Nodal Ratios in Node-Positive Breast Cancer—Long-Term Study to Clarify Discrepancy of Role of Supraclavicular and Axillary Regional Radiotherapy

Lymph Node Ratio after Neoadjuvant Chemotherapy for Stage II/III Breast Cancer: Prognostic Value Measured with Gini's Mean Difference of Restricted Mean Survival Times

Restricted mean survival time (RMST), recommended for reporting survival, lacks a tool to evaluate multilevel factors. The potential of the Gini’s mean difference of RMSTs (Δ) is explored in a comparison of a lymph node ratio-based classification (LNRc) versus a number-based classification (ypN) applied to stage II/III breast cancer patients who received neoadjuvant chemotherapy and underwent axillary dissection. Number of positive nodes (npos) classified patients into ypN0, npos = 0, ypN1, npos = [1,3], ypN2, npos = [4,9], and ypN3, npos ⩾ 10. Ratio npos/(number of nodes examined) of 0, (0,0.20], (0.20,0.65], and >0.65, classified patients into Lnr0 to Lnr3, respectively. Unadjusted and Cox-adjusted RMSTs were computed for the ypN and LNRc’s. At a follow-up time horizon of 72 months for 114 node-negative and 254 node-positive patients, unadjusted ypN0-ypN3 RMSTs were 62.4-41.4 months, Δ = 11.9 months (95%CI: 7.4-16.9), and Lnr0-Lnr3 62.4 to 36.3 months, Δ = 14.0 months (95%CI: 10.1-18.1). Cox models’ ypN1-ypN3 hazard ratios were 1.81-3.30, and Lnr1-Lnr3 1.52-4.39. Δ from Cox-fitted survival were ypN 8.1 months (95%CI: 5.9-10.5), LNRc 10.5 months (95%CI: 8.4-12.8). In conclusion, Gini’s mean difference is applicable to well established data in keeping with the literature on LNRc. It provides an alternative view on the improvement gained with a lymph node ratio-classification over using a number-classification.

Long-term outcome of breast cancer patients with one to two nodes involved - application of nodal ratio

Nodal ratio (NR) is defined as the number of involved nodes to the number of nodes examined. There is limited information on the application of NR on population data. Previous reports in breast cancer generally analyzed one to three positive axillary nodes as a single group. This study investigates whether one to three positive axillary nodes is a homogeneous group in prognosis by comparing one to two positive nodes to three positive nodes. The population-based registry of a Canadian province from 1981 through 1995 was searched. As the reliability of nodal assessment depends on the number of nodes sampled, we also studied the subgroup of patients with greater than or equal to eight nodes dissected. Of a total of 5,996 breast cancer patients, 1187 had one to three positive axillary nodes. The 263 patients with three positive nodes compared to the 924 patients with one to two nodes fared worse with a significantly reduced cause-specific survival (CSS) and overall survival (OS). Patients with one to two positive nodes had similar CSS (p=0.31) and OS (p=0.63). Among those with greater than or equal to eight nodes dissected, there were 677 patients with one to two positive nodes. CSS and OS were not significantly different between one versus two positive nodes (p=0.16 and 0.34, respectively), but with NR, the corresponding p values were 0.0068 and 0.08, respectively. The cutoff value of NR 0.15 was found to be most useful and confirmed by the validation dataset. NR is able to segregate patients better than the absolute number of positive nodes used in the current staging system. NR should be incorporated into the staging system.

Proposal of new classification for stage III breast cancer on the number and ratio of metastatic lymph nodes

BACKGROUND

The objective of the retrospective study was to confirm whether the current staging system of stage III was appropriate for breast cancer.

METHODS

Four hundred fifteen patients with breast cancer in stage III were analyzed. The survival analysis was performed by Kaplan-Meier.

RESULTS

Survival time of the patients with T1N3M0 was significantly better than the patients with other subgroups of stage IIIC (T2,3,4N3M0) and similar that of patients with T4N0,1,2M0 who formed the stage IIIB group based on pN stage. Tumor size, number of positive lymph nodes and lymph node ratio (LNR) were associated with overall survival (OS). The greatest survival difference was found when 0.60 as the cutoff point of LNR for the patients with current stage IIIC (pN3). rN1 included the patients in pN3 with LNR ≤ 0.60 and rN2 included the patients in pN3 with LNR >0.60. Survival time of the patients with T1,2,3,4N3(rN1)M0 and T1N3(rN2)M0 was differently better than the patients with T2,3,4N3(rN2)M0 and similar that of patients with T4N0,1,2M0.

