Prognostic value of axillary lymph node status after neoadjuvant chemotherapy. Results from a multicentre study

Value of postmastectomy radiotherapy on overall survival in stage II-III node-negative patients following neoadjuvant therapy: A surveillance, epidemiology, and end results-based population study

The necessity of postmastectomy radiotherapy (PMRT) for patients whose initially positive lymph nodes become node-negative (ypN0) after neoadjuvant therapy (NAT) is uncertain. This study analyzed data from the Surveillance, Epidemiology, and End Results database to evaluate PMRT's effect on these patients. Women with unilateral breast cancer who achieved ypN0 status post-NAT from 2010 to 2019 were categorized into PMRT and non-PMRT groups. Propensity score matching (PSM) minimized confounding factors. Statistical tests and multivariate analysis identified survival prognostic factors, while Kaplan-Meier curves and forest plots assessed survival outcomes. The study involved 699 cases, with 458 receiving PMRT and 241 not. After matching, 194 patient pairs were examined. Multivariate analysis revealed stage III disease (hazard ratio: 2.06; 95% CI: 1.12-3.79, p = 0.02) and lack of PMRT (hazard ratio: 2.48; 95% CI: 1.31-4.62, p = 0.01) as independent survival risk factors. PMRT significantly improved overall survival (hazard ratio: 0.43; 95% CI: 0.26-0.72, p < 0.001), especially in patients with clinical node status cN+ (cN1, hazard ratio: 0.47; 95% CI: 0.25-0.88, p = 0.016; cN2-3 hazard ratio: 0.35; 95% CI: 0.15-0.86, p = 0.017, respectively), grade 3 tumors(hazard ratio: 0.47; 95% CI: 0.25-0.88, p = 0.016), stage III disease (hazard ratio: 0.47; 95% CI: 0.26-0.83, p = 0.007), and triplenegative breast cancer (hazard ratio: 0.15; 95% CI: 0.05-0.42, p < 0.001). However, it did not significantly benefit those with grade 1-2 tumors, stage II disease, HER2-positive, or hormone receptor-positive/HER2-negative tumors. The study suggests PMRT may not be necessary for these groups, particularly for HR-positive/HER2-negative grade 1-2 with stage II disease, due to limited short-term benefits.

Is postmastectomy radiotherapy necessary for breast cancer patients with clinically node-positive downstaging to ypN0 after neoadjuvant chemotherapy?

PURPOSE

The significance of postmastectomy radiotherapy (PMRT) in breast cancer patients who initially have clinically node-positive (cN +) status but achieve downstaging to ypN0 following neoadjuvant chemotherapy (NAC) remains uncertain. This study aims to assess the impact of PMRT in this patient subset.

METHODS

Patients were enrolled from West China Hospital, Sichuan University from 2008 to 2019. Overall survival (OS), Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS) were estimated using the Kaplan-Meier method and assessed with the log-rank test. The impact of PMRT was further analyzed by the Cox proportional hazards model. Propensity score matching (PSM) was performed to reduce the selection bias.

RESULTS

Of the 333 eligible patients, 189 (56.8%) received PMRT, and 144 (43.2%) did not. At a median follow-up period of 71 months, the five-year LRFS, DMFS, BCSS, and OS rates were 99.1%, 93.4%, 96.4%, and 94.3% for the entire cohort, respectively. Additionally, the 5-year LRFS, DMFS, BCSS, and OS rates were 98.9%, 93.8%, 96.7%, and 94.5% with PMRT and 99.2%, 91.3%, 94.9%, and 92.0% without PMRT, respectively (all p-values not statistically significant). After multivariate analysis, PMRT was not a significant risk factor for any of the endpoints. When further stratified by stage, PMRT did not show any survival benefit for patients with stage II-III diseases.

CONCLUSION

In the context of comprehensive treatments, PMRT might be exempted in ypN0 breast cancer patients. Further large-scale, randomized controlled studies are required to investigate the significance of PMRT in this patient subset.

