Detection of Isolated Regional Lymph Node Recurrences by PET-CT in Follow-Up of Postoperative Breast Cancer Patients.

Abstract

Abstract Background: It is not recommended to use imaging diagnostic methods in order to find small distant metastases in follow-up of postoperative breast cancer patients because of lack of improvement in survival with use of them in old randomized trials. However, use of new imaging modalities in follow-up of postoperative breast cancer patients may improve their survival due to detection of small regional lymph node recurrences without distant metastases which are potentially curable.Patients and methods: Between April 2006 and December 2008, we used PET-CT to find small recurrences in follow-up of 1908 postoperative breast cancer patients who received definitive surgery at the National Hospital Organization Shikoku Cancer Center. A total of 3283 times (1 to 4 times per a patient; median 1) of PET-CT imaging without contrast medium were performed during the period. A median age at the PET-CT imaging was 58 years (range, 22 to 91 years, mean 58.5 years). A median interval from the definitive surgery to the PET-CT imaging was 48 months (range, 3 to 385 months, mean 57.8 months). The results were analyzed retrospectively.Results: Seven patients were found to have isolated axillary node recurrence by PET-CT, and additional 3 patients were shown to have isolated subclavian node recurrence. Furthermore, only PET-CT showed that other 7 patients had isolated supraclavicular node recurrences and 6 patients had isolated parasternal node recurrences. All of those lymph node recurrences were missed by palpation or nonpalpable. A median interval from the definitive surgery to the diagnoses of the isolated regional node recurrences was 50 months (range, 19-167 months, mean 58.3 months). Those recurrences were found by the first examination with PET-CT in 14 patients and by the second examination in 9 patients. Fifteen asymptomatic other cancers including contralateral mammographically invisible breast cancers were found only by PET-CT (1 lung cancer, 2 gastric cancers, 1 colon cancer, 2 rectal cancers, 2 pancreatic cancers, 1 endometrial cancer, 4 thyroid cancers, and 2 contralateral breast cancers). The pathological lymph node status at the definitive surgery of 23 patients with the isolated regional lymph node recurrences was positive in 17 patients (number of positive nodes: 1 to 3 positive nodes in 7 patients, 4 to 9 in 8, 10 or more in 2), negative in 4, and unknown in 2. If the patients are limited to those who had the pathologically positive node(s) at the definitive surgery, the incidence of the patients with the isolated regional node recurrences found only by PET-CT will be 2.6% (17/663 patients).Conclusion: Early detection of isolated loco-regional recurrences of breast cancer is suggested to result in an improvement of survival. Therefore, the use of PET-CT in follow-up of postoperative node positive breast cancer patients may improve their survival because of early detection of isolated regional node recurrences which are still potentially curable and screening of other asymptomatic cancers.Reference: Lu WL et al. Impact on survival of early detection of isolated breast recurrences after the primary treatment for breast cancer. a meta-analysis. Breast Cancer Res Treat 114: 403-412, 2009 Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4009.