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

Case Report: Personalized diagnosis and treatment strategies for three cases of cancer of unknown primary based on molecular testing techniques

Cancer of unknown primary (CUP) is a malignancy characterized by metastatic disease at diagnosis with an unidentified primary site, accounting for 3-5% of all cancers. Despite significant advancements in cancer diagnosis and treatment in recent years, CUP management has been challenging due to its complexity and heterogeneity; therefore, its prognosis remains poor. This report presents three cases of CUP. The first case involved a 59-year-old female whose abdominal metastatic cancer was identified to be originating from a primary cervical cancer using a 90-gene panel; the disease was controlled with targeted immunotherapy. The second case was a 56-year-old male with cervical lymph node metastatic cancer; genetic testing suggested renal cancer as the primary site, and dual-targeted therapy resulted in approximately 28% tumor reduction. The third case involved a 71-year-old female with subcutaneous metastatic cancer, which was confirmed by genetic profiling to be related to breast cancer; she achieved stable disease after chemotherapy. Diagnosis and treatment of these three CUP cases demonstrated that molecular testing could significantly improve treatment outcomes and extend patient survival. Precision medicine based on molecular detection has shown substantial value in identifying the primary site of CUP, developing personalized treatment plans, and managing the disease. However, treatment costs and patient compliance remain challenging, necessitating further research to optimize both diagnostic and therapeutic strategies.

Diagnostic Utility of a 90-Gene Expression Assay (Canhelp-Origin) for Patients with Metastatic Cancer with an Unclear or Unknown Diagnosis

BACKGROUND

Metastatic cancers with unclear or unknown origins pose significant challenges in diagnosis and management, frequently leading to suboptimal outcomes. Studies have demonstrated that a 90-gene expression assay is effective in predicting the primary origin and guiding the site-specific therapy to improve prognosis. This study aimed to evaluate the clinical effectiveness of a 90-gene expression assay in patients with unclear or unknown diagnoses.

METHODS

The study encompassed patients for whom a 90-gene expression assay was requested as part of standard care. Data on patient demographics, tumor characteristics, and clinical history were collected. The assay's performance was evaluated by comparing its predicted tumor type with the final histopathological diagnosis.

RESULTS

Among 303 cases analyzed, a 90-gene expression assay successfully identified a molecular-based tumor type for 295 (97.4%) patients. Comparison with histopathological diagnosis revealed an overall agreement of 88.5% (170/192). In patients with a single suspected primary site (n = 140), the assay confirmed the suspected diagnosis in 90.7% of cases. For those with a differential diagnosis (n = 52), the assay narrowed down the possibilities in 82.7% of cases. Moreover, in cases where the histopathology report indicated cancer of unknown primary (n = 103), the assay offered a molecular tumor type prediction with potential clinical significance.

CONCLUSIONS

This study demonstrates the significant impact of a 90-gene expression assay on diagnosis and potential treatment selection for difficult-to-diagnose patients, highlighting its clinical value as a standardized molecular approach to streamline further diagnostic testing for patients with metastatic cancer of unclear or unknown origin. Further prospective study is required to assess whether employing molecular diagnostic classifiers enhances clinical outcomes in these patients.

Deciphering the origin and therapeutic targets of cancer of unknown primary: a case report that illustrates the power of integrative whole-exome and transcriptome sequencing analysis

Cancer of unknown primary (CUP) represents a significant diagnostic and therapeutic challenge, being the third to fourth leading cause of cancer death, despite advances in diagnostic tools. This article presents a successful approach using a novel genomic analysis in the evaluation and treatment of a CUP patient, leveraging whole-exome sequencing (WES) and RNA sequencing (RNA-seq). The patient, with a history of multiple primary tumors including urothelial cancer, exhibited a history of rapid progression on empirical chemotherapy. The application of our approach identified a molecular target, characterized the tumor expression profile and the tumor microenvironment, and analyzed the origin of the tumor, leading to a tailored treatment. This resulted in a substantial radiological response across all metastatic sites and the predicted primary site of the tumor. We argue that a comprehensive genomic and molecular profiling approach, like the BostonGene© Tumor Portrait, can provide a more definitive, personalized treatment strategy, overcoming the limitations of current predictive assays. This approach offers a potential solution to an unmet clinical need for a standardized approach in identifying the tumor origin for the effective management of CUP.

