to 69 years of age. Young age is an independent risk factor and the threshold to offer chemotherapy may be lowered in younger women. Oestrogen negative tumours that are less likely to respond to tamoxifen may also lower the threshold for recommending chemotherapy. Chemotherapy is usually given in 6 cycles, each cycle lasting 3 to 4 weeks. A combination of drugs, usually 2 or 3, are used. Other types of drugs are given to reduce the incidence of side effects. Examples of regimens of chemotherapy for breast cancer include FEC (5 fluorouracil, epirubicin, and cyclophosphamide), FAC (substitute adriamycin for epirubicin in FEC) and AC (adriamycin and cyclophosphamide), combinations that include a taxane, either taxol, docetaxol or taxotere: examples include AC-T, FEC-T. (2) Primary chemotherapy is systemic therapy offered to specific cases of operable and locally advanced (stage III breast cancer). In operable cancers, women with tumours greater than 3cm may be recommended chemotherapy prior to surgery. Primary chemotherapy is often offered as part of a clinical trial. The size of the tumour can be monitored in response to chemotherapy. In some women, tumours considered to require a mastectomy may be downsized to surgical treatment by breast conservation after primary chemotherapy. More than 80% of operable breast cancers have a partial response to primary chemotherapy. Approximately 10% have a complete response as assessed on pathology after surgical excision. Primary chemotherapy does not mean that other modalities for breast cancer treatment are omitted. The multidisciplinary principle of operable breast cancer remains, and after primary chemotherapy, surgery and then radiotherapy as well as tamoxifen (if oestrogen receptor positive) is used. A complete pathological response in primary chemotherapy is in itself a good prognostic indicator. Primary chemotherapy for locally advanced stage III breast cancer may be followed by surgery and/or radiotherapy, and endocrine therapy where appropriate. (3) Chemotherapy may also be used for metastatic stage IV disease. Regimens will vary according to previous chemotherapy exposure and response. The pattern of metastatic disease may also determine the choice and timing of systemic chemotherapy in metastatic disease. In suitable patients, Herceptin can also be used in combination with chemotherapy – see trastuzumab, Hereceptin and also under What’s new.

Complex sclerosing lesion: a benign condition that can sometimes mimic cancer causing difficulty in diagnosis. See also radial scar entry.

Core cut biopsy: the use of a special needle to take a small piece of tissue under local anaesthetic to evaluate cells in relation to its supporting structure. Short of surgery, this is the best way to distinguish invasive cancer from carcinoma in-situ (see DCIS entry).

Cytology: the assessment of the appearance of cells taken by fine needle aspiration (see entry) and stained on a glass slide for examination. Cytological diagnosis of breast disease is classified as follows: C1 - an inadequate aspirate with insufficient material for cytological diagnosis of a breast lump, but may be representative of fatty involution of the breast or a scar. C2 - benign breast cells, eg a fibroadenoma (see entry) or fibrocystic change (see entry). C3 - cells that have an indeterminate appearance, but are probably benign. C4 - cells suspicious but not diagnostic of cancer. C5 - cells that are diagnostic of cancer on cytological criteria. C3 or C4 aspirates require further assessment, and may need to be repeated or subject to core cut biopsy (see entry).