A total of 183 cases of early stage breast cancer from patients who received neoadjuvant treatment were evaluated. The most commonly represented ethnicity was Asian with 72 cases (39.3%), followed by Native Hawaiian/Pacific Islander (NHPI) with 53 cases (29%), White with 48 cases (26.2%), and Other with 10 cases (5.5%) (Table1). The most common subtype was ER-/PR-/HER2- with 62 cases (33.9%), followed by ER-/PR-/HER2+ with 56 cases (30.6%), ER+ or PR+/HER2+ with 50 cases (27.3%), and ER+ or PR+/HER2- with 15 cases (8.2%). The ethnicity with the most predominant proportion of cases with a pCR was Other with 5 cases (50.0%), followed by NHPI with 26 cases (49.1%), Asian with 29 cases (40.3%), and White with 18 cases (37.5%) (Table 1).
Table 1 pCR according to Patient Race, Age and Subtype
Variable
|
|
N (%)
|
pCR N (%)
|
Race
|
Asian
|
72 (39.3)
|
29 (40.3)
|
|
NHPI
|
53 (29)
|
26 (49.1)
|
|
White
|
48 (26.2)
|
18 (37.5)
|
|
Other
|
10 (5.5)
|
5 (50)
|
Age
|
30-39
|
19 (10.4)
|
12 (63.1)
|
|
40-49
|
34 (18.6)
|
13 (38.2)
|
|
50-59
|
46 (25.1)
|
23 (50)
|
|
60-69
|
53 (29)
|
19 (35.8)
|
|
70+
|
31 (16.9)
|
11 (35.5)
|
Subtype
|
ER-/PR-/HER2-
|
62 (33.9)
|
19 (30.6)
|
|
ER+ or PR+/HER2-
|
15 (8.2)
|
2 (13.3)
|
|
ER-/PR-/HER2+
|
56 (30.6)
|
37 (66.1)
|
|
ER+ or PR+/HER2+
|
50 (27.3)
|
20 (40)
|
The percentage of sTILs in breast cancer tumors of all patients based on age at diagnosis, race and breast cancer subtype were evaluated. On univariable analysis, we found significantly greater percentages of sTILs among women who identified as Asian, NHPI and Other (33.4%, 33.7% and 40.5%, p=0.04, p=0.05 and p=0.04 respectively) (Table 2). On multivariable analysis, this remained significant for Asian and NHPI only (37.7% and 37.2%, p=0.01 and p=0.02 respectively) (Table 2). On univariable analysis, significantly lesser percentages of sTILs were seen among women between the ages of 60-69 years, however on multivariable analysis there were no significant differences found according to patient age (Table 2). With both univariable and multivariable analysis, there were significantly greater percentages of sTILs found among women who had ER-/PR-/HER2+ or TN breast cancer subtypes (Table 2).
Table 2 Percent sTILs for all breast cancer patients receiving neoadjuvant treatment
We evaluated additional variables from 79 cases including: BMI at diagnosis, stage, treatment regimen and pCR (Table 3). On univariable analysis, patients who obtained a pCR had a significantly higher sTIL percent (40.6% vs 28.6%, p=0.04) but this was not found on multivariable analysis (Table 3). Additionally, there were statistically significant race/ethnic differences in sTILs on both univariable and multivariable analysis where NHPI and Asian patients had significantly greater percentages of sTILs in their tumors compared to White patients (38.2%, 34.3% vs 20.7%, p=0.01 and p=0.05 respectively) (Table 3).
Table 3 Percent sTILs on subset of neoadjuvant cases with additional variables
Percentage of pCR in breast cancer tumors of all patients based on age at diagnosis, race, and breast cancer subtype were evaluated (Table 4). In both univariable and multivariable analyses, we did not see significant differences in pCR among racial/ethnic groups studied (Asian, NHPI and Other) compared to White women. On univariable analysis, there was a significantly less likelihood of a pCR among women between the ages of 60-69 years compared to other age groups; however there were no significant differences found among all ages on multivariable analysis. In both univariable and multivariable, there was a significantly higher likelihood of obtaining a pCR among women who had ER-/PR-/HER2+ breast cancer (3.02 and 3.06 vs 0.6 and 0.59, p=0.01 and p=0.02 respectively) compared to ER+/PR+/HER2- breast cancer (Table 4).
Table 4 Pathologic complete response (pCR) for all breast cancer patients