Occult breast cancer may originate from ectopic breast tissue present in axillary lymph nodes

Proteomic profiling reveals biological processes and biomarkers involved in the pathogenesis of occult breast cancer

BACKGROUND

Occult breast cancer (OBC) is defined as axillary lymph node metastasis without any evidence of a primary tumor in the breast. Because of the limited number of clinical cases, the clinicopathological features and treatment recommendations of OBC are still controversial. In addition, its natural history is poorly understood and its proteomic signature remains unknown.

MATERIALS AND METHODS

We compared the clinicopathological features and prognosis of OBC patients and Non-OBC patients from the Surveillance, Epidemiology, and End Results (SEER) database and analyzed the effects of local treatment on the survival outcomes of OBC patients. Additionally, we performed a quantitative proteomic analysis for tissue samples of metastatic lymph nodes from OBC patients (OBC-LN), and paired tissue samples of metastatic lymph nodes (Non-OBC-LN) and primary tumors (Non-OBC-PT) from Non-OBC patients. We identified differentially expressed proteins in different comparable groups using Student's t test. Functional enrichment and protein-protein interaction network analyses were used to interpret the functions and interactions of the differentially expressed proteins in the comparison of OBC-LN vs Non-OBC-LN. Immunohistochemistry was used for the validation of the hub proteins.

RESULTS

Analysis of data from the SEER database demonstrated that OBC patients had a better prognosis than Non-OBC patients did and that either mastectomy or radiation therapy improved the outcomes of OBC patients. A total of 7208 comparable proteins were successfully quantified. Compared with those of the Non-OBC-LN samples, the OBC-LN protein profiles exhibited an active extracellular matrix and a thoroughly upregulated epithelial-mesenchymal transition phenotype. COL1A1, COL1A2, COL3A1, MMP2 and LUM were overexpressed in the OBC-LN samples and were identified as hub proteins. Immunohistochemical staining demonstrated that the five hub proteins were overexpressed in OBC-LN samples.

CONCLUSION

Our results provide insights for the clinical management of OBC and the proteomic signature of OBC offers molecular basis for further biological research.

Occult breast cancer in an older woman: A case report

Occult breast cancer (OBC) is a relatively rare clinical condition that can complicate differential diagnosis efforts and delay the administration of specific treatments. The individualized therapy of patients with OBC should be performed based on their clinical symptoms, imaging findings and pathological diagnosis. The present case study describes a 51-year-old woman with a painless left axillary tumor. The axillary lymph nodes of the patient were affected by invasive ductal carcinoma, as determined by histological analysis. However, the primary lesion was missed by numerous testing. The patient underwent surgery and testing for positron emission tomography/computed tomography (PET/CT). The present study comprehensively examined this case and offered a systematic analysis of the relevant scholarly works on the diagnosis, treatment and prognosis of OBC. Ultrasonography revealed the presence of three homogenous hypoechoic masses with irregular margins in the left axilla of the patient. PET/CT scanning identified multiple enlarged left axillary hypermetabolic lymph nodes. After that, the patient underwent a nipple-sparing mastectomy and an axillary lymphadenectomy. With the lymph nodes showing metastatic, infiltrating ductal carcinoma from the breast, ductal carcinoma in situ of the breast diagnosis was supported by a histological examination. Immunohistochemical staining revealed that resected lymph nodes were positive for both estrogen and progesterone receptors, consistent with the status of the breast as the primary tumor site. Following surgery, the patient underwent adjuvant chemotherapy treatment. At 12 months post-surgery, the patient remained well without evidence of disease. OBC cases lack the typical clinical and imaging findings associated with breast cancer, and a combination of axillary lymph node examination and immunohistochemistry is essential for accurately diagnosing affected patients. Ensuring the best patient outcomes necessitates accurate and prompt diagnosis, achieved by thorough physical examination, cautious utilization of diagnostic tools, personalized surgical interventions and histological investigation.

Trends in management and related outcomes for occult primary breast cancer

PURPOSE

Occult Primary Breast Cancer (OPBC) is a rare clinical condition in which breast cancer is located within the axillary lymph nodes, but no primary tumor is identified in the breast. We evaluated trends of neoadjuvant chemotherapy (NAC) use and subsequent axillary procedures in OPBC as well as outcomes for these patients.

