BREAST CARCINOMA IN-SITU AND HIGH RISK PATIENTS

There are two types non-invasive breast cancers recognised on the basis of histological pattern; ductal carcinoma in-situ (DCIS) and lobular carcinoma in-situ (LCIS). DCIS is the commoner form and makes up to 5% of symptomatic and 18% of screen detected cancers. In contrast, LCIS constitutes only 0.5% of symptomatic and approximately 1% of screen detected cancers.

Please choose from the following:

Ductal carcinoma in situ - Lobular carcinoma in situ - High risk patients

Ductal Carcinoma in situ
DCIS was rarely found before mammography was widely introduced and has therefore increased as a clinical entity since the National Breast Screening Programme started. There are a number of classifications which are commonly used and these correlate to some extent to mammographic patterns of microcalcification (Table 1).

Table 1:

Presentation - DCIS may be diagnosed in symptomatic or screening patients. Symptomatic DCIS patients may present with a breast lump, nipple discharge, or Paget's disease. Screen detected DCIS is more likely to be diagnosed as impalpable mammographic microcalcification, which may be diffuse or discrete with characteristic branching and of variable size and density.

Studies have shown that DCIS progresses in about third of the cases to invasive carcinoma if untreated or inadequately treated.

Treatment of DCIS

Click here to see table for 'Management of DCIS'

Discrete DCIS (<4cm) : A mammographic abnormality which is occupies less than 4cm of area is normally treated by wide local excision which may be assisted by wire localisation in case of impalpable lesions. Wide local excision alone produces satisfactory local control in non-comedo DCIS (< 5% recurrence in 8 years) but not in comedo DCIS (30 - 50% recurrence at 8 years).

Radiotherapy and Tamoxifen: Preliminary data from an American study suggests additional benefit in reducing the recurrence rate using radiotherapy following complete surgical excision of localised DCIS. A UK National DCIS trial may provide more conclusive evidence. Tamoxifen might be expected to both reduce the incidence of recurrence and rate of contralateral disease is also being evaluated in the UK DCIS trial.

National DCIS trial :

The National study on DCIS has been organised in order to find out which, if any, additional treatment is best, and patients with screen detected localised DCIS are allocated in one of the four arms:

1) Complete excision of localised DCIS with histologically clear margins.
2) Local excision plus a course of radiotherapy to the breast for 4 -5 weeks.
3) Local excision and 20 mg tamoxifen for 5 years.
4) Local excision followed by both radiotherapy and tamoxifen.

All patients are followed up by trial protocol and annual mammography.

Diffuse DCIS (>4cm): In 80% of patients limit of DCIS can be estimated by measuring extent of malignant microcalcification on mammograms. Normally symptomatic DCIS involves larger a area than in screen detected patients and has been traditionally treated with mastectomy producing excellent results (98%) 5 year survival.

Malignant microcalcification representing diffuse DCIS

If you require further advice or information please contact the
Macmillan Breast Care Nurses, Hazel Ricard and Hilary Rickwood on 020 8565 5885