U. Chetty

Comparative pathology of breast cancer in a randomised trial of screening.

In the Edinburgh Randomised Breast Screening Project (EBSP) to December 1988 there were 500 cancers in the study population invited to screening and 340 cancers identified in the control population. The size and negative lymph node status characteristics of invasive cancers from the two populations were significantly different (P less than 0.05). The cancers detected by screening were predominantly early stage, with 16% noninvasive (PTIS) and 42% invasive stage I (pT1 node negative), whereas cancers were frequently late stage (more than pT2) and inoperable in nonattenders (44%) and controls (36%). Grouped according to customary size ranges of invasive cancers, the proportion of cases lymph node positive differed in those screen detected compared with controls, but the benefit in favour of screen detection was not constant. In comparisons of cancers detected at prevalence and incidence screens, as a test of conformity with screening theory, no significant differences were apparent according to size and lymph node status, yet the characteristics of histological type of cancer discriminated significantly (P less than 0.05). When these same histological characteristics were used to compare survival, the capacity to separate invasive cancers into two groups having good and poor survival probabilities was evident, with a significant improvement for the screen detected poor survival group compared with controls (P less than 0.05).

pS2 is an independent factor of good prognosis in primary breast cancer

In breast cancer, oestrogen regulated genes, such as pS2, may be expressed in well differentiated tumours with a good prognosis. We have examined pS2 mRNA expression in 78 primary, untreated breast cancers and related pS2 expression to disease behaviour and known prognostic factors. pS2 mRNA expression was detected in 25/78 (32%) of cancers and was significantly associated with a moderate/high oestrogen receptor content (P = 0.045, Chi Square test). pS2 mRNA expression was associated with freedom from disease at median 31 months clinical and radiological follow-up (P = 0.015, Fishers exact test, odds ratio 8.6). Using multiple logistic regression analysis of six potential prognostic factors only pathological axillary node status (P < 0.01) and pS2 mRNA expression (P < 0.05) provided independent prognostic information. Furthermore, pS2 was associated with a good prognosis in the axillary node positive patients where only 1/13 (8%) with pS2 mRNA expression compared with 13/29 (45%) without detectable expression had recurrence of their disease. These data provides strong support for pS2 as a useful independent prognostic factor in primary breast cancer.

PS2 mRNA expression adds prognostic information to node status for 6-year survival in breast cancer.

Expression of pS2, an oestrogen-regulated gene, has been associated with a good short-term prognosis and response to endocrine therapy. The aim of this study was to determine whether expression of mRNA for the pS2 gene in breast cancer could contribute useful information on disease behaviour and survival at medium-term follow-up. Northern blotting was used to detect pS2 messenger ribonucleic acid (mRNA) in the primary tumour tissue from each of 90 patients with breast cancer. Axillary node status was established by sampling or clearance, oestrogen receptor concentration by enzyme immunosorbant assay and follow-up was continued for at least 6 years or until death. At 83 months mean follow-up, 29 of 90 (32%) patients had recurrent disease and, of these, 18 (20%) had died from breast cancer. pS2 mRNA expression, present in 26 of 90 (29%) cancers, was associated with freedom from disease recurrence (P = 0.026) and was significantly associated with survival at a minimum of 6 years follow-up (P < 0.001). Pathological node status and tumour size were also significantly associated with disease recurrence (P < 0.001 and P = 0.002 respectively) and inversely with survival (P < 0.001 and P < 0.001 respectively). After multiple Cox regression analysis, pS2 expression was still a significant predictor of recurrence (but not survival) after adjusting for node status and tumour size; oestrogen receptor was an independent predictor of survival. The combination of node status and pS2 expression discriminated patients with particularly good prognosis (node negative, pS2 positive: no mortality at 6 years) or poor prognosis (node positive, pS2 negative; 41% mortality at 6 years). Evaluation of pS2 expression in breast cancer at diagnosis may provide additional useful prognostic information to conventional staging.

Pooled long‐term outcomes from two randomized trials of axillary node sampling with axillary radiotherapy versus axillary node clearance in patients with operable node‐positive breast cancer

The aim was to determine long‐term overall, breast cancer‐specific and metastasis‐free survival as well as axillary relapse rate from a pooled analysis of two randomized trials in women with operable breast cancer. These trials compared axillary node sampling (ANS), combined with axillary radiotherapy (AXRT) if the sampled nodes were involved, with axillary node clearance (ANC).