The impact of race and age on response to neoadjuvant therapy and long-term outcomes in Black and White women with early-stage breast cancer

Clinical and pathologic features

A total of 2196 women with early breast cancer identified from the ChiMEC database were included in this analysis; median follow up was 81 months. The median age of diagnosis (years) was 34.5 for young Black women, 35.3 for young White women, 65.9 for older White women, and 68.8 for older Black women (Table 1). Young women of both races trended towards diagnosis at a later stage compared to their older counterparts; young Black women had the highest incidence of stage 3 breast cancer (29.8%), compared to 16.6% of young White, 12.2% of older Black women, and 10.1% of older White women (p < 0.001). Young women of both races had higher rates of grade 3 tumors and more extensive lymph node involvement, with young Black women having the highest incidence of both measures. Black women had a higher rate of TNBC than their White counterparts, with young Black women having the highest rate overall (38.0%). Similar clinical and pathologic features were analyzed for the subset of women receiving NACT (Table 2).

Table 1 Clinical and pathologic features by racial/age groupTable 2 Clinical and pathologic features by racial/age group for patients receiving NACTWomen receiving neoadjuvant chemotherapy (NACT)pCR rates

In 397 women with early breast cancer who received NACT, 26.8% of young Black women achieved a pCR, compared to 47.5% of young White women, 27.7% of older Black women, and 27.7% of older White women (p = 0.004) (Fig. 1A). After adjusting for subtype, grade, and stage, young Black women were still less likely to achieve a pCR as compared to young White women (adjusted odds ratio: 0.41, 95% CI 0.19–0.88, p = 0.022) (Suppl Table 1). Young White women were significantly more likely to achieve a pCR as compared to their older counterparts when controlling for subtype, stage, and grade (adjusted odds ratio: 3.13, 95% CI 1.66–5.89, p < 0.001). There was no statistically significant difference in the odds of achieving pCR in a multivariable analysis model between older Black, older White, and younger Black women (Suppl Table 1). pCR rates were further analyzed by subtype within age and racial groups (Suppl Fig. S2). Young White women consistently had the highest rate of pCR between the four age/racial groups, with 35.5% in HR + /HER2− disease (n = 31), 58.3% in HR + /HER2 + disease (n = 24), 83.3% in HR-/HER2 + disease (n = 6), and 45.9% in TNBC (n = 37). In contrast, only 20.0%, 20.0%, 60.0%, and 33.3% of young Black women achieved a pCR for these same breast cancer subtypes (n = 20, 15, 5, 15, respectively). Older White and Black women had similar pCR rates to young Black women (Suppl Fig. 2).

Fig. 1figure 1

a Graph of pathological complete response rate amongst women receiving neoadjuvant chemotherapy between age and racial groups, p = 0.004 (Chi-squared test). b Graph of rates of trial enrollment amongst women receiving neoadjuvant chemotherapy between age and racial groups, p = 0.039 (Chi-squared test)

DFS and OS

Among women treated with NACT, young Black women had the worst DFS, followed closely by older Black women. The 10-year DFS rates for women receiving NACT were: 56.1% for young Black women, 81.7% for young White women, 50.8% for older Black women, and 74.5% for older White women. These differences in DFS amongst women receiving NACT were statistically significant (p = 0.0098, Suppl Fig. S3b). Before adjusting for stage, grade, subtype, and comorbidities, young Black women had a significantly increased hazard of death/recurrence compared to their young White peers (unadjusted hazard ratio: 2.19, 95% CI 1.11–4.32, p = 0.023). Similarly, older Black women had worse DFS than their older White peers (unadjusted hazard ratio: 1.90, 95% CI 1.10–3.28, p = 0.020). These differences were not statistically significant in the multivariable model (Suppl Table 2).

As with DFS, there was a marked difference in the 10-year OS rates of White and Black women receiving NACT, with rates being 71.4% in young Black women, 88.6% in young White women, 54.2% for older Black women, and 85.9% for older White women (p = 0.0043, Suppl Fig. S3a). Young Black women had worse OS compared to their young White counterparts (unadjusted hazard ratio: 2.22, 95% CI 0.94–5.29, p = 0.070; adjusted hazard ratio: 1.56, 95% CI 0.57–4.26, p = 0.386) (Suppl Table 2). Similarly, older Black women receiving NACT had worse OS than older White women (adjusted hazard ratio: 2.31, 95% CI 1.10–4.82, p = 0.026) (Suppl Table 2).

