The Metastatic Rate of Internal Mammary Lymph Nodes When Metastasis of Internal Mammary Lymph Node Is Suspected on PET/CT

Internal Mammary Node Irradiation in Patients With Node-Positive Early Breast Cancer: Fifteen-Year Results From the Danish Breast Cancer Group Internal Mammary Node Study

PURPOSE

The Danish Breast Cancer Group Internal Mammary Node study demonstrated improved 8-year overall survival (OS) with internal mammary node irradiation (IMNI) in patients with node-positive early breast cancer. Here, we present long-term results from the Danish Breast Cancer Group Internal Mammary Node study cohort.

PATIENTS AND METHODS

This nationwide, prospective cohort study allocated patients with node-positive early breast cancer to adjuvant radiotherapy with or without IMNI depending on cancer laterality. Patients with right-sided cancer received IMNI. Patients with left-sided cancer were treated without IMNI because of risk of radiation-induced heart disease. Other treatment was independent of laterality. The primary study end point was OS. Secondary end points were distant recurrence and breast cancer mortality. Analyses were by intention to treat.

RESULTS

During 2003-2007, 3,089 women were allocated to IMNI (right-sided, n = 1,491) or no IMNI (left-sided, n = 1,598). With a median follow-up of 14.8 years, 589 patients with and 701 patients without IMNI had died. The corresponding 15-year OS rates were 60.1% and 55.4%. The adjusted hazard ratio (HR) for death was 0.86 (95% CI, 0.77 to 0.96; P = .007) in favor of IMNI. The 15-year risk of developing distant recurrence was 35.6% (523 recurrences) and 38.6% (602 recurrences) with vs. without IMNI (adjusted HR, 0.88 [95% CI, 0.79 to 0.99; P = .04]). The 15-year breast cancer mortality with IMNI was 31.7% (467 deaths) compared with 33.9% (537 deaths) without IMNI (adjusted HR, 0.88 [95% CI, 0.78 to 1.00; P = .05]). The distribution of other deaths was similar across groups.

CONCLUSION

In patients with node-positive early breast cancer treated with IMNI or without IMNI depending on breast cancer laterality, IMNI reduced the risk of distant recurrence and death from breast cancer, thereby improving long-term survival.

Internal Mammary Lymph Node Biopsy during Microsurgical Breast Reconstruction: A Prospective Study

BACKGROUND

 Accurate assessment of regional lymph node basins is critical for oncological management of breast cancer. The internal mammary lymph node (IMLN) basin directly drains the medial pole of the breast, but biopsy is not commonly performed. While the axillary sentinel lymph node sample remains the standard of care, the majority of patients who have been found to have a positive IMLN biopsy have simultaneously had negative axillary sentinel lymph nodes. This study prospectively examines routine IMLN biopsy during microsurgical breast reconstruction.

METHODS

 An IRB-approved study of routine IMLN biopsies in 270 consecutive patients who underwent microsurgical breast reconstruction was performed from July 1, 2018, to June 1, 2021. Recorded data included unilateral or bilateral breast reconstruction, unilateral or bilateral IMLN sampling, patient demographics, disease stage, and pathologic findings of IMLN.

RESULTS

 The majority of patients, 240 of 270 patients (88.9%), had bilateral reconstruction. Overall, 5 out of 270 (1.9%) patients had positive IMLN; one of these patients had positive axillary sentinel lymph nodes. The IMLN biopsy results in two of the five patients affected the clinical course as they were upstaged and required chemoradiation.

CONCLUSION

 Direct visualization of the internal mammary lymph nodes during dissection of the recipient vessels for microsurgical breast reconstruction allows for convenient sampling, with minimal donor site morbidity and enhances the therapeutic management of patients in whom nodal involvement is present. As such, the authors recommend IMLN sampling.

