Axillary nodal metastases from carcinoma of unknown primary (CUPAx): a systematic review of published evidence

Clinicopathologic features and genomic profiling of female axillary lymph node metastases from adenocarcinoma or poorly differentiated carcinoma of unknown primary

PURPOSE

Axillary lymph node metastases from adenocarcinoma or poorly differentiated carcinoma of unknown primary (CUPAx) is a rare disease in women. This retrospective study intended to examine the clinicopathological features of CUPAx and compared CUPAx genetically with axillary lymph node metastases from breast cancer (BCAx), investigating differences in their biological behavior.

METHODS

We conducted the clinical and prognostic analysis of 58 CUPAx patients in West China Hospital spanning from 2009 to 2021. Gemonic profiling of 12 CUPAx patients and 16 BCAx patients was conducted by the FoundationOne CDx (F1CDx) platform. Moreover, we also compared the gene mutation spectrum and relevant pathways between the two groups and both TCGA and COSMIC databases.

RESULTS

The majority of the 58 CUPAx patients were HR-/HER2- subtype. Most patients received mastectomy combined radiotherapy (50 Gy/25f). CUPAx patients who received mastectomy instead of breast-conserving surgery had a more favorable overall prognosis. Radiotherapy in chest wall/breast and supraclavicular/infraclavicular fossa was the independent prognostic factor (HR = 0.05, 95%CI = 0.00-0.93, P = 0.04). In 28 sequencing samples (CUPAx, n = 12, BCAx, n = 16) and 401 TCGA-BRCA patients, IRS2 only mutated in CUPAx (33.33%) but amplified in BCAx (11.11%) and TCGA-BRCA (1.5%). Pathway analysis revealed that BCAx had more NOTCH pathway mutations than CUPAx. Enrichment analysis showed that CUPAx enriched more in mammary development and PML bodies than BCAx, but less in the positive regulation of kinase activity.

CONCLUSIONS

More active treatment methods, like chemotherapy, mastectomy and postoperative radiotherapy, could improve the prognosis of CUPAx. The differential mutation genes of CUPAx and BCAx might be associated with their respective biological behaviors like invasiveness and prognosis.

Analysis of Prognoses according to Breast MRI Results in Patients with Axillary Lymph Node Metastases from an Unknown Primary Origin

PURPOSE

To compare the prognosis of patients with axillary adenocarcinoma from an unknown primary (ACUPax) origin with negative MRI results and those with MRI-detected primary breast cancers.

MATERIALS AND METHODS

The breast MRI images of 32 patients with ACUPax without signs of primary breast cancer on mammography and ultrasound (US) were analyzed. Spot compression-magnification mammography and second-look US were performed for the area of MRI abnormality in patients with positive results; any positive findings corresponding to the MRI abnormality were confirmed by biopsy. If suspicious MRI lesions could not be localized on mammography or US, MR-guided biopsy or excision biopsy after MR-guided localization was performed. We compared the prognosis of patients with negative breast MRI with that for patients with MRI-detected primary breast cancers.

RESULTS

Primary breast cancers were confirmed in 8 (25%) patients after breast MRI. Primary breast cancers were not detected on MRI in 24 (75%) patients, including five cases of false-positive MRI results. Twenty-three patients underwent axillary lymph node dissection (ALND) followed by whole breast radiation therapy (WBRT) and chemotherapy (n=17) or subsequent chemotherapy only (n=2). Recurrence or distant metastasis did not occur during follow up in 7/8 patients with MRI-detected primary breast cancers and 22/24 patients with negative MRI results. Regional recurrence or distant metastasis did not occur in any MR-negative patient who received adjuvant chemotherapy after ALND and WBRT.

CONCLUSION

The prognoses of MR-negative patients with ACUPax who received ALND and WBRT followed by chemotherapy were as good as those of patients with MRI-detected primary breast cancers.

[Peritoneal carcinomatosis secondary to CUP syndrome : Diagnosis and indications for multimodal treatment]

CLINICAL PROBLEM

Peritoneal carcinomatosis secondary to cancer of unknown primary (CUP) syndrome is a rare entity for which there are no uniform treatment recommendations or guidelines. The median survival time is 3 months.

DIAGNOSIS

Computed tomography (CT), magnetic resonance imaging (MRI), and ¹⁸F‑FDG positron emission tomography (PET)/CT are valid imaging modalities for the detection of peritoneal carcinomatosis. The sensitivity of all techniques is highest for large, macronodular peritoneal carcinomatosis manifestations. A limitation of all imaging techniques is limited and small-nodular peritoneal carcinomatosis. Also, peritoneal metastasis in the small bowel mesentery or diaphragmatic domes can only be visualized with low sensitivity. Therefore, exploratory laparoscopy should be considered as the next diagnostic step. In half of these cases an unnecessary laparotomy can be avoided, because the laparoscopy revealed diffuse, small-nodule involvement of the small bowel wall and thus an irresectable situation.

TREATMENT

In selected patients, performing complete cytoreduction followed by hyperthermic intra-abdominal chemotherapy (HIPEC) is a good therapeutic option. Therefore, the identification of the extent of peritoneal tumor manifestation as accurately as possible is important for the definition of the increasingly complex oncological therapy strategies.

[Breast-like cancer of unknow primary : Implications for radiological diagnostics]

BACKGROUND

Cancer of unknown primary (CUP) is defined by the presence of metastatic disease with an undetectable primary tumor at the time of presentation despite standard-of-care imaging. Although the prognosis of most CUP patients is poor, certain subgroups with more favorable prognosis have been defined.

DIAGNOSTICS

Women with isolated axillary lymph node metastases and confirmed histologic adenocarcinoma or poorly differentiated subtype, no other distant metastases, and no evidence of a primary cancer including primary breast carcinoma evaluated by clinical examination, computed tomography of thorax and abdomen, mammography, breast ultrasound, and breast magnetic resonance imaging (MRI) represent a potentially curable subgroup of patients with CUP. Breast MRI is the most important radiological modality in the diagnostic workup of breast-like CUP to exclude a primary cancer in the breast.

THERAPY

Breast-like CUP patients are treated according to guidelines for patients with node-positive breast cancer. Standard-of-care adjuvant systemic therapy should be given. Axillary lymph node dissection (ALND) is indicated. If no primary cancer in the breast is detected, surgery of the ipsilateral breast should not be performed. Radiotherapy of the ipsilateral breast and supra-/infraclavicular lymph nodes should be discussed.