Assessing the utility of molecular diagnostic classification for cancers of unknown primary

BACKGROUND

Roughly 5% of metastatic cancers present with uncertain origin, for which molecular classification could influence subsequent management; however, prior studies of molecular diagnostic classifiers have reported mixed results with regard to clinical impact. In this retrospective study, we evaluated the utility of a novel molecular diagnostic classifier by assessing theoretical changes in treatment and additional testing recommendations from oncologists before and after the review of classifier predictions.

METHODS

We retrospectively analyzed de-identified records from 289 patients with a consensus diagnosis of cancer of uncertain/unknown primary (CUP). Two (or three, if adjudication was required) independent oncologists separately reviewed patient clinical information to determine the course of treatment before they reviewed results from the molecular diagnostic classifier and subsequently evaluated whether the predicted diagnosis would alter their treatment plan.

RESULTS

Results from the molecular diagnostic classifier changed the consensus oncologist-reported treatment recommendations for 235 out of 289 patients (81.3%). At the level of individual oncologist reviews (n = 414), 64.7% (n = 268) of treatment recommendations were based on CUP guidelines prior to review of results from the molecular diagnostic classifier. After seeing classifier results, 98.1% (n = 207) of the reviews, where treatment was specified (n = 211), were guided by the tissue of origin-specific guidelines. Overall, 89.9% of the 414 total reviews either expressed strong agreement (n = 242) or agreement (n = 130) that the molecular diagnostic classifier result increased confidence in selecting the most appropriate treatment regimen.

CONCLUSIONS

A retrospective review of CUP cases demonstrates that a novel molecular diagnostic classifier could affect treatment in the majority of patients, supporting its clinical utility. Further studies are needed to prospectively evaluate whether the use of molecular diagnostic classifiers improves clinical outcomes in CUP patients.

Cancer of unknown primary site in the mandibular region: A case report

The diagnosis and treatment of cancer of unknown primary site (CUP) present with difficulties and produce a poor prognosis. The current study presents the case of a patient with CUP in the mandibular region was treated with docetaxel and lobaplatin chemotherapy, and vascular embolization of the tumor. The tumor size was markedly reduced and the patient's quality of life improved following radiotherapy. The present case report is accompanied by a discussion of the literature to contextualize the treatment regimen for patients with CUP. These findings will support current treatment practices, inform oncologists and benefit patients with cancer.

Case Report: Successful Immunotherapy Improved the Prognosis of the Unfavorable Subset of Cancer of Unknown Primary

Background

Cancer of unknown primary (CUP) is heterogeneous and has a wide variety of clinical presentations and a poor prognosis in most patients, with a median overall survival of only 6 months. The development of molecular profiling contributes to precision therapy, and targeted drugs and immune checkpoint inhibitors (ICIs) greatly promote individualized treatment.

Case presentation

Here, we reported a case of an unfavorable subset of CUP who had a long time of survival after the immunotherapy-prominent comprehensive treatment. A 48-year-old man presented with back pain and a cough. A diagnostic work-up showed bone marrow, multiple bones, and lymph node metastasis. Lymph node pathology implies metastatic poorly differentiated cancer. Next-generation sequencing (NGS) showed no special targets, but the tumor proportion score (TPS) of programmed death-ligand 1 (PD-L1) was 80% and the tumor mutation burden (TMB) was 16.7 per million bases. After two cycles of pembrolizumab 200 mg D1 plus nanoparticle albumin-bound (nab)-paclitaxel 200 mg D1&8 (q3w), PET-CT and bone marrow aspiration cytology showed a complete response (CR). Subsequently, pembrolizumab alone was used for three months. The left inguinal lymph nodes showed new metastasis. After two cycles of the combination treatment of pembrolizumab and (nab)-paclitaxel, a partial response (PR) was achieved. After seven months, retroperitoneal lymph nodes showed new metastasis, and the sequential treatment with radiotherapy and pembrolizumab exhibited encouraging efficacy. To date, the patient has survived nearly 40 months with the combination therapy.

