Cancer of unknown primary sites: what radiologists need to know and what oncologists want to know

2-[18F]FDG-PET/CT in Cancer of Unknown Primary Tumor-A Retrospective Register-Based Cohort Study

We investigated the impact of 2-[18F]FDG-PET/CT on detection rate (DR) of the primary tumor and survival in patients with suspected cancer of unknown primary tumor (CUP), comparing it to the conventional diagnostic imaging method, CT. Patients who received a tentative CUP diagnosis at Odense University Hospital from 2014-2017 were included. Patients receiving a 2-[18F]FDG-PET/CT were assigned to the 2-[18F]FDG-PET/CT group and patients receiving a CT only to the CT group. DR was calculated as the proportion of true positive findings of 2-[18F]FDG-PET/CT and CT scans, separately, using biopsy of the primary tumor, autopsy, or clinical decision as reference standard. Survival analyses included Kaplan-Meier estimates and Cox proportional hazards regression adjusted for age, sex, treatment, and propensity score. We included 193 patients. Of these, 159 were in the 2-[18F]FDG-PET/CT group and 34 were in the CT group. DR was 36.5% in the 2-[18F]FDG-PET/CT group and 17.6% in the CT group, respectively (p = 0.012). Median survival was 7.4 (95% CI 0.4-98.7) months in the 2-[18F]FDG-PET/CT group and 3.8 (95% CI 0.2-98.1) in the CT group. Survival analysis showed a crude hazard ratio of 0.63 (p = 0.024) and an adjusted hazard ratio of 0.68 (p = 0.087) for the 2-[18F]FDG-PET/CT group compared with CT. This study found a significantly higher DR of the primary tumor in suspected CUP patients using 2-[18F]FDG-PET/CT compared with patients receiving only CT, with possible immense clinical importance. No significant difference in survival was found, although a possible tendency towards longer survival in the 2-[18F]FDG-PET/CT group was observed.

Malignant adnexal tumor of the skin on breast: A case report of apocrine carcinoma

INTRODUCTION

Malignant adnexal tumors of the skin (MATS) are a group of rare and varied tumors that lack standardized guidelines for their management. Apocrine carcinoma (AC) is a highly uncommon form of breast malignancy, contributing to less than 1 % of all female invasive breast carcinomas. AC has a similar microscopic growth pattern to invasive ductal carcinoma, which can result in early misdiagnosis.

PRESENTATION OF CASE

This report presents a case of a 67-year-old female with a lump in the superior lateral quadrant of her left breast for six years. Surgical therapy was performed with wide excision due to clinical operability, no significant involvement of the axillary lymph nodes, and without metatasis. During the operation, Wide excision of 1-2 cm free margin according to standard and local reconstruction flaps were performed, with berry packing for the identified lymph nodes.

DISCUSSION

The tumor was ER and PR negative, so hormonal treatment would be ineffective, assuming that this is an apocrine carcinoma of the breast. A metastatic work up was already done, and no metastasis was found. A mastectomy would appear to be a viable option.

CONCLUSION

It is important to perform a clinical reevaluation to provide optimal treatment for breast malignancy. Misdiagnosis can occur early. In this case, a surgical procedure involving wide excision was performed, and as of now, the patient has not reported any recurrence.

Diagnostic efficiency of PET/CT in patients with cancer of unknown primary with brain metastasis as initial manifestation and its impact on overall survival

Background

Carcinoma of unknown primary (CUP) is a diagnostic and therapeutic challenge; correct diagnostic approach results in better outcomes in patients with brain metastasis. Whole body 18 F-FDG PET/CT is a helpful modality to detect the origin of primary tumor and assess metastasis in the rest of the body. We assessed the value of PET/CT in detection of unknown primary in 39 patients with brain metastases as initial presentation and detected its impact on their overall survival.

Results

PET/CT could correctly detected the primary tumor in 49% of patients which occurred mainly in the lung, 63% of patients had additional extracerebral metastatic sites mostly in lymph nodes. Specificity, sensitivity, and accuracy of PET/CT in CUP patients were 95%, 79%, and 87%, respectively. No significant difference was noticed in estimated overall survival time between patients with an identified primary tumor and patients with unidentified primary tumor.