Left Axilla Adenocarcinoma of Unknown Origin

A 76-year-old woman presents with a palpable left axillary mass, yet no breast lesions are found. What is your diagnosis?

Reconceptualizing the clinicopathological features, locoregional therapy and prognostic factors of occult breast cancer in the era of molecular subtyping

To evaluate the clinical features, molecular subtypes, therapeutic strategies, and prognostic factors of occult breast cancer (OBC). Patients with T0-3/N1-3/M0 breast cancer diagnosed in 2010-2018 (n = 114,303, including 691 with OBC) were retrieved from the Surveillance, Epidemiology, and End-Results (SEER) database. The endpoints were overall survival (OS) and breast cancer-specific survival (BCSS). Compared with non-OBC, OBC presented significantly more adverse clinicopathological prognostic features. More patients with OBC underwent breast-conserving treatment (BCT) and less had axillary lymphadenectomy (ALD). Outcomes were more favorable in OBC cases compared with non-OBC cases (p = .002 for OS, p = .002 for BCSS). Triple-negative (TNBC) and HER2-enriched were the subtypes with the worst prognosis in OBC (p < .05). Prognosis was better for triple-negative OBC compared with the same subtype of non-OBC. N-stage was not a strong prognostic indicator of OBC (p > .05 for OS). Cases who underwent systemic chemotherapy alone without surgery had the worst prognosis among OBC patients. For locoregional therapy, mastectomy and radiotherapy could confer survival advantage; standard axillary lymph node dissection (ALND) and positive lymph node dissection (PLND) contributed notably to OS in OBC patients. Both OS and BCSS were better in OBC cases compared with non-OBC. Systemic chemotherapy alone without surgery is not appropriate for OBC treatment, and mastectomy plus standard axillary surgery is recommended. Patients with hormone receptor-positive and low burden of axillary lymph node metastasis may be spared from radiotherapy after undergoing standard axillary lymphadenectomy.

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.

Case report: Unique ultrasound feature of thyroid metastases in occult breast cancer

Occult breast cancer is an uncommon type of breast cancer. Metastases of occult breast cancer to other tissues are rather rare. We present a rare case of thyroid metastases in a 46-year-old woman who underwent occult breast cancer. The first ultrasound (US) examination of the thyroid showed that the left lobe was enlarged but had normal thyroid function. At first, this case was misdiagnosed as thyroiditis based on the thyroid US features. However, the cytological and histological results showed that nests of the neoplastic cells were found. Further immunohistochemistry results confirmed that these neoplasms were derived from breast tissue. Analysis using the successive US scans revealed that the sizes and echo of the thyroid repeatedly changed after the radiotherapy and chemotherapy treatment. To our knowledge, this is the first reported case of occult breast carcinoma presenting with thyroid metastases. This case can easily be misdiagnosed as thyroiditis due to the metastasis area not manifesting as regular suspicious nodules or diffused punctate calcifications.

ACR Appropriateness Criteria® Imaging of the Axilla

This publication reviews the current evidence supporting the imaging approach of the axilla in various scenarios with broad differential diagnosis ranging from inflammatory to malignant etiologies. Controversies on the management of axillary adenopathy results in disagreement on the appropriate axillary imaging tests. Ultrasound is often the appropriate initial imaging test in several clinical scenarios. Clinical information (such as age, physical examinations, risk factors) and concurrent complete breast evaluation with mammogram, tomosynthesis, or MRI impact the type of initial imaging test for the axilla. Several impactful clinical trials demonstrated that selected patient's population can received sentinel lymph node biopsy instead of axillary lymph node dissection with similar overall survival, and axillary lymph node dissection is a safe alternative as the nodal staging procedure for clinically node negative patients or even for some node positive patients with limited nodal tumor burden. This approach is not universally accepted, which adversely affect the type of imaging tests considered appropriate for axilla. This document is focused on the initial imaging of the axilla in various scenarios, with the understanding that concurrent or subsequent additional tests may also be performed for the breast. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Axillary lymph‐node metastases as the primary presentation of high‐grade serous ovarian carcinoma: A case report

We reported a female presented with an initial diagnosis of metastatic axillary lymph‐node carcinoma that comprehensive assessments revealed a definitive diagnosis of high‐grade serous ovarian carcinoma as the primary tumor.

Axillary metastasis from occult breast cancer and synchronous contralateral breast cancer initially suspected to be cancer with contralateral axillary metastasis: a case report

Background

Initial detection of axillary metastasis without known ipsilateral breast cancer could be a challenging diagnostic problem. Four options could be considered for the primary site of the malignancy: ipsilateral occult breast cancer, contralateral breast cancer, tumors in other distant organs, and primary axillary malignancy itself. Although breast cancer is known as the most common primary cancer of axillary metastasis, both occult breast cancer and breast cancer with contralateral axillary metastasis (CAM) are rare.

Case presentation

A 63-year-old woman presented with palpable right axillary metastasis, and a tiny contralateral breast cancer was detected by breast magnetic resonance imaging. No lesion was found in the ipsilateral right breast and contralateral left axillary region. Both right axillary metastasis and contralateral breast cancer were positive for estrogen receptor. The diagnostic issue was to determine whether the axillary metastasis was derived from the contralateral breast cancer or not. Right axillary dissection and left breast conserving surgery were performed. The final diagnosis was occult breast cancer that presented with axillary lymph node metastasis and early-stage synchronous contralateral breast cancer, based on clinical evidence and postoperative pathologic results. After surgery, systemic treatment and whole breast irradiation were administered. No recurrence or metastasis was observed 15 months postoperatively.

Conclusion

For accurate diagnosis of axillary metastasis without detectable ipsilateral breast cancer, multifaceted diagnostic approach considering clinical, radiological, and pathological evidences is required.

Prognosis of patients with axillary lymph node metastases from occult breast cancer: analysis of multicenter data

Purpose

This study was conducted to evaluate prognosis of patients with level I/II axillary lymph node metastases from occult breast cancer (OBC).

