Skip to main content

Table 6 Relationship between treatment duration and tumor response

From: Neoadjuvant letrozole in postmenopausal estrogen and/or progesterone receptor positive breast cancer: A phase IIb/III trial to investigate optimal duration of preoperative endocrine therapy

  Clinical assessment Mammography Breast ultrasound
  ITT (n = 28) PP (n = 24) ITT (n = 21) PP (n = 17) ITT (n = 27) PP (n = 23)
Pearson correlation r = -0.3146 r = -0.4003 r = -0.2396 r = -0.2956 r = -0.2099 r = -0.3188
  p = .1030 p = .0526 p = .2955 p = .2494 p = .2934 p = .1382
Spearman correlation r = -0.3839 r = -0.5092 r = -0.1037 r = +0.0409 r = -0.4111 r = -0.3371
  p = .0437 p = .0110 p = .6548 p = .8761 p = .0331 p = .1158
Multiple regression analysis F = 1.96 F = 1.66 F = 0.87 F = 0.60 F = 0.73 F = 1.05
  p = 0.1471 p = 0.2070 p = 0.4748 p = 0.6278 p = 0.5465 p = 0.3928
  R2 = 0.1967 R2 = 0.1996 R2 = 0.1334 R2 = 0.1212 R2 = 0.0866 R2 = 0.1424
  R2* = 0.0963 R2* = 0.0795 R2* = -0.0195 R2* = -0.0816 R2* = -0.0326 R2* = 0.0070
  1. * adjusted.
  2. Threefold statistical analysis performed for clinical tumor assessment, MG, and breast US included: a) Pearson correlation of percent change in tumor size from baseline to Individual End vs. days on letrozole treatment; b) Spearman correlation of tumor response categories (1 = CR to 4 = PD) at Individual End vs. days on letrozole treatment; and c) multiple regression analysis of percent change in tumor size as criterion vs. days on treatment, age, and tumor size at baseline as predictors (3 degrees of freedom). Deviations in ITT and PP population sizes from 29 and 25, respectively, were due to non-analyzable patients.