Evaluation of internal mammary lymph node biopsy during microsurgical breast reconstruction: An analysis of 230 consecutive patients

INTRODUCTION

Clinical significance of internal mammary (IM) lymph node biopsy during microvascular free flap breast reconstruction remains controversial. Some microsurgeons may choose to biopsy an IM lymph node during routine IM vessel dissection. The authors reviewed the results of IM lymph node biopsy during autologous breast reconstruction.

METHODS

A retrospective chart review of patients who underwent autologous breast reconstruction during a seven-year period (January 2010 to January 2017) was performed. Patient demographic data, disease staging, flap details, pathology reports, and adjuvant treatment were evaluated.

RESULTS

A total of 230 patients with a mean age of 52.1 (SD 9.3) underwent IM lymph node biopsy (n = 297). Single IM lymph node was removed in 169 patients, 2 nodes were removed in 56 patients, 3 nodes in 4 patients, and 4 nodes in a single patient. Histopathologic analysis demonstrated presence of IM lymph node metastasis in 16 patients (7.0%). Thirteen patients were found to have metastatic IM lymph nodes in the setting of immediate reconstruction. Three patients were found to have metastatic IM lymph nodes in the setting of delayed. Five out of 16 patients (31.3%) had negative axillary sentinel lymph node biopsy and IM lymph nodes were the only site of nodal metastases. All five of these patients were upstaged accordingly and received adjuvant therapy based on the discussion at the multidisciplinary breast tumor conference.

CONCLUSIONS

Opportunistic internal mammary lymph node sampling during autologous breast reconstruction can be performed with minimal morbidity and has significant impact on the disease staging and adjuvant treatment.

Imaging and Management of Internal Mammary Lymph Nodes

Internal mammary lymph nodes (IMLNs) account for approximately 10%-40% of the lymphatic drainage of the breast. Internal mammary lymph nodes measuring up to 10 mm are commonly seen on high-risk screening breast MRI examinations in patients without breast cancer and are considered benign if no other suspicious findings are present. Benign IMLNs demonstrate a fatty hilum, lobular or oval shape, and circumscribed margins without evidence of central necrosis, cortical thickening, or loss of fatty hilum. In patients with breast cancer, IMLN involvement can alter clinical stage and treatment planning. The incidence of IMLN metastases detected on US, CT, MRI, and PET-CT ranges from 10%-16%, with MRI and PET-CT demonstrating the highest sensitivities. Although there are no well-defined imaging criteria in the eighth edition of the American Joint Committee on Cancer Staging Manual for Breast Cancer, a long-axis measurement of ≥ 5 mm is suggested as a guideline to differentiate benign versus malignant IMLNs in patients with newly diagnosed breast cancer. Abnormal morphology such as loss of fatty hilum, irregular shape, and rounded appearance (which can be quantified by a short-axis/long-axis length ratio greater than 0.5) also raises suspicion for IMLN metastases. MRI and PET-CT have good sensitivity and specificity for the detection of IMLN metastases, but fluorodeoxyglucose avidity can be seen in both benign conditions and metastatic disease. US is helpful for staging, and US-guided fine-needle aspiration can be performed in cases of suspected IMLN metastasis. Management of suspicious IMLNs identified on imaging is typically with chemotherapy and radiation, as surgical excision does not provide survival benefit and is performed only in rare cases.

FDG-PET/CT in the Postoperative Period: Utility, Expected Findings, Complications, and Pitfalls

FDG-PET/CT as a modality is increasingly used for detection of recurrence and for restaging in patients with clinical suspicion of malignancy, as well as in patients with elevated tumor markers. However, there are many pitfalls in the interpretation of these scans when the studies are performed after some treatment. Some of these are attributed to normal physiological distribution and are compounded when there are inflammatory changes occurring after surgery. The body's inherent response to the surgical insult results in this inflammation. In addition, there are also complications that can happen following surgery, causing increased FDG uptake. Despite various fallacies, FDG-PET/CT provides valuable information in evaluation of residual and recurrent malignant disease. In this article, we aim to describe some of these postsurgical changes secondary to inflammation, common surgical complications, and finally, the utility of FDG-PET/CT in these patients to detect recurrent disease, even in the background of postsurgical changes.

