Preoperative Assessment and Staging of Breast Cancer: Preliminary Communication

Survival with breast cancer: the importance of estrogen receptor quantity

The survival of 1184 British Columbian women whose primary breast cancers were diagnosed and assayed for estrogen receptor (ER) between 1975 and 1981 was studied. Median follow-up was 60 months. ER concentrations yielded greater prognostic information than simple positive and negative categories. When ER data were divided into four strata: less than or equal to 1, 2-9, 10-159 and greater than or equal to 160 fmol/mg cytosol protein, the association of higher ER with prolonged survival was highly significant (P less than 0.0001) and independent of TNM stage, nodal status and menopausal status. ER less than or equal to 1 and ER = 2-9 groups were distinct with respect to overall disease-specific survival. Patient age did not predict survival when controlled for ER. Prolonged recurrence-free survival was associated with higher ER (P = 0.0001) for at least 5 years after diagnosis. This significant trend persisted after adjustments for nodal status, TNM stage, menopausal status and the type of systemic adjuvant therapy.

Detection of micrometastases in patients with primary breast cancer

An immunocytochemical method was used to screen smears obtained at primary surgery from multiple bone-marrow sites in 110 patients with breast cancer; at this time other techniques did not reveal metastases. Tumour cells were detected in the bone-marrow of 31 (28%) patients. The number of cells detected ranged from 1 to greater than 500; none was detected in conventionally stained smears. Patients in whom conventional criteria indicated a very poor prognosis seemed more likely to have such micrometastases. A further follow-up period is required to determine whether patients with micrometastases relapse earlier than those in whom no tumour cells are demonstrable.

Estrogen receptor quantitation and staging as complementary prognostic indicators in breast cancer: a study of 583 patients

Estrogen receptor (ER) quantity was measured at the time of primary diagnosis on 583 patients with breast cancer seen at the major treatment centre in British Columbia between 1975 and 1979. Survival rates (overall, recurrence-free and post-recurrence) were assessed relative to ER concentration, staging, menopausal status, age, differentiation, and therapy. A linear trend in increased survival was demonstrable through variations in ER concentration from less than 1 to greater than 260 fmoles/mg cytosol protein. This trend was highly significant and remained after adjustment for stage, menopausal status, and age, and was seen for all groups of patients except those with metastatic disease. The association of high ER concentration with increased recurrence-free survival was not due to differing responses to adjuvant therapy, but the trend in post-recurrence survival was only significant in patients who had received hormonal therapy. Survival was as strongly associated with receptor concentration as with staging, and these two factors were almost completely independent. A proportional hazards model was fitted to produce predictions of survival, and showed that TNM stage III patients with high ER concentrations have a better survival than stage I or II patients with lower ER concentrations. This suggests that quantitative assessment of ER status is essential to definition of risk in breast cancer patients and that stratification in clinical trials and consideration for adjuvant therapy ought to be guided, in part, by a standardized ER-quantitative determination performed on the primary tumor.