Conclusions

The ICI-prominent comprehensive treatment provided clinical benefit for the reported case of CUP. Thus, CUP patients with markers of benefiting from immunotherapy should be actively treated with immunotherapy to improve their prognosis.

SEOM-GECOD clinical guideline for unknown primary cancer (2021)

Cancer of unknown primary site (CUP) is defined as a heterogeneous group of tumors that appear as metastases, and of which standard diagnostic work-up fails to identify the origin. It is considered a separate entity with a specific biology, and nowadays molecular characteristics and the determination of actionable mutations may be important in a significant group of patients. In this guide, we summarize the diagnostic, therapeutic, and possible new developments in molecular medicine that may help us in the management of this unique disease entity.

Comprehensive evaluation on cancer of unknown primary site and how we managed it: A case report

Introduction and importance

Cancer of unknown primary site (CUP) is metastatic cancer without primary tumor found from comprehensive medical history, physical examination, and regular laboratory examination. Eighty percent of CUP include unfavorable groups with 3 to 6 months of median survival despite chemotherapy treatment.

Case presentation

A 52-year-old male was presented with a chief complaint of a recurrent lump in the neck and axilla. After comprehensive examinations over three years, the primary site of the metastatic tumor could not be found. Therefore, this patient was diagnosed with cancer of an unknown primary site.

Clinical discussion

In patient with CUP, more precise therapy can only begin when the exact form of cancer is identified. However, the delay in diagnosis would worsen the patient's condition, as treatment measures cannot be implemented.

Conclusion

Trimodal modalities including surgery, chemotherapy, and radiotherapy are suitable for CUP with squamous cell carcinoma proven in immunohistochemistry evaluation.

•

Precise therapy for patients with CUP can only begin when the exact form of cancer is identified.

•

Although PET/CT is suitable to assess the complete body state for CUP, other radiological and histopathology modalities are needed to confirm the diagnosis.

•

Trimodal modalities including surgery, chemotherapy, and radiotherapy are required for CUP with squamous cell carcinoma.

Analyses of the clinical characteristics of 49 cases of malignancy with multiple bone lesions as the first manifestation

Objective

To investigate the clinical features of several cases of malignancy with multiple bone lesions as the first manifestation.

Methods

Forty-nine cases of malignancy with multiple bone lesions as the first manifestation were retrospectively analyzed from May 2018 to July 2019. All patients complained of “pain at the site of bone lesion” upon admission. Baseline patient information, such as age, gender, location of bone lesions, etiology, diagnosis method, time of onset was collected.

Results

The median age of the patients was 56 years old, of which 83.7% (41/49) were aged ≥50 years. The median time of onset was 2 months. Among the cases, 40 were confirmed as solid tumor bone metastasis, whereas the remaining 9 cases as hematological system tumor. Lung cancer and multiple myeloma were the main tumor types, accounting for 40.8% (20/49) and 16.3% (8/49), respectively. Other common causes were seven cases of cancer affecting the digestive system (three cases of liver cancer, three cases of gastric cancer, and one case of esophageal cancer), as well as seven cases of unknown primary cancer. Half of the solid tumors had only multiple bone metastases but no other distant metastasis.

Conclusion

Multiple bone lesions accompanied by pain may be the first clinical manifestation in various malignant tumors. The common tumor types were lung cancer, multiple myeloma, and digestive system tumor. It is more common in people aged 50 years and older. Multiple bone lesions might be the only metastasis site of some solid tumors, and its mechanism needs further investigation.

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%.

Site-Specific and Targeted Therapy Based on Molecular Profiling by Next-Generation Sequencing for Cancer of Unknown Primary Site: A Nonrandomized Phase 2 Clinical Trial

Importance

Although profiling of gene expression and gene alterations by next-generation sequencing (NGS) to predict the primary tumor site and guide molecularly targeted therapy might be expected to improve clinical outcomes for cancer of unknown primary site (CUP), to our knowledge, no clinical trial has previously evaluated this approach.

Objective

To assess the clinical use of site-specific treatment, including molecularly targeted therapy based on NGS results, for patients with CUP.

