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Volume 102 Issue 15 Interview Transcript

Adam Weiss: Welcome to the JNCI podcast, a production of the journal of the National Cancer Institute. I'm Adam Weiss.

Adam Weiss: A diagnosis of breast cancer is never a good thing. But if you're an uninsured African American woman, it could be even worse. A number of studies have shown that African Americans have poorer breast cancer survival rates than non Hispanic whites. But a study published in Issue 15 of JNCI was the first to compare these two populations on equal footing. In the past, differences in geography, economic situation and quality of care have made it hard to work out what part of the difference in survival rate is due to what. This study looks at people with similar socioeconomic backgrounds, getting care from the same doctors at the same hospital. Because all the patients in the study got the same care, the researchers were able to look at factors like ethnicity, education, employment status and income levels to see what really made a difference in cancer survival. After analyzing ten years of medical records from almost 600 people, this innovate approach led to some interesting findings. Ian Komenaka is a doctor at Wishard Hospital in Indianapolis and a lead author of the paper. He joins me via phone from his office. Welcome, Dr. Komenaka.

Ian Komenaka: Thank you.

Adam Weiss: So, as I said, it's fairly well known that African American women do worse when it comes to breast cancer. And I know that’s partly because of a biological reason of more aggressive tumors. But, the big that you’ve found, and that people have said in the past, is that it's socioeconomic circumstances. But that kind of common knowledge isn’t exactly what your study showed in the end, right?

Ian Komenaka:
Yes. Everything that you’ve mentioned is correct in that initial studies looking at African American compared to non Hispanic white women have found a discrepancy with African American women having poorer survival. However, with further research, we've found that biological differences, meaning more aggressive tumor subtypes, like the hormone receptor negative, or the hormone receptor negative and Hertu [ph?] negative breast cancers are more common in the African American women, explain part of the difference in the survival. We’ve also found that barriers to health care access and underutilization of breast cancer screening, have also contributed to this difference as well. And then more recently, socioeconomic or socio-demographic variables contribute as well.

Ian Komenaka: So what we've tried to do at Wishard Hospital is to investigate the clinical, the biological and the socio-demographic variables in this patient population. The interesting thing about the population at Wishard Hospital is, although it is a county hospital it has a pretty similar number of non Hispanic white women and African American women. Many of the other county hospital populations are predominantly African American women. And therefore, a comparison of similarly disadvantaged non Hispanic white women, versus African American women is not possible.

Adam Weiss: Now, one of the things that you're actually able to do because of that somewhat special place that Wishard Hospital has is, take a look at people on equal footing. Usually when you see reports of African American women being worse off when it comes to breast cancer, it's because unfortunately, they're worse off in general when it comes to health, when it comes to socioeconomic status. When it comes to a lot of different things. But in this case, you have a lot of people coming into the hospital that are pretty much the same, in terms of background, except for race. And you can compare them directly using the same treatment plans and the same doctors, even, right?

Ian Komenaka: Yes. That’s correct. Many, many of the other studies have African American women and non Hispanic white women who are very dissimilar, socio-demographic or socioeconomic backgrounds. That is a unique finding, or an uncommon finding of the Wishard hospital population, is that our patient populations are very similar, other than the fact that some are non Hispanic white and some are African American. They are both predominantly an obese population. Both populations are majority smokers. Both populations do not use screening mammograms most of the time. And they're undereducated. Very likely to be not employed, and also underinsured. So, that is a difference in our patient population compared to other studies, which have looked at African Americans compared to non Hispanic whites.

Adam Weiss: So I guess the advantage there, is that you're able to take the similarities between the two groups and set things up so they sort of cancel each other out. When you did that, what did you find?

Ian Komenaka: So, what we did in our initial analysis was to see if there was differences in non Hispanic whites compared to African American women, for disease free and overall survival. And, then later the breast cancer specific survival. And where there were significant differences, and I guess in our final model we were looking at breast cancer specific survival. We tried to identify factors which contributed significantly to that difference. So, with regard to breast cancer specific survival, there was a difference between the African Americans and the non Hispanic white patients. With African Americans more likely to die from breast cancer. The interesting thing was, when you compare the death from breast cancer with the deaths from other causes, both of these patient populations died from a significant number of deaths from other causes. And this finding also was different from previous studies, which often times in deaths from comorbidities, or deaths from other causes, the African Americans tend to have more deaths than non Hispanic whites. However, again because our population are similarly disadvantaged, underinsured, higher number of smokers. More people being obese, that both of these populations died from causes other than breast cancer. Then when we looked at only breast cancer deaths, the African Americans had significantly more deaths than the non Hispanic whites.

