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Study: The chance of a second breast cancer is higher among some Hawai'ian women

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Contents

At a glance Clinical trials
Study findings Guidelines
Strengths and limitations Questions for your doctor
What does this mean for me? Resources
In depth  

 

STUDY AT A GLANCE

What is this study about?

This study is about determining the risk of second breast cancers after a diagnosis of among women who are Native Hawai'ian.

 

Why is this study important?

Cases of ductal carcinoma in situ (), an breast cancer, have increased as breast screening has improved. Most women with can be cured and have no subsequent breast cancer. However, 40 percent of women with develop a second breast cancer—28 percent of those second breast cancers are invasive.

Concerns about overtreatment of for patients with low risk are weighed against concerns about undertreatment of patients with higher risk. To better understand the risk of a second breast cancer among women with , the researchers of this study evaluated cancer rates among different racial or ethnic groups within Hawai'i. Hawai'i is the most ethnically diverse U.S state with the greatest percentage of Native Hawai'ian and Pacific Islander (NHPI) women.

Some studies have shown that Asian American and Pacific Islander women have similar rates of second breast cancers compared to white women. However, experts now recognize that grouping Native Hawai'ian and Pacific Islander women with Asian American women may mask underlying differences.

When studied as a separate group, NHPI people have one of the highest mortality rates from cancer, highest chronic disease rate and shortest life spans of groups in the U.S. NHPI women are four times more likely to develop breast cancer than Asian American women.

In this study, researchers looked at the rate of second breast cancers among women from the state of Hawai'i who were diagnosed with .

 

Study findings

Researchers gathered Information from 6,221 women with from the Hawai'ian Tumor Registry. The patients included:

  • 2,207 Japanese women (37%)
  • 1,411 white women (23%)
  • 840 Filipino women (14%)
  • 821 Native Hawai'ian women (13%)
  • 491 Chinese women (8%).
  • Information about 388 patients of other races or ethnicities (6%) were combined.

 

For each woman, researchers looked at information about the original diagnosis, treatment received and whether a second breast cancer was diagnosed. Because the second diagnosis could have been a recurrence or residual cancer from the original , women were excluded if they had a second breast cancer diagnosis within six months of their diagnosis.

  • 93% of women with did not have a second breast cancer.
  • Women who were under age 50 at the time of their original diagnosis were more likely to have a second breast cancer after than women over age 50.
  • The frequency of second breast cancers differed among different racial and ethnic groups. Among women from Hawai'i included in the Hawai'ian Tumor Registry:
    • Native Hawai'ian, Filipino and Japanese women were up to 2-fold more likely to have a second breast cancer than white women.
    • Chinese women had similar rates of second breast cancer in the same breast as their and a lower risk of breast cancer in the opposite breast than white women.
  • The rate of a second breast cancer after varied among women who received different treatments for their .
    • Women who had breast-conserving surgery (BCS) alone ( with no radiation therapy) were less likely to develop a second breast cancer than those who had no treatment. 
    • Women who had breast-conserving therapy ( and radiation therapy) had fewer second breast cancers in the same breast than those who only had BCS.
  • However, rates of breast cancer in the opposite breast were similar among women who had BCS with or without radiation therapy.
    • Women who had BCS and were less likely to have a second breast cancer in either breast than women who only had BCS.
    • Women who had a mastectomy rather than BCS were 4-fold less likely to have a second breast cancer in the same breast and 1.4-fold less likely to have a second breast cancer in the opposite breast.
       

Strengths and limitations

Strengths

  • This study looked at a large group of racially and ethnically diverse women, including those with Native-Hawai'ian, Filipino, Chinese and Japanese ancestry. This study allows more accurate determination of risk for several groups.

Limitations

  • This was a anonymous analysis, so some information was incomplete. Hormone-receptor status was missing for 40% of patients, preventing conclusions about its impact on second breast cancers.
  • This study used data from the Hawai'ian Tumor Registry and may not reflect rates of second breast cancers in other geographical regions of the U.S. or among racial groups (e.g., African American or Hispanic American women).

 

What does this mean for me?

If you are a person of Hawai'ian, Filipino or Japanese ancestry who has been diagnosed with , you may be at greater risk of a second breast cancer. It is important to inform your doctor of your heritage because it may help them better understand your risk of subsequent cancers and help you decide together what treatment reduces your risk and best fits your situation.

If you have a family history of breast or other cancers, your risk of breast cancer may be higher. You might consider consulting with a genetic counselor to better understand your cancer risk, whether genetic testing could be helpful and whether there are preventive steps you may want to consider.

