Should Stage 0 breast or prostate cancer be treated?
Some breast and prostate cancer tumors pose little likelihood of rapidly spreading in the near future, or at all. In fact, some health experts debate whether they should even be called cancer, as the word scares patients and may result in overtreatment.
The debate has gone on for years. At a 2012 National Cancer Institute conference, participants recommended slow-growing and asymptomatic tumors be called indolent tumors, according to a Jan. 17, 2025, article in JAMA Network.
At a Dec. 12, 2024, San Antonio Breast Cancer Symposium, findings from the COMET study were presented showing women with ductal carcinoma in situ (DCIS) had similar results two years after diagnosis, whether they had surgery and radiation or active surveillance with mammograms. This was announced the same day by the Dana-Farber Cancer Institute, which had investigators participating in the study.
“I think it’s interesting,” breast surgeon Naomi J. Kalliath, DO, said of the debate. She practices at Cape Cod Healthcare Breast Surgery - Falmouth and Cape Cod Healthcare Breast Surgery - Hyannis. “A cancer diagnosis can be very stressful.”
Despite this, Dr. Kalliath does not support calling asymptomatic ductal carcinoma in situ (DCIS) something other than cancer. DCIS, also known as Stage 0 breast cancer, is when abnormal cells are found in milk ducts. The American Cancer Society calls it a pre-invasive cancer. It comprises 20 to 25 percent of breast cancer diagnoses in the United States, according to a Feb. 27, 2023, National Library of Medicine article. The piece also said a 2020 National Cancer Institute study estimated 36-100 percent of DCIS cases would eventually become invasive if untreated.
“An important part of the surgeon’s job is to educate the patient,” Dr. Kalliath said, adding “if you’re going to have breast cancer, (DCIS) is the earliest form, often requiring a lesser amount of treatment.”
She recommends surgical excision of DCIS, often followed by radiation. This is standard of care, and she provides patients with options, which take into consideration the individual’s health, age, genetics and family history.
“You’re the boss,” Dr. Kalliath said, adding she aims to "educate and empower the patient to make the right individualized decision.”
Is Active Surveillance an Option?
The COMET study looked at rates of progression to invasive cancer, as well as quality of life issues, including anxiety and depression. The occurrence of invasive cancer at two years was 5.9 percent for the surgery and radiation group and 4.2 percent for the active monitoring group.
The surgery and radiation group also differed in that members reported some arm and breast pain. Breast oncologist Ann Patridge, MD, of Dana-Farber Cancer Institute in Boston, who presented the findings, said the study suggests active surveillance could be used in the short term, and it could be an option “if longer-term follow-up supports the safety of active management from a cancer outcomes standpoint.”
Dr. Kalliath said she would also like to see long-term results. For now, she favors continuing to treat DCIS with surgery, often followed by radiation.
“Ethically, I don’t think we’re able to recommend monitoring or imaging alone for long-term management of DCIS. Currently, there is just not enough data to support that," she said.
Difficulty Determining a Diagnosis
Most DCIS is detected through screening mammography. If a breast lesion or abnormality is seen by imaging, a core biopsy is done using a needle and imaging guidance. Tissue from that lesion is microscopically examined by a pathologist. But classifying whether or not it is DCIS isn’t always cut and dried, Dr. Kalliath said.
“Pathologists sometimes disagree,” she said. One may decide the tissue is DCIS, but another may describe it as ADH (atypical ductal hyperplasia). ADH shares some characteristics of DCIS, according to the American Cancer Society. Because it’s associated with a risk of developing cancer, ADH is also typically surgically removed, Dr. Kalliath said.
The limits of microscopic examination for biopsies were cited in an Oct. 1, 2024, article in the Journal of the National Cancer Institute, which compiled findings from an international symposium on whether prostate cancer Grade Group 1 (GG1) should be called cancer. Prostate cancer GG1 is considered slow growing and not usually biopsied. These tumors are so common they might be considered a normal part of aging in men and “pure” GG1 tumors have no ability to spread or metastasize, according to the article.
However, the article said pathologists have found advanced analysis of prostate sections show a range of genetic changes, including those associated with malignancy, in areas that appeared normal under microscopic review. For this reason, they argued these tumors should not be considered normal and urged active surveillance.
“The designation of cancer based entirely on conventional pathology findings increasingly seems arbitrary, at least to an extent,” wrote the article’s authors.
Call It Cancer and Treat It
A cancer diagnosis may be scary, but a little fear may be a good thing, Dr. Kalliath said.
“If they didn’t have this diagnosis of cancer, would they just ignore it? Would they say, ‘That’s OK, it’s not cancer… I’m not going to follow up’?”
The prostate cancer symposium article also noted patient concerns of the psychological weight of a cancer diagnosis and possible overtreatment, but said it wasn’t known if patients would stick with surveillance without a cancer diagnosis. The authors said their goal was to reduce cancer deaths while also avoiding overtreatment and undertreatment.
Excess diagnosis and overtreatment of low-risk prostate cancer has declined in recent years as authorities have recommended more focused screening with PSA (prostate-specific antigen) tests. But as a result of reduced screening, high-grade cancer and metastasis are increasingly being found at diagnosis, according to an April 22, 2022, article from Weill Cornell Medicine.
DCIS can be successfully treated with surgery, Dr. Kalliath said, and removal may alleviate a patient’s worry.
“If we remove that cancer through surgery, there's peace of mind knowing it won't progress to invasive disease, which may require more treatment, such as chemotherapy,” Dr. Kalliath said.
