2024 Volume 63 Issue 4 Pages 159-166
Objective : The treatment effect of neoadjuvant chemotherapy (NAC) is determined by postoperative histology. However, there are no reports describing the cytological prediction of treatment efficacy or use of lymph node cytology. We therefore conducted a cytological study of metastatic lymph nodes to predict the efficacy of NAC.
Study Design : We selected 17 triple-negative cases with malignant findings on preoperative lymph node cytology following surgical resection after NAC between 2018 and 2021.
Results : The pathological response to NAC was grade 0 in 1 case, grade 1 in 8 cases, grade 2 in 2 cases, and pathological complete response (pCR) in 6 cases.
The background findings of lymph node cytology showed necrosis in 7 of 10 patients with grade 1 or 2. The appearance of metastatic cells differed according to the response to NAC. Small clusters (＜20 cells) were seen in 7 of the 8 grade 0 or 1 cases and were more common in cases with a poor response to NAC. Scattered cells were seen in 9 cases of grade 0 to 2 and in 1 case of pCR and were more common in cases with a poor response to NAC. Large clusters (≥150 cells) were found in 9 cases and were more common in cases with a high response to NAC. Cellular atypia of the metastatic cells was not associated with the response to NAC.
Conclusion : Lymph node cytology findings are expected to be useful for predicting the response to NAC and may help in selection of the optimal therapy.