Materials and Methods

Data of 53 patients with OBC who received axillary lymph node dissection (ALND) positive/negative (+/–) breast-conserving surgery between 2001 and 2013 were retrospectively collected at seven hospitals in Korea. The median number of positive lymph nodes (+LNs) was 2. Seventeen patients (32.1%) had >3 +LNs. A total of 48 patients (90.6%) received radiotherapy. Extents of radiotherapy were as follows: whole-breast (WB; n = 11), regional lymph node (RLN; n = 2), and WB plus RLN (n = 35).

Results

The median follow-up time was 85 months. Recurrence was found in four patients: two in the breast, one in RLN, and one in the breast and RLN. The 5-year and 7-year disease-free survival (DFS) rates were 96.1% and 93.5%, respectively. Molecular subtype and receipt of breast radiotherapy were significantly associated with DFS. Patients with estrogen receptor negative, progesterone receptor negative, and human epidermal growth factor receptor 2 negative (ER-/PR-/HER2-) subtype had significantly lower 7-year DFS than those with non-ER-/PR-/HER2- tumor (76.9% vs. 100.0%; p = 0.03). Whole breast irradiation (WBI) was significantly associated with a higher 7-year DFS rate (94.7% for WBI group vs. 83.3% for non-WBI group; p = 0.01). Other factors including patient’s age, number of +LNs, taxane chemotherapy, and RLN irradiation were not associated with DFS.

Conclusion

Patients with OBC achieved favorable outcome after ALND and breast-targeting treatment. Molecular subtype and receipt of WBI was significant factors for DFS.

Axillary Nodal Metastases from Carcinoma of Unknown Primary (CUPAx): Role of Contrast-Enhanced Spectral Mammography (CESM) in Detecting Occult Breast Cancer

Axillary lymph node metastases of occult breast cancer (CUPAx) is an unusual condition that represents both a diagnostic and therapeutic challenge. The first steps in the diagnostic work-up of patients with CUPAx are the histological analysis of the lymph node metastasis and the execution of basic breast diagnostic imaging (mammography and ultrasound). In the case of occult breast cancer, breast Magnetic Resonance (MR) must be performed. Breast MR identifies a suspicious lesion in many patients and second-look ultrasound detects a corresponding ultrasound alteration in about half of cases, allowing the performance of a US-guided biopsy. In the case of an MR-only lesion, MR-guided biopsy is mandatory. We present a case of CUPAx in which contrast-enhanced spectral mammography (CESM) is used to help the detection of occult breast cancer and to guide stereotactic vacuum breast biopsy (VABB). CESM is a new breast imaging technique that is proving to have good performance in breast cancer detection and that is showing potential in the identification of occult breast cancer in a CUPAx setting. The use of an innovative and personalized breast imaging approach in breast cancer patients improves diagnostic possibilities and promises to become the focus in decision strategies.

A Review of Breast Imaging for Timely Diagnosis of Disease

Breast cancer (BC) is the cancer with the highest incidence in women in the world. In this last period, the COVID-19 pandemic has caused in many cases a drastic reduction of routine breast imaging activity due to the combination of various factors. The survival of BC is directly proportional to the earliness of diagnosis, and especially during this period, it is at least fundamental to remember that a diagnostic delay of even just three months could affect BC outcomes. In this article we will review the state of the art of breast imaging, starting from morphological imaging, i.e., mammography, tomosynthesis, ultrasound and magnetic resonance imaging and contrast-enhanced mammography, and their most recent evolutions; and ending with functional images, i.e., magnetic resonance imaging and contrast enhanced mammography.

Cancer of unknown primary

Cancers of unknown primary (CUPs) are histologically confirmed, metastatic malignancies with a primary tumor site that is unidentifiable on the basis of standard evaluation and imaging studies. CUP comprises 2-5% of all diagnosed cancers worldwide and is characterized by early and aggressive metastasis. Current standard evaluation of CUP requires histopathologic evaluation and identification of favorable risk subtypes that can be more definitively treated or have superior outcomes. Current standard treatment of the unfavorable risk subtype requires assessment of prognosis and consideration of empiric chemotherapy. The use of molecular tissue of origin tests to identify the likely primary tumor site has been extensively studied, and here we review the rationale and the evidence for and against the use of such tests in the assessment of CUPs. The expanding use of next generation sequencing in advanced cancers offers the potential to identify a subgroup of patients who have actionable genomic aberrations and may allow for further personalization of therapy.

Metastases from Occult Breast Cancer: A Case Report of Carcinoma of Unknown Primary Syndrome

Carcinoma of unknown primary (CUP) syndrome occurs when metastases from an unknown primary site spread to multiple organs. Occult breast cancer (OBC) is defined as a clinically recognizable metastatic carcinoma from an undetectable primary breast tumor. It accounts for 0.3–1% of all breast cancers, often presenting with lymph node, bone, and skin metastases. Clinical and radiological examinations represent the first steps in the diagnostic algorithm for CUP syndrome from OBC. However, histological and immunohistochemical analyses, multidisciplinary team evaluation, and a multidisciplinary therapy are essential in the diagnosis and treatment of CUP syndrome from OBC. We report the case of a 52-year-old woman who underwent the removal of a parietal skin lesion. The histological and immunohistochemical analyses suggested a breast cancer origin. Clinical assessment and laboratory and radiological examinations did not locate the primary tumor. Hormone therapy was offered to the patient; however, she refused it. After 28 months, the patient reported a right cervical lump, and a total-body positron emission tomography showed dissemination of the disease to the lymph nodes and bone. A CUP syndrome from OBC was diagnosed. A multimodality approach with radiotherapy and hormone and biological therapy was started. At present, 5 years from the first presentation, the patient is asymptomatic despite the disseminated disease.

Occult breast cancer: Where are we at?

Occult breast cancer (OBC) is described as an axillary metastatic carcinoma without detection of a primary breast lesion and is uncommon. Significant advances in breast imaging have occurred since its description, decreasing its incidence. However current management is based upon old studies, with variable clinical, radiological and pathological definitions of OBC. We suggest standardised definitions of OBC to facilitate more homogenous data representation in the literature. This review also discusses the conflicting heterogeneous data and its influence in determining the current management guidelines. We discuss whether the current significant surgical recommendations are necessary and postulate whether they could be safely substituted with less invasive management.

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Pathological occult breast cancer is defined as no lesion detectable on MRI or pathological breast lesion post-surgery when examined at 5mm slices

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NAC in OBC may result in the de-escalation of axillary surgery.

