Dr. Lawrence Tseu, a retired Honolulu dentist and noted philanthropist, has donated $720,000 to the American Cancer Society Hawaii Pacific for research to stop breast cancer from spreading to other parts of the body.

The gift is the largest ever given to the ACS Hawaii Pacific for research, organization officials said.

The donation is named the “;Dr. Lawrence and Mrs. BoHing Chan Tseu American Cancer Society Grant for Breast Cancer Research.”;

Tseu's wife survived breast cancer after undergoing a mastectomy many years ago and died in 2008 after a three-year battle with lung cancer.

“;Every six months she would have an operation and they would take out a part of her lung,”; Tseu said. “;It's devastating to see your loved one deteriorate.”;

His sister, Miriam, died in the 1960s when cancer in her uterus metastasized to her surrounding organs.

“;I lost the two women I loved the most to cancer,”; Tseu said.

Jackie Young, ACS Hawaii Pacific chief staff officer for mission, said, “;This very generous gift will fund an important research project that could improve how breast cancer is treated and dramatically increase the survival rate.”;

Tseu agreed to give $500,000 for the project when Young first approached him about a donation, then he called her and said he wanted to donate the entire amount needed for the research.

Wael ElShamy, a Cancer Research Center of Hawaii researcher, discovered that a certain molecule plays a key role in breast cancer metastasis, ACS said.

When the molecule is active in breast cancer cells, it promotes an abnormal number of chromosomes, called aneuploidy.

Aneuploid breast cancer cells are often observed in early lesions, the ACS said. “;Therefore, targeting the molecule that is responsible for aneuploidy with drugs will be beneficial in eradicating breast and perhaps other types of cancer metastases.”;

A portrait honoring the gift will be unveiled in a ceremony at 2:30 p.m. tomorrow at the American Cancer Society Hawaii Pacific office in Nuuanu.

Tseu pledged $1 million last November to Chaminade University to build an undergraduate nursing facility.