Racial Disparities Revealed in Surgical Outcomes in Gastrointestinal Tract Cancer

Sajid A. Khan MD, FACS, FSSO

Lower rates of negative surgical margins and adequate lymphadenectomies were found in Black patients with gastrointestinal (GI) tract cancer vs White patients, according to results from a retrospective study.1,2 These findings included surprising data that could point to health care provider biases as a factor for these disparities, according to Sajid A. Khan MD, FACS, FSSO.

The study, conducted by Yale Cancer Center, evaluated 565,124 patients who underwent surgical resection of their GI tract cancer. Black patients had lower rates of negative surgical margins compared with White patients (odds ratio [OR], 0.96; 95% CI, 0.93-0.98). Additionally, Black patients were less likely to have adequate lymphadenectomy (OR, 0.89; 95% CI, 0.87-0.91).

Khan noted study authors were surprised to find that Black patients were 8% less likely to receive adjuvant chemotherapy and 35% less likely to receive adjuvant radiotherapy compared with White patients.

“We looked to see if there were differences in a patient, based on race and ethnicity, to wanting adjuvant chemotherapy or wanting radiation therapy, and we found that Black and White [patients] were equally likely to refuse chemotherapy or radiation therapy. That suggests that there’s a provider bias playing a role here,” Khan said.

In an interview with OncLive^®, Khan, associate professor of surgery (oncology); section chief of Hepato-Pancreato-Biliary and Mixed Tumors; co-director of Team Science, Yale Center for Clinical Investigation, Yale School of Medicine, discussed findings from the study on racial disparities in surgical outcomes and quality of care for GI tract cancer, plus what issues need to be addressed to close the gap in care.

OncLive^®: Could you highlight what inspired this research?

Khan: We’ve all been through quite a bit over the past 2 years with the COVID-19 pandemic. There are a lot of other stories related to COVID-19, and one story that caught my attention is the racial and ethnic disparities that exist in clinical care for the treatment of [patients with] COVID-19.

I am a surgical oncologist with a focus on GI cancers. Cancer is the number 2 cause for death in the United States, and GI cancers account for about one-third of cancer deaths. African Americans have a higher GI cancer burden compared with Whites, with a higher risk for death due to the GI cancer. I wanted to see if there are disparate outcomes in GI surgical cancer patients, based on race and ethnicity.

There have been some smaller studies that have focused on GI surgical oncology, but there haven’t been any studies that looked comprehensively at all GI cancer surgery outcomes [regarding] treatment disparities. That was what [my team and I] wanted to look at, in regard to this study.

Could you elaborate on the patient population examined in this study?

We looked at Americans diagnosed with [GI tract] cancer from 2004 to 2017 using the National Cancer Database [NCDB]. This is a rich, valuable database that other investigators have used across the country. The reason it’s so valuable is because it captures about 72% of the United States population for newly diagnosed cancers. We thought this would give us a good timeframe and a number of patients to look at to see what’s going on nationally.

What methods were utilized when conducting this research?

Our study mostly used multivariable regression models and chi square tests. We were cognizant to control for factors such as a patient’s performance status, their insurance status, and social factors that are available using the NCDB.

What were some of the key results found in this research?

Our findings were striking. Compared with White [patients], we found that Black [patients] had lower rates of negative surgical margins. These are curative-intent operations, and the aim is to get negative surgical margins. That is not always possible for various reasons, because of some technicalities [in] some of these technically complex operations. But we found that despite all of that, Black [patients] had less likelihood of having a negative surgical margin compared with White patients, which was an [interesting] finding for us.

We found these [differences in negative surgical margins between Black and White patients] across the board when we looked at all GI cancers. These findings were the most pronounced for patients who had surgery for esophagus cancer, rectal cancer, and bile duct cancer. We aim for negative surgical margins, and [it is] important to understand that negative surgical margins lead to better cancer-specific survival.

Another metric that we focused on was the removal of enough lymph nodes for GI cancers. A lot of GI cancers are epithelial-based cancers, and part of a good oncologic operation is to remove an adequate number of lymph nodes. We found in our study that Black [patients] were less likely than White [patients] to have an adequate number of lymph nodes removed for GI cancers in general. These disparate outcomes were most pronounced for cancers of the pancreas, esophagus, colon, and small intestine.

Were there any outcomes of the study that surprised you?