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Current evidence indicates that ALND with ipsilateral breast RT has equivalent outcomes compared to ALND with mastectomy

Different Clinicopathological Characteristics and Prognostic Factors for Occult and Non-occult Breast Cancer: Analysis of the SEER Database

Purpose: The aim of our study was to evaluate the different clinicopathological characteristics and prognostic factors for occult and non-occult breast cancer. Methods: 572 OBC cases and 117,217 non-OBC patients between 2004 and 2015 was selected from Surveillance, Epidemiology, and End Results (SEER) database. We analyzed the clinicopathological characteristics and survival outcomes between OBC and non-OBC patients. Furthermore, the propensity score matching method was utilized to reduce the influences of baseline differences in demographic and clinical characteristics on outcome differences. Univariable and multivariable analyses were used to evaluate the prognostic factors of OBC patients. Results: Compared with non-OBC patients, OBC patients in this study presented a higher proportion of older age, American Joint Committee on Cancer (AJCC) N3 stage, estrogen receptor (ER)-negative status, progesterone receptor (PR)-negative status, and human epidermal growth factor receptor-2 (HER-2)-positive status, and underwent more chemotherapy. Multivariate analysis revealed a better survival in overall patients with OBC patients according to breast cancer-specific survival (BCSS) and overall survival (OS). Propensity score analysis also achieved a similar result for OBC patients. Stratified analyses by nodal status and molecular subtypes indicated that these survival advantage were mainly presented in patients with AJCC N2/N3 stage or hormone receptor (HR)-positive tumors. In addition, nodal status, HER-2 status, and radiation status were demonstrated to be three independent prognostic factors for OBC patients. Conclusion: Patients with OBC retained exclusive clinical characteristics and were shown to have a better outcome compared with non-OBC patients, especially for those with N2/N3 stage or HR-positive tumors.

Sentinel node theory helps tracking of primary lesions of cancers of unknown primary

Background

Sentinel lymph node is the first stop of lymphatic spreading of cancer with known primary. The lymph node metastasis pattern of cancer of unknown primary (CUP) is unclear and has been presumed to follow the same pathway. To test this hypothesis, data of all 716 patients clinically diagnosed as CUP in our center were collected.

Methods

Diagnoses of lymph node metastasis were established by ¹⁸F-FDG PET-CT and/or biopsy pathology. Three hundred and forty-seven cases meeting the criteria were divided into three groups: pathology-confirmed primary with invasive biopsy or surgery of the suspicious lesion (group A, n = 64), primary still unknown even with invasive biopsy or surgery of the suspicious lesion (group B, n = 204), and others with no suspicious lesion or lesions who had not been sampled due to medical or other reasons (group C, n = 79). We assessed the clinicopathological features between these groups, and the relationship between lymph node metastasis pattern and confirmed primary site.

Results

In group A, the primary sites of 61 cases were compatible with sentinel node theory, resulting in a positive predictive value of 95%. No significant differences in age, sex, bone metastasis, or visceral metastasis observed between group A and group B, except that group A had a higher ratio of differentiated carcinoma (94% vs. 77%, P = 0.003).

Conclusion

To our knowledge, this is the first evidence indicating that the majority of clinical CUP cases follow the sentinel node theory to spread in lymph nodes, which helps tracking the primary, especially for differentiated carcinoma.

Axillary Nodal Metastasis with Papillary Morphology: An Uncommon Origin

BACKGROUND

Metastases to axillary lymph nodes are commonly and readily confirmed by fine needle aspiration cytology (FNAC). Most likely, these arise from breast primaries. However, the diagnosis can become complicated when unusual cytomorphology is encountered.

CASE

We report a 60-year-old woman presenting with bilateral axillary lymphadenopathies but without breast lesions. History showed increasing CA-125 levels. FNAC yielded carcinoma cells showing prominent papillary pattern, being composed of mild to moderately differentiated malignant cells, with focal abortive glandular formation and squamous metaplasia. IHC stains were done and the tumor cells were PAX-8 positive, but GATA-3 and GCDFP-15 negative. Coupled with the clinical history, a diagnosis of metastatic endometrioid adenocarcinoma was made.

CONCLUSION

Nodal metastases with papillary cytomorphology can rarely arise from nonbreast primaries. The presence of papillary pattern, particularly in the absence of a clinically detectable breast lesion, should raise the possibility of a metastasis. Correlation with patient history, imaging findings and judicious use of IHC studies are crucial for a correct diagnosis.

A Review on Cancer of Unknown Primary Origin: The Role of Molecular Biomarkers in the Identification of Unknown Primary Origin

The primary site cannot be found after clinical and pathological evaluation, which are called cancers of unknown primary origin (CUP). CUPs may resemble a specific primary tumor site which shares common clinicopathological characteristics and prognosis. However, it may be present as a distinct disease entity with undifferentiated pathological features. More than 4% of patients are diagnosed as CUP. These patients were diagnosed as malignant tumors by cytology or pathology. And they were usually treated with empirical chemotherapy and associated with a poor prognosis. How to accurately diagnose and treat a cancer of unknown primary origin is a major clinical concern. To address this question, a complex assessment is carried out which includes a complete medical history of the patient, physical examination, complete blood count, urinalysis, serum chemistries, histologic evaluation, chest radiograph, computed tomography, magnetic resonance imaging, and immunohistochemistry (IHC) studies. Molecular diagnostic information reflects that CUP's molecular characteristics are similar to primary tumors with the development of genomics and the expansion of gene sequencing technology. Gene expression profiling is the most commonly used molecular diagnostic method for CUP. In this chapter, we summarize the current diagnostic methods and challenges of CUP, and the clinical value of the molecular-level tumor diagnostic technique.

Bone and lymph node metastases from occult mammary carcinoma: a case report of carcinoma of unknown primary (CUP) Syndrome

Cancer of unknown provenance is a rare disease, accounting approximately for up to 1% of all breast cancers. A 68-year-old female was admitted to the Medical Oncology Unit of Policlinico Universitario G.Martino

because of diffused bone-involvement, with mixed (osteolytic/osteoblastic) features, which interested almost every skeletal structure of the body (vertebral bodies of the entire column, costal skeleton, sternum, proximal third of both humeri, scapulae, clavicles, pelvis and femurs), suspicious for metastatic disease.

