WEDNESDAY, Jan. 5, 2005 (HealthDayNews) -- Women whose breast cancer is detected by physical examination are about three times more likely to receive chemotherapy than women whose breast cancer is detected by mammography, a Dartmouth-Hitchcock Medical Center study finds.
The reason: Screening mammography detects breast cancer at an earlier stage, the study said.
Researchers reviewed data on 992 women with invasive breast cancer. Of those, 532 had their cancer detected by physical examination and 460 had their cancer detected by mammography.
The study found that, overall, women whose breast cancer was found by physical examination were three times more likely to have chemotherapy than women whose breast cancer was detected by mammography.
Women aged 40 to 49 were about twice as likely to have chemotherapy if their cancer was detected by physical examination. Women 70 and older were about five times more likely to receive chemotherapy.
Overall, women whose breast cancer was detected by physical examination were more than twice as likely to have a mastectomy rather than breast conservation surgery. Women aged 70 and older were five times more likely to have a mastectomy if their breast cancer was detected by physical examination rather than mammography.
The study authors noted that chemotherapy is commonly recommended for women with breast tumors larger than 1 centimeter in diameter or if the cancer has spread to the lymph nodes. Cancers detected by mammography were only half as large as those detected by physical examination, the study found.
It also found that breast cancer had spread to the lymph nodes in 16 percent of the women whose tumors were detected by mammography, compared with 42 percent of the women whose breast cancer was detected by physical examination.
The study findings indicate that screening mammography detects breast cancer at an earlier stage and increases the likelihood that it can be treated with less toxic therapy, the authors concluded.
The findings appear in the January issue of the American Journal of Roentgenology.
More information
The U.S. National Cancer Institute has more about breast cancer screening.