Prospective study found that peripheral lymph node sampling reduced the false-negative rate of sentinel lymph node biopsy for breast cancer

Background

Although sentinel lymph node biopsy (SLNB) can accurately predict the status of axillary lymph node (ALN) metastasis, the high false-negative rate (FNR) of SLNB is still the main obstacle for the treatment of patients who receive SLNB instead of ALN dissection (ALND). The purpose of this study was to evaluate the clinical significance of SLNB combined with peripheral lymph node (PLN) sampling for reducing the FNR for breast cancer and to discuss the effect of “skip metastasis” on the FNR of SLNB.

Methods

At Shandong Cancer Hospital Affiliated to Shandong University between March 1, 2012 and June 30, 2015, the sentinel lymph nodes (SLNs) of 596 patients with breast cancer were examined using radiocolloids with blue dye tracer. First, the SLNs were removed; then, the area surrounding the original SLNs was selected, and the visible lymph nodes in a field of 3–5 cm in diameter around the center (i.e., PLNs) were removed, avoiding damage to the structure of the breast. Finally, ALND was performed. The SLNs, PLNs, and remaining ALNs underwent pathologic examination, and the relationship between them was analyzed.

Results

The identification rate of SLNs in the 596 patients was 95.1% (567/596); the metastasis rate of ALNs was 33.7% (191/567); the FNR of pure SLNB was 9.9% (19/191); and after the SLNs and PLNs were eliminated, the FNR was 4.2% (8/191), which was significantly decreased compared with the FNR before removal of PLNs (P = 0.028). According to the detected number (N) of SLNs, the patients were divided into four groups of N = 1, 2, 3, and ≥4; the FNR in these groups was 19.6, 9.8, 7.3, and 2.3%, respectively. For the patients with ≤2 or ≤3 detected SLNs, the FNR after removal of PLNs was significantly decreased compared with that before removal of PLNs (N ≤ 2: 14.0% vs. 4.7%, P = 0.019; N ≤ 3: 12.2% vs. 4.7%, P = 0.021), whereas for patients with ≥4 detected SLNs, the decrease in FNR was not statistically significant (P = 1.000). In the entire cohorts, the “skip metastasis” rate was 2.5% (15/596); the FNR caused by “skip metastasis” was 2.1% (4/191).

Conclusions

The FNR of SLNB was associated with the number of SLNs. For patients with ≤3 detected SLNs, PLN sampling can reduce the FNR of SLNB to an acceptable level of less than 5%. Because of the existence of the “skip metastasis” and distinct metastasis patterns, the FNR of SLNB cannot be completely eliminated.

Incidence and Potential Significance of Internal Mammary Lymphadenopathy on Computed Tomography in Patients with a Diagnosis of Primary Breast Cancer

INTRODUCTION

The importance of internal mammary nodes (IMNs) in the staging and treatment of breast cancer patients is controversial.

METHODS

A retrospective cohort of patients diagnosed with primary breast cancer over a 4-year period (January 2009 to December 2012) was assessed. The number and size of any IMNs visible on spiral computed tomography (CT) were recorded.

RESULTS

A total of 830 patients were diagnosed with primary breast cancer within the identified time frame, of which 150 patients met the inclusion criteria. Of these 42% (63) had IMNs present, although the majority were small (<5 mm). However, 16% (25) had larger nodes, greater than 5 mm in short axis, present on CT. Significantly more patients with the presence of large (>5 mm) IMNs had more advanced disease with CT evidence of other distant spread.

CONCLUSION

We have demonstrated that IMNs are present in a substantial number of our primary breast cancer patients. We suggest that further histological research is required to establish reliable CT size criterion for pathological IMNs. In addition, routine imaging of the IM chain, as well as axilla, should be considered in the staging of breast cancer.