CONCLUSION

We suggested current staging system should be modified combining pN with rN. We presumed the patients with T1N3M0 and T2,3,4N3(rN1)M0 disease were excluded from the current stage IIIC and included in stage IIIB group.

Prognostic Significance of the Number of Removed and Metastatic Lymph Nodes and Lymph Node Ratio in Breast Carcinoma Patients with 1-3 Axillary Lymph Node(s) Metastasis

We evaluated the prognostic significance of lymph node ratio (LNR), number of metastatic lymph nodes divided by number of removed nodes in 924 breast carcinoma patients with 1-3 metastatic axillary lymph node(s). The most significant LNR threshold value separating patients in low- and high-risk groups with significant survival difference was 0.20 for disease-free survival (P < 0.001), 0.30 for locoregional recurrence-free survival (P < 0.001), and 0.15 for distant metastasis-free survival (P < 0.001), and the patients with lower LNR had better survival. All three LNR threshold values had independent prognostic significance in Cox analysis (P < 0.001 for all three of them). In conclusion, LNR is a useful tool in separating breast carcinoma patients with 1-3 metastatic lymph node(s) into low- and high-risk prognostic groups.

The prognostic value of the nodal ratio in N1 breast cancer

BACKGROUND

Although the nodal ratio (NR) has been recognized as a prognostic factor in breast cancer, its clinical implication in patients with 1-3 positive nodes (N1) remains unclear. Here, we evaluated the prognostic value of the NR and identified other clinico-pathologic variables associated with poor prognosis in these patients.

METHODS

We analyzed 130 patients with N1 invasive breast cancer who were treated at Seoul National University Bundang Hospital from March 2003 to December 2007. Disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and distant metastasis-free survival (DMFS) were compared according to the NR with a cut-off value of 0.15.

RESULTS

We followed patients' recovery for a median duration of 59 months. An NR > 0.15 was found in 23.1% of patients, and a median of 18 nodes were dissected per patient (range 1-59). The NR was statistically independent from other prognostic variables, such as patient age, T stage, extent of surgery, pathologic factors in the chi square test. On univariate analysis, patients with a NR > 0.15 had significantly lower 5-year LRRFS (88.7% vs. 97.9%, p = 0.033) and 5-year DMFS (81.3% vs. 96.4%, p = 0.029) and marginally lower 5-year DFS (81.3% vs. 94.0%, p = 0.069) than those with a NR ≤0.15, respectively. Since the predictive power of the NR was found to differ with diverse clinical and pathologic variables, we performed adjusted analysis stratified by age, pathologic characteristics, and adjuvant treatments. Only young patients with a NR > 0.15 showed significantly lower DFS (p = 0.027) as well as those presenting an unfavorable pathologic profile such as advanced T stage (p = 0.034), histologic grade 3 (p = 0.034), positive lymphovascular invasion (p = 0.037), involved resection margin (p = 0.007), and no chemotherapy (p = 0.014) or regional radiotherapy treatment (p = 0.039). On multivariate analysis, a NR > 0.15 was significantly associated with lower DFS (p = 0.043) and DMFS (p = 0.012), but not LRRFS (p = 0.064).

CONCLUSIONS

A NR > 0.15 was associated with an increased risk of recurrence, especially in young patients with unfavorable pathologic profiles.

Using nodal ratios to predict risk of regional recurrences in patients treated with breast conservation therapy with 4 or more positive lymph nodes

Purpose. The value of nodal ratios (NRs) as a prognostic variable in breast cancer is continually being demonstrated. The purpose of this study was to use NR in patients with ≥4+ nodes to assess a correlation of NR with regional (lymph node) recurrence. Methods. Inclusion criteria was ≥8 nodes dissected with ≥4+ nodes after breast conservation therapy. Of 1060 patients treated from 1975 to 2003 who had a minimum of 8 nodes dissected, 273 were node+; 56 patients had ≥4+ involved nodes and were the focus of this study. Nodal ratios were calculated for each patient and grouped into 3 categories: high (≥70%), intermediate (40%–69%) and low (<40%). Each nodal ratio was correlated with patterns of local, regional, and distant failures and OS. Results. Outcomes for the entire cohort were BRFS-83%, NRFS-93%, DMFS-61%, and OS 63% at 10 yrs. The OS, DMFS, and NRFS correlated with N2 (4–9 nodes+) versus N3 (≥10+) status but did not correlate with BRFS, as expected. When evaluating NR, 18 pts had high NR (>70%). Only 3 patients experienced nodal recurrences, all within previously radiated supraclavicular fields. All 3 in-field regional failures occurred in the N3 group of patients with NR >70%. All were treated with a single AP field prescribed to a dose of 46 Gy at a standard depth of 3 cm. Conclusions. In this group of N2/N3 patients treated with BCT, we were able to identify patients at high risk for regional failures as those with high NR of >70% and ≥10+ nodes. While these findings need to be reproduced in larger datasets, this group of patients with NR of >70% in 4 or more positive axillary lymph nodes may benefit from meticulous targeting of regional nodes, dose escalation, and/or more intensive systemic therapies.

