Population-Based Data Show Amputations in Malignant Foot Neoplasms Correlate With Hispanics, Males

Amputations were found to be associated with Hispanic ethnicity and male sex in patients with neoplasms of the foot, according to data from a population-based registry that were published in the Journal of Surgical Oncology.

Neoplasms that originate from small bones of the lower limb and overlapping joints are rare but are linked with a serious prognosis. To characterize foot malignancies, investigators used a US population-based registry from the National Cancer Institute’s Surveillance, Epidemiology, and End Result (SEER) database from 1975 to 2017 that had incidence and survival data of 514 patients. Prognostic factors for survival were evaluated using Kaplan-Meier and Cox Regression, and a Chi square test was used to assess correlative factors.

Results showed that hematologic cancers, as the predominant histologic subtype, comprised 14.8% of the overall cohort, and the incidence of foot neoplasms was 0.024 per 100,000 persons in 2017; this has not changed significantly since 1975 (P > .05). The 5-year disease-free survival rate in the overall cohort was 73%.

Notably, there was a significant correlation between amputation with male sex and Hispanic ethnicity. Additionally, localized stage and extent of surgical resection was found to be predictors of improved outcomes as part of a multivariate analysis in younger age groups.

The data could infer that there could be socioeconomic and/or access to care issues occurring within this patient demographic, explained R. Lor Randall, MD, a senior author on the study.

“There are some real health care disparities that are happening in the United States, as we know, but it's interesting to look at it from the lens of where we are in musculoskeletal oncology,” said Randall.

In an interview with OncLive®, Randall, The David Linn Endowed Chair for Orthopaedic Surgery and professor and chair of the Department of Orthopaedic Surgery, University of California Davis Health, discussed the population-registry findings in more detail.

OncLive®: Let’s dive into this research on malignant neoplasms of the foot. What did you set out to achieve in this analysis?

Randall: This is actually one part of a series that we're working on—to do a deep dive into health care disparities in in cancers—and [now we're looking into] the musculoskeletal system, including sarcomas. There have been a lot of data and publications in the SEER database, and the SEER database has its limits. However, we thought this was a good exercise to start raising awareness about cancer care disparities in the United States.

We have taken up a variety of projects, and this one happened to be in the area of the foot, and we wanted to focus on disparities, which has not been looked at stringently in quite some time, if at all, in terms of anatomic locations and things of that sort.

We went through the database and mined a couple of areas, and the foot popped up in there; we were able to find data points in over 500 cases. What was interesting was that the predominant histologic type were hematologic malignancies, not primary solid tumors; leukemias and infiltrative tumors of the hematopoietic system were far more common than primary tumors. They made up about 15% [of the overall cohort].

However, what was also interesting and is the real take-home message on all this, is that we found that people have who self-identified as Hispanic had a higher predilection of amputation compared with non-Hispanics. It raises questions about: Why is this? Are there socioeconomic issues? Are there access issues? There are a variety of things. The real point of doing this is to shine a light on some of these things for further investigation across cancer domains.

We are really, really committed to equity and health care and making sure that no one is left behind. Those are the 2 take-home messages: [these patients predominantly have] more non-solid tumors and that, for these malignancies undergoing intervention, there seems to be more amputations happening in Hispanic populations than non-Hispanic.

Were there other demographics linked with intriguing findings of this analysis?

We didn't find any other demographic criteria that they had a predilection for more radical procedures such as this. It really raises as many questions as it does provide any answers. What we're seeing across the health care system is just that potentially those with socioeconomic challenges, which tend to be non-Caucasian, non-White individuals have more access issues, and this is completely inferential.

This is not supported by our data, but they have more challenges to access and, therefore, they may present with more advanced disease and they may not have access to some of other treatments. They [could be] getting more ablative procedures.

We didn't see it in African American populations. It may be that we just had a larger population size of Hispanics to see [this disparity], but I don't think it's specific to Hispanics.

Over this last year, there has been an increased number of oncology studies looking at access to care and racial and gender disparities compared with prior years. There was a big spotlight on this at the 2021 ASCO Annual Meeting, too.

It's about time, right? It is reflective of societies coming to grips with the injustices, and health care is a big part of that. The health care community is very sensitive to it. With Black Lives Matter, the health care community was very outspoken. “White Coats for Black Lives” was one of the big mantras that we said. We don't want to just speak with emotion; we want to speak with data. We need to start looking at what we have done as health care providers over the decades. This SEER database set was from 1975 to 2017 and [comprised] 514 patients. What is interesting is [that the rates and incidence] did not change over the course of that long period of time of 40 years.

A total 14.8% of the cohort had hematologic malignancies, which is 0.024 per 100,000 people in 2017. Rarely, rare stuff [is interesting to look up data on] because [not a lot exists or hasn't been investigated yet]. You can find stuff about distal femur, proximal tibia, proximal humerus, and shoulder, knee, hip, pelvis—all those sorts of things, or the literature is replete. We thought we would go look at areas that have sort of been forgotten about.

What similar types of studies would you like to pursue either in this area or in sarcomas?

We are going to have a few of these [analyses] coming out; we are looking at hand tumors now. What will be a nice thing to know will be if we're seeing the similar binding in all these anatomic areas. I would say that, for amputations around the foot, there is a much lower threshold to move forward with that for a patient because the outcomes are very good.

However, around the hand, obviously, we don't anticipate we'll see an increased incidence of amputations. This is because we go out of our way to preserve the hand because its quality of life and functionality are much more compromised without a hand than they are without a foot. Prosthetics now are remarkable. I'm getting older and my feet would probably be better served with carbon graphite than the beat up feet I'm walking around on now.

Reference

1. Jawad MU, Farhan SB, Haffner MR, et al. Malignant neoplasms originating from the bones of the foot: Predilection of hematological malignancies and sex-related and ethnic disparities in amputation. J Surg Oncol. Published online August 5, 2021. doi:10.1002/jso.26633