METHODS

The National Cancer Database was used to identify adult women with cT0N1-3M0 breast cancer between 2012 to 2021 that underwent axillary lymph node surgery. Kaplan-Meier curves were used to evaluate survival between groups.

RESULTS

2759 patients met inclusion criteria. 86.2% underwent ALND alone in 2012, and this decreased to 65.6% in 2021. 4.7% underwent SLNB alone in 2012 and this increased to 16.2% in 2021 (p < 0.001). For patients who had undergone NAC, 46.4% of ALND patients had nodal pathologic complete response (nPCR), compared to 42.7% of SLNB + ALND and 66.4% of SLNB only patients. For patients with nPCR, there was no difference in overall survival (OS) between ALND, SLNB + ALND, and SLNB alone groups (p = 0.9912).

CONCLUSION

Most OPBC patients were treated with ALND, with a modest increase towards SLNB use during the study period. There was no difference in OS with respect to axillary surgical procedure in our population for those with nPCR after NAC. This suggests that for carefully selected OPBC patients with an excellent clinical response to NAC and negative SLNB, omission of ALND may be considered.

A Case Report of Occult Breast Cancer Detected by Diagnostic Laparoscopy for Suspected Ovarian Cancer

Diagnostic laparoscopy is useful in the management of gynecological cancers; however, it can occasionally result in the detection of other malignancies. Occult breast cancer (OBC) is metastatic breast cancer without a recognized primary breast lesion. We report a rare case of OBC that was detected laparoscopically. A 64-year-old female presented to our hospital with back pain. Magnetic resonance imaging (MRI) revealed a 50 mm multicystic tumor with an internal nodule in the right ovary. Positron emission tomography/computed tomography showed abnormal accumulation in multiple lymph nodes, moderate accumulation in the ovarian tumor nodule, and no accumulation in the breasts. Ovarian cancer was suspected, and a diagnostic laparoscopy was performed. Laparoscopically, a cystic tumor in the right ovary and 10 mm nodule in the right round ligament were observed and partially resected. Immunohistopathologically, the nodules of the round ligament exhibited features consistent with those of breast cancer, but the ovarian tumor was a seromucinous borderline tumor. MRI revealed no breast lesions. Therefore, the malignancy was diagnosed as an OBC.

Best treatment options for occult breast cancer: A meta-analysis

Objectives

Occult breast cancer (OBC) is a rare malignant breast tumor. Because of the rare cases and limited clinical experience, a huge therapeutic difference has existed all over the world and standardized treatments have yet been established.

Methods

A meta-analysis was conducted using MEDLINE and Embase databases to identify the choice of OBC surgical procedures in all studies: (1) patients undergoing axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB) only; (2) patients undergoing ALND with radiotherapy (RT); (3) patients undergoing ALND with breast surgery (BS); (4) patients undergoing ALND with RT and BS; and (5) patients undergoing observation or RT only. The primary endpoints were mortality rates, the second endpoints were distant metastasis and locoregional recurrence.

Results

Among the 3,476 patients, 493 (14.2%) undergo ALND or SLNB only; 632 (18.2%) undergo ALND with RT; 1483 (42.7%) undergo ALND with BS; 467 (13.4%) undergo ALND RT and BS, and 401 (11.5%) undergo observation or RT only. After comparing the multiple groups, both groups 1 and 3 have higher mortality rates than group 4 (30.7% vs. 18.6%, p < 0.0001; 25.1% vs. 18.6%, p = 0.007), and group 1 has higher mortality rates than groups 2 and 3 (30.7% vs.14.7%, p < 0.00001; 30.7 vs. 19.4%, p < 0.0001). Group (1 + 3) had a prognosis advantage over group 5 (21.4% vs. 31.0%, p < 0.00001). There was no significant difference both in the distant recurrence rates and locoregional rates between group (1 + 3) and group (2 + 4) (21.0% vs. 9.7%, p = 0.06; 12.3% vs. 6.5%, p = 0.26).

Conclusion

On the basis of this meta-analysis, our study indicates that BS including modified radical mastectomy (MRM) and breast-conserving surgery (BCS) combined RT may appear as the optimal surgical approach in patients with OBC. RT cannot prolong both the time of distant metastasis and the local recurrences.

