Surveillance after a breast cancer diagnosis aims to detect local recurrence or metastatic disease by using information obtained during routine visits, including medical history, physical examination, and annual mammography, with additional imaging guided by the patient’s signs and symptoms. The typical follow-up schedule over the first years after diagnosis varies by year. While surveillance is still largely standardized, additional data are needed to individualize follow-up in the future.

We stratify recurrence risk by site (local vs distant) and timing (early vs late), but our posttreatment surveillance strategies remain, in many ways, quite similar, regardless of the varying risks. In early breast cancer, surveillance often focuses on monitoring for late recurrences.

At present, posttreatment surveillance criteria remain fairly standardized. A generally recommended routine follow-up cadence might be described as follows: history and physical examinations every 3 to 6 months for the first 3 years, every 6 to 12 months for years 4 and 5, and annually thereafter. Annual mammography is recommended in cases of breast-conserving surgery, generally commencing 6 to 12 months following the completion of radiation therapy.

A major area of real-world variability involves the use of imaging beyond mammography, particularly ultrasound or magnetic resonance imaging (MRI). It has been suggested that routine supplemental breast MRI be reserved for patients at elevated risk, including those with dense breast tissue or hereditary predispositions (eg, BRCA mutations).

Thus, many of the same tests and procedures that are used initially to diagnose and evaluate breast cancer (eg, mammograms, physical examinations, and medical history) are used in surveillance. While advanced imaging modalities (eg, computed tomography, bone, and positron emission tomography scans) are generally contraindicated for routine surveillance, these studies are warranted for evaluating symptoms or equivocal findings on standard imaging. The follow-up schedule during surveillance allows for the assessment of symptoms such as new lumps, bone pain, or respiratory issues that may indicate recurrence. Some of the most common symptoms include pain (eg, back, hip, chest, or abdominal pain), shortness of breath, or cough.

Recently, novel techniques and assays have emerged—primarily liquid biopsy–based tests detecting circulating tumor DNA—that can potentially help identify metastatic disease earlier. The use of artificial intelligence in surveillance imaging is another promising area of study. However, there is a need for strategies intended to intervene upon recurrence to carry the same levels of evidence and benefit as those recommendations for the initial active phase of treatment. Large studies with longer follow-up are needed, as the ultimate goal would be to ensure that we are improving the overall survival and quality of life of our patients. While the circulating tumor DNA assays show strong promise for identifying measurable residual disease or early signs of metastatic recurrence much sooner than traditional imaging or clinical follow-up, we need dedicated trials with extended follow-up to show that earlier detection translates into improved survival or other meaningful clinical benefits.

Of course, there are important connections between surveillance and survivorship, and not all aspects of monitoring are specific to identifying recurrence (eg, bone density monitoring for aromatase inhibitor users, gynecologic surveillance for tamoxifen users, and cardiovascular risk management). Many patients seek to be more active participants in their care, and some may find it helpful to learn that dietary patterns, physical activity levels, and alcohol consumption are modifiable lifestyle factors that have been associated with reductions in breast cancer recurrence and mortality.

Still, there are certain patients who might have different needs during surveillance (ie, needs that might be better addressed in the future). We are starting to see some encouraging signs regarding the potential for individualization. For example, the authors of updated guidance from the American College of Radiology (ACR) recommend that women with a personal history of breast cancer and dense breasts should undergo annual supplemental breast MRI. Patients with lobular carcinoma represent another group who may benefit from alternative surveillance strategies.

In the coming years, I think that tailoring surveillance intensity based on personalized risk assessments and other variables is the path forward. Although we are not quite at that point yet in the field, this could change in the future. The development of better assays may be a part of the solution, but we also need to develop better drugs.