Design, Setting, and Participants

This phase 2 clinical trial was conducted at 19 institutions in Japan and enrolled 111 previously untreated patients with the unfavorable subset of CUP between March 2015 and January 2018, with 97 patients being included in the efficacy analysis. Eligibility criteria included a diagnosis of unfavorable CUP after mandatory examinations, including pathological evaluation by immunohistochemistry, chest-abdomen-pelvis computed tomography scans, and a positron emission tomography scan.

Interventions

RNA and DNA sequencing for selected genes was performed simultaneously to evaluate gene expression and gene alterations, respectively. A newly established algorithm was applied to predict tumor origin based on these data. Patients received site-specific therapy, including molecularly targeted therapy, according to the predicted site and detected gene alterations.

Main Outcomes And Measures

The primary end point was 1-year survival probability. Secondary end points included progression-free survival (PFS), overall survival (OS), objective response rate, safety, efficacy according to predicted site, and frequency of gene alterations.

Results

Of 97 participants, 49 (50.5%) were women and the median (range) age was 64 (21-81) years. The cancer types most commonly predicted were lung (21 [21%]), liver (15 [15%]), kidney (15 [15%]), and colorectal (12 [12%]) cancer. The most frequent gene alterations were in TP53 (45 [46.4%]), KRAS (19 [19.6%]), and CDKN2A (18 [18.6%]). The 1-year survival probability, median OS, and median PFS were 53.1% (95% CI, 42.6%-62.5%), 13.7 months (95% CI, 9.3-19.7 months), and 5.2 months (95% CI, 3.3-7.1 months), respectively. Targetable EGFR mutations in tumor specimens were detected in 5 patients with predicted non-small-cell lung cancer (5.2%), 4 of whom were treated with afatinib; 2 of these patients achieved a durable PFS of longer than 6 months.

Conclusions and Relevance

This study's findings suggest that site-specific treatment, including molecularly targeted therapy based on profiling gene expression and gene alterations by NGS, can contribute to treating patients with the unfavorable subset of CUP.

Trial Registration

UMIN Identifier: UMIN000016794.

Minimalist approaches to cancer tissue-of-origin classification by DNA methylation

Classification of cancers by tissue-of-origin is fundamental to diagnostic pathology. While the combination of clinical data, tissue histology, and immunohistochemistry is usually sufficient, there remains a small but not insignificant proportion of difficult-to-classify cases. These challenging cases provide justification for ancillary molecular testing, including high-throughput DNA methylation array profiling, which promises cell-of-origin information and compatibility with formalin-fixed specimens. While diagnostically powerful, methylation profiling platforms are costly and technically challenging to implement, particularly for less well-resourced laboratories. To address this, we simulated the performance of "minimalist" methylation-based tests for cancer classification using publicly-available and internal institutional profiling data. These analyses showed that small and focused sets of the most informative CpG biomarkers from the arrays are sufficient for accurate diagnoses. As an illustrative example, one classifier, using information from just 53 out of about 450,000 available CpG probes, achieved an accuracy of 94.5% on 2575 fresh primary validation cases across 28 cancer types from The Cancer Genome Atlas Network. By training minimalist classifiers on formalin-fixed primary and metastatic cases, generally high accuracies were also achieved on additional datasets. These results support the potential of minimalist methylation testing, possibly via quantitative PCR and targeted next-generation sequencing platforms, in cancer classification.

Defining a Distinct Immunotherapy Eligible Subset of Patients with Cancer of Unknown Primary Using Gene Expression Profiling with the 92-Gene Assay

Background

Although recent advances in immunotherapy have transformed the treatment landscape for many anatomically defined cancers, these therapies are currently not approved for patients diagnosed with cancer of unknown primary (CUP). Molecular cancer classification using gene expression profiling (GEP) assays has the potential to identify tumor type and putative primary cancers and thereby may allow consideration of immune checkpoint inhibitor (ICI) therapy options for a subset of patients with CUP. Herein, we evaluated and characterized the ability of a 92‐gene assay (CancerTYPE ID) to provide a molecular diagnosis and identify putative tumor types that are known to be sensitive to ICI therapies in patients with CUP or uncertain diagnosis.