Case report: Uncommon multiple metastases from occult breast cancer revealed by 68Ga-DOTATATE PET/CT

Occult breast cancer is an uncommon type of breast cancer and its diagnosis is challenging. It is usually invisible on multiple imaging examines. Metastases to the rectum and inguinal lymph nodes from occult breast lobular cancer are even rarer. ⁶⁸Ga-DOTA peptides can image neuroendocrine tumors by targeting specific somatostatin receptors. Besides, other tumors, including breast cancer, have been shown to express somatostatin receptors. In this case, we presented a 63-year-old woman who underwent both ¹⁸F-FDG and ⁶⁸Ga-DOTATATE PET/CT due to a rectal polyp. An endoscopic excision biopsy confirmed metastatic carcinoma of suspected breast origin, but subsequent ultrasound and MRI showed no signs of malignancy in the breast and adnexa uteri. PET/CT showed obvious ⁶⁸Ga-DOTATATE activity in bilateral axillary and right inguinal lymph nodes with mild ¹⁸F-FDG uptake. Final histopathology at the left axillary, right inguinal lymph nodes, and rectum indicated metastases from breast cancer while the origin remained radiologically occult. Additionally, one uterine fibroids was found with positive uptake of ⁶⁸Ga-DOTATATE and negative uptake of ¹⁸F-FDG. This case suggested that ⁶⁸Ga-DOTATAE PET/CT may be an effective supplement in diagnosing OBC lymph node metastases with mild ¹⁸F-FDG uptake, and it may provide a new technology for the clinical diagnosis of occult breast cancer.

Axillary lymph node dissection plus radiotherapy may be an optimal strategy for patients with occult breast cancer

Background

Because of the rarity of occult breast cancer (OBC) and limited experience in OBC treatment, the optimal treatment strategy is unknown. This study aimed to compare the efficacy of axillary lymph node dissection (ALND) plus radiotherapy with that of mastectomy plus ALND in patients with OBC.

Methods

Relevant clinical data between January 2004 and December 2015 were retrospectively collected from the Surveillance, Epidemiology, and End Results database. The clinical characteristics and prognoses of patients who underwent ALND plus radiotherapy or mastectomy plus ALND were compared before and after propensity score matching.

Results

Overall, 569 eligible patients with OBC were included in this study. Of these, 247 patients underwent ALND plus radiotherapy and 322 underwent mastectomy plus ALND. The 5-year overall survival (OS) rates in the ALND plus radiotherapy group and the mastectomy plus ALND group were 89.2% and 80.6%, respectively; and the corresponding 5-year breast cancer-specific survival (BCSS) rates were 95.2% and 93.0%, respectively. After propensity score matching, the OS in the ALND plus radiotherapy group was significantly better than that in the mastectomy plus ALND group. In addition, further subgroup analyses revealed that ALND plus radiotherapy prolonged OS in the pN3 subgroup. Among patients receiving adjuvant chemotherapy, those who underwent ALND plus radiotherapy had better BCSS and OS than those who underwent mastectomy plus ALND.

Conclusions

ALND plus radiotherapy could improve the OS of patients with OBC, especially those with pN3 disease and those receiving chemotherapy. ALND combined with radiotherapy is the optimal treatment strategy for patients with imaging-negative OBC.

Breast and Thyroid Surgery in 2021 and Beyond

Several studies in the literature report the association between breast and thyroid pathologies; however, the underlying causes (genetic, environmental, hormonal or immunological) have not yet been well explicated [...]

Surgical treatment trends and identification of primary breast tumors after surgery in occult breast cancer: a study based on the Japanese National Clinical Database-Breast Cancer Registry

BACKGROUND

Occult breast cancer (OBC) is classified as carcinoma of an unknown primary site, and the adequate therapy for OBC remains controversial. This retrospective study aimed to reveal the transition in breast cancer therapy and the frequency of primary breast tumors after resection in clinical OBC (cT0N+) patients using the Japanese Breast Cancer Registry database.

METHODS

We enrolled OBC patients with cT0N+ from the registry between 2010 and 2018. On the basis of the period of diagnosis, OBC patients were divided into the following two groups: 2010-2014 and 2015-2018. We described the transition in treatments and tumor characteristics. After breast resection, the frequency of pathological identification of primary tumors and tumor sizes was assessed.