Outcome of breast-conserving treatment for axillary lymph node metastasis from occult breast cancer with negative breast MRI

Purpose

We conducted this study to investigate the prognosis and failure pattern after breast-conserving treatment (BCT) in patients with occult breast cancer (OBC) with negative breast magnetic resonance imaging (MRI) (MRI-OBC).

Materials and methods

Survival rates and failure patterns in 66 patients who received axillary lymph node dissection (ALND) and BCT for MRI-OBC between 2001 and 2013 at seven hospitals were analyzed. OBC was defined as adenocarcinoma in the axillary lymph node (ALN) +/− supraclavicular (SCN) or internal mammary lymph node (IMN) with a negative breast MRI.

Results

Fifty-four patients had only ALN metastasis (ALN only), and 12 patients had ALN metastasis along with SCN or IMN metastasis (ALN + SCN/IMN). Median follow-up was 82 months. The 5-year overall, disease-free, and breast cancer-free survival rates were 93.4%, 92.1%, and 96.8%, respectively. Nine patients experienced recurrence: breast (n = 4), regional lymph nodes (RLN, n = 1), distant metastases (DM, n = 2), breast/RLN (n = 1), and breast/RLN/DM (n = 1). Five-year disease-free survival was significantly higher in ALN only patients compared to ALN + SCN/IMN patients (96.1% vs. 75.0%; p = 0.02).

Conclusions

Patients with MRI-OBC were successfully treated with BCT. There was a small risk of ipsilateral breast cancer recurrence. Failure patterns depended on the extent of initial disease.

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Occult breast cancer (OBC) presenting with axillary metastases is a rare disease.

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This study reports on the outcome of OBC with negative breast MRI (MRI-OBC).

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Patients with MRI-OBC were successfully treated with breast-conserving treatment.

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Very few breast recurrences occurred when whole breast radiotherapy was used.

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Failure patterns of MRI-OBC depended on the initial extent of nodal involvement.

CUP Syndrome-Metastatic Malignancy with Unknown Primary Tumor

BACKGROUND

2-4% of newly diagnosed cases of malignant disease involve cancer of unknown primary (CUP). This mixed entity is one of the 6 most common types of malignant disease in Germany. Highly refined treatment strategies can now be offered to patients with CUP.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed with an emphasis on articles from the past decade. The current guidelines and recommendations of specialty societies were also considered in the evaluation.

RESULTS

CUP most commonly manifests itself as metastases to the lymph nodes, lungs, liver, or bones. With the aid of imaging studies, including functional hybrid imaging and further medical examination, a primary tumor can be discovered in up to 40% of patients initially diagnosed with CUP. Immunohistochemistry guided by histomorphology often enables precise characterization of the lesion and can be supplemented, in selected cases, by molecular-genetic diagnostic evaluation. The most commonly detected types of primary tumor are cancers of the lung, pancreas, liver, and biliary system. For patients with local metastases, surgical resection or radiotherapy with curative intent is usually indicated, sometimes in the framework of a multimodal treatment concept. The median 2-year survival of patients with disseminated CUP is only 20%. For such patients, specific types of systemic therapy are recommended on the basis of the diagnostic characterization of the disease. Immune-modulatory antibodies can be effective, particularly in the treatment of CUP that has been characterized with biomarkers, but should still be considered experimental at present.

CONCLUSION

A combination of conventional and innovative diagnostic methods enables the provision of highly refined therapeutic strategies to patients with CUP who are undergoing treatment in interdisciplinary cancer centers.

Clinicopathological characteristics and treatment outcomes of occult breast cancer: a SEER population-based study

Background

Occult breast cancer (OBC) is a rare type of breast cancer that has not been well studied. The clinicopathological characteristics and treatment recommendations for OBC are based on a limited number of retrospective studies and thus remain controversial.

Patients and methods

We identified 479 OBC patients and 115,739 non-OBC patients from 2004 to 2014 in and the Surveillance, Epidemiology, and End Results (SEER) database. The clinicopathological characteristics and survival outcomes were compared between OBC and non-OBC patients. We used the propensity score 1:1 matching analysis to evaluate OBC vs non-OBC comparison using balanced groups with respect to the observed covariates. We further divided the OBC population into four groups based on different treatment strategies. Univariable and multivariable analyses were used to calculate and compare the four treatment outcomes within the OBC population.

Results

OBC patients were older, exhibited a more advanced stage, a higher rate of negative estrogen receptor and progesterone receptor status, a higher rate of HER2-positive status, and a higher rate of ≥10 positive lymph nodes, and were less likely to undergo surgical treatment than non-OBC patients. After adjustments for clinicopathological factors, the OBC patients exhibited a significantly better survival than the non-OBC patients (P<0.001). This result was confirmed in a 1:1 matched case–control analysis. Within the four OBC treatment groups, we observed no difference in survival among the mastectomy group, the breast-conserving surgery (BCS) group, and the axillary lymph node dissection (ALND)-only group. The multivariable analysis revealed that the sentinel lymph node dissection-only group had the worst prognosis (P<0.001). Conclusion: OBC has unique clinicopathological characteristics and a favorable prognosis compared with non-OBC. BCS plus ALND and radiotherapy showed a survival benefit that was similar to that of mastectomy for OBC patients.

Axillary lymph node metastases from unknown primary: A French multicentre study

PURPOSE

The aim of the study was to investigate the management and prognosis of axillary cancers from unknown primaries (CUPax).

METHODS

We included all patients with lesions described as axillary nodal metastases from an unknown primary referred to four French tertiary breast cancer centres between January 1988 and December 2012. The inclusion criteria comprised: no sign of primary breast cancer on clinical examination nor on imaging (mammography, ultrasonography and breast MRI) and no primary tumour identified elsewhere.

RESULTS

CUPax represented 1.8% of all metastatic axillary lymphadenopathies in our institutions. The overall survival rate was 71%, and 16.7% of patients had secondary inflammatory breast cancer signalling a posteriori that CUPax originated from the breast. Factors that favourably affected survival according to univariate analysis were: histological type of non specific adenocarcinoma (versus other types, p = 0.02), only one lymph node involved (versus several, p = 0.04), a normal CA153 serum-level (p = 0.02), no distant metastasis at initial assessment (p = 0.02), no secondary distant metastasis (p = 0.005) and radiotherapy to the ipsilateral breast/chest wall/lymph nodes (p = 0.04). On multivariate analysis including these factors, a histological type of non-specific adenocarcinoma (p = 0.03) and distant metastases (p = 0.03) were identified as independent factors affecting survival.