Findings

A total of 24,426 cases from a large‐scale research database of 92‐gene assay clinical cases were classified, of which 9,350 (38%) were predicted to have an ICI‐eligible tumor type. All ICIs with approved indications as of March 2020 were included in the analysis. Non‐small cell lung cancer (NSCLC) was the most frequent molecular diagnosis and accounted for 33% of the ICI‐eligible tumor types identified and 13% of the overall reportable results. In addition to NSCLC, the assay also frequently identified urothelial carcinomas, gastric cancer, and head and neck squamous cell carcinoma. The distributions of identified tumor types with indications for ICI therapy were similar across age and gender.

Conclusions

Results suggest that molecular profiling with the 92‐gene assay identifies a subset of ICI‐eligible putative primary cancers in patients with CUP. We propose a treatment strategy based on available tests, including clinicopathologic features, GEP, and ICI biomarkers of response.

Regulatory approval of immune checkpoint inhibitors (ICI) is restricted to anatomically defined cancers with a known primary. This article reports cases submitted for 92‐gene assay testing with an unknown or uncertain diagnosis for which the subsequent post‐test report included a tumor type linked to an FDA‐approved ICI therapy, with the goal of identifying characteristics of cancers of unknown primary tumors that might benefit from immunotherapy.

Expanding cancer predisposition genes with ultra-rare cancer-exclusive human variations

It is estimated that up to 10% of cancer incidents are attributed to inherited genetic alterations. Despite extensive research, there are still gaps in our understanding of genetic predisposition to cancer. It was theorized that ultra-rare variants partially account for the missing heritable component. We harness the UK BioBank dataset of ~ 500,000 individuals, 14% of which were diagnosed with cancer, to detect ultra-rare, possibly high-penetrance cancer predisposition variants. We report on 115 cancer-exclusive ultra-rare variations and nominate 26 variants with additional independent evidence as cancer predisposition variants. We conclude that population cohorts are valuable source for expanding the collection of novel cancer predisposition genes.

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.

Cancer of Unknown Primary Site: Real Entity or Misdiagnosed Disease?

Metastasis is a late event in the progression of any tumour. However, invasive cancers are occasionally detected in the form of metastatic lesions without a clearly detectable primary tumour. Cancer of unknown primary site (CUP) is defined as a confirmed metastatic tumour, with unknown primary tumour site, despite the standardized diagnostic approach that includes clinical history, routine laboratory tests, and complete physical examination. Due to the lack of basic research on its primary causes, CUP is appropriately termed an 'orphan' cancer. Nevertheless, CUP accounts for 2-5% of diagnosed malignancies. To date, it is unclear whether CUP is an entity with primary dormancy as its hallmark or an entity with genetic abnormalities that cause it to manifest as a primary metastatic disease. In this review, we discuss different aspects of CUP, including its current diagnostic methods, angiogenesis effectors, relationship with cancer stem cells and current treatments.

A global epidemic increase of an HPV-induced tonsil and tongue base cancer - potential benefit from a pan-gender use of HPV vaccine

In 2007, human papillomavirus (HPV) type 16 was finally recognized as a risk factor, besides smoking and alcohol, for oropharyngeal squamous cell carcinoma (OPSCC), including tonsillar squamous cell carcinoma (TSCC), by the International Agency for Research against Cancer. Just before, in 2006, the Food and Drug Administration had approved Gardasil, the first vaccine against HPV16, 18, 6 and 11, for preventive vaccination women against cervical cancer. Concurrently, some Western countries, where smoking was decreasing, disclosed an epidemic increase in the incidence of OPSCC, especially of TSCC and base of tongue cancer (BOTSCC), together accounting for 80-90% of all OPSCCs, and mainly affecting men. The epidemic was later revealed to be due to a rise in HPV-positive cases, and scientists in the field suggested HPV vaccination also of boys. Globally, there are roughly 96 000 incident OPSCC cases/year of which 20-24% are caused by HPV, thereby accounting for around 22 000 OPSCC cases annually. Of these cases, 80-90% are due to HPV16 infection and would be prevented with the presently registered HPV vaccines. In Western countries, such as Sweden (with almost 400 TSCC and BOTSCC cases per year) and the United States, HPV prevalence in OPSCC is higher and around 70%. HPV vaccination of girls has been initiated in many countries, and the vaccines have been efficient and their side effects limited. HPV vaccination of boys has, however, been the exception, but should definitely not be delayed any further. It would benefit both girls and boys directly, and result in better and more robust herd immunity. Today, we have the possibility to eliminate several high-risk HPV types in the younger generations and avoid more than 600 000 cancer cases annually worldwide, and this possibility should be embraced by offering global pan-gender HPV vaccination.