RESULTS

Of the 687,468 patients registered, we identified 148 cT0N+ patients with a median age of 61 years. Of these patients, 64.2% (n = 95) received breast surgery (2010-2014: 79.1%, 2015-2018: 50.0%). Axillary lymph node dissection was performed in 92.6% (n = 137, 2010-2014: 91.6%, 2015-2018: 93.4%). The breast tumor size in the resected breast was 0-7.0 cm (median: 0 cm, 2010-2014: 0-7.0 cm [median: 0 cm], 2015-2018: 0-6.2 cm [median: 0 cm]). The pathological identification rate of the primary tumor was 41.1% (n = 39, 2010-2014: 40.4%, 2015-2018: 42.1%).

CONCLUSIONS

Breast surgery for cT0N+ decreased between 2010 and 2018. Despite the high identification rate of primary tumors, most tumors were small, and there was no significant change in the identification rate or invasive diameter of the identified tumors after 2010.

Cutaneous metastasis of occult breast cancer: a case report

Occult breast cancer (OBC) is characterized by metastatic presentation of undetectable breast tumor on imaging exams. OBC is a rare disease (accounting for 0.3% to 1.0% of all breast cancers) that represents a major diagnostic challenge. The aim of this study was to report a case of OBC with primary presentation of multiple cutaneous metastases with subsequent emergence of bone metastasis. A 70-year female patient had multiple cutaneous metastatic lesions in the left cervical region, left breast, left axillary region, left subscapular region, in three chirodactylus of the right hand and three chirodactylus of the left hand. Imaging tests (mammogram, ultrasonography and magnetic resonance imaging of the breast) did not show alterations. Biopsy, histology sections and immunohistochemistry of the left cervical cutaneous lesion were compatible with OBC. After two years of anastrozole treatment (1mg/day), there was regression of all cutaneous lesions and stabilization of bone metastasis. OBC has a better prognosis. It may exhibit spontaneous regression or respond to less aggressive treatment strategies, as described in this case.

Histologic Discordance Between Primary Tumor and Nodal Metastasis in Breast Cancer: Solving a Clinical Conundrum in the Era of Genomics

Next-generation sequencing (NGS) technologies have become increasingly used for managing breast cancer. In addition to the conventional use of NGS for predicting recurrence risk and identifying potential actionable mutations, NGS can also serve as a powerful tool to understand clonal origin and evolution of tumor pairs and play a unique role in clarifying complex clinical presentations. We report an unusual case of early-stage breast cancer in which the primary tumor and draining axillary node were histologically discordant. The primary tumor was invasive lobular carcinoma, whereas the nodal metastasis was invasive ductal carcinoma. This discordance led us to question whether the tumors had the same origin. NGS performed on both specimens identified no overlapping variants, leading us to conclude that the patient had two separate primary breast cancers, with the nodal tumor representing metastasis from an occult breast cancer. DNA sequencing of the primary tumor and the nodal metastasis allowed us to predict the patient's recurrence risk, and we initiated adjuvant chemotherapy and hormonal therapy based on these results. This case illustrates the utility of NGS for successfully managing a rare and challenging case. KEY POINTS: A degree of molecular concordance is expected for tumors originating from a common stem or progenitor cell. Histological discordance and absence of any genomic overlap should raise suspicion for two separate primary tumors. Paired DNA sequencing of the primary tumor and nodal metastasis can inform clinical decisions when primary breast tumor and axillary metastasis are histologically discordant. Molecular/Precision Oncology Tumor Board is the best setting to facilitate such decisions in these challenging cases. Paired DNA sequencing under these rare circumstances may suggest an occult breast tumor.

Potential drug delivery nanosystems for improving tumor penetration

Nanosystems, as one of the most important drug delivery systems, play a crucial rule in tumor therapy. However, the deep tumor penetration is retarded by the tumor physiological factors and nanomedicine properties. In this review, we firstly elaborate the factors which impact tumor penetration, including the tumor physiological factors and nanomedicine properties. Then, the latest and potential drug delivery nanosystems for improving tumor penetration are summarized and analyzed in detail. Moreover, recent combination therapies for improving penetration are described to enhance penetration. Finally, we summarize the typical clinical therapies of potential drug delivery nanosystems.