Issues related to sentinel lymph node assessment in the management of breast cancer-what are relevant in pathology reports?

Most cancer centers now perform sentinel node (SN) biopsies. The limited number of SNs sampled compared with an axillary dissection has allowed more comprehensive lymph node analysis resulting in increased detection of micrometastases. Many node-negative cases are now reclassified as micrometastatic. Recent research on SN biopsy focuses on whether axillary dissection is always necessary when the SN is positive. Some subgroups of patients have a higher risk of more nodal metastases when completion axillary dissections were performed. This paper summarizes the different studies and examines what are the clinically relevant items to report on SN node pathology: volume or size of nodal metastasis, location within the node, extranodal extension, number of involved SN(s) and non-SN(s), total number of SN, and total number of nodes on axillary dissection, if performed.

Prognostic significance of number of positive nodes: a long-term study of one to two nodes versus three nodes in breast cancer patients

PURPOSE

Previous reports of breast cancer have generally analyzed patients with one to three positive lymph nodes as a single group, often leading to controversy regarding the practical clinical applicability. The present study separately analyzed the survival outcomes of Stage T1-T2 breast cancer patients according to whether one, two, or three axillary nodes were pathologically positive.

METHODS AND MATERIALS

The records of 5,996 patients were available for analysis from the population-based Saskatchewan provincial registry between 1981 and 1995. Because the reliability of the nodal assessment depends on the number of lymph nodes sampled, only those 755 patients with Stage T1-T2 disease and eight or more nodes examined were analyzed further for overall survival and cause-specific survival (CSS).

RESULTS

Patients with one and two positive nodes had nearly indistinguishable survival plots, but those with three positive nodes had a distinct trend toward worse survival. The overall survival rate of patients with one, two, and three nodes at 5, 10, and 15 years was 82.7%, 77.0%, and 79.0%, 64.8%, 60.9%, and 52.8%, and 48.8%, 48.0%, and 40.9%, respectively (p = .11). The corresponding CSS rates at 5, 10, and 15 years were 89.4%, 82.0%, and 81.3%, 78.87%, 72.9%, and 62.1%, and 72.7%. 69.0%, and 55.6% (p = .0004). The use of regional radiotherapy did not confer any apparent survival benefit in terms of either overall survival or CSS.

CONCLUSION

Patients with one or two positive nodes had a similar CSS. However, those with three positive nodes fared worse, with a significantly reduced CSS compared with those with one or two involved nodes. Thus, the survival data among patients with one to three nodes positive reveals clearly relevant differences when analyzed separately.

Prognostic value of nodal ratios in node-positive breast cancer: a compiled update

The number of positive axillary nodes is a strong prognostic factor in breast cancer, but is affected by variability in nodal staging technique yielding varying numbers of excised nodes. The nodal ratio of positive to excised nodes is an alternative that could address this variability. Our 2006 review found that the nodal ratio consistently outperformed the number of positive nodes, providing strong arguments for the use of nodal ratios in breast cancer staging and management. New evidence has continued to accrue confirming the prognostic significance of nodal ratios in various worldwide population settings. This review provides an updated summary of available data, and discusses the potential application of the nodal ratio to breast cancer staging and prognostication, its role in the context of modern surgical techniques such as sentinel node biopsy, and its potential correlations with new biologic markers such as circulating tumor cells and breast cancer stem cells.

Adjuvant regional irradiation after breast-conserving therapy for early stage breast cancer: a survey of canadian radiation oncologists

AIMS

To document the use of adjuvant regional irradiation after breast-conserving therapy for early stage breast cancer by Canadian radiation oncologists and to identify the factors influencing their clinical decisions.

MATERIALS AND METHODS

We conducted a survey to assess the above aims. In April 2008, a questionnaire was sent to 167 members of the Canadian and Quebec Associations of Radiation Oncologists with interest in breast cancer management. The answers were obtained through a dedicated website, which collected the raw data collected for analysis.

