Posted on December 22, 2022

By Heather Perkins (she/her), Deputy Director

The Burden of Overtreatment – DCIS and BabyTam Research Reprised at SABCS 2022 vs 2018

As a person living in breast cancer survivorship, I value Breast Cancer Action’s (BCACtion) unabashed response, research, and stance to provide unbiased and comprehensive information, so people gain the opportunity to decide the best approach and treatment for their cancer diagnosis. Also, I appreciate that BCAction gives voice to another reality within the breast cancer industry – overtreatment. 

Overtreatment within the breast cancer industry adds burden to an already overwhelming reality people are faced with when learning they have breast cancer.   

Overtreatment is a side-effect of many factors within the breast cancer industry: corporate profiteering, lawsuits, liabilities, stressed-out doctors and nurses, biases to treatment options, over-standardizing treatment guidelines, Big Pharma influences, capitalist economic structures, and …you get the point.  BCAction advocates for people at risk of and living with breast cancer which is why it is essential we give continued voice to how overtreatment of a breast cancer diagnosis occurs and brings added burdens to our communities.  

BCAction eagerly participates in the San Antonio Breast Cancer Symposium (SABCS) annually. It’s a space where we learn, question, and share the latest of what is happening and not happening within the breast cancer industry.  This was my first year attending the symposium. BCAction has numerous factsheets available to everyone, at no cost, on our website. One such factsheet is titled “Ductal Carcinoma In Situ (DCIS)”. This year’s SABCS program hosted multiple sessions speaking to updates in regards to the industry’s philosophies, approaches, and guidelines in regards to treatment of DCIS. In addition to BCAction’s interests in DCIS, I personally, know people living with a DCIS diagnosis, and because of this I attended a cluster of sessions focusing on this very topic.  

One such session was “10-year Results of Phase 3 Trial of Low-dose Tamoxifen in Non-Invasive Breast Cancer,” with lead author Dr. Andrea DeCensi, MD, Director of the Medical Oncology Unit at Ente Ospedaliero Ospedali Galliera in Italy, who presented a follow up of a 5-year study of data presented at SABCS in 2018.  

To start, DCIS is a condition of abnormal cells found in the lining of the milk ducts that has not spread into nearby tissue. It is the most common type of non-invasive breast cancer. DCIS accounts for 20% of breast cancer diagnoses and would be the fifth most common cancer in people assigned female sex at birth if classified independently. Unfortunately, experts cannot tell which of them with untreated DCIS will eventually develop invasive breast cancer and which will not. However, there is a general consensus that DCIS represents an intermediate step between normal breast tissue and invasive breast cancer. Treatment guidelines are often the least agreed upon within the industry. It’s a space where overtreatment has opportunity.  

There are several treatment options for people diagnosed with DCIS. Treatments are recommended to reduce the risk of developing a local recurrence and/or an invasive breast cancer.  Tamoxifen is a common treatment option for people with a DCIS diagnosis.  Tamoxifen is a drug used to treat all stages of hormone receptor-positive breast cancer.  The dosage, longevity of use, and outcome continues to be researched.  Below are my takeaways from DeCensi’s findings over the past 5 years in regards to tamoxifen, its outcomes and its opportunities to be an alternative or additive for treatment options.  

Babytam is the 5-mg daily dose of tamoxifen being studied in the ongoing TAM-01 study, which is investigating incidence of invasive breast cancer or ductal carcinoma in situ (DCIS) among high-risk women who have received the treatment regimen for 3 years.  

Tamoxifen, a selective estrogen receptor modulator, was first approved in the United Kingdom in 1972 and this was followed by approvals in the United States for stage IV breast cancer in postmenopausal women in 1977 and for primary or contralateral breast cancer risk reduction in 1988. Indications now for treatment in male and female patients, adjuvant treatment after completion of primary treatment (surgery and radiation), to reduce risk in certain high-risk patient populations, and for hormone receptor–positive and estrogen receptor (ER)–positive breast cancers. It is available as an oral tablet or solution. In the United States, the standard dose ranges from 20 to 40 mg/d depending on risk and disease state.  

