Abstract P2-11-15: Clinical trial enrollment for initial therapy of breast cancer: Exploring factors associated with poor accrual and significant disparities
Authors: Advani Pooja P , Spaulding Aaron , Hochwald Alexander , Baksh Mizba , Hodge David , Chumsri Saranya , Monestime Shanada , Ailawadhi Sikander 
Published: March 2022

Background: There is an urgent need to improve clinical trial (CT) enrollment of breast cancer (BC) patients (pts), especially from unrepresented minorities. In this regard, our study aims to better understand the characteristics and factors associated with CT enrollment to inform strategies to enhance CT accrual rates. Method: We included 1,308,767 female pts from the National Cancer Data Base diagnosed from 2010 to 2017 with known ER, PR, and HER2 status. Demographic, socioeconomic, Charlson-Deyo Score (CDS) and BC specific data were compared between CT versus non-CT enrolled pts for initial therapy. Comparisons were assessed by Chi-square test. Logistic regression was utilized to determine associations between characteristics and CT enrollment. Odds ratios (OR) and p-values are reported for each group. Results: A total of 1797 pts (0.14%) were enrolled in CT for initial BC therapy. Focusing on the CT group, majority of pts were non-Hispanic White (W;(78.2%), followed by non-Hispanic black (AA;12.2%); Hispanic (H; 5.6%); and non-Hispanic Asian (A; 4%). Most pts (29.3%) were in 50-59 age quartile. TNBC pts formed 22% of CT pts and non-TNBC were 78%. Most pts were from academic centers (54%), followed by comprehensive community cancer (CCC; 23.5%), community cancer (3.9%) and integrated network cancer (INC; 5.6%) programs. Most had private insurance (70%) versus government insurance (27%) and others (3%). Stage IV pts were only 10% of the CT group while most pts (41%) had Stage II BC. CDS of 0 was noted in 90% pts while 1.3% pts had CDS of 2 or more. Most CT pts traveled &lt; 50 miles from treatment center (88.5%), and only 1.2% CT pts traveled 200 or more miles. Most CT pts resided in areas with highest literacy rate (30%) while 15% were from areas with lowest literacy rate. In multivariable model, non-white pts were less likely than Whites to be enrolled in CT (OR 0.81, p&lt;0.05). The odds of CT enrollment in 40-49, 50-59 and 60-69 age quartiles were 3.5, 2.7 and 2.3 times respectively that of pts 70 years or older (p&lt;0.001). TNBC pts were 1.9 times more likely to be enrolled in CT than non-TNBC pts (p&lt;0.001). Academic center pts were 3 times more likely (p&lt;0.001) while INC program pts were less likely than CCC pts to be enrolled (OR 0.7, p=0.006). Pts with government insurance and other insurance were less likely to enroll in CT (OR 0.74, and 0.55, p &lt;0.001 and p=0.003, respectively) compared to private insurance. The odds of a patient with stage II, III, IV BC enrolling in CT was about 2, 3.5 and 4 times higher than a stage I pt (p -&lt;0.001). Pts with CDS 1 (OR 0.8, p=0.025) or 2 or more (OR 0.5, p=0.002) were less likely than CDS 0 pts to be enrolled. Pts who traveled 50-99 or 100-199 miles from the treatment center conducting CT, were 1.9 (p&lt;0.001) and 1.5 times (p&lt;0.05) more likely to be enrolled while those with &gt; 200 miles were less likely (OR 0.75, p=0.442). The group of pts who belonged to a residential area with the highest literacy rate (&lt;6.3% of no high school diploma) were 1.4 times more likely to accrue in CT (p&lt;0.001) than those with high school diploma rate between 6.3 and 10.8%. Compared to metro areas, pts from rural areas were less likely to be enrolled (OR 0.5, p=0.04) as was a lower median income &lt; $40,227 (OR 0.77, p= 0.016).Conclusion: CT enrollment is poor for initial therapy of BC treatment. We identify several modifiable factors including sociodemographics which are associated with BC pts not getting treated on CT. There are other factors that are non-modifiable, e.g., disease stage but may point to the need for more CT development in these areas. Addressing these disparities would lead to improved CT enrollment and overall advancement in BC management landscape.

Citation Format: Pooja P Advani, Aaron Spaulding, Alexander Hochwald, Mizba Baksh, David Hodge, Saranya Chumsri, Shanada Monestime, Sikander Ailawadhi. Clinical trial enrollment for initial therapy of breast cancer: Exploring factors associated with poor accrual and significant disparities [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-11-15.