Multiclass cancer classification in fresh frozen and formalin-fixed paraffin-embedded tissue by DigiWest multiplex protein analysis

Histomorphology and immunohistochemistry are the most common ways of cancer classification in routine cancer diagnostics, but often reach their limits in determining the organ origin in metastasis. These cancers of unknown primary, which are mostly adenocarcinomas or squamous cell carcinomas, therefore require more sophisticated methodologies of classification. Here, we report a multiplex protein profiling-based approach for the classification of fresh frozen and formalin-fixed paraffin-embedded (FFPE) cancer tissue samples using the digital western blot technique DigiWest. A DigiWest-compatible FFPE extraction protocol was developed, and a total of 634 antibodies were tested in an initial set of 16 FFPE samples covering tumors from different origins. Of the 303 detected antibodies, 102 yielded significant correlation of signals in 25 pairs of fresh frozen and FFPE primary tumor samples, including head and neck squamous cell carcinomas (HNSC), lung squamous cell carcinomas (LUSC), lung adenocarcinomas (LUAD), colorectal adenocarcinomas (COAD), and pancreatic adenocarcinomas (PAAD). For this signature of 102 analytes (covering 88 total proteins and 14 phosphoproteins), a support vector machine (SVM) algorithm was developed. This allowed for the classification of the tissue of origin for all five tumor types studied here with high overall accuracies in both fresh frozen (90.4%) and FFPE (77.6%) samples. In addition, the SVM classifier reached an overall accuracy of 88% in an independent validation cohort of 25 FFPE tumor samples. Our results indicate that DigiWest-based protein profiling represents a valuable method for cancer classification, yielding conclusive and decisive data not only from fresh frozen specimens but also FFPE samples, thus making this approach attractive for routine clinical applications.

An Analysis of Patients with DNA Repair Pathway Mutations Treated with a PARP Inhibitor

BACKGROUND

Molecular analysis has revealed four subtypes of pancreatic ductal adenocarcinoma (PDAC). One subtype identified for the presence of DNA damage repair deficiency can be targeted therapeutically with the poly (ADP-ribose) polymerase (PARP) inhibitor olaparib. We performed a single institution retrospective analysis of treatment response in patients with PDAC treated with olaparib who have DNA damage repair deficiency mutations.

SUBJECTS, MATERIALS, AND METHODS

Patients with germline or somatic mutations involving the DNA repair pathway were identified and treated with olaparib. The primary objective was to examine the objective response rate (ORR). The secondary objectives were assessing tolerability, overall survival, and change in cancer antigen 19-9. Quantitative texture analysis (QTA) was evaluated from CT scans to explore imaging biomarkers.

RESULTS

Thirteen individuals with metastatic PDAC were treated with Olaparib. The ORR to Olaparib was 23%. Median overall survival (OS) was 16.47 months. Four of seven patients with BRCA mutations had an effect on RAD51 binding, with a median OS of 24.60 months. Exploratory analysis of index lesions using QTA revealed correlations between lesion texture and OS (hepatic lesion tumor texture correlation coefficient [CC], 0.683, p = .042) and time on olaparib (primary pancreatic lesion tumor texture CC, 0.778, p = .023).

CONCLUSION

In individuals with metastatic PDAC who have mutations involved in DNA repair, Olaparib may provide clinical benefit. BRCA mutations affecting RAD51 binding domains translated to improved median OS. QTA of individual tumors may allow for additional information that predicts outcomes to treatment with PARP inhibitors.

IMPLICATIONS FOR PRACTICE

Pursuing germline and somatic DNA sequencing in individuals with pancreatic ductal adenocarcinoma may yield abnormalities in DNA repair pathways. These individuals may receive benefit with poly (ADP-ribose) polymerase (PARP) inhibition. Radiomics and deep sequencing analysis may yet uncover additional information that may predict outcome to treatment with PARP inhibitors.