CONCLUSION

We believe that these results will shed light on current investigations and treatment of this rare entity.

Male occult breast cancer with axillary lymph node metastasis as the first manifestation: A case report and literature review

RATIONALE

Occult breast cancer (OBC) is extremely rare in males with neither symptoms in the breast nor abnormalities upon imaging examination.

PATIENT CONCERNS

This current case report presents a young male patient who was diagnosed with male OBC first manifesting as axillary lymph node metastasis. The physical and imaging examination showed no primary lesions in either breasts or in other organs.

DIAGNOSES

The pathological results revealed infiltrating ductal carcinoma in the axillary lymph nodes. Immunohistochemical (IHC) staining was negative for estrogen receptor (ER), progesterone receptor (PR), cytokeratin (CK)20 and thyroid transcription factor-1 (TTF-1), positive for CK7, gross cystic disease fluid protein-15 (GCDFP-15), epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA), and suspicious positive for human epidermal receptor-2 (Her-2). On basis of IHC markers, particularly such as CK7, CK20 and GCDFP-15, and eliminating other malignancies, male OBC was identified in spite of negativity for hormone receptors.

INTERVENTIONS

The patient underwent left axillary lymph node dissection (ALND) but not mastectomy. After the surgery, the patient subsequently underwent chemotherapy and radiotherapy.

OUTCOMES

The patient is currently being followed up without any signs of recurrence.

LESSONS

Carefully imaging examination and pathological analysis were particularly essential in the diagnosis of male OBC. The guidelines for managing male OBC default to those of female OBC and male breast cancer.

Diagnosis and management of metastatic neoplasms with unknown primary

In cancer of unknown primary (CUP), metastases are clinically and histologically confirmed, but the primary tumor site remains elusive after extensive work-up. CUPs make up for 2-3% of all epithelial malignancies. The two prevailing histologies are adenocarcinomas and undifferentiated carcinomas, whereas squamous cell carcinomas, neuroendocrine carcinomas and rare histologies account for the remaining 10%. The diagnostic work-up in CUP relies strongly on a detailed immunohistological (IHC) analysis in order to characterize the tumor type, nowadays aided by molecular techniques. Diagnostics also include a thorough clinical examination, a basic lab draw with the most relevant tumor markers, and cross sectional imaging. Additional PET-CT is recommended in cervical lymph nodes suggestive of head and neck cancer and in limited metastases potentially treatable in curative intent. As for treatment, it is paramount to identify patients who fall into one of the six well defined "favorable" subset categories, namely extragonadal germ cell tumors, adenocarcinoma with isolated unilateral axillary lymph nodes in female patients, squamous cell carcinoma with neck lymph nodes, squamous cell carcinoma with inguinal lymph nodes, serous papillary peritoneal carcinomatosis in females and blastic bone metastasis in males with elevated PSA. These subsets are distinct both regarding the required treatment and the comparably favorable prognosis. Within the remaining "unfavorable" group, patients of colon and renal cancer type should be identified based on IHC and clinical picture, since the prognosis of these patients seems to improve with the use of therapy tailored to the presumed primary as well. For the few patients with limited metastases it should be assessed whether they are candidates for surgery, radiotherapy or surgery followed by irradiation in curative intent. The remaining majority of patients are treated with empiric palliative chemotherapy, typically a platinum - paclitaxel combination, though the level of evidence for this therapy recommendation is low. Gemcitabine alone or in combination can be used as an alternative. Decoding of the molecular profiles in CUP offers the prospect of targeted therapy with novel agents. However, there appears to be no uniform molecular pattern for CUP, and the observed molecular diversity thus poses a challenge to respective clinical trials.

Clinical and pathological portraits of axillary presentation breast cancer and effects of preoperative systemic therapy

There is a lack of investigation into the biological characteristics and preoperative systemic therapy (PST) for occult breast cancer (OBC). For this study, departmental records in Breast Disease Center of Peking University First Hospital from January 2008 to December 2015 were retrospectively reviewed to identify cases of OBC. Eleven cases were included, and all patients were female, with a median age of 56 (range: 29-75) years. The sensitivity of magnetic resonance imaging (MRI) was 100%, and the false positive rate was 33.3%. Based on histologic analysis of the axillary node, 9 (81.8%) cases were grade 3, and 2 (18.2%) cases were grade 2; 4 (36.4%) cases were ≥10% estrogen receptor (ER) positive and 6 (54.5%) human epidermal growth receptor 2 (HER2) positive. Nine cases (81.8%) exhibited over 30% Ki67 expression. PST was performed in 5 of the 11 cases. The lymph node response rate was 100% (5/5), but no complete remission was achieved. In conclusion, aggressive subtypes were predominant among the included cases, and PST should be considered for OBC treatment options.

Squamous cell carcinoma of unknown primary site presenting with an abdominal wall lesion as the primary symptom: A case report and review of the literature

Squamous cell carcinoma of unknown primary site (SC CUP) is a rare malignant tumor, and its histogenesis and appropriate treatment are unclear. To the best of our knowledge, this type of carcinoma with abdominal wall lesions as the primary presenting symptom 3 months after laparoscopic surgery, has not been previously described in the literature. In the present study, a postmenopausal 54-year-old female patient was diagnosed with pain from the right abdominal puncture site 3 months after laparoscopic unilateral left salpingo-oophorectomy at a local hospital, at which time the left ovary and Fallopian tube were free of malignant tumor. Computed tomography (CT) imaging showed a subcutaneous nodule with a size of 6.2×3.3 cm. A wide excision of the lesion with safety margins and repair of the abdominal wall was performed, and the histopathological results and various investigations lead to the diagnosis of metastatic well-differentiated SC CUP. The patient underwent three surgeries and eight cycles of Taxol and cisplatin/carboplatin chemotherapy, and received a total of 10.8 Gy palliative radiation. However, the patient succumbed to intestinal bleeding, thrombocytopenia and multiple organ failure with pelvic recurrence and liver metastases at 10 months post-diagnosis. The prognosis of SC CUP, particularly with multiple metastases, is extremely poor. Although chemotherapy, surgery and radiotherapy have a certain role in the treatment, no regimen has been established as a standard therapy and palliative care could be recommended.

