Breast screening in Britain

Breast cancer screening: another point of view

The breast cancer screening programmes (BCSP) are very controversial at the present time. They are evaluated by different socio-economic sectors, each with its own particular point of view. Large numbers of breast cancer cases are concentrated in the Oncology Services, which are, therefore, sensitive to the changes that these programmes could bring about. All patients attending the medical oncology and radiotherapy services of the Reina Sofia University Hospital, Cordoba from January 1994 until January 2003 were reviewed. Of 1785 patients, 829 went to these services after the start of the BCSP introduced in March 1999 and 956 before it. The variables analysed were age, presentation form, stage and treatment received. In conclusion, the BCSP has produced favourable changes with respect to stage (increasing the percentage of early breast cancer) and therapeutic management (increasing conservative surgery and decreasing the number of adjuvant treatments (radiotherapy and chemotherapy)). These changes are more outstanding in the population group covered by the BCSP.

Screening status in relation to biological and chronological characteristics of breast cancers: a cross sectional survey

OBJECTIVE

To determine the pathological and biological characteristics of breast cancers diagnosed by screening and examined at the Edinburgh University pathology department.

METHODS

These cancers were classified by screening status: never screened (n = 111), prevalence screen detected (n = 105), and previously screened (n = 74). The last category arose in women who had been regularly screened during the trial; the cancers were diagnosed as interval cases before the first invitation to service screening (n = 33) or were incidence screen detected at that time (n = 41).

RESULTS

Association (for operable invasive cancers, n = 250) of cancer characteristics with screening status reflects influences of biology (aggressiveness) or chronology (time of diagnosis), or both. The prognostic indicators tumour grade, histological type, and oestrogen receptor status were found in a smaller percentage of the patients with poor prognosis among the prevalence screen detected cases (9%, 77%, 18%) than among those previously screened (29%, 84%, 35%). The chronological factors size and node status were found in a smaller percentage of patients with poor prognosis among women previously screened (31%, 24%) than among those never screened (62%, 39%). Apart from these two, no other factors improved the diagnosis in the previously screened group compared with the never screened group.

CONCLUSIONS

These results suggest that favourable characteristics of screen detected cases are often due to the effects of length bias on "biological factors" and fail to show that current local screening practice has succeeded in advancing the diagnosis of breast cancers to a less aggressive phase.