Obesity increases second cancer risk in women with breast cancer

This article is from the NEJM Journal Watch High BMI Increases Risk of Second Cancers in Women with Breast Cancer.
Comment by William J.
Gradishar, MD when breast cancer was first diagnosed.
Women who are overweight or obese have an increased risk of being diagnosed with a second cancer
.

Patients often ask what factors they can control to reduce the risk of new or recurring cancer
.

Discussions usually focus on diet, drinking, and exercise, but for women with breast cancer, the impact of a high body mass index (BMI) on the second cancer is still unclear
.

Through the tumor registration data and medical records of 7,500 women with non-metastatic breast cancer in the Kaiser Permanente system, the researchers obtained BMI, tumor characteristics, treatment options, and other cancer diagnostic information
.

When breast cancer was first diagnosed, 33% of women were overweight (BMI 25 to <30 kg/m2), 34% were obese (BMI ≥ 30 kg/m2), the average age was 61 years, and 82% were white
.

Most patients are initially diagnosed as stage I breast cancer; however, obese patients are more likely to be diagnosed as stage II/III breast cancer than patients with normal BMI
.

During an average follow-up of 88 months, 12.
7% of patients were diagnosed with a second cancer, 62% of which were related to obesity (including postmenopausal breast cancer, colorectal cancer, uterine body cancer, ovarian cancer, pancreatic cancer, kidney cancer, Thyroid cancer, multiple myeloma, meningioma, liver cancer, cardia cancer, gallbladder cancer and esophageal cancer)
.

In a multivariate analysis, for every 5 kg/m2 increase in BMI, the patient’s risk of being diagnosed with a second cancer increased by 7%, the risk of being diagnosed with obesity-related cancer increased by 13%, and the risk of being diagnosed with second breast cancer increased by 11%.
The risk of developing second estrogen receptor (ER)-positive breast cancer increases by 15%
.

Comment This study proves that breast cancer survivors who are overweight and obese have an increased risk of developing a second cancer
.

The authors acknowledge the limitations of the study, including uncertainty about whether the patient population follows screening recommendations, exercise, and weight loss strategies
.

But these data still highlight the cancer-related risks faced by the overweight patient population
.

Whether weight loss can reduce the above risks is a concern of clinical research
.

Feigelson HS et al.
Body mass index and risk of second cancer among women with breast cancer.
J Natl Cancer Inst 2021 Apr 5; [e-pub].
(https://doi.
org/10.
1093/jnci/djab053 ) Related reading NEJM Journal Watch is published by NEJM Group.
Internationally renowned doctors are invited to comment on important papers in the medical field to help doctors understand and use the latest developments
.

"NEJM Frontiers of Medicine" is translated several times a week, published on the app and official website, and selected 2-3 articles are published on WeChat
.

Copyright information This article was translated, written or commissioned by the "NEJM Frontiers of Medicine" jointly created by the Jiahui Medical Research and Education Group (J-Med) and the "New England Journal of Medicine" (NEJM)
.

The Chinese translation of the full text and the included diagrams are exclusively authorized by the NEJM Group
.

If you need to reprint, please leave a message or contact nejmqianyan@nejmqianyan.
cn
.

Unauthorized translation is an infringement, and the copyright owner reserves the right to pursue legal liabilities
.