Does the TNM classification of solitary internal mammary lymph node metastases in breast cancer still apply?

Contrast enhanced mammography (CEM) versus magnetic resonance imaging (MRI) for staging of breast cancer: The pro CEM perspective

In women with newly diagnosed breast cancer, preoperative staging is required to assess disease extent, enabling us to decide on the most optimal treatment strategy. For locoregional staging, assessment of intramammary tumor extent and presence of axillary and perhaps also internal mammary lymph node metastases is required. Due to the similarity in the underlying principle, contrast-enhanced mammography is increasingly considered instead of breast MRI for this purpose. When considering the combination of CEM and US as a single appointment imaging strategy for preoperative staging of breast cancer, there is only limited room for an additional benefit of breast MRI. For tumor size measurements, equal performance of both CEM and MRI are observed. Sensitivity of both techniques for detecting breast cancer is comparable, meaning that both techniques are capable of detecting additional ipsilateral or contralateral tumor foci. However, specificity is in favor of CEM, meaning that there is a slightly lower chance of having false positive findings in preoperative staging of the breast. Axillary US can be performed during the same appointment as CEM, with equal performance and limitations as evaluation of the axilla on standard breast MRI examinations. Finally, there is no need to actively pursue the detection of IMLN metastases, meaning that additional MRI to do so is not required. This review provides a 'pro-CEM' perceptive on the arguments why breast MRI is hardly necessary when CEM in combination with US has been performed as a single appointment imaging strategy in breast cancer patients.

Value of Ultrasound-Guided Biopsy in Evaluating Internal Mammary Lymph Node Metastases in Breast Cancer

OBJECTIVES

This retrospective study aimed to assess the value of a real-time, ultrasound-guided biopsy in evaluating internal mammary lymph nodes (IMLNs) in breast cancer.

METHODS

Patients who were diagnosed with breast cancer and underwent real-time, ultrasound-guided core-needle biopsy (CNB) or fine-needle aspiration (FNA) in suspected IMLN metastasis were retrospectively analyzed. Patient information and ultrasonographic images were reviewed and correlated with pathology results.

RESULTS

Of the 164 IMLNs that were subjected to CNB, 131 were positive for metastasis by histopathologic confirmation, 8 were negative, and 25 were insufficient. By FNA, 84 IMLNs were regarded as positive for metastasis, 4 were negative, and 4 were insufficient. In total, there were 215 (83.98%) metastatic IMLNs, 12 benign IMLNs, and 29 unconfirmed by histopathology. There were statistically significant differences in the success of puncture sampling and detection of IMLN metastasis between the CNB and FNA groups (P < .05). There were no significant complications reported after FNA or CNB, including bleeding, nerve injury, infection, pneumothorax, or hemothorax.

CONCLUSIONS

Our study showed that ultrasonography accurately detected nodes that were likely to be malignant IMLNs, and that real-time, ultrasound-guided CNB and FNA are accurate and valuable techniques for the determination of status in breast cancer patients. Moreover, performing ultrasound-guided CNB and FNA on suspicious IMLN metastasis does not have additional severe complications.

Prevention of locoregional recurrence and distant metastasis in Japanese breast cancer patients using Japanese standard postoperative radiation fields: Experience at a single institution

BACKGROUND

Radiotherapy is an effective local control therapy for breast cancer. Locoregional control is associated with distant metastasis risk and survival after surgery.

AIM

We aimed to evaluate whether Japanese standard postoperative radiotherapy after surgery correlates with disease-free survival (DFS) and overall survival and clarify the characteristics of patients who benefit from it.

METHOD AND RESULTS

This retrospective study included 626 operable breast cancer patients. Tumor characteristics and survival outcomes were compared between patients who received radiotherapy and those who did not. Cox proportional hazard analysis was used to analyze prognostic factors for DFS and perform subgroup analysis. Propensity score matching was used to evaluate the efficacy of radiotherapy using a logistic regression model in patients who received radiotherapy or did not. The median follow-up duration after diagnosis of breast cancer was 63 months. DFS and overall survival were better in the irradiated group (P= .002 and P = .001, respectively). Radiotherapy was more effective for estrogen receptor (ER)-positive disease and for early breast cancer without lymph node metastasis. Multivariate analysis revealed that radiotherapy was a dependent risk factor for recurrence or metastasis.