Sarcomatoid carcinoma presenting as cancers of unknown primary: a clinicopathological portrait

Background

Sarcomatoid carcinoma of unknown primary (SCUP) is a rare entity of either poorly differentiated carcinoma with sarcoma-like differentiation or a true mixed lineage neoplasm. Limited data regarding clinicopathological profile and management exists.

Methods

We retrospectively reviewed the MD Anderson Cancer of Unknown Primary database and tumor registry to identify 48 SCUP patients between 2001 and 2017. Patient characteristics, pathology, molecular diagnostics, treatments, and outcomes were obtained. Kaplan-Meier method was used to estimate overall survival (OS) and compared using log rank test.

Results

Median age at diagnosis was 59 years (range 27–86). Majority of patients were female (58%) and presented with ≥3 metastatic sites (52%), commonly lymph node (50%), bone (42%), lung (27%), and liver (21%). First line treatment included chemotherapy (35%), surgery (27%), and radiation (24%). Gemcitabine and docetaxel (18%) was the most common chemotherapy regimen. Median OS for entire cohort was 11 months (95% CI: 5.6 to 16.4). Poor performance status (PS), > 1 metastatic site, elevated lactate dehydrogenase (LDH), and high neutrophil-to-lymphocyte ratio (NLR) were significantly associated with worse OS on univariate analyses. On multivariate analyses, poor PS (HR 8.7; 95%CI: 3.0–25.0; p <  0.001) and high NLR (HR 3.4; 95%CI: 1.3–8.8; p = 0.011) emerged as independent prognostic factors for OS.

Conclusions

SCUP is a rare presentation with an aggressive clinical course and limited survival. Diagnosis is difficult to make and requires careful review and synthesis of histology, immunohistochemistry, and molecular diagnostics. Chemotherapy resistance remains a challenge. Early mutational profiling is warranted, and clinical trial participation should be encouraged for this subset.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

Skeletal metastases of unknown primary (SMUP) represent a clinical challenge in dealing with patients diagnosed with bone metastases. Management of these patients has improved significantly in the past few years. however, it is fraught with a lack of evidence. While some patients have achieved impressive gains, a more systematic and tailored treatment is required. Nevertheless, in real-life practice, the outlook at the beginning of treatment for SMUP is decidedly somber. An incomplete translational relevance of pathological and clinical data on the mortality and morbidity rate has had unsatisfactory consequences for SMUP patients and their physicians. We examined several approaches to confront the available evidence; three key points emerged. The characterization of the SMUP biological profile is essential to driving clinical decisions by integrating genetic and molecular profiles into a multi-step diagnostic work-up. Nonetheless, a pragmatic investigation plan and therapy of SMUP cannot follow a single template; it must be adapted to different pathophysiological dynamics and coordinated with efforts of a systematic algorithm and high-quality data derived from statistically powered clinical trials. The discussion in this review points out that greater efforts are required to face the unmet needs present in SMUP patients in oncology.

Familial cancer of unknown primary

Cancer of unknown primary site (CUP) is a deadly disease diagnosed through metastases at various organs without primary tumor identification. Despite the major molecular and technological advances, the carcinogenesis of CUP remains enigmatic which hampers adequate study design of treatments leading to survival improvement. To date, the pathogenesis of CUP is still debatable with one hypothesis considering CUP simply a group of metastatic tumors with unidentified primaries and another considering it a distinct entity with specific genetic and phenotypic aberrations. Familial CUP seems to favor the first hypothesis due to common genetic predisposition factors between known primaries and CUP. Two clinical implications may be withdrawn from the pathogenesis of familial clustering of CUP. The detailed family history and environmental risk factors may orient towards the primary tumor identification. Smoking avoidance and adherence to general population guidelines for cancer screening would be strongly encouraged.

Somatic Testing: Implications for Targeted Treatment

OBJECTIVE

To provide an overview of key considerations for somatic testing for the purpose of targeting cancer treatment.

DATA SOURCES

Literature; research reports.

CONCLUSION

Genomic testing of cancer cells to identify variants that drive the carcinogenic process is becoming common in clinical settings. Providers and patients need to weigh the potential benefits of testing with technologic and logistic issues.