Conclusion

PET–CT was a helpful non-invasive imaging modality in detecting primary in CUP patients with metastatic brain lesion. It helped in the diagnosis of unexpected extracerebral metastatic lesions. However, the identification of the primary tumor by PET/CT has no significant prognostic effect on patient overall survival.

A Machine Learning Approach for Tracing Tumor Original Sites With Gene Expression Profiles

Some carcinomas show that one or more metastatic sites appear with unknown origins. The identification of primary or metastatic tumor tissues is crucial for physicians to develop precise treatment plans for patients. With unknown primary origin sites, it is challenging to design specific plans for patients. Usually, those patients receive broad-spectrum chemotherapy, while still having poor prognosis though. Machine learning has been widely used and already achieved significant advantages in clinical practices. In this study, we classify and predict a large number of tumor samples with uncertain origins by applying the random forest and Naive Bayesian algorithms. We use the precision, recall, and other measurements to evaluate the performance of our approach. The results have showed that the prediction accuracy of this method was 90.4 for 7,713 samples. The accuracy was 80% for 20 metastatic tumors samples. In addition, the 10-fold cross-validation is used to evaluate the accuracy of classification, which reaches 91%.

Factors associated with subcentimeter pulmonary nodule outcomes followed with computed tomography imaging in oncology patients

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PNs with irregular, lobuled or spiculated margins exhibited faster growth than PNs with regular, smooth margins.

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Malignancy was significantly associated with male gender, a colorectal cancer diagnosis and advanced stage disease.

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Oncologic patients should have an individualized CT follow-up strategy, as the rate of malignant pulmonary nodules is higher than in the general population.

Introduction

Technological advancements in computed tomography (CT) have enabled the frequent detection of small pulmonary nodules (PNs), especially in patients with an oncologic history. It is important the malignant versus benign etiology of PNs be determined. The aim of the present study was to evaluate the behavior and clinical/radiological characteristics of subcentimeter PNs detected by CT in oncologic patients.

Methods

An observational, longitudinal, retrospective and single-center study was conducted with a sample of 100 patients with a diagnosis of a primary malignant solid tumor outside of the lungs who developed indeterminate subcentimeter PNs (n = 251) detected on consecutive thoracic CT scans from 2015 to 2017. Follow-up CTs for each patients were examined in each of three periods (0–3 months, 3–6 months, and 6 months to 1 year).

Results

In our study sample, 28 patients (28 %) showed one or more signs suspicious of pulmonary metastasis, including ≥50 % PN growth, nodule growth followed by size reduction in patients undergoing chemotherapy, and the appearance of multiple nodules. The majority (56 %) of the PNs were detected during the 3–6-month follow-up CT scan. PNs with irregular, lobuled, or spiculated margins exhibited faster growth than PNs with regular, smooth margins. Malignancy of PNs was found to be significantly associated with being male, a primary colorectal cancer diagnosis, and advanced stage disease.

Conclusion

Our findings reinforce the necessity of an individualized CT follow-up strategy for patients with an oncologic history, as well as the importance of early nodule screening, with the inter-scan interval being dependent on the primary neoplasm.

Detection efficiency of 18F-flourodeoxyglucose positron emission tomography/computed tomography for primary tumors in patients with carcinoma of unknown primary

