Lower Rates of Negative Surgical Margins Found in Black Patients Vs White Patients with GI Tract Cancer

Rates of negative surgical margins and adequate lymphadenectomies were lower in Black patients with gastrointestinal (GI) tract cancer compared with White patients, according to data from a retrospective cohort study published in JAMA Network Open.¹

Results showed that Black patients were less likely than White patients to have negative surgical margins overall (odds ratio [OR], 0.96; 95% CI, 0.93-0.98). Additionally, Black patients were less likely overall to receive adequate lymphadenectomy (OR, 0.89; 95% CI, 0.87-0.91).

Furthermore, Black patients were more likely than White patients not to be recommended for chemotherapy (OR, 1.15; 95% CI, 1.10-1.21) and radiotherapy (OR, 1.49; 95% CI, 1.35-1.64) because of comorbidities and were more likely not to receive recommended chemotherapy (OR, 1.68; 95% CI, 1.55-1.82) and radiotherapy (OR, 2.18; 95% CI, 1.97-2.41) for unknown reasons.

“We recommend adjuvant radiation therapy for patients after they undergo curative-intent surgery, and it was found that Black patients were less likely to receive adjuvant radiation therapy compared [with] White patients for reasons unknown,” study author Sajid A. Khan MD, FACS, FSSO, associate professor of surgery (oncology), section chief, Hepato-Pancreato-Biliary and Mixed Tumors, co-director of Team Science, Yale Center for Clinical Investigation, Yale Cancer Center, said in an interview with OncLive^®.

“Black patients and, very likely, American Indian patients are more likely than White patients to not receive the standard-of-care GI cancer surgery,” Khan added. “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.”

The ongoing COVID-19 pandemic has shed additional light on the prevalence of racial and ethnic disparities in the health care system that have caused gaps in survival outcomes.2 Black men and women have a 19% and 13% increase in the risk of cancer death compared with White patients, respectively.³

This data analysis aimed to address the unknown reasons behind the gap in negative surgical margins for Black and White patients with GI tract cancers, plus the gaps in recommendations for chemotherapy and radiotherapy.

Patient information was extracted from the National Cancer Database (NCDB) 2017 Participant Use File. Patients were required to be at least 18 years of age and diagnosed with a GI tract malignant neoplasm between January 1, 2004, and December 31, 2017. Moreover, patients were required to have undergone surgical resection of their primary cancer site.

Patients were excluded from the analysis based on lack of demographic information or clinical data, in addition to unknown surgery type, tumor type, or lack of tumor resection.

Resection margins were considered negative if all surgical resection margins were grossly and microscopically negative. Patients who had margins with residual tumor that was macroscopic, microscopic, or not otherwise specified were classified as having positive margins.

Moreover, adequate lymphadenectomies were determined by standards previously set forth by the National Comprehensive Cancer Network, the American Joint Committee on Cancer, or based on expert consensus. The number of lymph nodes were then examined and recorded for each respective cancer site. Having 12 or more lymph nodes was adequate for cancers of the colon, rectosigmoid, rectum, and anus. However, for the esophagus, pancreas, and stomach, a total of 15 lymph nodes was used. For the small intestine and gallbladder, a cutoff of 8 and 6 lymph nodes was recorded, respectively.^4-6

A variable from the NCDB was utilized to determine if a patient had been recommended to receive adjuvant therapy, specifically chemotherapy or radiotherapy, as well as if the patient received the therapy. Survival outcomes were determined based on a patient’s time from diagnosis to death.

A patient’s age at diagnosis, sex, race, ethnicity, primary payer at the time of diagnosis, and facility type were extracted from the NCDB Participant File.

To further examine of the association between surgical outcome data and how it relates to race, 4 multivariable regression models were utilized. Model 1 was unadjusted; model 2 was adjusted for sex, age group, race, and organ site; model 3 was adjusted for primary payer, facility type, and Charlson Comorbidity Index score; and model 4 was adjusted for model 2 and 3 covariates and clinical tumor, node, metastasis stage group and grade.

The analysis examined 565,124 evaluable patients who underwent surgical resection of their GI tract cancer. The study population was predominantly male (54.7%). Additionally, 83.5% of patients were White, 90.3% were non-Hispanic, 0.3% were American Indian, 3.4% were Asian, 10.9% were Black, 0.2% were Pacific Islander, and 0.8% were of unknown race or ethnicity. The most common primary cancer site was the colon (44.9%).