NACT clinical trial enrollment

We examined pCR rates in our young/old, Black/White cohorts based on clinical trial participation. Of the 397 women who received NACT, 53 participated in therapeutic trials. Young White women had the highest percent enrollment in a NACT trial, at 19.6%. 16.4% of older White women participated in a NACT trial, while 8.5% of young Black women did, and only 6.7% of older Black women were involved in a NACT trial (Fig. 1b). Young Black women receiving NACT were less likely to enroll in a trial compared to young White women (unadjusted odds ratio: 0.43, 95% CI 0.15–1.21, p = 0.111) (Suppl Table 3). Similarly, older Black women were less likely to enroll in a trial compared to young White women (unadjusted odds ratio: 0.34, 95% CI 0.14–0.80, p = 0.013) (Suppl Table 3). Neither of these differences were statistically significant after adjusting for subtype, stage, grade, and comorbidities.

Interestingly, there was no statistically significant difference in the odds of achieving a pCR based on whether or not a patient was enrolled in a clinical trial (unadjusted odds ratio: 1.00, 95% CI 0.53–1.90, p = 0.991). But, there was an improvement in OS (p = 0.036) and DFS (p = 0.022) for women who participated in a clinical trial (Suppl Fig. S4).

All women with early-stage breast cancerDisease-free survival (DFS)

Looking at all of the women with early-stage breast cancer, regardless of treatment regimen, the 5-year DFS rate was 74.2% for young Black women, and for young White women was 80.5%. The 5-year DFS rate for older White women was 89.2%, while that of older Black women was 76.7% (p < 0.001, Fig. 2b). Similar trends were observed in 10-year DFS rates (p < 0.001, Fig. 2b). There was no statistically significant difference in DFS between young White and young Black women either before or after the 5-year stratification (adjusted hazard ratio ≤ 5 years: 1.11, 95% CI 0.64–1.94, p = 0.710; adjusted hazard ratio > 5 years: 1.53, 95% CI 0.51–4.58, p = 0.450) (Table 3). Older Black women had worse DFS outcomes compared to older White women in the first five years (adjusted hazard ratio ≤ 5 years: 1.95, 95% CI 1.45–2.62, p < 0.001) (Table 3). Past 5 years, there was no statistically significant difference in DFS between older White and older Back women.

Fig. 2figure 2

Kaplan–Meier survival curves of a overall survival and b disease-free survival by race and age, c graph of cumulative incidence of recurrence of the different racial/age groups

Table 3 Association between race and age and disease-free and overall survival

Of the four groups, young Black women had the highest risk of recurrence, which was 22% higher than young White women (p = 0.434) and 76% higher than older Black women (p = 0.008). These age/racial differences in recurrence rates were not statistically significant after adjusting for subtype, stage, and grade (Table 4, Fig. 2c).

Table 4 Association between race and age and risk of recurrenceOverall survival (OS)

In terms of OS, older Black women had the worst outcomes. The 5-year OS rate was 82.7% for young Black women, 89.4% for young White women, 92.1% for older White women, and 80.8% for older Black women (p < 0.001, Fig. 2a). The 10-year OS rate was 76.8% for young Black women, 82.7% for young White women, 82.4% for older White women, and 62.3% for older Black women (p < 0.001, Fig. 2a). There was no statistically significant difference in OS between young Black and young White women over the full follow-up period. Young Black women did have improved OS compared to their older counterparts past 5 years (adjusted hazard ratio > 5 years: 0.17, 95% CI 0.07–0.41, p < 0.001) (Table 3). However, this difference was not significant in the first 5-year interval (Table 3). After adjusting for stage, grade, subtype and comorbidities, increased mortality in older Black vs. older White women persisted for the first five years (adjusted hazard ratio ≤ 5 years: 2.09, 95% CI 1.48–2.49, p < 0.001) (Table 3). This difference in OS was not statistically significant beyond five years of follow up.

Clinical trial enrollment

Once again, we evaluated how involvement in clinical trials may correlate with clinical outcomes. 2230 women in our cohort study had information about trial participation. Within this group, young White women had the highest percent involvement in clinical trials, at 12.4%. Older White women had the next highest percentage of patients involved in trials, at 6.1%. Young Black women had a 5.3% involvement in trials, while older Black women had a 4.2% involvement in trials (p < 0.050, Chi squared test) (Suppl Fig. S5). After adjusting for subtype, stage, and grade, young Black and older Black women were still less likely to be included in a trial compared to young White women (adjusted odds ratio: 0.34, 95% CI 0.13–0.90, p = 0.030; adjusted odds ratio: 0.53, 95% CI 0.29–0.99, p = 0.045 respectively) (Suppl Table 4).

Women who were enrolled in a therapeutic trial had improved OS compared to those who were not (p = 0.002) (Suppl Fig. S6). Whether or not a patient participated in a trial was not a significant determinate of DFS (p = 0.088) (Suppl Fig. S6).

留言 (0)

沒有登入
gif