After breast cancer diagnosis, risk of thyroid cancer goes up

March 07, 2015

San Diego, CA-- Breast cancer survivors are at increased risk of developing thyroid cancer, especially within five years of their breast cancer diagnosis, according to a new analysis of a large national database. The study results will be presented Thursday at the Endocrine Society's 97th annual meeting in San Diego.

"Recognition of this association between breast and thyroid cancer should prompt vigilant screening for thyroid cancer among breast cancer survivors," said lead investigator Jennifer Hong Kuo, MD, assistant professor of surgery at Columbia University, New York City.

Breast cancer survivors, whose numbers are increasing, should receive counseling regarding their higher-than-average risk of thyroid cancer, Kuo recommended.

Until now, Dr. Kuo said, the relationship between breast and thyroid cancer has been controversial, largely based on single-institution studies that have suggested a possible increase in thyroid cancer incidence after breast cancer.

The researchers used the National Cancer Institute's Surveillance, Epidemiology, and End Results 9, or SEER 9, database to identify the number of individuals with a diagnosis of breast and/or thyroid cancer between 1973 and 2011. They found 704,402 patients with only breast cancer, 49,663 patients with only thyroid cancer and 1,526 patients who developed thyroid cancer after breast cancer.

Compared with patients with breast cancer alone, women who had breast cancer followed by thyroid cancer were younger on average when diagnosed with their breast cancer. They also were more likely to have had invasive ductal carcinoma (the most common type of breast cancer), a smaller focus of cancer, and to have received radiation therapy as part of their breast cancer treatment.

There was no difference in risk based on whether the breast cancer was hormone receptor positive or had spread to lymph nodes, according to the investigators.

Compared with patients who had only thyroid cancer, breast cancer survivors who developed thyroid cancer were more likely to have a more aggressive type of thyroid cancer, but the cancers were smaller in size and fewer patients required additional radioactive iodine treatment. Because thyroid cancer tends to occur at younger ages than breast cancer does, breast cancer survivors who then developed thyroid cancer were older on average than those with only thyroid cancer: 62 versus 45 years, respectively, Dr. Kuo reported.

The study findings showed that breast cancer survivors developed thyroid cancer at a median of five years. Therefore, Dr. Kuo recommended that every year for the first five years after a breast cancer diagnosis, especially survivors who received radiation therapy should undergo a dedicated thyroid exam.

Dr. Kuo said she plans to study whether tamoxifen treatment, typically given for five years after a breast cancer diagnosis, may play a role in increasing the risk of thyroid cancer.

Radiation therapy to the head, neck or chest is a known risk factor for thyroid cancer, according to the Endocrine Society's Hormone Health Network. Female sex raises the risk of both thyroid and breast cancer. The incidence of thyroid cancer is increasing, and Dr. Kuo said researchers must have a better understanding of the etiology for this increase.
-end-


The Endocrine Society

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.