Abstract P6-02-08: SUV max of 18F FDG-PET/CT: A predictive factor associated with pathologic complete response in luminal HER2–negative breast cancer patients (receiving neoadjuvant chemotherapy)
Authors: Lee IH , Lee SJ , Lee J , Lee RK , Jung J , Park H , Lee S-w , Chae YS 
Published: May 2019

Purpose Neoadjuvant chemotherapy (NAC) is considered to be the standard of care for locally advanced breast cancer. When pathological complete response (pCR) is obtained with NAC it is a predictor of better outcome and often used as a surrogate for survival. However, response to NAC of luminal type breast cancer is variable and mostly limited. This study investigated the predictive relevance of several clinicopathological factors, including parameters of 18F FDG-PET/CT, on the pCR to NAC in patients with luminal HER2–negative breast cancer.

Methods From 2009 to 2015, 117 hormone receptor-positive, HER2-negative breast cancer patients who were treated with NAC followed by curative surgery at the Kyungpook National University Hospital (Daegu, Korea) were retrospectively analyzed. pCR was defined as the absence of cancer cells in breast and axillary node. 18F FDG-PET/CT maximum standardized uptake value (SUV max) was measured at baseline. Patients received from 6 to 8 cycles of anthracycline-based and taxane-based NAC.

Results The median age of the patients was 48 years (range-29-68 years). 104 patients (88.9%) were PR-positive, and forty-nine (41.9%) patients showed high ki-67 expression at initial diagnosis. After NAC, nine patients (7.7%) achieved pCR and patients who had high initial SUV max (≥ 9.09) achieved improved pCR rate compared to low initial SUV max (&lt; 9.09) patients (77.8 % vs. 22.2%).

Conclusion In luminal HER2-negative breast cancer, 18F FDG-PET/CT SUV max was useful for predicting pathologic complete response after NAC

Table 1Characteristics of study populationMedian, range48 (29-68)Initial clinical T stage 1 2 3 48 (6.8) 83 (70.9) 19 (16.2) 7 (6.0)Initial clinical N stage 0 1 2 310 (8.5) 49 (41.9) 47 (40.2) 11 (9.4)Initial ER expression Negative (0-2) Weak (3-5) Strong (6-8)8 (6.8) 14 (12) 95 (81.2)Initial PR expression Negative (0-2) Weak (3-5) Strong (6-8)13 (11.1) 20 (17.1) 84 (71.8)Initial Ki-67 expression &lt;14% ≥14% Not assessed55 (47) 49 (41.9) 13 (11.1)Pathologic T stage 0 I II III16 (13.7) 50 (42.7) 42 (35.9) 9 (7.7)Pathologic Stage (AJCC) pCR 1A 1B 2A 2B 3A 3C9 (7.7) 23 (19.7) 7 (6.0) 27 (23.1) 21 (17.9) 23 (19.7) 7 (6.0)Histologic grade 1 2 322 (18.8) 61 (52.1) 14 (12)Nuclear Grade 1 2 316 (13.7) 9 (7.7) 50 942.7)Pathologic complete response Yes9 (7.7)Recurrence18 (15.4)Death10 (8.5)table 2Association between pathologic complete response and clinicopathologic featuresFactorsPathologic CR NoPathologic CR YesP- valueAll patients108 (92.3)9 (7.7) Age &lt;40 40-55 56-7016 (18.2) 54(61.4) 18 (20.5)2 (22.2) 6 (66.7) 1 (11.1)0.789Initial clinical T stage 1 2 3 48 (7.4) 76 (70.4) 7 (6.5) 17 (15.7)0 (0) 7 (77.8) 2 (22.2) 0 (0)0.676Initial ER expression Negative (0-2) Weak (3-5) Strong (6-8)7 (6.5) 12 (11.1) 89 (8.4)1 (11.1) 2 (22.2) 6 (66.7)0.504Initial PR expression Negative (0-2) Weak (3-5) Strong (6-8)11 (10.2) 20 (18.5) 77 (71.3)2 (22.2) 0 (0) 7 (77.8)0.247Initial Ki-67 expression &lt;14% ≥14%52 (54.7) 43 (45.3)3 (33.3) 6 (66.7)0.301SUV max (tumor) &lt; 9.09 ≥ 9.0972 (66.7) 36 (33.3)2 (22.2) 7 (77.8)0.012SUV max (axilla) &lt; 6.08 ≥ 6.0858 (67.4) 28 (32.6)3 (42.9) 4 (57.1)0.228

Citation Format: Lee IH, Lee SJ, Lee J, Lee RK, Jung J, Park H, Lee S-w, Chae YS. SUV max of 18F FDG-PET/CT: A predictive factor associated with pathologic complete response in luminal HER2–negative breast cancer patients (receiving neoadjuvant chemotherapy) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-08.