Carcinoma of unknown primary (CUP) is defined as biopsy proven tumor metastases that remains unidentified after a thorough diagnostic evaluation. The purpose of this study was to find the detection efficiency of ¹⁸F-flourodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG PET/CT) in patients with CUP. This prospective study was conducted at PET/CT Section of Department of Radiology, Aga Khan University Hospital Karachi, Pakistan from August 2017 to January 2018. Patients with a history of CUP referred for ¹⁸FDG PET/CT scan for detection of primary sites during the study were recruited. ¹⁸FDG PET/CT scan was acquired using standardized protocol, and patients with suspected primary sites underwent biopsies. Scan findings and biopsy results were analyzed to find the detection rate, sensitivity, area under curve (AUC), and positive predictive value (PPV). As no biopsy was performed in negative scan, true negative, and specificity could not be calculated. During the study, 46 consecutive patients with CUP were included. Mean age of cohort was 58 ± 17 years (63% male and 37% female) having a mean body mass index of 24.70 ± 4.97 kg/m². Thirty-four patients (34/46) found to have a hypermetabolic focus suggestive of the primary tumor with known metastatic sites and subjected to biopsy which turned out to be positive in 26/34 patients (true positive). The primary tumor was detected in gastrointestinal and hepatobiliary in 8 (17%), head and neck in 6 (13%), genitourinary 4 (09%), lung 3 (06%), and miscellaneous sites in 5 (11%) patients. Detection rate, sensitivity and PPV of ¹⁸FDG PET/CT were 57%, 68%, and 76%, respectively. Remaining 12/46 patients with negative ¹⁸FDG PET/CT for primary focus did not have biopsy. Receiver operating character curve revealed fair diagnostic strength of ¹⁸FDG PET/CT for detecting unknown primary (AUC 0.667; P = 0.054; standard error = 0.083; confidence interval: 0.504–0.830). We conclude that ¹⁸FDG PET/CT is an effective tool for detecting primary tumor in patients with CUP and its upfront use could preclude the use of many futile diagnostic procedures. Furthermore, higher resolution scanners and acquiring delayed images in patients with negative study could reduce false-negative results in patients with CUP.

A Challenging Case of Poorly Differentiated Transitional Cell Carcinoma of the Kidney

When describing carcinomas, poorly differentiated defines how little the tumor tissue resembles the normal tissue it came from. The origin of these types of tumors cannot be determined by histological findings alone. Imaging findings and patient history play a strong role in determining the source of the patient’s cancer. Imaging features of urothelial cancer of the renal pelvicaliceal system can be challenging for any sonographer or radiologist. When tumors are hyperechoic relative to nearby renal parenchyma, they may be obscured by the surrounding hyperechoic renal sinus fat, causing these carcinomas to be difficult to detect regardless of whether they are well defined or poorly differentiated. This case study delves into the difficulty in sonographically imaging a poorly differentiated transitional cell carcinoma without sonographic evidence of a primary circumscribed mass.

An integrated tool for determining the primary origin site of metastatic tumours

Aims

Cancers of unknown primary sites account for 3%–5% of all malignant neoplasms. Current diagnostic workflows based on immunohistochemistry and imaging tests have low accuracy and are highly subjective. We aim to develop and validate a gene-expression classifier to identify potential primary sites for metastatic cancers more accurately.

Methods

We built the largest Reference Database (RefDB) reported to date, composed of microarray data from 4429 known tumour samples obtained from 100 different sources and divided into 25 cancer superclasses formed by 58 cancer subclass. Based on specific profiles generated by 95 genes, we developed a gene-expression classifier which was first trained and tested by a cross-validation. Then, we performed a double-blinded retrospective validation study using a real-time PCR-based assay on a set of 105 metastatic formalin-fixed, paraffin-embedded (FFPE) samples. A histopathological review performed by two independent pathologists served as a reference diagnosis.

Results

The gene-expression classifier correctly identified, by a cross-validation, 86.6% of the expected cancer superclasses of 4429 samples from the RefDB, with a specificity of 99.43%. Next, the performance of the algorithm for classifying the validation set of metastatic FFPE samples was 83.81%, with 99.04% specificity. The overall reproducibility of our gene-expression-classifier system was 97.22% of precision, with a coefficient of variation for inter-assays and intra-assays and intra-lots <4.1%.

Conclusion

We developed a complete integrated workflow for the classification of metastatic tumour samples which may help on tumour primary site definition.

Metastatic melanoma of unknown primary in the temporalis muscle

Melanomas are aggressive cancers that present as cutaneous, mucosal and ocular lesions with the ability to metastasise widely. There are, however, occasions where lesions are found in distant sites such as lymph nodes, viscera and subcutaneous tissues without clinically apparent skin involvement. This is known as metastatic melanoma of unknown primary (MUP). Its presentation in skeletal muscle is rare, and the available literature is sparse. This article presents an 85-year-old woman with a MUP presenting in the right temporalis muscle, which was diagnosed with the aid of the ultrasound-guided core biopsy. The melanoma deposit was successfully excised, and no recurrence was identified. The patient is now under close follow-up.

