Benefits of Biologic Agents in Metastatic Colorectal Cancer Similar in Both Black and White Patients

A mature adult physician is meeting with a patient in the patient’s home. The patient is a black woman with cancer. The patient is wearing a headscarf to hide hair loss from chemotherapy treatment. The doctor and patient are seated next to each other on a couch. The doctor is holding a wireless tablet computer. The concerned patient is asking the doctor a question.
Researchers assessed whether the overall survival benefit of biologic agents is consistent among both Black and White patients with metastatic colorectal cancer.

The addition of biologic agents to chemotherapy significantly improved overall survival (OS) for patients with metastatic colorectal cancer (mCRC) compared with chemotherapy alone; these benefits were similar in both Black and White patients, according to study results published in JAMA.

Patients from Black communities have been underrepresented in clinical trials, which results in poorly defined outcomes in this patient population. Given this disparity, researchers aimed to assess whether the OS benefit of biologic agents in Black patients is consistent with the outcomes observed in White patients in a real-world setting.

Researchers conducted a retrospective, population-based cohort study using the SEER-Medicare linked database. They identified patients aged 65 years or older with mCRC diagnosed between 2004 and 2011 who had received at least 1 dose of chemotherapy and had complete Medicare claims information. Data were analyzed between August 1, 2020, and March 31, 2021. Patient data were grouped based on the intervention used: chemotherapy or biochemotherapy (biological agents).

The primary objective of the study was to assess if survival times improved when patients were prescribed biologic agents within 3 months of receiving chemotherapy. Survival times were defined as starting from the day a patient received their first chemotherapy treatment until the day of their death or last follow-up.

A total of 5617 patients with mCRC were identified from the database, of which 3969 patients (70.7%) received biologic agents between 2004 and 2011. Treatment with biologic agents was initiated within 3 months of chemotherapy in 2894 patients (72.9%). Data from 4542 patients were included in the main analysis; the median patient age was 72 years, 52% were women, 12.2% were Black patients, 87.8% were White patients, and 75.8% had their primary cancer site in the colon.

Results of the study reported no differences between Black and White patients with respect to receiving 1 (76.7% vs 74.8%) vs 2 or more lines of therapy (23.3% vs 25.2%; P =.92) and in the use of chemotherapy or biologic agents (63.6% vs 64.3%; P =.33).

In both Black and White patients, biologic agents were associated with a significant survival benefit with a median OS of 17.9 months (95% CI, 17.3-18.7) compared with chemotherapy alone (8.8 months; 95% CI, 9.1-9.9). Overall, the survival benefit was similar between White and Black patients.

Limitations of the study include SEER database discrepancies and lack of information on the status of tumor mutations, including KRAS and NRAS, which are high among Black patients, and BRAF, which is high among White patients.   

Researchers concluded, “In this comparative effectiveness analysis of a cohort of Medicare recipients with mCRC, biochemotherapy was associated with an improvement in OS with a similar rate of reduction in mortality among Black and White patients. Clinicians may offer biochemotherapy therapy to all patients to maximize clinical benefit, factoring in clinical variables, but not their race.”


Goel S, Negassa A, Acuna-Villaorduna A. Comparative effectiveness of biologic agents among black and white medicare patients in the US with metastatic colorectal cancer. JAMA Netw Open. 2021;4(12):e2136378. doi:10.1001/jamanetworkopen.2021.36378