Study highlights gender and racial disparities in receiving optimal treatment for kidney cancer

A study published in JAMA Network Open showed that female, Black, and Hispanic patients with renal cell carcinoma (RCC) have a higher likelihood of receiving non–guideline-based treatment.¹

Findings from the retrospective cohort study identified that in the overall study population, female patients were treated more aggressively vs their male counterparts, with statistically significantly lower adjusted odds of undertreatment (odds ratio [OR], 0.82; P <.001) and higher adjusted odds of overtreatment (OR, 1.27; P <.001). Moreover, Black race was also associated with a statistically significantly higher adjusted odds of both undertreatment (OR, 1.42; P <.001) and overtreatment (OR, 1.09; P <.001) vs White race. An association with undertreatment (OR, 1.20; P = .004) and overtreatment (OR, 1.06; P = .01) was also identified in patients with Hispanic ethnicity.

“To our knowledge, this study represents the first attempt to assess the associations between demographic factors and receipt of non–guideline-based treatment among patients with kidney cancer,” the authors of the study wrote. “We found that female patients with kidney cancer had higher odds of receiving more aggressive treatment than men, which was associated with increased rates of overtreatment for small kidney masses and potentially increased risk for unjustified complications.”

A trend towards downstaging for patients with kidney cancer has been observed, due in part to the fact that smaller tumors of 4 cm or less have a lower potential for metastases and are associated with a higher likelihood of death from competing causes.^2,3 As such, a number of guidelines have been implemented advocating for nephron-sparing approaches or active surveillance in those with smaller tumors.^4-6

However, while the overtreatment of indolent tumors needs to be recognized, attention also needs to be paid to aggressive disease that is being undertreated, particularly in underserved racial and ethnic groups and those who are uninsured.^7-9 As the association between patient demographics and clinical decision making are not yet understood, investigators set out to assess the link between certain demographic factors and receipt of non–guideline-based treatment for RCC.

The study pulled data from the National Cancer Database, which featured 339,641 patients with a primary diagnosis of RCC from January 1, 2010, to December 31, 2017. After exclusions, investigators had a final population of 158,445 patients with cT1-2, N0, M0 RCC.

The population included in the study was notably young and healthy, among whom age and comorbidities were unlikely to be associated with treatment decisions. The median age was 58 years (interquartile range [IQR], 50-64) with 75.7% of all patients being white, 62.8% being male, 57.6% having private insurance. Additionally, 23.2% of the population had a Charlson-Deyo Comorbidity Index score of 0 and 76.8% had a score of 1.

Guideline-based treatment was administered to 69.4% of the population whereas 30.6% were given a non-guideline treatment. Among those who were given a non-guideline treatment, 2.5% were undertreated and 28.2% were overtreated.

“The total number of patients increased over time, and the proportion of patients receiving guideline-based treatment increased over the study period, from 11,206 of 16,934 (66.2%) in 2010 to 15,055 of 21,126 patients (71.3%) in 2017 (P <.001),” the authors wrote.

A subgroup analysis revealed that the association between female sex and overtreatment was preserved for both small cT1a kidney tumors of less than 2 cm (OR, 1.15; P = .001) and large cT1a tumors of 2 to 4 cm (OR, 1.13; P <.001). Moreover, women were found to have statistically significantly lower adjusted odds of undertreatment for cT1b tumors (OR, 0.79; P <.001), although no association was identified for cT2 tumors.

Additionally, a statistically significant association was identified between Black race and undertreatment of cT1b and cT2 kidney tumors. Those with smaller tumors had significantly lower adjusted odds of overtreatment (OR, 0.72; P < .001) and those with larger tumors (OR, 1.20; P = .003) had statistically significant higher adjusted odds for overtreatment.

Investigators also identified a significant association between uninsured status and less aggressive treatment vs those with private insurance. Those who had an uninsured status were found to have a statistically significant higher adjusted odds ratio of undertreatment (OR, 2.63; P < .001) and lower odds of overtreatment (OR, 0.72; P <.001). A subgroup analysis found that the association for overtreatment of small cT1a tumors were significant (OR, 0.40; P < .001), as well as for undertreatment of cT1b (OR, 2.49; P <.001) and cT2 tumors (OR, 2.77; P < .001). However, similar findings were not identified for the overtreatment of large cT1a lesions (OR, 1.01; P = .92).

Moreover, those with Medicare had a statistically significant association with higher adjusted odds of undertreatment (OR, 1.67; P <.001), as well as overtreatment (OR, 1.21; P <.001)

The investigators of the study concluded that it is important to keep these disparities in mind when selecting a treatment strategy for individual patients and should be further considered by health care policy makers.

References

1. Howard JM, Nandy K, Woldu SL, et al. Demographic factors associated with non-guideline–based treatment of kidney cancer in the United States. JAMA Netw Open. 2021;4(6):e2112813. doi:10.1001/jamanetworkopen.2021.12813
2. Smaldone MC, Kutikov A, Egleston BL, et al. Small renal masses progressing to metastases under active surveillance: a systematic review and pooled analysis. Cancer. 2012;118(4):997-1006. doi:10.1002/cncr.26369
3. Kutikov A, Egleston BL, Canter D, et al. Competing risks of death in patients with localized renal cell carcinoma: a comorbidity based model. J Urol. 2012;188(6):2077-2083. doi:10.1016/j.juro.2012.07.100
4. Finelli A, Ismaila N, Bro B, et al. Management of small renal masses: American Society of Clinical Oncology Clinical Practice Guideline. J Clin Oncol. 2017;35(6):668-680. doi:10.1200/JCO.2016.69.9645
5. Campbell S, Uzzo RG, Allaf ME, et al. Renal mass and localized renal cancer: AUA Guideline. J Urol. 2017;198(3):520-529. doi:10.1016/j.juro.2017.04.100
6. NCCN. NCCN Clinical Practice Guidelines in Oncology. Kidney Cancer, version 4.2021. Accessed June 29, 2021. https://bit.ly/3w5lLl8
7. Schwartz K, Ruterbusch JJ, Colt JS, et al. Racial disparities in overall survival among renal cell carcinoma patients with young age and small tumors. Cancer Med. 2016;5(2):200-208. doi:10.1002/cam4.578.
8. Tan, HJ, Chuang RJ, Shirk JD, et al. Health insurance status and disparities in kidney cancer care. Urol Prac. 2016;3(1):18-24. doi:10.1016/j.urpr.2015.05.009
9. Batai K, la Rosa AH, Zeng J, et al. Racial/ethnic disparities in renal cell carcinoma: Increased risk of early-onset and variation in histologic subtypes. Cancer Med. 2019;8(15):6780-6788. doi:10.1002/cam4.2552