The prognostic role of lymph node ratio in breast cancer patients received neoadjuvant chemotherapy: A dose-response meta-analysis

BACKGROUND

As neoadjuvant chemotherapy is widely used in breast cancer patients, the lymph node ratio has not been fully validated as a prognostic indicator of breast cancer received neoadjuvant chemotherapy. This study was conducted to investigate the prognostic value of lymph node ratio in breast cancer patients received neoadjuvant chemotherapy.

METHODS

Systematic searches were performed in the PubMed, Embase, and Cochrane Library databases until 15 December 2021 for studies on the association between lymph node ratio and the prognosis of breast cancer after neoadjuvant chemotherapy. Overall survival and disease-free survival were used as outcome events, and hazard ratio was chosen as the parameter to evaluate the correlation. The dose-response relationship was assessed by restricted cubic splines. In the subgroup analyses, which were used to explore potential heterogeneity among the included studies according to study region and sample size. Sensitivity analysis was performed to assess the stability of individual studies, and publication bias was determined with funnel plots, Begg's test, and Egger&apos;s test. All statistical analyses were performed using Stata 15.1.

RESULTS

A total of 12 studies with 4,864 patients were included in this meta-analysis. In this study, high lymph node ratio was significantly associated with decreased overall survival (HR: 4.74; 95%CI: 3.36-6.67; P < 0.001) and disease-free survival (HR: 4.77; 95%CI: 3.69-6.17; P < 0.001). Moreover, the dose-response meta-analysis showed a linear association between higher lymph node ratio and shorter overall survival and disease-free survival in breast cancer patients after neoadjuvant chemotherapy.

CONCLUSIONS

The meta-analysis suggested that high lymph node ratio was significantly associated with short overall survival and disease-free survival in breast cancer patients after neoadjuvant chemotherapy. Therefore, lymph node ratio is an independent predictive factor for the prognosis of breast cancer patients after neoadjuvant chemotherapy, which may better refine the cancer staging system.

Association of Tumor Molecular Subtype and Stage with Breast and Axillary Pathologic Complete Response After Neoadjuvant Chemotherapy for Breast Cancer

BACKGROUND

Axillary pathologic complete response (pCR) confers higher overall and recurrence-free survival than residual axillary disease. Although breast pCR (ypT0) is associated with a pathologically negative axilla (ypN0) in human epidermal growth factor receptor 2-positive (HER2+) and triple-negative breast cancer (TNBC), how clinical T (cT) and N (cN) staging are associated with ypN0 in other tumor subtypes is incompletely understood.

METHODS

A single-institution cancer registry was retrospectively reviewed for patients receiving neoadjuvant chemotherapy (NAC) followed by surgery from 2010 to 2018. Fisher's exact tests compared proportion of breast and axillary pCR by tumor subtype (hormone receptor [HR]-positive /HER2-,HR+/HER2+,HR-/HER2+,HR-/HER2-). Logistic regression determined factors associated with ypN0. Sensitivity analyses determined how cN status affected ypN status by tumor subtype.

