Patient-reported outcomes and objective assessments with arm measurement and bioimpedance analysis for lymphedema among breast cancer survivors.

PURPOSE: Lymphedema (LE) decreases the quality of life of breast cancer patients. Objective quantification of PRO may improve the discordance between patient-reported outcomes (PROs) and objective assessments of LE by establishing a standard follow-up for LE. This study determined the prevalence of subjective and objective LE and evaluated the correlation between objective assessment and PRO of LE in primary breast cancer patients undergoing breast and axilla surgery. METHODS: Breast cancer patients who underwent sentinel lymph node biopsy (SN) or axillary lymph node dissection (ALND) more than 1 year after surgery were enrolled. We prospectively evaluated LE using the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) and two objective assessments (arm circumference and bioimpedance) and analyzed their correlations. RESULTS: Between November 2018 and January 2019, 631 patients (SN; n = 415, ALND; n = 216) were enrolled. The median age, body mass index, and duration from surgery was 56 years, 21.9 kg/m2, and 3.8 years, respectively. The prevalences of subjective and objective LE were 4.1% and 1.4% in the SN group and 51.8% and 24.1% in the ALND group, respectively. The objective assessments were weakly positively correlated with PRO-CTCAE. Arm circumference measurement correlated better than bioimpedance overall and was most strongly correlated with "frequency" (r = 0.485, p < 0.01). CONCLUSIONS: LE occurred in few SN patients. The prevalence of subjective LE was higher than that of objective LE. Arm circumference measurements better reflected PRO than did bioimpedance. These results underscore the limitation of LE detection by subjective or objective methods alone.

Occult breast cancer may originate from ectopic breast tissue present in axillary lymph nodes.

PURPOSE: Occult breast cancer (OBC) is classified as a carcinoma of unknown primary, and involves axillary lymphadenopathy and is histologically consistent with metastatic breast cancer. OBC has been conventionally considered as a metastatic lymph node lesion, the origin of which is an undetectable breast tumor. Therefore, OBC patients would usually have undergone axillary lymph node dissection, and mastectomy or whole breast radiotherapy (WBRT). However, majority of OBC reports have been based on cases that were diagnosed during a period when diagnostics was still relatively primitive, and when magnetic resonance imaging was not yet a standard preoperative assessment. Therefore, there have been many false negatives in the breast based on preoperative assessment. METHODS: We herein hypothesize that the origin of OBC is ectopic breast tissue present in axillary lymph nodes (ALNs). If our hypothesis is true, mastectomy and WBRT may be unnecessary for OBC patients. RESULTS: Our hypothesis is supported by several findings. First, advances in radiological imaging have suggested that a primary breast tumor is absent in OBC patients. Second, proliferative breast lesions arising from ectopic breast present in ALNs have been reported. Lastly, cellular subtypes in OBC based on immunohistochemistry are of various types including ordinary breast cancer and the prognosis is not worse than stage II breast cancer. CONCLUSION: It is important to distinguish between "primary" OBC in ALNs and "metastatic" OBC from micro-primary breast tumor. Further studies are required to determine if omission of mastectomy and WBRT is acceptable.