Impact of 3T multiparametric MRI and FDG-PET-CT in the evaluation of occult primary cancer with cervical node metastasis

Background

This study aimed to determine the ability of multimodal evaluation with multiparametric 3T-MRI (MPMRI) and positron emission tomography - computed tomography (PET/CT) to detect cancer of unknown primary origin (CUP) with neck lymph node (LN) metastasis.

Methods

The study group comprised 38 retrospectively analysed consecutive patients with LN metastasis in the head and neck (HN) region without known primary tumours (PTs). Statistical values of 3T-MRI and of FDG-PET/CT scans were evaluated.

Results

Of the 38 CUPs, conventional native T1-, T2-weighted and STIR sequences detected 6 PTs. Native sequences plus diffusion-weighted imaging (DWI) found 14-, and with fat suppression contrast-enhanced T1-weighted measurement as well as with the complex MPMRI found 15 primaries and with PET/CT 17 CUPs could be evaluated, respectively. The detection rates were 15.8, 36.8, 39.5, 39.5 and 44.7 % for conventional native MRI, native plus DWI, native with contrast-enhanced MRI (CE-MRI), for MPMRI, and for PET/CT, respectively. The overall detection rate proved by histology was 47.4 %. PET/CT provided the highest sensitivity (Sv: 94.4 %) but a lower specificity (Sp: 65.0 %), using MPMRI (Sv: 88.2 %) the specificity increased to 71.4 %. DWIincreased specificity of the native sequences (Sp: 76.2 %). Conventional native sequences plus DWI as well as 3T-MPMRI and PET/CT were same accurate (Acc: 79.0 %) and had similar likelihood ratio (LR: 3.42, 3.03 and 2.62) in detecting unknown PT sites.

Conclusions

The accuracy of FDG-PET/CT and MPMRI in case of CUP in finding the primary cancer in the neck regions is identical. While using PET/CT whole body information can be obtained in one examination. MPMRI shows the local soft tissue status more accurately. In cases of CUP PET/CT should be the first method of choice if it is available. MPMRI can clarify the exact primary tumor stage, and it can be advantageous in clarifying the prognostic factors, which is necessary in case of advanced tumor stage and when surgery is under consideration. In case low N stage is likely after the clinical examination and wait and see policy can be considered, MPMRI is recommended, and in this case the significance the of radiation free MPMRI is increasing.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0097-x) contains supplementary material, which is available to authorized users.

Integrative analysis of the colorectal cancer proteome: potential clinical impact

INTRODUCTION

Colorectal cancer (CRC) is one of the common types of cancer that affects a significant proportion of the population and is a major contributor to cancer related mortality. The relatively poor survival rate of CRC could be improved through the identification of clinically useful biomarkers. Areas covered: This review highlights the need for biomarkers and discusses recent proteomics discoveries in the aspects of CRC clinical practice including diagnosis, prognosis, therapy, screening and molecular pathological epidemiology (MPE). Studies have been evaluated in relation to biomarker target, methodology, sample selection, limitations, and potential impact. Finally, the progress in proteomic approaches is briefly discussed and the main difficulties facing the translation of proteomics biomarkers into the clinical practice are highlighted. Expert commentary: The establishment of specific guidelines, best practice recommendations and the improvement in proteomic strategies will significantly improve the prospects for developing clinically useful biomarkers.

[Standard of care of carcinomas on cancer of unknown primary site in 2016]

Patients with Cancer of unknown primary (cup) represent 2-10%, and have disseminated cancers for which we cannot find the primary site despite the clinical, pathological and radiological exams at our disposal. Diagnosis is based on a thorough clinical and histopathologic examination as well as new imaging techniques. Several clinicopathologic entities requiring specific treatment can be identified. Genome sequencing and liquid biopsy (circulating tumor cells and tumor free DNA) could allow further advances in the diagnosis. Therapeutically, in addition to surgery, radiotherapy and chemotherapy, precision medicine provides new therapeutic approaches.

Comprehensive Genomic Profiling of Carcinoma of Unknown Primary Site: New Routes to Targeted Therapies

IMPORTANCE

For carcinoma of unknown primary site (CUP), determining the primary tumor site may be uninformative and often does not improve outcome.