CONCLUSION

Radiotherapy prevents distant metastasis and recurrence in early breast cancer patients. In particular, ER-positive, node-negative patients benefit from Japanese standard tangent field radiation.

Internal mammary lymph node metastases in breast cancer: what should radiologists know?

The internal mammary lymph node (IMLN) chain is a pathway through which breast lymphatic drainage flows. The internal mammary lymphatic vessel runs around the internal mammary artery and veins with IMLN in the parasternal intercostal spaces. IMLN metastasis, which forms a part of clinical TNM staging, may negatively affect the prognosis of primary breast cancer patients. IMLN metastasis is clinically detected using ultrasound, computed tomography, magnetic resonance imaging, and ¹⁸F-deoxyglucose positron emission tomography computed tomography. The uptake of radioactive tracers in IMLN with clinically negative axillary lymph nodes is often identified using sentinel lymph node mapping (SLNM) in primary breast cancer patients. The indication for IMLN biopsy or resection that is clinically detected or visualized using SLNM is controversial. The clinically suspicious IMLN may be considered for ultrasound-guided fine-needle aspiration. First IMLN recurrence needs to be biopsied. Irradiation of the breast, chest wall, and/or regional nodal irradiation, including IMLN, following lumpectomy or postmastectomy is recommended. Although radiation therapy for IMLN recurrence may improve clinical outcomes, it is also associated with pulmonary and cardiac toxicities. This review covers the local anatomy of IMLN, lymph drainage and image findings of IMLN with a discussion.

Prediction of tumor mutation burden in breast cancer based on the expression of ER, PR, HER-2, and Ki-67

Objective

Cancer immunoediting is the process of eliminating highly immunogenic tumor cells by somatic evolution and protecting the host from tumor development in the host immune system. Frequencies of somatic mutations or tumor mutation burden (TMB) were associated with immunogenicity of breast cancer. This study aimed to predict the level of TMB in patients with breast cancer by the expression of estrogen (ER), progesterone (PR), HER-2, and Ki-67, thereby anticipating the prognosis of patients and the possible response to immunotherapy.

Patients and methods

In 53 patients with breast cancer, the 453 multigenes panel based on NGS was used to determine the TMB value of breast cancer in the patient’s primary tumor tissues. The predicted TMB value was divided into 4 groups: A (0–3.33), B (3.33–5.56), C (5.56–8.89), and D (>8.89), according to the quartile method, with group A as reference level. Logistic regression was used to analyze the risk ratio of each molecule type, and the prediction model was established. Survival probabilities by covariates were assessed using Kaplan–Meier estimator survival analysis and Cox’s proportional hazards models.

Results

In 53 patients, the TMB value measured by the NGS polygenic panel was between 0 and 14.4/Mb. TMB distribution in 53 cases of breast cancer tissue: 18 cases in A group, 22 cases in B group, 10 cases in C group, and 3 cases in D group. HER-2 expression positivity was significantly associated with TMB (HER-2 positive vs HER-2 negative, odds ratio [OR] =34.81, 95% confidence interval [CI]: 3.711–821.689, P=0.0065). Higher TMB was distributed in the patients who were Ki-67 expression positive (>14%) than those who were Ki-67 expression negative (≤14%) (OR =0.217, 95% CI: 0.054–0.806, P=0.0242). However, no significant differences of TMB were found between ER-positive group and ER-negative group (OR =3.133, 95% CI: 0.124–127.687, P=0.4954) and between PR-positive group and PR-negative group in terms of TMB (OR =1.702, 95% CI: 0.162–20.335, P=0.6492). The predicted model is TMB = −1.14×ER +0.53×PR +3.55×HER-2-1.53×Ki-67+ CONSTANT (INTERCEPT). Patients with low TMB had a better disease-free survival (DFS) than those with high TMB (83 vs 59 m, P=0.002). In a multivariate analysis, high TMB (>5.56) was an independent predictive factor for decreased DFS (adjusted hazard ratio [HR], 5.594; 95% CI: 1.694–18.473; P = 0.005).

Conclusion

The preliminary results suggest that the level of TMB value in patients with breast cancer can be predicted based on the expression levels of ER, PR, HER-2, and Ki-67, which may indicate the prognostic and predictive value of immunotherapy in patients with breast cancer.