PET/CT Scanning May Provide Accurate Staging of Younger Patients With Breast Cancer
In breast cancer patients under the age of 40, positron-emission tomography/computed tomography (PET/CT) scanning may provide accurate clinical staging for stage IIB and III disease, according to the study findings presented by Riedl et al in The Journal of Nuclear Medicine. The utilization of PET/CT in younger patients has the potential to reduce the morbidity and cost of unnecessary therapies.
A question commonly discussed among oncologists is at what clinical stage is PET/CT of benefit in staging patients with breast cancer. Current guidelines from the National Comprehensive Cancer Network recommend the use of PET/CT scanning only in patients with stage III disease or when standard staging studies are equivocal or suspicious. However, more recent studies have demonstrated that PET/CT may lead to stage changes in patients with earlier-stage disease.
There is also some debate over whether the traditional TNM staging system is the only basis for deciding when PET/CT scanning is warranted for staging patients with breast cancer, and some clinicians suggest that biologic differences among breast cancer types should also be a factor, because certain biologic subtypes of breast cancer have a greater propensity to develop metastases, even at an early stage. Indeed, PET/CT may be of more value in patients with breast cancer who are younger (< 40 years of age).
Thus, Riedl and colleagues evaluated the impact of PET/CT scanning as a viable tool in staging patients younger than age 40 with breast cancer. In addition, they compared the rate of upstaging among biologic subgroups.
Study Details
The investigators analyzed the medical records of 134 patients under age 40 with initial stage I to IIIC breast cancer. All patients had undergone PET/CT scanning. The medical records were obtained from the Memorial Sloan Kettering Cancer Center Hospital Information System. Biologic data included age at diagnosis, race, clinical stage before PET/CT, histology, tumor grade, and receptor phenotype. Patients who underwent PET/CT were compared with patients who did not undergo PET/CT. PET/CT was conducted utilizing 18F–fluorodeoxyglucose injection.
The median age of the PET/CT cohort was 36.2 years (range, 22.2–39.9 years). Prior to undergoing PET/CT imaging, 15% of the patients were classified as clinical stage I, 33% were classified as clinical stage IIA, 35% were classified as clinical stage IIB, and 17% were classified as clinical stage III. Most patients had invasive ductal cancers (92%). In relationship to the two study cohorts, patients who received PET/CT scanning were of higher stages than those who did not receive PET/CT scanning.
PET/CT Scanning Identified Undetected Regional Nodes and Metastases
Findings from patients undergoing PET/CT scanning led to an upstaging to stage III or IV in 28 patients (21%). In addition, unsuspected extra-axillary regional nodes were found in 15 patients (11%), and distant metastases were noted in 20 patients (15%), with 7 patients (5%) demonstrating both regional nodes and distant metastases.
No statistically significant relationships were found between upstaging and race (P = .27), tumor grade (P = .99), or receptor phenotype (P = .52). Similarly, race, grade, and receptor phenotype were not found to relate to distant metastases (P = .33–.41) or extra-axillary lymphadenopathy (P = .63–.96).
Closing Thoughts
According to the investigators, PET/CT scanning, especially in younger women with metastatic breast cancer, may spare patients from unnecessary breast surgeries, possibly changing the therapeutic approach from cure to palliation. In addition, early detection of oligometastatic disease may lead to potentially curative local therapies.
The investigators noted, “Our data suggest that PET/CT might be valuable in younger patients with stage IIB and III disease. Use of PET/CT in younger patients has the potential to reduce the morbidity and cost of unnecessary therapies in young breast cancer patients.”
Gary A. Ulaner, MD, PhD, of the Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, is the corresponding author of this article in The Journal of Nuclear Medicine.
The study was financially supported by grants from Susan G. Komen for the Cure and the Memorial Sloan Kettering Biostatistics Core. The authors reported no potential conflicts of interest.
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