Association of breast cancer grade with response to neoadjuvant chemotherapy assessed postoperatively

Abstract

Currently, breast cancer chemotherapy response can be predicted based on various parameters, with common reporting of tumour grade and Ki67 proliferation index. We analysed their association with pathological complete response (pCR) in a multivariate approach. The study was carried out in a group of 353 patients, treated by preoperative chemotherapy and prospectively observed. In selected patients, parallel to routing core needle biopsy assessment, gene expression profile of tumour was analysed by oligonucleotide microarrays. Tumour parameters associated with pCR in univariate analysis were: tumour grade, nuclear grade, mitotic index, Ki67, oestrogen and progesterone receptor (all p < 0.0001), and triple-negative status (p = 0.0032). The highest increase of pCR chance was observed in patients with high-grade tumours and with Ki67 ≥ 20%. In multivariate analysis, only tumour grade and oestrogen receptor status were predictive for pCR independently of other variables, with high grade increasing the odds of pCR 2.42 fold, and high ER decreasing the chance of pCR 0.41 fold. Tumour grading reflects important biological features of breast cancer and is not inferior to proliferation markers, including Ki67. It should be taken into account in decision-making for preoperative chemotherapy in parallel to breast cancer biologic subtypes, because grade 3 tumours exhibit a higher proportion of pCR.

Relationship between pathological response and molecular subtypes in locally advanced breast cancer patients receiving neoadjuvant chemotherapy

“…Diaz-Casas et al reported the pCR rate as 21.3% in grade 3 tumors [31]. In the study of Jarzab et al, the pCR rate was reported as 30.9% in patients with grade 3 nuclear differentiation [32].…”

Resistance to Neoadjuvant Treatment in Breast Cancer: Clinicopathological and Molecular Predictors

“…Tumor grade 3 versus the other grades was associated with pCR (OR 6.36, p = 0.004). In univariate analysis, tumor grade was noticeably associated with pCR status in patients with G1 and G2 tumors, where pCR rarely occurs, while 31.3% of G3 tumors had pCR ( p < 0.0001) [ 31 ]. Finally, in 2019, Diaz-Redondo et al, in a HER2+ cohort of 259 patients treated with NAC-Trastuzumab ± Pertuzumab, determined that histological grade 3 was significantly related to pCR in a multivariate analysis [ 32 ].…”

Is pathological complete response predictable after neoadjuvant chemotherapy in breast cancer? A single institution's retrospective experience

“…16 Grade 3 tumours have a higher rate of pCR. 17 Pathological CR rates have been noted to be significantly higher in tumours with pre-treatment Ki67 >50%. 18 High TILs (>59%) is associated with higher pCR rates in all breast cancer subtypes.…”