RESULTS

The study enrolled 1348 patients. The median age was 54 years (interquartile range [IQR], 44-63 years), and 55% of the patients (n = 736) were postmenopausal. The tumor subtypes were HR+/HER2- (12%, n = 155), HR+/HER2+ (48%, n = 653), HR-/HER2+ (25%, n = 343), and TNBC (15%, n = 197). In the study, cT included T0 (1%, n = 18), T1 (20%, n = 272), T2 (53%, n = 713), T3 (17%, n = 230), and T4 (9%, n = 111), and cN included cN0 (51%, n = 687), cN1 (41%, n = 549), cN2 (5%, n = 61), and cN3 (3%, n = 43). Breast pCR and ypN0 occurred most in the HER2+ and TNBC subtypes. A negative association was found between ypN0 and age at diagnosis (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97-0.99; p < 0.001), cT4 stage (OR, 0.29; 95% CI, 0.09-0.91; p = 0.034), and HR+ subtypes (HR+/HER2-: OR, 0.54; 95% CI, 0.31-0.94; p = 0.028; HR+/HER2+: OR, 0.60; 95% CI, 0.39-0.93; p = 0.024). The HR-/HER2+ subtype was associated with ypN0 (OR, 1.70; 95% CI, 1.05-2.73; p = 0.030), and cN2/cN3 was negatively associated with ypN0 in HR+/HER2+ disease (OR, 0.26; 95% CI, 0.11-0.61; p = 0.002), HR-/HER2+ disease (OR, 0.42; 95% CI, 0.22-0.77; p = 0.005), and TNBC (OR, 0.11; 95% CI, 0.03-0.40; p = 0.001).

CONCLUSION

Tumor subtype, clinical stage, and age at diagnosis may be important in consideration of de-escalation of axillary staging.

Prognostic Value of Lymph Node Ratio in Breast Cancer Patients with Adequate Pathologic Evidence After Neoadjuvant Chemotherapy

BACKGROUND The prognostic role of axillary lymph node ratio (LNR) after neoadjuvant chemotherapy (NAC) in breast cancer has not been illuminated. This study was designed to investigate the prognostic role of LNR in breast cancer compared with traditional ypN stage. MATERIAL AND METHODS A total of 306 breast cancer patients diagnosed with positive axillary lymph nodes from January 2007 to December 2014 were eligible for this retrospective analysis. All enrolled patients were treated with a median of 4 cycles of NAC followed by mastectomy and level I, II, and III axillary lymph node dissection (ALND). RESULTS The median duration of follow-up was 78 months (range, 7-147 months). Univariate analysis indicated that both the LNR category (P<0.001) and ypN stage (P<0.001) were significant associated with event-free survival (EFS) and overall survival (OS). However, multivariate analysis indicated that the LNR category was independently associated with EFS (P<0.001) and OS (P<0.001), while the ypN stage showed no statistical effect on EFS (P=0.391) or OS (P=0.081). On additional analyses stratified by molecular subtypes, we found that the prognosis of triple negative breast cancer could be better discriminated when the cutoff value of LNR was set at 0.15. CONCLUSIONS LNR showed a superior predictive value in evaluating prognosis of breast cancer patients after NAC. In addition, the LNR cutoff point 0.15 can accurately discriminate survival outcomes for different triple negative breast cancer subtypes.

Does Neoadjuvant Chemotherapy for Breast Cancer Affect Lymph Node Harvest Rates?

Some authors report that patients receiving neoadjuvant chemotherapy have fewer lymph nodes harvested during axillary dissection and more dissections with < 10 nodes compared with patients who undergo surgery initially. We sought to determine whether there was a difference between these patient groups in terms of number of nodes harvested and number of dissections with < 10 nodes. Retrospective review of 258 patients diagnosed with breast cancer who underwent an axillary lymph node dissection between July 1,2015, and December 31, 2017 was performed. Chi-squared test was used to assess differences between patient groups. Of 258 patients undergoing dissection, 48 per cent received neoadjuvant chemotherapy; 52 per cent underwent surgery as first therapeutic intervention. Mean number of nodes resected; 14.3 + 6.3 for patients with no prior chemotherapy versus 14.9 + 6.6 for patients with neoadjuvant chemotherapy ( P = 0.48). For patients undergoing surgery as first intervention, 21 per cent had < 10 nodes harvested. For patients receiving neo-adjuvant chemotherapy, 20 per cent had < 10 nodes harvested. Patients who received neoadjuvant chemotherapy showed no statistically significant difference in the number of lymph nodes harvested during axillary dissection compared with patients undergoing surgery as first intervention. Neoadjuvant chemotherapy does not reduce the node harvest at the time of axillary dissection.