[Axillary lymph node metastases with an occult breast: About 16 cases from a cohort of 7770 patients]

OBJECTIVES

Isolated axillary lymph node metastases is an unusual clinical presentation of breast carcinoma. We studied its different issues.

METHODS

This study is a follow-up study of 16patients, treated between 1996 and 2012, presenting with axillary metastases with an occult breast carcinoma, which could not be identified by physical examination nor by a conventional imaging or a breast MRI. Clinical characteristics, histological analysis, treatment, monitoring and five-year survival rate were studied.

RESULTS

The incidence of this kind of breast cancer was 0.20%. A breast MRI was performed in 75% of the patients. The histology of these tumors showed a rate of hormono-sensibility of 50% and an HER2 overexpression of 44%. Sixty-nine percent of the patients had no breast surgery or radiotherapy; global five-year survival rate for these women was 77.4%±11.5.

CONCLUSION

The survival rates of this study should lead the practitioner to choose a less aggressive breast therapy. Moreover, the histological characteristics explain the high metastatic potential of these tumors, and relate them to the HER2+ subclass of gene expression patterns of breast carcinomas.

Occult Breast Lobular Carcinoma with Numerous Circulating Tumor Cells in Peripheral Blood

We experienced a very rare case of occult breast lobular carcinoma with numerous circulating tumor cells in peripheral blood. The diagnosis was very difficult because there were no symptoms of breast cancer and the preceding chief complaints such as general fatigue and weight loss or abnormality of peripheral blood findings were suggestive of a hematological disease. We could make a correct diagnosis of this case by checking the findings of complete blood count and bone marrow biopsy at the same time using immunohistochemistry.

Cancer of Unknown Primary origin in the genomic era: Elucidating the dark box of cancer

Cancer of Unknown Primary (CUP) comprises a heterogeneous disease group with diagnosis of metastatic malignancy in the absence of an identifiable primary site after diagnostic work up. CUP may either resemble a specific primary tumor site sharing common clinicopathological characteristics and prognosis, or present as a distinct disease entity with undifferentiated pathological features, usually bearing dismal prognosis. Diagnosis and management have traditionally been based on clinicopathological characteristics and therapeutic strategies have been mainly empirical. In the last decade, the advent of massive gene sequencing and the advances in genomic technologies have shed light on the genomic landscape of CUP. Several gene panel tests are currently commercially available and are used in an effort to correlate the genomic characteristics of a specific CUP tumor to those of a known primary tumor, guiding thus therapeutic management. Nevertheless, these efforts are hampered by the rarity of CUP and the inability to validate the results of such tests due to the paucity of randomized clinical trials. In the current work, we provide an overview of CUP with emphasis on the impact of the genome sequencing technologies on diagnosis and management of these tumors. We also discuss potential implications of genomics for the future treatment of CUP and address the challenges of the implementation of these therapeutic strategies in routine clinical practice.

The migration ability of stem cells can explain the existence of cancer of unknown primary site. Rethinking metastasis

Cancers of unknown primary site are metastatic cancers for which primary tumors are not found after detailed investigations. In many cases, the site of origin is not identified even on postmortem examination. These cancers are the fourth most common cause of cancer death. The biological events involved in the development of this type of cancers remain unknown. This manuscript discusses that, like metastatic cells, stem cells have a natural ability to migrate. A cancer of unknown primary site would form when deregulated, premalignant or cancerous stem cells migrated away from their natural tissue and gave rise to a cancer in a new site before or without generating a tumor in their original tissue. It is important to realize that forming a tumor in a tissue is not a prerequisite for stem cells to migrate away from that tissue. This view is in accordance with recent observations that strongly support the tumorigenesis model in which cancer arises from normal stem cells. Evidence has accumulated that cancer stem cells may play a key role in cancer progression and resistance to therapy. Successful treatment of cancer, including that of unknown primary site, may therefore require the development of therapies against cancer stem cells.

A mini review on cancer of unknown primary site: A clinical puzzle for the oncologists

Cancer of unknown primary (CUP) is a well recognized clinical syndrome, accounting for 3–5% of all malignancies. It is characterized as a disease with an early dissemination of metastases without a primary detected site after extensive laboratory and clinical investigations. CUP is divided into the favorable and unfavorable groups based on histopathological and clinical manifestations. Adenocarcinoma of various differentiations is the commonest histopathological subtype. Favorable groups are treated with local or systemic treatment and some of them are enjoying long-term survival. On the contrary, unfavorable groups are treated with empirical chemotherapy having usually a dismal prognosis. Gene-profiling microarray diagnosis has a high diagnostic sensitivity, but its predictive or prognostic value remains uncertain.

[Surgical options in cancer of unknown primary (CUP)]

BACKGROUND

Cancer of unknown primary site (CUP) comprises a relatively frequently occurring group of heterogeneous malignant tumors in the clinical routine, which currently has an abysmal prognosis for affected patients. Based on the improved diagnostic tools it is now possible to identify subgroups of patients with different clinical prognoses. New therapies adapted to these identified subgroups are becoming increasingly more relevant.

AIM

This review aims to evaluate the role of surgery and different surgical options in the therapy of patients with CUP.

RESULTS

For the treatment of patients with CUP it is important to identify subgroups of patients with a better prognosis. Surgical resection of CUP metastasis is a therapy option leading to a prolonged survival in (1) women with papillary peritoneal adenocarcinomatosis, (2) women with axillary lymph node metastasis of adenocarcinoma, (3) patients with cervical lymph node metastasis of squamous cell carcinoma, (4) patients with inguinal lymph node metastasis, (5) patients with poorly differentiated carcinomas with midline distribution (e.g. extragonadal germ cell syndrome) and (6) patients with small resectable tumors.

CONCLUSION

Surgery is an important therapy option in different subgroups of patients with CUP. Together with multimodal therapy, adjusted according to the identified most likely origin of the primary tumor, it is possible to prolong patient survival.

[Radiotherapeutic concepts in cancer of unknown primary site]

BACKGROUND

The term cancer of unknown primary (CUP) encompasses a group of entities which differ to a great extent regarding etiology, prognosis and therapeutic management.

OBJECTIVES

The aim of the study was an elaboration of the role of radiotherapy in CUP syndrome.