OBJECTIVE

To discover opportunities for targeted therapies in patients with CUP not currently searched for in routine practice.

DESIGN, SETTING, AND PARTICIPANTS

Comprehensive genomic profiling on 200 CUP formalin-fixed paraffin-embedded specimens (mean, 756× coverage) using the hybrid-capture-based FoundationOne assay at academic and community oncology clinics.

MAIN OUTCOMES AND MEASURES

Presence of targetable genomic alterations (GAs) in CUP and responses to targeted therapies.

RESULTS

There were 125 adenocarcinomas of unknown primary site (ACUPs) and 75 carcinomas of unknown primary site without features of adenocarcinoma (non-ACUPs). At least 1 GA was found in 192 (96%) of CUP specimens, with a mean (SD) of 4.2 (2.8) GAs per tumor. The most frequent GAs were in TP53 (110 [55%]), KRAS (40 [20%]), CDKN2A (37 [19%]), MYC (23 [12%]), ARID1A (21 [11%]), MCL1 (19 [10%]), PIK3CA (17 [9%]), ERBB2 (16 [8%]), PTEN (14 [7%]), EGFR (12 [6%]), SMAD4 (13 [7%]), STK11 (13 [7%]), SMARCA4 (12 [6%]), RB1 (12 [6%]), RICTOR (12 [6%]), MLL2 (12 [6%]), BRAF (11 [6%]), and BRCA2 (11 [6%]). One or more potentially targetable GAs were identified in 169 of 200 (85%) CUP specimens. Mutations or amplifications of ERBB2 were more frequent in ACUPs (13 [10%]) than in non-ACUPs (3 [4%]). Alterations of EGFR (10 [8%] vs 2 [3%]) and BRAF (8 [6%] vs 3 [4%]) were more common in ACUPs than in non-ACUPs. Strikingly, clinically relevant alterations in the receptor tyrosine kinase (RTK)/Ras signaling pathway including alterations in ALK, ARAF, BRAF, EGFR, FGFR1, FGFR2, KIT, KRAS, MAP2K1, MET, NF1, NF2, NRAS, RAF1, RET, and ROS1 were found in 90 (72%) ACUPs but in only 29 (39%) non-ACUPs (P < .001).

CONCLUSIONS AND RELEVANCE

Almost all CUP samples harbored at least 1 clinically relevant GA with potential to influence and personalize therapy. The ACUP tumors were more frequently driven by GAs in the highly druggable RTK/Ras/mitogen-activated protein kinase (MAPK) signaling pathway than the non-ACUP tumors. Comprehensive genomic profiling can identify novel treatment paradigms to address the limited options and poor prognoses of patients with CUP.

Adenocarcinoma of Mullerian origin: review of pathogenesis, molecular biology, and emerging treatment paradigms

Traditionally, epithelial ovarian, tubal, and peritoneal cancers have been viewed as separate entities with disparate origins, pathogenesis, clinical features, and outcomes. Additionally, previous classification systems for ovarian cancer have proposed two primary histologic groups that encompass the standard histologic subtypes. Recent data suggest that these groupings no longer accurately reflect our knowledge surrounding these cancers. In this review, we propose that epithelial ovarian, tubal, and peritoneal carcinomas represent a spectrum of disease that originates in the Mullerian compartment. We will discuss the incidence, classification, origin, molecular determinants, and pathologic analysis of these cancers that support the conclusion they should be collectively referred to as adenocarcinomas of Mullerian origin. As our understanding of the molecular and pathologic profiling of adenocarcinomas of Mullerian origin advances, we anticipate treatment paradigms will shift towards genomic driven therapeutic interventions.

Metastatic Adenocarcinoma of Unknown Origin Presenting as Small Bowel Perforation

Metastatic malignant tumors that originate from occult primaries are defined as “cancers of unknown origin.” We herein present the case of a 59-year-old man who presented with small bowel perforation secondary to metastatic adenocarcinoma of an unknown primary site. Imaging exhibited two pulmonary nodules, neither of which was dominant, along with mediastinal and retroperitoneal lymphadenopathy. Immunohistochemical profiling of the small bowel biopsy specimens revealed the tumor was most likely pulmonary in origin.

