Vincent Lebon1, Jean-Louis Alberini2,3, Jean-Yves Pierga4,5, Véronique Diéras4, Nina Jehanno6, Myriam Wartski6. 1. Service de Médecine Nucléaire, Institut Curie, Paris, France vincent.lebon@cea.fr. 2. Service de Médecine Nucléaire, Institut Curie, Saint-Cloud, France. 3. Faculté de Médecine, Université Versailles Saint-Quentin, Versailles, France. 4. Département d'Oncologie Médicale, Institut Curie, Paris, France; and. 5. Faculté de Médecine, Université Paris-Descartes, Paris, France. 6. Service de Médecine Nucléaire, Institut Curie, Paris, France.
Abstract
Women who have breast cancer and are younger than 40 y have a poorer outcome than older women. A higher rate of undetected metastases at the time of diagnosis in younger women has been proposed to account for this difference. Our main objective was to test this hypothesis by comparing the distant metastasis rate (DMR) on initial 18F-FDG PET/CT in a group of breast cancer patients younger than 40 y (<40 y group) with that in a group of breast cancer patients older than 40 y (≥40 y group). An assessment of associations between distant metastases and tumor characteristics was a second objective of the present study. METHODS: A retrospective single-institution study was performed on women who had breast cancer and no prior malignancy, who were asymptomatic for metastatic lesions on initial clinical examination, and who had initial 18F-FDG PET/CT within 3 mo after pathologic breast cancer diagnosis and before initial treatment. On the basis of these criteria, data for 2 groups of women differing only in age (<40 y and ≥40 y) were extracted from the hospital information system of Curie Institute-Paris. 18F-FDG PET/CT examinations were reviewed, and the DMR was recorded for each clinical stage subgroup (stages I-III). RESULTS: For each group (<40 y and ≥40 y), 107 patients were included, with the same number of patients in each clinical stage subgroup (12 stage I patients, 32 stage IIA patients, 30 stage IIB patients, and 33 stage III patients). The ages of the patients (mean ± SD) were 34.5 ± 4.0 y (<40 y group) and 56.0 ± 10.7 y (≥40 y group). No significant difference in DMRs was observed between the <40 y group and the ≥40 y group (DMRs, 21% and 22%, respectively; P = 1). The DMRs in patients not selected for age were 8% for stage I, 11% for stage IIA, 15% for stage IIB, and 44% for stage III. CONCLUSION: The DMR was not significantly higher in younger breast cancer patients (<40 y) than in older breast cancer patients (≥40 y), ruling out the assumption that undetected metastases at diagnosis explain the poorer outcome of younger women. However, our results highlight the high yield of 18F-FDG PET/CT for initial breast cancer staging, even in stage II patients, whatever their age.
Women who have breast cancer and are younger than 40 y have a poorer outcome than older women. A higher rate of undetected metastases at the time of diagnosis in younger women has been proposed to account for this difference. Our main objective was to test this hypothesis by comparing the distant metastasis rate (DMR) on initial 18F-FDG PET/CT in a group of breast cancerpatients younger than 40 y (<40 y group) with that in a group of breast cancerpatients older than 40 y (≥40 y group). An assessment of associations between distant metastases and tumor characteristics was a second objective of the present study. METHODS: A retrospective single-institution study was performed on women who had breast cancer and no prior malignancy, who were asymptomatic for metastatic lesions on initial clinical examination, and who had initial 18F-FDG PET/CT within 3 mo after pathologic breast cancer diagnosis and before initial treatment. On the basis of these criteria, data for 2 groups of women differing only in age (<40 y and ≥40 y) were extracted from the hospital information system of Curie Institute-Paris. 18F-FDG PET/CT examinations were reviewed, and the DMR was recorded for each clinical stage subgroup (stages I-III). RESULTS: For each group (<40 y and ≥40 y), 107 patients were included, with the same number of patients in each clinical stage subgroup (12 stage I patients, 32 stage IIA patients, 30 stage IIB patients, and 33 stage III patients). The ages of the patients (mean ± SD) were 34.5 ± 4.0 y (<40 y group) and 56.0 ± 10.7 y (≥40 y group). No significant difference in DMRs was observed between the <40 y group and the ≥40 y group (DMRs, 21% and 22%, respectively; P = 1). The DMRs in patients not selected for age were 8% for stage I, 11% for stage IIA, 15% for stage IIB, and 44% for stage III. CONCLUSION: The DMR was not significantly higher in younger breast cancerpatients (<40 y) than in older breast cancerpatients (≥40 y), ruling out the assumption that undetected metastases at diagnosis explain the poorer outcome of younger women. However, our results highlight the high yield of 18F-FDG PET/CT for initial breast cancer staging, even in stage II patients, whatever their age.