Identification of Patients With Documented Pathologic Complete Response in the Breast After Neoadjuvant Chemotherapy for Omission of Axillary Surgery

Importance

A pathologic complete response (pCR; no invasive or in situ cancer) occurs in 40% to 50% of patients with HER2-positive (HER2+) and triple-negative (TN) breast cancer. The need for surgery if percutaneous biopsy of the breast after neoadjuvant chemotherapy (NCT) indicates pCR in the breast (hereinafter referred to as breast pCR) has been questioned, and appropriate management of the axilla in such patients is unknown.

Objective

To identify patients among exceptional responders to NCT with a low risk for axillary metastases when breast pCR is documented who may be eligible for an omission of surgery clinical trial design.

Design, Setting, and Participants

This prospective cohort study at a single-institution academic national comprehensive cancer center included 527 consecutive patients with HER2+/TN (T1/T2 and N0/N1) cancer treated with NCT followed by standard breast and nodal surgery from January 1, 2010, through December 31, 2014.

Main Outcomes and Measures

Patients who achieved a breast pCR were compared with patients who did not based on subtype, initial ultrasonographic findings, and documented pathologic nodal status. Incidence of positive findings for nodal disease on final pathologic review was calculated for patients with and without pCR and compared using relative risk ratios with 95% CIs.

Results

The analysis included 527 patients (median age, 51 [range, 23-84] years). Among 290 patients with initial nodal ultrasonography showing N0 disease, 116 (40.4%) had a breast pCR and 100% had no evidence of axillary lymph node metastases after NCT. Among 237 patients with initial biopsy-proved N1 disease, 69 of 77 (89.6%) with and 68 of 160 (42.5%) without a breast pCR had no evidence of residual nodal disease (P < .01). Patients without a breast pCR had a relative risk for positive nodal metastases of 7.4 (95% CI, 3.7-14.8; P < .001) compared with those with a breast pCR.

Conclusions and Relevance

Breast pCR is highly correlated with nodal status after NCT, and the risk for missing nodal metastases without axillary surgery in this cohort is extremely low. These data provide the fundamental basis and rationale for management of the axilla in clinical trials of omission of cancer surgery when image-guided biopsy indicates a breast pCR.

Lymph Node Ratio Analysis After Neoadjuvant Chemotherapy is Prognostic in Hormone Receptor-Positive and Triple-Negative Breast Cancer

BACKGROUND

Lymph node ratios (LNR), the proportion of positive lymph nodes over the number excised, both defined as ranges and single ratio values are prognostic of outcome. Little is known of the prognostic value of LNR after neoadjuvant chemotherapy (NAC) according to molecular subtype.

METHODS

From 2003 to 2014, patients who underwent definitive surgery after NAC were identified. LNR was calculated for node-positive patients who received axillary dissection or had at least 6 nodes removed. DFS was calculated using the Kaplan-Meier log rank test for yp N0-3 status, LNR categories (LNRC) ≤0.20 (low), 0.21-0.65 (intermediate), >0.65 (high), and single LNR values.

RESULTS

Of 428 NAC recipients, 263 were node negative and 165 (38.6 %) node positive: ypN1 = 97 (58.8 %), ypN2 = 43 (26.1 %), and ypN3 = 25 (15.2 %). Among node-positive cancers, the median number of LN removed was 14 (range, 6-51) and the median LNR was 0.22 (range, 0.03-1.0). Nodal stage was inversely associated with 5-year DFS: 91.5 % (ypN0), 74.5 % (ypN1), 49.8 % (ypN2), and 50.7 % (ypN3) (p < 0.001). LNRC was similarly inversely associated with DFS: 69.1 % (low), 71.4 % (intermediate), 49.3 % (high) (p < 0.001). Significant associations between LNRC and DFS were demonstrated in hormone receptor (HR)-positive and triple negative breast cancer (TNBC) subtypes, p = 0.02 and p = 0.003. A single-value LNR ≤ 0.15 in node-positive, HR-positive (94.1 vs 67.7 %; p = 0.04) and TNBC (94.1 vs 47.8 %; p = 0.001) groups was also significant.