I expected to see some of the disparate findings previously mentioned on surgical margins and lymph node status. But a few unexpected findings were also [observed]. First, we also looked at [rates of patients receiving] adjuvant chemotherapy. After a patient has curative-intent surgery, they would get adjuvant chemotherapy in certain circumstances. We found that Black [patients] were less likely than White [patients] to receive adjuvant chemotherapy, which was about 68%, and [this finding] was for reasons unknown.

[Regarding] the second [surprising] finding, sometimes we recommend adjuvant radiation therapy for patients after they undergo curative-intent surgery. We found that Black [patients] were less likely to receive adjuvant radiation therapy compared with White [patients], again for reasons unknown.

Those were striking findings, and they did surprise me when we found them. We used various statistical methods. We accounted for multiple factors that may account for these multivariable regressions, and those numbers still held true.

What makes the [adjuvant radiotherapy and chemotherapy] finding even more impressive is we also looked at patient preference.

Another [impressive and unexpected finding] is that we looked to see if other races or ethnicities are subjected to some of these similar findings. We found that [Native Americans] also experienced similar disparate outcomes in all measures in regard to surgical margins and lymph nodes. There are less [Native American patients] in the United States compared with Black patients, so it is harder to power those studies to show statistical significance consistently, but the trend was there.

Are there plans for any additional research in this area?

[Although] our study presents some important findings, it also leads to some additional questions as to why these outcomes are happening. The NCDB is a beautiful database [that] provides a good bird’s-eye view of what’s going on across the country. But some of the particular, granular, detailed clinical information is not in the NCDB. Our plan is to look at this more specific, granular data at a hospital level to find why these treatment disparities may exist.

One thing that we’re interested in and have already started to look at is [if there are] some clinician biases. [For example], the chemotherapy and radiation finding was an unexpected finding, but it does suggest that there are some biases in the way that medical providers and physicians such as myself have in taking care of patients and communicating with patients. We are exploring to see if [these biases may help] account for these findings.

We are also looking at if there are any differences in surgical and pathology care for patients in one hospital vs another. Maybe [those differences] account for some of these treatment disparities. Is there an issue with access to transportation? Is it harder for Black patients to come to the hospital to get chemotherapy or radiation therapy? Those are some of the things that we’re looking at right now at less of a national level and more at a hospital level.

What is an important takeaway for your colleagues?

Black patients, and likely [Native American] patients, are more likely than White patients to not receive standard-of-care GI cancer surgery. This may be due to potential lapses in our health care system. We need to look at that as a society and as a medical community to see why these problems exist and work to eliminate these treatment disparities.

What further research on the topic is being conducted at Yale Cancer Center and in your lab?

Our study suggests that there are societal problems that need to be addressed to narrow or eliminate these gaps in treatment disparities. The people that were involved in our study include the full gamut of expertise that we have at Yale Cancer Center. One of the experts that is the co-senior author [of this research is], Caroline Johnson, PhD, and [together], we do a lot of basic science cancer research.

Some of our lab’s findings have shown that cancer can behave differently in people by race and ethnicity. The reason I mention that is because historically, minorities are underrepresented in industry-based clinical trials. A lot of treatment decisions that are made, whether it’s with surgery, systemic chemotherapy, or radiation therapy, are [not] based on a [population that’s] representative of the United States population. Some of the work that we’re doing at the basic science level is to look at the biological differences. What are the differences in the tumor biology of patients based on their race and ethnicity?

Some of our work, plus work from others across the United States and across the globe, have suggested [differences in tumor biology due to race or ethnicity]. [Additional research in this area will be] important, in addition to looking at things at a hospital system level or a national societal level. By doing more basic science studies, it will allow us to understand and provide more specific treatment. In the long run, [we will be able to] better represent all races and ethnicities in our clinical trials to allow a provider to better treat patients.

References

1. Bakkila BF, Kerekes D, Nunez-Smith M, et al. Evaluation of racial disparities in quality of care for patients with gastrointestinal tract cancer treated with surgery. JAMA Netw Open. 2022;5(4):e225664. doi:10.1001/jamanetworkopen.2022.5664
2. Yale Cancer Center study reports racial disparities for gastrointestinal surgery. Yale Cancer Center. April 4, 2022. Accessed April 28, 2022. https://bit.ly/3ODB6nr