Gender, Racial, and Socioeconomic Status Disparities Linked With Incidence of Metastatic Bone Disease

R. Lor Randall, MD

Multiple sex-related, racial/ethnic, and socioeconomic status disparities are associated with an increased incidence of metastatic bone disease originating from cancers in the prostate, renal, colon, lung, and breast, according to a report published in the Journal of Surgical Oncology.¹

The data, which were extracted from the National Cancer Institute’s Surveillance Epidemiology End Results (SEER) program, were pulled from patients with metastatic bone disease at presentation for 5 of the most common primary anatomical sites: lung (n = 59,739), prostate (n = 19,732), breast (n = 16,244), renal (n = 7718), and colon (n = 3068).

Results showed that overall, there was an increase in metastatic bone disease incidence in prostate cancers (annual percentage change [APC], 4.94), renal cell carcinoma (APC, 2.55), and colon cancer (APC, 3.21; P <.005 for all). Moreover, non-Hispanic Black patients were found to have a higher incidence of metastatic bone disease for primary sites in the breast and prostate (P <.0001), while non-Hispanic American Indian Alaskan Native had a higher incidence of metastatic bone disease that stemmed from the renal (P <.001) and colon (P = .049).

Additionally, in those with lower socioeconomic status for the selected sites, there was also a higher incidence of metastatic bone disease.

In an interview with OncLive^®, R. Lor Randall, MD, The David Linn Endowed Chair for Orthopaedic Surgery and professor and chair of the Department of Orthopaedic Surgery, University of California Davis Health, and also senior study author of the analysis, spoke to the intriguing findings and how to apply the disparities data to clinical practice.

OncLive^®: Please discuss the details of this disparities analysis in metastatic bone disease.

Randall: We really are excited about looking into socioeconomic disparities across musculoskeletal health and, with my interest, cancer. Up until now, what we have looked at are the conventional sarcomas—soft tissue sarcomas and bone sarcomas and things of that sort. However, we decided to look through a different lens on this, and those are the lens of patients with metastatic bone disease.

We looked at the SEER database, and we mined it to look at the big 5 if you will; we looked at breast, prostate, lung, colon, and kidney cancer. We looked at those 5, and we looked at socioeconomic indicators, as well as demographics, and looked at outcomes. What was interesting to find was that there was an increased incidence of the cancers. We also found that non-Hispanic Whites and non-White individuals actually had an increased incidence of breast and prostate cancers compared with other demographics.

[We demonstrated the] incidence of primary cancers with metastatic bone disease stratified by socioeconomic status. What you find is when you look at colon cancer, and you look at breast cancer and prostate cancer, in these lower socioeconomic [status patients, the incidence] was statistically significant. These patients with less financial support and less resources did seem to have an increasing incidence of cancer.

[We also evaluated] race and socioeconomic status, and found that non-Hispanic White and non-Hispanic Black patients have an increased incidence of lung cancer and particularly [this was] in the lower socioeconomic group. Within the race categories, you see this trend downward, but then across from group 1 to group 5, which is the socioeconomic group, you see this trending downwards as well. This tells us that underrepresented populations with worse socioeconomic situations have increasing incidence of lung, prostate, and breast cancers.

We are now mining [these data] for survivorship to see if [these patients] survived; these are just incidence data. However, there is clearly more cancer happening in patients of minority background who have less resources. We don't know why; it may be that they have dietary issues, or they may have lifestyles that put them in environments that are more at risk for developing cancer. Stress itself could be involved. We don't know the etiology of this; it's just an empiric finding. Nonetheless, it's very concerning.

How could clinicians utilize these data in clinical practice?

In the current, national debate around access to health care, it's very important to have data to show that the equity and the access issue are really important for those who are socially and economically deprived and are underrepresented populations of our country. These minorities, if you will, are not getting the same [results]; they're having more health care problems. That informs policy, and that informs access issues and insurance plans.

Of course, we need to drill into it further with population sciences to get at some of the root causes of this. The message is that people with adverse socioeconomic status, which are underrepresented, have bigger challenges than the rest of us.

What are some of the next steps involved in this research?

We mined all of the carcinomas that metastasized to bone, and what we are saying here is that these patients have increased [incidence]. When we talk about breast cancer, for example, we are saying that patients with breast cancer metastases to the bone have a higher incidence based upon their socioeconomic status and their demographics.

One of the things that we have found as a byproduct of our investigation is that there is a large number of patients who we have found have bone-only metastases early on, that then go on later to develop metastasis at other sites. That begs the question: is the bone tumor microenvironment some sort of waystation for the in-transit metastasis?They leave their home organ, metastasize to the bone, and then develop further anaplasia or some other predilection to metastasize to other sites. This is because we found a very large number of patients with bone-only metastases relatively early in their clinical course, that then went on to have other sites of disease. It really does beg the question: is the bone tumor microenvironment somehow a waystation to further development of aggressivity? That's important from a clinical research standpoint. Is it true that if you can block metastases and transit to bone, that you can improve overall survival of patients?

The oncology community has really dived into exploring disparities in cancer care over the last several years. What does it mean that investigators are turning the tide towards this angle of research?

You can see it on the national stage and politics how appropriately the national attention is focused on this issue of diversity, equity, and inclusion. It's well past due. I'm not going to get into politics here, but it is important as the stewards of health care that we, as a medical community, a health care community, be vigilant and take this on.

Is there anything else about this research that you would like to alert people on?

Here at UC Davis Health, we really are taking this wholeheartedly. We have hired a whole research crew to look at metastatic bone disease in terms of its socioeconomic disparities, but also to look at the tumor microenvironment for the idea around a waystation for in-transit metastases. We are very interested in looking at metastatic bone disease from the socioeconomic [component] all the way down to the tumor microenvironment enterprise here at UC Davis.

Reference

1. Jawad MU, Pollack BH, Wise BL, et al. Sex, racial/ethnic and socioeconomic disparities in patients with metastatic bone disease. J Surg Oncol. 2021;1-9. doi:10.1002/jso.26765.