Additional data showed negative surgical resection margins were observed in 88.5% of all patients, and adequate lymphadenectomy was observed in 71.2% of all patients.

Moreover, Black patients were less likely to have negative surgical margins after esophagectomy (OR, 0.71; 95% CI, 0.58-0.87), proctectomy (OR, 0.71; 95% CI, 0.66-0.76), and biliary resection (OR, 0.75; 95% CI, 0.61-0.91). Moreover, when examining gallbladder cancers, Black patients were 29% more likely than White patients to have negative resection margins (OR, 1.29; 95% CI, 1.11-1.50) but were 29% less likely to have negative resection margins after esophagectomy. In other biliary site resections, Black patients were 25% less likely to have negative resection margins.

Black patients were also less likely to receive adequate lymphadenectomy after colectomy (OR, 0.89; 95% CI, 0.87-0.92), esophagectomy (OR, 0.72; 95% CI, 0.63-0.83), pancreatectomy (OR, 0.90; 95% CI, 0.85-0.96), proctectomy (OR, 0.93; 95% CI, 0.88-0.98), proctocolectomy (OR, 0.90; 95% CI, 0.81-1.00), enterectomy (OR, 0.71; 95% CI, 0.65-0.79), and gastrectomy (OR, 0.94; 95% CI, 0.89-1.00).

Regarding survival, at a median follow-up of 41.0 months (interquartile range [IQR], 19.4-72.0), negative resection margins were associated with a longer median survival than positive margins (87.3 months [IQR, 28.5-161.9] vs 22.9 months [IQR, 8.8-69.2]; P < .001). Additionally, Black patients with negative resection margins had increased risk of death (HR, 1.12; 95% CI, 1.10-1.14).

White patients with positive resection margins had increased risk of death (HR, 2.54; 95% CI, 2.51-2.57), as well as Black patients with positive resection margins (HR, 2.65; 95% CI, 2.57-2.71). Black patients with negative resection margins after proctocolectomies had a 35% higher risk of death than White patients with negative resection margins (HR, 1.35; 95%CI, 1.26-1.45), a 27% higher risk after proctectomies with negative resection margins (HR, 1.27; 95% CI, 1.08-1.50), and a 24% higher risk after enterectomies with negative resection margins (HR, 1.24; 95% CI, 1.13-1.36).

At a median follow-up of 40.7 months (IQR, 19.0-72.0), adequate lymphadenectomy was associated with a longer median survival than inadequate lymphadenectomy (80.7 months [IQR, 25.6-not reached] vs 57.6 months [IQR, 17.7-153.8]; P < .001). Black patients with adequate lymphadenectomy had an increased risk of death (HR, 1.13; 95%CI, 1.11-1.15) compared with White patients, as well as White patients with inadequate lymphadenectomy (HR, 1.10; 95% CI, 1.09-1.11) and Black patients with inadequate lymphadenectomy (HR, 1.20; 95% CI, 1.17-1.23).

This study had indicated a need to better understand the effect of racial disparities on patients. Khan said further research must be done to better evaluate the causes of these disparities to provide better care for patients with cancer.

“One thing that we have already started to look at is biases by clinicians. The chemotherapy and radiation findings [were] unexpected. However, it suggests that there [are] biases in the way medical providers and physicians [are taking] care of patients and communicating with patients. We are exploring to see if that is a possibility,” Kahn concluded.

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. Mackey K, Ayers CK, Kondo KK, et al. Racial and ethnic disparities in COVID-19–related infections, hospitalizations, and deaths: a systematic review. Ann Intern Med. 2021;174(3):362-373. doi:10.7326/M20-6306
3. DeSantis CE, Miller KD, Goding Sauer A, Jemal A, Siegel RL. Cancer statistics for African Americans, 2019. CA Cancer J Clin. 2019;69(3):211-233. doi:10.3322/caac.21555
4. Tomlinson JS, Jain S, Bentrem DJ, et al. Accuracy of staging node-negative pancreas cancer: a potential quality measure. Arch Surg. 2007;142(8):767-723. doi:10.1001/archsurg.142.8.767
5. Aloia TA, Járufe N, Javle M, et al. Gallbladder cancer: expert consensus statement. HPB (Oxford). 2015;17(8):681-690. doi:10.1111/hpb.12444
6. Chun YS, Pawlik TM, Vauthey JN. 8th edition of the AJCC Cancer Staging Manual: pancreas and hepatobiliary cancers. Ann Surg Oncol. 2018;25(4):845-847. doi:10.1245/s10434-017-6025-x