 

References

Taparra K, Fukui J, Kileen J, et al. Racial and Ethnic Disparities in Rates of Invasive Second Breast Cancer Among Women With Ductal Carcinoma In Situ in Hawaiʻi. JAMA Network Open 2021; 4(10):e2128977. doi:10.1001/jamanetworkopen.2021.28977.

 

Disclosure: FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board before publication to assure scientific integrity.

 

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posted 3/15/22

This article is relevant for:

women of Hawai’ian, Filipino or Asian American ancestry.

This article is also relevant for:

People with breast cancer

People newly diagnosed with cancer

People with a genetic mutation linked to cancer risk

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IN-DEPTH REVIEW OF RESEARCH

Study background

With improved breast screening, breast cancer is detected at increasingly early stages. Diagnoses of ductal carcinoma in situ (), an early form of breast cancer, have risen as cases of later-stage breast cancer have fallen. Early detection of breast cancer is linked to better outcomes, less burdensome treatment and fewer related deaths. Most women with can be cured and have no subsequent breast cancer. However, 40 percent of women with have a second breast cancer, and 28 percent of those breast cancers are invasive.

The best treatment approach for is controversial. Concerns about overtreating for patients with low risk are weighed against concerns about undertreating those with higher risk. Better understanding the risk of individuals would inform and improve treatment decisions.

Beginning with 2000, the U.S. Census allowed people to identify as Native Hawai'ian and Pacific Islander (NHPI) separately from Asian Americans. Studies of NHPI people show that they generally have among the highest mortality rates from cancer, the highest rate of chronic disease and the shortest life span of groups in the U.S. Prior studies have shown that NHPI women have breast cancer four times more often than Asian American women. However, many studies continue to group NHPI with Asian American individuals, which limits our understanding of risk.

To better define the risk of a second breast cancer among women with , the researchers of this study evaluated cancer rates among different racial or ethnic groups in Hawai'i. Hawai'i is the most ethnically diverse U.S state, with the greatest percentage of NHPI women.

 

Researchers of this study wanted to know

Researchers wanted to know the risk of a second breast cancer among women from Hawai'i who had been diagnosed with ductal carcinoma in situ ().

 

Populations looked at in this study

This study included 6,221 women from the Hawai'ian Tumor Registry who were diagnosed with between 1973 and 2017. All women were age 20 or older and the majority (77%) were over 50 at the time of their diagnosis.

The patients included:

  • 2,207 Japanese women (37%)
  • 1,411 white women (23%)
  • 840 Filipino women (14%)
  • 821 Native Hawai'ian women (13%)
  • 491 Chinese women (8%)
  • Information about 388 other patients of other races or ethnicities (6%) were combined.

 

 Because the second diagnosis could have been a recurrence or residual cancer from their original , women were excluded if they had a second breast cancer diagnosis within six months of their diagnosis.

 

Study design

Information about women with was collected retrospectively from the Hawai'ian Tumor Register, one of the original National Institute of Cancer Surveillance, Epidemiology and End Result () registries. Researchers evaluated information about the original , including pathology, hormone receptor status and treatment received. They looked for statistical correlations between the original diagnosis, whether a woman had a second breast cancer, and if so, in which breast.

 

Study findings

Most women with did not have a second breast cancer.

Of the 6,221 women with DCIS:

  • 5,777 (93%) had no second breast cancer within the time of the study.
  • 441 (7%) were diagnosed with an invasive second breast cancer. Of these:
    • 190 had a second breast cancer in the same breast as the original .
    • 254 had a second breast cancer in the opposite breast.

 

Women under age 50 at the time of their original diagnosis were more likely to have a second breast cancer after than women over 50.

 

The frequency of second breast cancers differed among racial and ethnic groups.

After adjusting for age, cancer type, diagnosis year and time of first treatment, the frequency of second breast cancers in the same breast were evaluated in comparison to white women.

Demographic group in Hawai'i Frequency of a second breast cancer in the same breast as
white women comparison group
Native Hawai'ian women 3-fold more common
Filipino women 2-fold more common
Japanese women 1.5-fold more common
Chinese women did not differ

 

 

 

 

 

 

After adjusting for age, cancer type, diagnosis year and time of first treatment, the frequency of second breast cancers in the opposite breast were evaluated in comparison to white women.

Demographic group in Hawai'i Frequency of a second breast cancer in the same breast as
white women comparison group
Native Hawai'ian women 1.7-fold more common
Filipino women 1.7-fold more common
Japanese women 1.3-fold more common
Chinese women 1.25-fold less common

 

 

 

 

 

 

The rate of a second breast cancer after differed depending on the treatment received for the original .