RESULTS

In total, 67 radiation oncologists completed the survey, corresponding to a 40% response rate. Most respondents were experienced and high-volume providers. We identified several areas of variation in the decision-making regarding regional lymph node irradiation after breast-conserving therapy. Regarding the decision to combine regional nodal irradiation with irradiation of the breast, the number of positive nodes after axillary dissection (1-3 vs > or =4) was a crucial determinant. For patients with between one and three positive nodes and a nodal ratio of 50%, most respondents added regional irradiation. Similarly, the same nodal ratio of 50% was the main factor for inclusion of the axillary nodal region in the radiation field. However, few radiation oncologists have chosen to include the internal mammary chain in their treatment plan. The number of positive lymph nodes, the nodal ratio, the number of lymph nodes removed and the presence of extracapsular extension were the primary self-reported factors that directed the decision to offer regional radiotherapy.

CONCLUSIONS

This survey showed that there is a wide variation of practices among radiation oncologists in Canada. These results support the need for treatment guidelines and provide guidance on which factors should be included in a decision-making algorithm.

Effects of variable placement of superior tangential/supraclavicular match line on dosimetric coverage of level III axilla/axillary apex in patients treated with breast and supraclavicular radiotherapy

PURPOSE

To determine the differences in dosimetric coverage of the Level III axillary node target as a function of the superior tangential/supraclavicular match line in breast cancer patients undergoing with tangential breast and supraclavicular fossa radiotherapy.

METHODS AND MATERIALS

The data from 20 consecutive breast cancer patients who were treated with breast conservation surgery and Level I and II axillary dissection followed by radiotherapy to the undissected Level III axilla/supraclavicular fossa were retrospectively analyzed. The nodal volumes were delineated from the computed tomography simulation data set. Three composite treatment plans were generated for each patient according to the placement of the match line.

RESULTS

Coverage of the contoured Level III/axillary apex varied significantly with respect to the ipsilateral clavicular head, depending on the placement of the superior tangential/supraclavicular match line. The mean volume of the Level III/axillary apex covered by the 90% isodose line (45 Gy) was 100% for caudal placement of the match line, significantly greater than the 92% for intermediate placement (bisecting the clavicular head; p = 0.001) and the 68% for cranial placement with respect to the clavicular head (p < 0.001).

CONCLUSION

Placement of the superior tangential/supraclavicular match line caudal to the clavicular head results in statistically improved dosimetric coverage of the Level III axilla/axillary apex in breast cancer patients undergoing tangential/supraclavicular radiotherapy.

Clinical significance of axillary nodal ratio in stage II/III breast cancer treated with neoadjuvant chemotherapy

PURPOSE

Neoadjuvant chemotherapy may modify the yield of involved axillary lymph nodes. The purpose of this study was to identify the clinical significance of the involved nodal ratios in patients with stage II/III breast cancer treated with neoadjuvant chemotherapy.

METHODS

Two hundred and five stage II and III breast cancer patients who received neoadjuvant docetaxel/doxorubicin chemotherapy were enrolled in this prospective study. The patients received three cycles of neoadjuvant chemotherapy followed by curative surgery, either breast-conserving surgery or mastectomy with axillary lymph node dissection, and received three additional cycles of docetaxel/doxorubicin chemotherapy as adjuvant. Adjuvant radiotherapy and hormonal therapy were given after adjuvant chemotherapy when indicated.

RESULTS

The median follow-up duration was 28.9 months. The overall response rate (RR) for neoadjuvant chemotherapy was 77.6%. The mean nodal ratio was 0.29 (range, 0-1.0; nodal ratio <or=0.25, 121 [59.0%] vs. >0.25, 84 [41.0%]). Relapse free survival (RFS) of the patients who had a nodal ratio >0.25 was significantly shorter (Hazard Ratio (HR) = 2.701, P = 0.001). A nodal ratio >0.25 was also associated with a shorter overall survival (OS) (HR = 4.109, P = 0.006). However, RFS and OS were not different according to the absolute number of involved nodes (ANIN) (P = 0.166, P = 0.248, respectively). In multivariate analysis, the nodal ratio was an independent prognostic factor for RFS and OS (HR = 4.246, P < 0.001; HR = 7.764, P < 0.001).

CONCLUSION

Axillary nodal ratios have an independent prognostic value in stage II/III breast cancer treated with neoadjuvant chemotherapy. Nodal ratio might be a useful tool to identify the patients at high risk of relapse in the neoadjuvant setting.