CONCLUSIONS

Residual nodal disease after NAC, analyzed by LNRC or LNR = 0.15 cutoff value, is prognostic and can discriminate between favorable and unfavorable outcomes for HR-positive and TNBC cancers.

Prognostic Value of Axillary Nodal Ratio after Neoadjuvant Chemotherapy of Doxorubicin/Cyclophosphamide Followed by Docetaxel in Breast Cancer: A Multicenter Retrospective Cohort Study

Purpose

The purpose of this study is to investigate the prognostic value of lymph node (LN) ratio (LNR) in patients with breast cancer after neoadjuvant chemotherapy.

Materials and Methods

This retrospective analysis is based on the data of 814 patientswith stage II/III breast cancer treated with four cycles of doxorubicin/cyclophosphamide followed by four cycles of docetaxel before surgery. We evaluated the clinical significance of LNR (3 categories: low 0-0.20 vs. intermediate 0.21-0.65 vs. high 0.66-1.00) using a Cox proportional regression model.

Results

A total of 799 patients underwent breast surgery. Pathologic complete response (pCR, ypT0/isN0) was achieved in 129 patients (16.1%) (hormone receptor [HR] +/human epidermal growth factor receptor 2 [HER2] –, 34/373 [9.1%]; HER2+, 45/210 [21.4%]; triple negative breast cancer, 50/216 [23.1%]). The mean numbers of involved LN and retrieved LN were 2.70 (range, 0 to 42) and 13.98 (range, 1 to 64), respectively. The mean LNR was 0.17 (low, 574 [71.8%]; intermediate, 170 [21.3%]; high, 55 [6.9%]). In univariate analysis, LNR showed significant association with a worse relapse-free survival (3-year relapse-free survival rate 84.8% in low vs. 66.2% in intermediate vs. 54.3% in high; p < 0.001, log-rank test). In multivariate analysis, LNR did not show significant association with recurrence after adjusting for other clinical factors (age, histologic grade, subtype, ypT stage, ypN stage, lymphatic or vascular invasion, and pCR). In subgroup analysis, the LNR system had good prognostic value in HR+/HER2–subtype.

Conclusion

LNR is not superior to ypN stage in predicting clinical outcome of breast cancer after neoadjuvant chemotherapy. However, the prognostic value of the LNR system in HR+/HER2–patients is notable and worthy of further investigation.

Using the Lymph Node Ratio to Evaluate the Prognosis of Stage II/III Breast Cancer Patients Who Received Neoadjuvant Chemotherapy and Mastectomy

Purpose

This study was conducted to investigate the prognostic value of lymph node ratio (LNR) in stage II/III breast cancer patients who undergo mastectomy after neoadjuvant chemotherapy.

Materials and Methods

Clinical and pathological data describing stage II/III breast cancer patients were included in this retrospective study. The primary outcomes were locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS).

Results

Among 277 patients, there were 43 ypN0, 64 ypN1, 89 ypN2, and 81 ypN3 cases. Additionally, there were 43, 57, 92 and 85 cases in the LNR 0, 0.01-0.20, 0.21-0.65, and > 0.65 groups, respectively. The median follow-up was 49.5 months. Univariate analysis showed that both ypN stage and LNR were prognostic factors of LRFS, DMFS, DFS, and OS (p < 0.05). Multivariate analysis showed that LNR was an independent prognostic factor of LRFS, DMFS, DFS, and OS (p < 0.05), while ypN stage had no effect on prognosis (p > 0.05).

Conclusion

The integrated use of LNR and ypN may be suitable for evaluation the prognosis of stage II/III breast cancer patients who undergo mastectomy after neoadjuvant chemotherapy.