 

Researchers looked at how often women had second breast cancers in the same breast compared to women who had breast-conserving surgery (BCS) only.

Treatment Frequency of a second breast cancer in the same breast as
BCS only comparison group
no treatment 2-fold more common
BCS + radiation therapy 2-fold less common
BCS + radiation therapy* over 2-fold less common
mastectomy  4-fold less common
mastectomy + just under 2-fold less common

 

 

 

 

 

 

*Systemic therapy includes chemotherapy and/or hormonal therapy

 

Researchers also reviewed how often women had second breast cancers in the opposite breast compared to women who had breast-conserving surgery (BCS) only.

Treatment Frequency of a second breast cancer in the same breast as
BCS only comparison group
no treatment 1.5-fold more common
BCS + radiation therapy similar frequency to BCS only
BCS + radiation therapy* 2-fold less common
mastectomy  1.4-fold more common
mastectomy + 1.6-fold more common

 

 

 

 

 

 

*Systemic therapy includes chemotherapy and/or hormonal therapy

 

One caveat is that underlying differences based on pathology or receptor status in each group of women may make them more or less likely to have a second breast cancer (e.g., some other factor may have put women who received after mastectomy at higher risk).

 

Strengths and limitations

Strengths

  • This study looked at a large group of racially and ethnically diverse women, including those of Native Hawai'ian, Filipino, Chinese and Japanese ancestry. Unlike studies in which white women were the overwhelming majority and other groups are statistically underrepresented, this study allows a more accurate determination of risk for several groups.
  • Differences in treatment approaches were evaluated and linked to different rates of second breast cancers.

Limitations

  • This is a anonymous analysis, so some information was incomplete. The hormone-receptor status was missing for 40 percent of patients, preventing conclusions about its impact on second breast cancers.
  • This study used data from the Hawai'ian Tumor Registry and may not reflect rates of second breast cancers in other geographical regions of the U.S. or among other racial groups (e.g., African American or Hispanic American women).

 

Context

Prior studies have shown variations in the risk of second breast cancer among people of different ethnicities or races. African American women have higher rates of a second breast cancer in the same or opposite breast than white women. Hispanic women have a higher rates of secondary breast cancer in the same breast as compared to white women. Some studies show that Asian American and Pacific Islander women have similar rates of second breast cancers compared to white women. However, experts now recognize that grouping Native Hawai'ian and Pacific Islander women with Asian American women may mask underlying differences.

 

Conclusions

This study indicates that race and ethnicity are important factors in understanding the risk of second breast cancer among women with . Hawai'ian, Filipino and Japanese women may have a higher risk of secondary breast cancer than previously recognized. Women with under age 50 may also be at greater risk than those diagnosed at older ages. Improving our understanding of the risk of subsequent breast cancer may allow for treatment decisions that better fit patients. This study and others highlight the importance of assessing the risk for racial and ethnic groups independently so that the decreased risk of one group does not mask the increased risk of another group.

 

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posted 3/15/22

Expert Guidelines Expert Guidelines

The National Comprehensive Cancer Network (NCCN) guidelines include the following options for treatment of DCIS:

  • Breast-conserving therapy ( followed by radiation therapy) without lymph node surgery.
  • Total mastectomy with or without lymph node surgery.
  • Breast-conserving surgery without lymph node surgery followed by accelerated partial breast irradiation.
  • Breast-conserving surgery without lymph node surgery (and without radiation therapy).   

Following surgery, the NCCN recommends that patients:

  • Consider endocrine therapy for 5 years for people with ER-positive who:
    • received breast conservation and radiation therapy.
    • were treated with surgical excision only. 
  • Receive counseling regarding risk reduction.

Updated: 03/12/2022

Questions to Ask Questions to Ask Your Doctor

  • I have and am of Native Hawai'ian, Filipino or Japanese ancestry. What is my risk of a second breast cancer?
  • What treatment for best fits my personal and family history?
  • Would I benefit from genetic counseling?
  • How does my age at diagnosis affect my treatment?
  • What are the risks or benefits of different treatments for ?

Open Clinical Trials Open Clinical Trials

The following clinical research studies focus on addressing health disparities in cancer. 

Updated: 03/16/2022

Peer Support Peer Support

The following organizations offer peer support services for people with, or at high risk for breast cancer:

Updated: 02/25/2022

Who covered this study?

Scope

Native Hawaiian resident shines a light on health disparities This article rates 4.0 out of 5 stars

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