MATERIAL AND METHODS

Systematic literature search and specification of the available treatment options.

RESULTS

Radiotherapy is an integral part of interdisciplinary management approaches for patients with CUP in both curative and palliative situations. Radio-oncological techniques, such as intensity-modulated radiotherapy and stereotactic body radiotherapy increase the therapeutic window. Modern diagnostic modalities from radiology and nuclear medicine are the cornerstone of radiotherapeutic interventions, especially in terms of target volume definition and pretherapeutic staging. In the interdisciplinary setting radiation oncology offers the possibility of curative and often organ preserving approaches in patients with axillary and cervical CUP. In addition, improvement and preservation of quality of life can be achieved in patients with metastatic disease.

CONCLUSION

Radiation oncology is a crucial component of the interdisciplinary management of patients with CUP. Therapeutic decisions in patients with CUP should be made in an interdisciplinary setting.

A case of breast cancer in the axillary tail of Spence - enhanced magnetic resonance imaging and positron emission tomography for diagnostic differentiation and preoperative treatment decision

Background

The management of cancer in the axillary area depends on the etiology of the tumor.

Case Report

A 37-year-old woman presented with a 2 cm mass in the axillary fossa. Core needle biopsy revealed adenocarcinoma. There were no abnormal breast findings on physical examination, mammography, or ultrasonography. However, enhanced magnetic resonance imaging (MRI) and positron emission tomography (PET) showed a segmentally-distributed, abnormal area in the upper-outer quadrant, continuous with the axillary mass. Samples of this area obtained by vacuum-assisted biopsy showed intraductal carcinoma. These findings indicated that the axillary lesion was a part of primary breast cancer originating from the axillary tail. Based on these results, the patient underwent total mastectomy with sentinel lymph node biopsy. Pathological examination of the specimen showed invasive ductal carcinoma accompanied by intraductal carcinoma extending up to 8.5 cm. Our case suggests that enhanced MRI and PET can provide useful preoperative information for the management of axillary breast lesions.

Geographic and temporal trends in the management of occult primary breast cancer: a systematic review and meta-analysis

BACKGROUND

Management of occult primary breast cancer (OPBC), including the role of magnetic resonance imaging (MRI), is controversial. We conducted a pooled analysis of OPBC patients and a meta-analysis of MRI accuracy in OPBC in order to elucidate current practices.

METHODS

A literature search yielded 201 studies. Patient-level data for clinically/mammographically OPBC from studies published after 1993 and from our institution were pooled; logistic regression examined associations between patient/study data and outcomes, including treatments and recurrence. We report adjusted odds ratios (OR) and 95 % confidence intervals (95 % CI) significant at 2-tailed p < 0.05. Meta-analysis included data for patients who received MRIs for workup of clinically/mammographically OPBC. We report pooled sensitivity and specificity with 95 % CIs.

RESULTS

The pooled analysis included 92 patients (15 studies [n = 85] plus our institution [n = 7]). Patients from Asia were more likely to receive breast surgery (OR = 5.98, 95 % CI = 2.02-17.65) but not chemotherapy (OR = 0.32, 95 % CI = 0.13-0.82); patients from the United States were more likely to receive chemotherapy (OR = 13.08, 95 % CI = 2.64-64.78). Patients from studies published after 2003 were more likely to receive radiotherapy (OR = 3.86, 95 % CI = 1.41-10.55). Chemotherapy recipients were more likely to have distant recurrence (OR = 9.77, 95 % CI = 1.10-87.21). More patients with positive MRIs received chemotherapy than patients with negative MRIs (10 of 12 [83.3 %] vs 5 of 13 [38.5 %]; p = 0.0414). In the MRI-accuracy meta-analysis (10 studies, n = 262), pooled sensitivity and specificity were 96 % (95 % CI = 91-98 %) and 63 % (95 % CI = 42-81 %), respectively.

CONCLUSIONS

OPBC management varied geographically and over time. We recommend establishing an international OPBC patient registry to facilitate longitudinal study and develop global treatment standards.

Occult primary breast cancer at a comprehensive cancer center

BACKGROUND

Management of occult primary breast cancer (OPBC), that is, breast cancer that first presents through regional nodal or distant disease without clinical or mammographic evidence of disease in the breast, has been controversial and inconsistent. Here, we review OPBC patients treated at our institution.

METHODS

We conducted a retrospective review of women diagnosed with a first primary breast cancer between March 1999 and September 2010 to identify patients who presented with isolated axillary lymphadenopathy proven to be histologically consistent with primary breast malignancy but had no evidence of a breast mass on physical examination, mammography, or ultrasound. Descriptions of treatments received, recurrence, morbidity, and mortality as of October 2012 are reported.

RESULTS

Of 5533 patients reviewed, seven (0.1%) patients were identified. The median age was 65 y old (range, 40-72), and the median length of follow-up was 86 mo (range, 42-124). Four patients underwent modified radical mastectomy, one patient had a lumpectomy and axillary lymph node dissection, and two patients had axillary lymph node dissection without breast surgery. Four patients received adjuvant radiation therapy. All seven patients received chemotherapy. Three patients received endocrine therapy, and two patients received anti-HER2 therapy. At the last follow-up, all seven patients were alive with no evidence of disease.

CONCLUSIONS

Although there was some variation in the management of OPBC at our institution, our patients had excellent outcomes after multimodal treatment. Our results support a curative intent approach to the treatment of OPBC and illustrate the need for individualized treatment algorithms based on tumor biology and extent of the disease at diagnosis.

Optimal therapeutic management of patients with distinct clinicopathological cancer of unknown primary subsets

Cancer of unknown primary sites (CUP) is a compilation of various malignant entities--the majority of which behave aggressively and carry poor prognosis. CUP is classified into two different clinicopathological groups: the unfavourable (poor-prognosis) and the favourable (good-prognosis) group. Patients with favourable subsets are treated relevant to the hidden primary tumour chemotherapy regimens and/or radiotherapy. These patients exhibit better responses and prolonged survival. On the other hand, patients of unfavourable subsets are treated with various chemotherapy combinations of platinum- or taxane-containing regimens. Unfortunately, responses and overall survival in this group of CUP patient are not very promising. Several independent prognostic factors have been associated with survival of CUP patients. Since CUP is not an unknown disease, emerging therapeutic innovations are warranted.