Axillary lymph node status, adjusted for pathologic complete response in breast and axilla after neoadjuvant chemotherapy, predicts differential disease-free survival in breast cancer

BACKGROUND

Our retrospective study in breast cancer patients evaluated whether integrating subtype and pathologic complete response (pcr) information into axillary lymph node restaging after neoadjuvant chemotherapy (nac) adds significance to its prognostic values.

METHODS

Patients included in the analysis had stage ii or iii disease, with post-nac axillary lymph node dissection (alnd), without sentinel lymph node biopsy before completion of nac, with definitive subtyping data and subtype-oriented adjuvant treatments. The ypN grading system was used to restage axillary lymph node status, and ypN0 was adjusted by pcr in both breast and axilla into ypN0(pcr) and ypN0(non-pcr). Univariate and multivariate survival analyses were performed.

RESULTS

Among the 301 patients analyzed, 145 had tumours that were hormone receptor-positive (hr+) and negative for the human epidermal growth factor receptor (her2-), 101 had tumours that were positive for her2 (her2+), and 55 had tumours that were triple-negative. The rate of pcr in both breast and axilla was 11.7%, 43.6%, and 25.5% respectively for the 3 subtypes. Compared with the non-pcr patients, the pcr patients had better disease-free survival (dfs) and overall survival (os): p = 0.002 for dfs and p = 0.011 for os. In non-pcr patients, dfs and os were similar in the ypN0(non-pcr) and ypN1 subgroups, and in the ypN2 and ypN3 subgroups. We therefore grouped the ypN grading results into ypN0(pcr) (n = 75), ypN0- 1(non-pcr) (n = 175), and ypN2-3 (n = 51). In those groups, the 3-year dfs was 98%, 91%, and 56%, and the 3-year os was 100%, 91%, and 82% respectively. The differences in dfs and os between those three subgroups were significant (all p < 0.05 in paired comparisons). Multivariate Cox regression showed that subtype and ypN staging adjusted by pcr were the only two independent factors predicting dfs.

CONCLUSIONS

Axillary lymph node status after nac, adjusted for pcr in breast and axilla, predicts differential dfs in patients without prior sentinel lymph node biopsy.

Does the axillary lymph node ratio have any added prognostic value over pN staging for South East Asian breast cancer patients?

Introduction

Lymph node ratio (LNR, i.e. the ratio of the number of positive nodes to the total number of nodes excised) is reported to be superior to the absolute number of nodes involved (pN stage) in classifying patients at high versus low risk of death following breast cancer. The added prognostic value of LNR over pN in addition to other prognostic factors has never been assessed.

Methods

All patients diagnosed with lymph node positive, non-metastatic invasive breast cancer at the National University Hospital (Singapore) and University of Malaya Medical Center (Kuala Lumpur) between 1990–2007 were included (n = 1589). Overall survival of the patients was estimated by the Kaplan Meier method for LNR [categorized as low (>0 and <0.2), intermediate (0.2–0.65) and high (>0.65–1)] and pN staging [pN1, pN2 and pN3]. Adjusted overall relative mortality risks associated with LNR and pN were calculated by Cox regression. The added prognostic value of LNR over pN was evaluated by comparing the discriminating capacity (as indicated by the c statistic) of two multivariate models, one including pN and one including LNR.

Results

LNR was superior to pN in categorizing mortality risks for women ≥60 years, those with ER negative or grade 3 tumors. In combination with other factors (i.e. age, treatment, grade, tumor size and receptor status), substituting pN by LNR did not result in better discrimination of women at high versus low risk of death, neither for the entire cohort (c statistic 0.72 [0.70–0.75] and 0.73 [0.71–0.76] respectively for pN versus LNR), nor for the subgroups mentioned above.

Conclusion

In combination with other prognosticators, substitution of pN by LNR did not provide any added prognostic value for South East Asian breast cancer patients.