p53 immunohistochemical staining and survival after adjuvant chemotherapy for breast cancer

Abstract

We have investigated the relationship between immunohistochemically determined p53 status and outcome in 277 women with node‐positive primary breast cancer who, following tumour excision and axillary clearance, were randomised to receive either 6 cycles of cyclophosphamide/methotrexate/5‐fluorouracil (CMF) (n = 130) or no such post‐operative treatment (n = 147). Follow‐up data (median = 9 years) were available on all patients. A significant association was found between p53 status and survival. Patients with p53‐positive tumours had a less favourable outcome than those with p53‐negative disease. Women receiving adjuvant CMF chemotherapy had a significantly more favourable outcome compared to those who did not. The effect was seen both in women with p53‐positive and p53‐negative tumours; multivariate analysis showed relative risks for overall survival attributable to chemotherapy of 2.3 (95% CI 1.2–4.3) for women with p53‐positive tumours and of 2.1 (95% CI 1.4–3.0) for those with p53‐negative tumours. Thus, adjuvant chemotherapy with CMF is associated with a survival benefit in women with node‐positive breast cancer irrespective of immunohistochemically determined p53 status. Int. J. Cancer 74:605–608, 1997.