Adam Weiss: Yeah. Looking at the paper, it looks like all else being equal, there are 50 percent more people dying in the African American population than in the non Hispanic white population.

Ian Komenaka: Correct. The hazard ratio was about 1.64, which means that there's an excess risk of about, exactly a little bit more than half.

Adam Weiss:
And is this where that biological difference that African American women tend to get more aggressive breast cancer comes in?

Ian Komenaka: Yes. Yes. So once we found that there was a difference in the risk of dying from breast cancer, between these two populations, then we wanted to try and tease out, to see what contributes to that difference. And, when we initially looked at clinical variables, which are commonly used in breast cancer analysis such as age of diagnosis and stage of disease, there was very little change in the risk of dying from breast cancer with the African Americans still having a higher risk compared to the non Hispanic whites. However, when we factored in the hormone receptor which is kind of an indicator of the biology of the disease, that significantly contributed to the risk of dying of breast cancer in African Americans. Therefore, making the difference not statistically significant once the hormone receptor status, or the biology was considered.

Adam Weiss: So if you take two people, or two populations, one African American, and one non Hispanic white and you pick people that have the same type of cancer, then there isn’t a difference. It's just that more African Americans get that more aggressive kind of cancer.

Ian Komenaka: I don't think it's quite that simple. But, you're more likely to have similar outcomes when your cancers are similar.

Adam Weiss: So I guess the fact that this is being reported as you know, “Breast cancer kills more uninsured African American women,” isn’t quite the whole story. It sounds like there are more differences in the background of these people than just race, that has an effect on their outcomes in terms of breast cancer.

Ian Komenaka: Yes. When you look at our analysis again, of the risk of dying from breast cancer, when you factor in the biology which we use the hormone receptor status as an indicator of the biology, that explained or contributed a significant proportion to the differences between the African American and the non Hispanic white women. However, also, the socio-demographic variables or socioeconomic variables do contribute significantly as well. And we show that when we factor in employment status, which was the one variable that was factored into the risk of dying from breast cancer. That further explained the differences between the two races.

Adam Weiss: So are you saying that, all of the things being equal, besides race, the biggest difference in survival between your two groups was whether or not someone had a job?

Ian Komenaka: According to our model, it did. So why employment came out of the analysis as the most important socio-demographic variable, I'm not sure. But it's probably a very complicated answer.

Adam Weiss: So if those two things are the main factors, what I see as the new thing that comes out of the study is this. If people come from the same socioeconomic background, get treated at the same hospital by the same doctors, under the same circumstances, they make the same decisions and have pretty much the same outcomes, with the exception of this one biological difference that does seem to exist, between African Americans and non Hispanic whites.

Ian Komenaka: Yes. So as far as the overall findings of this study, we did find that African Americans do have more aggressive types of breast cancer. And, this was found even though the patients were of similar age, and similar socioeconomic background. And they were equally unlikely to undergo screening mammograms. The African Americans still presented with a more advanced clinical stage. And did have a higher risk of dying from breast cancer. However, what was new in this study is that, number one, again, in this similarly disadvantaged population, the African Americans were equally likely to choose a breast conserving operation as well as undergo all types of adjuvant therapy, compared to the non Hispanic white patients.

Adam Weiss: And adjuvant therapy is things like chemotherapy?

Ian Komenaka: Chemotherapy, radiation, hormone therapy. And then, when we’re looking at all the factors contributing to risk of breast cancer, again, the biology was an important contributor to the difference in risk of death in African Americans compared to non Hispanic white patients. But, also importantly we found that socio-demographic variables contribute to this difference in deaths, as well. And, for that reason, I think that it is important for future research and especially in clinical trials, that the socio-demographic variables be collected and reported and considered as a possible contributor to differences in outcomes in

Adam Weiss: Well, it sounds like you found both that people are more alike than a lot of people thought, while also confirming that there are important biological differences. It's also good to know that you can use a place like Wishard Hospital to nail it down to what's actually different. Ian Komenaka, thanks for talking with me.

Ian Komenaka:
Well, thank you very much for your time. We appreciate it.

Adam Weiss: And thank you for listening to the JNCI podcast. For more interviews, audio summaries of JNCI issues, and more information about today’s topic, visit JNCI.Oxfordjournals.org. to get in touch with us, send an email to podcasts@oxfordjournals.org, or follow us on Twitter. We’re @JNCI_Now. If you liked this episode, please share it with your colleagues and friends. I'm Adam Weiss. Thanks again for listening.

Adam Weiss: So what could be done after this study to expand upon what they found to draw out some more information? What other studies could build on this, and what would those studies do to give you the information that you’re really looking for?