Smoking associated with hormone receptor negative breast cancer

Women who smoke have less favourable prognosis following breast-cancer diag nosis. Some studies suggest that this is due to a more advanced stage at di agnosis, on average. Our present aim was to assess whether smoking is assoc iated with other prognostic markers as well, e.g., hormone receptor status, histopathology and tumour differentiation. The evaluation was based on 268 incident cases in a cohort of 10,902 women (35% smokers) followed for an a verage of 12.4 years. An immunohistochemical method on recuts of tumour tis sue was used to assess hormone receptor status. One pathologist classified all tumours according to the WHO system, Nottingham grade and Nottingham Pr ognostic Index. The relative risk (RR) of oestrogen receptor-negative tumou rs was, for current smokers, 2.21 [95% confidence interval (Cl) 1.23-3.96] and, for ex-smokers, 2.67 (95% Cl 1.41-5.06) compared to never-smokers. Ex- smokers had an increased risk of progesterone receptor-negative tumours (RR = 1.61, 95% CI 1.07-2.41), but there were no other significant association s between smoking habits and oestrogen receptor-positive or progesterone re ceptor-positive or -negative tumours. The incidence of Nottingham grade III tumours was higher in ex-smokers than in never-smokers (RR = 2.03, 95% Cl 1.17-3.54). In terms of histopathological type or Nottingham Prognostic Ind ex, there were no significant differences between smoking groups. We conclu de that smoking is associated with an increased occurrence of hormone recep tor-negative tumours. (C) 2001 Wiley-Liss, Inc.