Breast Cancer

Breast Cancer and 9/11

PCBs (polychlorinated biphenyls) have been reported in several exposure assessment studies of responders or survivors of the September 11, 2001, terrorist attacks in New York City.  PCBs are reasonably anticipated to be a human carcinogen and there is evidence that PCBs cause breast cancer.

In April 2013, the Director of the National Institute for Occupational Safety issued a report that certified breast cancer as a covered illness for the World Trade Center Health Program.

PCB exposures from dust or smoke associated with the 9/11 attacks (including response and remediation activities) qualify as another exposure basis - in addition to nighttime sleep disruption related to response and cleanup activities (including shiftwork) - for certifying a member's breast cancer for treatment.


The WTC Program Administrator has found that PCBs were present in WTC dust in the New York City disaster area and, accordingly, the Program will now certify breast cancer in eligible WTC responders and survivors who were exposed to either shiftwork/nighttime sleep disruption or PCBs as a result of the 9/11 attacks.
— John Howard, Director of NIOSH, April 2013

About Breast Cancer

Breast cancer starts in the cells of the breast. A cancerous (malignant) tumour is a group of cancer cells that can grow into and destroy nearby tissue. It can also spread (metastasize) to other parts of the body.

Cells in the breast sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous (benign) breast conditions such as atypical hyperplasia and cysts. They can also lead to non-cancerous tumours such as intraductal papillomas.

But in some cases, changes to breast cells can cause breast cancer. Most often, breast cancer starts in cells that line the ducts, which are the tubes that carry milk from the glands to the nipple. This type of breast cancer is called ductal carcinoma. Cancer can also start in the cells of the lobules, which are the groups of glands that make milk. This type of cancer is called lobular carcinoma. Both ductal carcinoma and lobular carcinoma can be in situ, which means that the cancer is still where it started and has not grown into surrounding tissues. They can also be invasive, which means they have grown into surrounding tissues.

Less common types of breast cancer can also develop. These include inflammatory breast cancer, Paget disease of the breast and triple negative breast cancer. Rare types of breast cancer include non-Hodgkin lymphoma and soft tissue sarcoma.