Race of patients after neoadjuvant therapy for breast cancer has no significant effect on pathological CR

Significant disparities were observed in the subgroup of women who did not achieve a complete pathological response (pCR), but the patient race was pCR and event-free in high-risk breast cancer patients who received targeted neoadjuvant chemotherapy. According to the results presented by Beverly Calwaj, BS at the 2021 San Antonio Breast Cancer Symposium, which did not significantly affect survival (EFS).¹

According to the National Cancer Institute Surveillance, Epidemiology, and End Results Program, black women with breast cancer are about 40% more likely to die of their illness than white women with breast cancer.²

“Breast cancer treatment and management is constantly evolving with advances in immunotherapy, but there remains a permanent mortality gap between white and black women with breast cancer,” said Pritzker, University of Chicago. Calwaji, the lead author of the University of Chicago’s analysis and a medical student, said in a statement.³

In a Phase 2 I-SPY2 platform trial, 990 women with stage II or III breast cancer are at increased risk of early recurrence to either paclitaxel and anthracycline standard chemotherapy alone or standard chemotherapy or study drug. It was randomized. After a median follow-up of 4.4 years, this analysis assessed whether pCR was affected by the patient’s race. In addition, researchers evaluated changes in immune-related gene signature expression.

“It is important to understand and address this underlying disparity and work to develop interventions to improve outcomes for women who have not experienced pCR,” said Senior Author and Senior Author of the University of Chicago Clinical Cancer Center. The director, Dr. Orhun Mirayoolopade, FAACR Genetics, said in a press release. “Improved knowledge of how tumor biology predicts response not only helps researchers target tumors and the immune microenvironment, but also helps guide the design of clinical trials. Helps develop new approaches that take into account. “

Since the number of patients belonged to a racial group of less than 10, 16 patients were excluded from this analysis, for a total of 974 being evaluated for pCR. 907 was rated for EFS. Of the patients evaluable by pCR, the self-reported racial group included 786 (81%) Caucasian patients, 120 (12%) Black or African American patients, and 68 (7%) Asian patients. ) Was included. Ethnicity is not considered in this analysis. The race was not significantly associated with the pretreatment scarf-bloom-Richardson grade (P = .49), expression-based subtype (P = .25), or subtype defined by hormone receptor (HR) / HER2 (P = .09).

The pCR rates were not significantly different by racial group, with pCR odds ratios of 1.00 for Asian patients and 0.89 for black or African American patients compared to Caucasian patients. There was no significant difference in the distribution of residual cancer burden classes (P = .88), there was also no Scarff-Bloom-Richardson grade. Thirty-two percent of Caucasian patients experienced pCR, 30% of black or African-American patients experienced 32% of Asian patients.

In the univariate Cox model, researchers observed that EFS was not associated with the patient’s race. The hazard ratio for white patients was 1.37 for black or African-American patients (P = .13) and 1.10 (1.10) for Asian patientsP = .73).

There was a significant difference in EFS in patients who did not experience pCR. Black or African-American patients had a higher recurrence or mortality rate than Caucasian patients, with a hazard ratio of 1.61 (95% CI, 1.02-2.45). P = .003). In addition, HR-positive and HER2-negative black patients who did not achieve pCR had a higher recurrence rate than white females, with a hazard ratio of 1.95 (95% CI, 1.03-3.73;). P = .04).

There was no statistically significant difference between triple-negative, HR-positive, HER2-positive, or HR-negative, HER2-positive breast cancer patients. “In these sub-analyses, P Value … decreased due to the small sample size, “Kyalwazi said in the presentation.

Similar pCR and EFS results among women of different races, according to Kyalwazi, showed that tumor molecular subtypes are more important in breast cancer survival than race. “This is reassuring because it helps us know that biomarker-based therapies are effective for patients in all racial groups who have equal access to quality care,” Kyalwazi said in a press release. It is stated in. “These results show that achievement and survival of pCR is race-independent if women have access to appropriate and effective treatments based on their tumor profile.”

Investigating the relationship between racial groups and 28 expression signatures associated with immune signaling pathways, immune cell types, and checkpoint inhibitor targets, researchers found interferon in black patients with HR-positive and HER2-negative breast cancer. We have observed that the module signatures are significantly different. From a white patient (P = .007). In the same subtype, Asian patients had higher expression of the estrogen / progesterone module than black patients (P = .011), and black patients had higher mitosis scores than Asian patients (= .011).P = .008).

To evaluate the results of this analysis, logistic regression was used for pCR association, Cox proportional hazard modeling of EFS, and a chi-square test of the association between racial demographics and patient characteristics. Fluctuations in immune-related gene signature expression were investigated using ANOVA and Tukey’s test.

“We are committed to ensuring access to all women in the I-SPY trial, especially those who are traditionally underrated in the trial. Our trial site is the geographic of the country. And it reflects both racial diversity. Colored females have a higher mortality from breast cancer, and trials with personalized treatments and complete genome profiling improve outcomes in all females. “It helps,” said Laura Esserman, director of breasts at the University of California, San Francisco. Principal Investigator for Care Center and I-SPY2 trials.

In a presentation, Kyalwazi said that women in the I-SPY 2 trial suffer from high-risk breast cancer, which is different from the general population of women with breast cancer. The study included a smaller number of self-reported black and Asian patients compared to self-reported white patients, although it reflected US demographics. Finally, patient socio-economic factors and comorbidities such as diabetes and hypertension are not considered in this analysis.

“As long as there is racial disparity, race will continue to be part of the debate about breast cancer,” Kyalwazi said. “To increase access to quality cancer treatments in women who are underestimated in clinical trials by understanding that race is less likely to predict response to treatment than tumor biology. The focus is on strategy. “

References

1. Analysis of racial clinical outcomes and expression-based immune signatures in the Kyalwazi B, Yau C, Olopade O, et al. I-SPY2 trials. Place of presentation: 2021 San Antonio Breast Cancer Symposium; 7-10 December 2021; San Antonio, Texas. Abstract GS4-02. https://bit.ly/3dCx4KH
2. Cancer Statistics: Breast Cancer. National Cancer Institute Monitoring, Epidemiology, and Final Results Program. Accessed on December 6, 2021. https: //bit.ly/3rMoYHT
3. Black and white women who received neo-adjuvant therapy were equally likely to have a complete pathological response. American Cancer Society. Published December 7, 2021. Accessed December 9, 2021. https: //bit.ly/3lGpenM