A tiny spot on a precautionary ultrasound that former `` Good Morning America '' co-host Joan Lunden received after getting an all-clear on her annual mammogram was the first sign of trouble . A biopsy was taken . `` I knew the minute the doctor walked in the office , '' Lunden told CNN Chief Medical Correspondent Dr. Sanjay Gupta in an interview . `` You could just tell by her demeanor . She said , 'you definitely have breast cancer . ' '' Lunden , who co-hosted `` GMA '' from 1980 to 1997 and promotes health and wellness for women , said she `` jumped into action , '' immediately consulted specialists and sought other opinions before starting with chemotherapy . `` When I heard those words -- it does n't make any difference if you 're a doctor -- those are scary words and they 're shocking , '' Lunden said . Doctors earlier this month discovered two small tumors in her right breast , she said . It was triple negative breast cancer , a rare and aggressive form that occurs more often in younger women and African-American or Hispanic women . `` This is kind of subset , '' she said . `` One thing I learned is that breast cancer , you think of it as one thing . Every woman has a different kind of breast cancer as far as how the pathology comes out , where it is . And you really need to get a lot of opinions . '' On Tuesday , Lunden , 63 , first revealed her recent diagnosis to fans via Twitter and a letter on her website JoanLunden.com . She considered keeping the news private . What would she say to her 9- and 11-year-old twins ? She thought herself somehow exempt from all this ? `` I was scared that people would think I let them down , '' she said . `` In the first two days or so , I just wanted to go away somewhere and not let anybody find out . I also felt like I did n't want to tell the kids because my younger kids would be worried . We were advised by everyone that that was really a mistake . '' Lunden recently offered her first TV interview about having the disease to current `` GMA '' co-host and breast-cancer survivor Robin Roberts , who advised her on dealing with her hair loss and other issues . `` GMA '' co-host Amy Robach is currently being treated for breast cancer . Lunden told CNN that she decided to shave her hair before losing it to chemotherapy , enabling her to `` stay in an empowered position instead of woe-is-me patient position . '' `` When it starts to go , it 's shocking , embarrassing and depressing , '' she said she learned of the hair loss . `` Preempt it . Get it shaved off . I did that . And I thought it was going to be like the biggest deal in the world . And you know what ? I felt I did n't have it done to me . I walked in and I said , 'Do this . ' '' After consulting doctors , Lunden said , she decided on therapy aimed at reducing the size of a tumor with chemotherapy , a lumpectomy to remove the cancer , followed by radiation therapy . `` What I say I 'm doing does n't mean that 's what you should be doing , '' she said . `` Every woman 's breast cancer is different . '' Lunden said her tumor was picked up after an ultrasound , which is used for women who have dense fibrous breast tissue where cancers are not always detectible on mammograms . Lunden , whose late father was a cancer surgeon , said she had no symptoms before her diagnosis or family history of cancer . `` Most women do not have any symptoms before they 're diagnosed with breast cancer , '' Dr. Valerie Montgomery-Rice , dean of the Morehouse School of Medicine , told CNN . `` A lot of women will pick up something that feels strange on their own . '' Drug offers hope for some cancer survivors who want children .
`` GMA '' host Joan Lunden revealed this week that she is in treatment for breast cancer . Discovery came after a precautionary ultrasound and biopsy . Lunden : `` I was scared that people would think I let them down ''