TAM-01, a national multicenter randomized trial out of Italy, has been investigating babytam by comparing outcomes among 500 women 75 years and younger (mean study age, 54 years) randomized to babytam (n = 253; 43%, premenopausal) or placebo (n = 247; 40%, premenopausal) who have atypical ductal hyperplasia (20% of each group), lobular carcinoma in situ (11%, babytam group; 10%, placebo group), or ductal carcinoma in situ (DCIS; 69% and 70%, respectively)—all types of intraepithelial neoplasia. All are receiving at least 3 years of treatment following surgery, have a follow-up of at least 7 years, and were enrolled from 14 centers in Italy. Follow-up comprises a visit and quality of life questionnaire every 6 months for 3 years, followed by mammography every year for 10 years. The current primary end point is incidence of invasive breast cancer or DCIS.  

Five-year data presented at SABCS in 2018 showed the trial regimen to have reduced by 52% overall (22 events with tamoxifen, 37 with placebo) the recurrence of invasive breast cancer or DCIS (HR, 0.48; 95% CI, 0.26-0.92) vs placebo. Among women with contralateral breast cancer, this reduction was even greater: 76% (HR, 0.24; 95% CI, 0.07-0.87). Further, those in the treatment arm were shown to have only 1 additional hot flash per day vs placebo. After these data were announced in 2018, the National Comprehensive Cancer Network began to recommend babytam after DCIS in a patient if symptomatic or unwilling/unable to take the full dose, DeCensi noted.  

“In the present study, we update the findings on breast cancer recurrence after a median of 9.14 years (IQR, 7.16-10.73) and a total of 10.57 person years of follow up to see if the treatment effect is retained,” DeCensi said, “with more events and after a median of approximately 6 years from treatment cessation. The follow-up was updated with the most recent visit within 12 months in two-thirds of the participants.”  

The newest analysis is based on a median of 9.7 (range, 8.3-10.9) years of data.  

Overall, these 10-year data show babytam continuing to reduce incidence of invasive breast cancer or DCIS. There was a 42% reduction in the primary end point (HR, 0.58; 95% CI, 0.35-0.95), with the survival curves remaining noticeably separated at 10 years, favoring babytam in cumulative breast cancer incidence rate.  

What does this mean 5 years later for people living with cancer? There is a reduction of breast cancer in high-risk patients with a new potential standard of care for DCIS, and DeCensi noted that the effect on contralateral breast cancer shows potential for reopening the door to prevention in DCIS and high-risk women.   

Babytam also has potential as an alternative to treatment cessation for people living with cancer’s tolerance level to the 20-mg daily dose, to reduce interval cancers in premenopausal women with dense breasts, to effectively reduce risk in young women following chest radiation, and to be effective in women with BRCA2 or who are moderate penetrance gene carries (PALB2, CHEK2, ATM).  

DeCensi concluded that babytam 5 mg daily for 3 years lowers recurrence from noninvasive breast cancer at 10 years, with carryover effect and without significant adverse events; opens a door for primary prevention in contralateral cancer; and has a low risk of death (0.6% at 10 years), supporting treatment de-escalation in DCIS.  

For me, this means action must be taken within the industry to allow for doctors to have more time with their patients, and dollars must be allocated to include trained patient navigators who assist patients in understanding various treatment options, side-effects and outcomes.  For me, it means a health journey is personal and people must have the power and comprehensive information available so they may make decisions that match their values and their unique beautiful selves.  It means recognizing the immediate reaction of wanting to act fast when you hear “You have cancer,” but also being relentlessly adamant that doctors must add, “And you have some time to learn treatment options, seek information, and discover the treatment philosophy, approach, and plan that matches your values and diagnosis. This will assure your wellbeing, and assure we do not over treat you with unnecessary toxins or create painful lasting health effects. Together, we will seek the best outcome that includes your values and your quality of life.” 

Cancer’s effects are unique in every case.  Standardized structures and language in the cancer industry must evolve to align with this uniqueness and must take actions to avoid overtreatment. Overtreatment is costly to people’s overall physical, emotional, spiritual, and financial wellbeing. It is time to evolve the current rigid and limiting systems and structures within the breast cancer industry. It is time for the breast cancer industry to see and hear people and recognize people for being their beautiful unique selves.   

It is time for unbiased comprehensive available information, personalized and humanized language, systems, and structures, and the prioritizing of people over profits.   


De Censi A, Lazzeroni M, Puntoni M, et al. 10-year results of a phase 3 trial of low-dose tamoxifen in non-invasive breast cancer. Presented at: SABCS; December 6-10, 2022; San Antonio, Texas. Abstract GS4-08.