Metastatic "Ductal Carcinoma In Situ-Like" Lobular Carcinoma in a Lymph Node: A Case Report and Review of the Literature

Metastatic breast cancer resembling ductal carcinoma in situ (DCIS) is a rare phenomenon. In this article, we present a unique case of metastatic lobular carcinoma with DCIS-like morphology in the left axillary lymph nodes of a 52-year-old female. She presented with 2 lesions in the left breast on mammography, and a mastectomy with axillary lymph node dissection was performed. Gross examination showed a 3.5 × 2.5 × 1.0 cm indistinct tumor in the lower outer quadrant and a 2.5 × 2.5 × 1.8 cm tumor in the upper outer quadrant. Microscopic assessment revealed a pleomorphic lobular carcinoma in the lower outer quadrant and a grade 2 invasive ductal carcinoma in the upper outer quadrant. Sixteen of the 17 axillary lymph nodes showed metastatic lobular carcinoma with foci of solid and comedo-type DCIS-like features. Immunohistochemical analysis of the primary and metastatic lobular carcinoma showed no expression of E-cadherin and p63 antibodies. To our knowledge, metastatic lobular carcinoma exhibiting this pattern has not been reported. The case suggests that lobular carcinoma can morphologically recreate a primary microenvironment at a distant site and simulate in situ growth. Recognition of this pattern is important to avoid misdiagnosis.

Metastatic ductal adenocarcinoma of the breast presenting with pericardial effusion-Challenges in the diagnosis of breast cancer

Breast cancer is a common entity that can be difficult to diagnose. This case demonstrates the limitations of breast cancer diagnostics. Particularly, how the available imaging techniques and even biopsy can potentially miss a malignancy. It exemplifies the role immunohistochemistry staining plays in the diagnosis of cancers of unclear origin.

The first case of gland inclusion in an intrapulmonary lymph node: a mimic of metastasis

BACKGROUND

Lymph node inclusions are foci of ectopic tissue in lymph nodes, which were reported in different areas of the body. However, inclusions in the mediastinal lymph node are rare. Here, we report the first case of glandular inclusion within the parenchyma of the intrapulmonary lymph node in a patient with primary lung adenocarcinoma.

CASE PRESENTATION

A computed tomography (CT) scan showed a solid pulmonary nodule in the right upper lobe in a 44-year-old man. After a fine needle aspiration biopsy diagnosis of adenocarcinoma, lobectomy and lymph dissection were performed. Histological sections of the lung demonstrated a papillary predominant adenocarcinoma and one intrapulmonary lymph node, which displayed glandular inclusion occupying the node parenchyma. The gland inclusion was very similar to metastasis, but was formed by two layers of epithelial cells, and the abluminal cells were positive for P63, P40, and CK5/6. The patient has remained alive without recurrence and metastasis at the last follow-up before publication.

CONCLUSIONS

It is very important to correctly diagnose a lymph node inclusion for proper clinical management.

An occult urothelial carcinoma with wide multiorgan metastases and its genetic alteration profiling: Case report and literature review

RATIONALE

Urothelial carcinoma, also named transitional cell carcinoma, is the most frequent occurring malignancy in the urinary system. It mainly invades the surrounding tissues and metastasizes to distant organs in later stages.

PATIENT CONCERNS

Here, we presented an unusual case of occult urothelial carcinoma primarily manifested as a multiorgan metastatic cancer in a 59-year-old man. The patient complained of pain on the left thigh root for a month. The imaging and histopathological examination revealed multiple malignancies in lung, bone, and liver.

DIAGNOSES

The histological evaluation and the immunohistochemistry (IHC) profile of liver, lung, and bone were consistent with the diagnosis of metastases from the original urothelial cancer, while imaging examination was not able to detect a primary lesion in the urinary system.

INTERVENTIONS

Based on the mutation of STK11 M51Ifs*106 detected by next generation sequencing (NGS), we started targeted therapy with everolimus.

OUTCOMES

The patient deteriorated after 3 months of treatment and passed away.

LESSONS

In this initial report of occult urothelial carcinoma, we obtained information on genetic variations of tumor tissue which could provide important information for subsequent studies on this kind of disease.

Screening Colonoscopy Unmasking Colonic Metastasis from an Occult Breast Ductal Carcinoma: A Case Report and Review of the Literature

Metastatic spread from breast cancer to the gastrointestinal tract is rare. Such cases are predominantly lobular carcinomas and they usually occur later on during the course of disease progression with the stomach being the most common site involved. Furthermore, occult breast primary tumor is extremely uncommon. To the best of our knowledge, we describe here the first case of incidental colonic metastasis as first presentation of an occult breast ductal carcinoma. We also provide a review of the literature on gastrointestinal—and specifically colonic—involvement from breast ductal carcinoma.