[Cancer of unknown primary. Epidemiology and pathogenesis]

DEFINITION

The term cancer of unknown primary (CUP) describes by definition epithelial malignancies for which no primary tumor can be found after primary diagnostics have been performed.

EPIDEMIOLOGY

The CUP syndrome constitutes 2-3% of all fatal cases of malignancies in both men and women. The proportion of women has increased in parallel to the increase of tobacco consumption in women.

PATHOGENESIS

The most frequent origin appears to lie in the lungs or upper abdominal organs, while notable differences can be found between older autopsy findings and recent gene expression data with respect to identified primary tumors or tissue assignation. The fact that a primary tumor cannot be identified is probably based on various reasons: a complete regression of a primary tumor in isolated cases seems to be just as plausible as the misclassification of a primary tumor as a metastasis.

CONCLUSION

In combination with the fact that a primary tumor cannot be identified by autopsy in more than 20 % of cases, the important conclusion can be drawn that curative approaches seem appropriate for localized CUP cases.

[Structured diagnostics and therapy of the CUP syndrome]

BACKGROUND

In the majority of cases, patients with cancer of unknown primary (CUP) have a poor prognosis with no prospect of being cured. Hence, a reasonable focus of diagnostics on its essential targets seems appropriate.

PATIENTS

Particularly important is the identification of all patients who can be assigned to subgroups with a favorable prognosis and who might benefit from a specific therapy. For all other patients, platinum-based combination therapy is the standard cytostatic therapy.

THERAPY

In addition to platinum derivatives, taxanes, gemcitabine and irinotecan can also be used. Promising innovative approaches include targeted therapies, in particular bevacizumab and erlotinib, and identification of the tissue origin with micro-RNA or gene expression analyses which can help identify the most suitable organ-specific therapy for individual patients.

PERSPECTIVES

It would be desirable if the group of patients treated with unspecific therapy could be reduced by improved diagnostics so that these patients could be treated with organ-specific therapy or with molecularly targeted approaches. Micro-RNA and gene expression analyses appear to be interesting for this purpose. Another complementary approach is to improve the treatment results of patients receiving an unspecific standard combination therapy by additional administration of new targeted substances.

When heat casts a spell on the DNA damage checkpoints

Peregrine Laziosi (1265–1345), an Italian priest, became the patron saint of cancer patients when the tumour in his left leg miraculously disappeared after he developed a fever. Elevated body temperature can cause tumours to regress and sensitizes cancer cells to agents that break DNA. Why hyperthermia blocks the repair of broken chromosomes by changing the way that the DNA damage checkpoint kinases ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related (ATR) are activated is an unanswered question. This review discusses the current knowledge of how heat affects the ATR–Chk1 and ATM–Chk2 kinase networks, and provides a possible explanation of why homeothermal organisms such as humans still possess this ancient heat response.

Population-based incidence, treatment and survival of patients with peritoneal metastases of unknown origin

AIM

Until recently, peritoneal metastases (PM) were regarded as an untreatable condition, regardless of the organ of origin. Currently, promising treatment options are available for selected patients with PM from colorectal, appendiceal, ovarian or gastric carcinoma. The aim of this study was to investigate the incidence, treatment and survival of patients presenting with PM in whom the origin of PM remains unknown.

METHODS

Data from patients diagnosed with PM of unknown origin during 1984-2010 were extracted from the Eindhoven Cancer Registry. European age-standardised incidence rates were calculated and data on treatment and survival were analysed.

RESULTS

In total 1051 patients were diagnosed with PM of unknown origin. In 606 patients (58%) the peritoneum was the only site of metastasis, and 445 patients also had other metastases. Chemotherapy usage has increased from 8% in the earliest period to 16% in most recent years (p=.016). Median survival was extremely poor with only 42days (95% confidence interval (CI) 39-47days) and did not change over time. Median survival of patients not receiving chemotherapy was significantly worse than of those receiving chemotherapy (36 versus 218days, p<.0001).

CONCLUSION

The prognosis of PM of unknown origin is extremely poor and did not improve over time. Given the recent progress that has been achieved in selected patients presenting with PM, maximum efforts should be undertaken in order to diagnose the origin of PM as accurately as possible. Potentially effective treatment strategies should be further explored for patients in whom the organ of origin remains unknown.