IMPLICATIONS FOR NURSING PRACTICE

Testing is available for thousands of genomic variants to identify one or more to guide targeted treatment. Oncology nurses need to understand the benefits and limitations of participating in patient-centered implementation of this testing.

Genomics-Enabled Precision Medicine for Cancer

Genomic information is increasingly being incorporated into clinical cancer care. Large-scale sequencing efforts have deepened our understanding of the genomic landscape of cancer and contributed to the expanding catalog of alterations being leveraged to aid in cancer diagnosis, prognosis, and treatment. Genomic profiling can provide clinically relevant information regarding somatic point mutations, copy number alterations, translocations, and gene fusions. Genomic features, such as mutational burden, can also be measured by more comprehensive sequencing strategies and have shown value in informing potential treatment options. Ongoing clinical trials are evaluating the use of molecularly targeted agents in genomically defined subsets of cancers within and across tumor histologies. Continued advancements in clinical genomics promise to further expand the application of genomics-enabled medicine to a broader spectrum of oncology patients.

[2018 Consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary]

Cancer of unknown primary is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, cancer of unknown primary can account for 2-9% of all cancer patients, mostly 60-75 years old. This article reviews the main clinical, pathological and molecular studies conducted to analyse and determine the origin of cancer of unknown primary. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

Multi-Institutional, Prospective Clinical Utility Study Evaluating the Impact of the 92-Gene Assay (CancerTYPE ID) on Final Diagnosis and Treatment Planning in Patients With Metastatic Cancer With an Unknown or Unclear Diagnosis

Purpose

Metastatic cancers of unknown primary or with unclear diagnoses pose diagnostic and management challenges, often leading to poor outcomes. Studies of the 92-gene assay have demonstrated improved diagnostic accuracy compared with standard pathology techniques and improved survival in patients treated on the basis of assay results. The current study assessed the clinical impact of the 92-gene assay on diagnostic and treatment decisions for patients with unknown or uncertain diagnoses.

Methods

Patients in this prospective, multi-institutional, decision-impact study included those for whom the 92-gene assay was ordered as part of routine care. Participating physicians completed electronic case report forms that contained standardized, specialty-specific questionnaires. Data collection included patient and tumor characteristics and clinical history. The key study objective of clinical impact was calculated on the basis of changes in final diagnosis and treatment after testing.

Results

Data collection included 444 patients, 107 physicians (73 oncologists and 34 pathologists), and 28 sites. Molecular diagnoses from 22 different tumor types and subtypes across all cases were provided in 95.5% of patients with a reportable result (n = 397). Physicians reported that the 92-gene assay was used broadly for diagnostic dilemmas that ranged from single suspected tumor type (29%) to a differential diagnosis of two or more suspected tumor types (30%) or cancers of unknown primary (41%). Integration of 92-gene assay results led to a change in the recommended treatment in 47% of patients.

Conclusion

Findings from this clinical utility study demonstrate that the 92-gene assay led to a change in treatment decisions in every other patient case. These data additionally define the role of this assay in clinical practice and strongly support the consideration of molecular tumor typing in the diagnosis and treatment planning of patients with metastatic cancer with unknown or uncertain diagnosis.

Molecular Diagnostics in Clinical Oncology

There are multiple applications of molecular tests in clinical oncology. Mutation analysis is now routinely utilized for the diagnosis of hereditary cancer syndromes. Healthy carriers of cancer-predisposing mutations benefit from tight medical surveillance and various preventive interventions. Cancers caused by germ-line mutations often require significant modification of the treatment strategy. Personalized selection of cancer drugs based on the presence of actionable mutations has become an integral part of cancer therapy. Molecular tests underlie the administration of EGFR, BRAF, ALK, ROS1, PARP inhibitors as well as the use of some other cytotoxic and targeted drugs. Tumors almost always shed their fragments (single cells or their clusters, DNA, RNA, proteins) into various body fluids. So-called liquid biopsy, i.e., the analysis of circulating DNA or some other tumor-derived molecules, holds a great promise for non-invasive monitoring of cancer disease, analysis of drug-sensitizing mutations and early cancer detection. Some tumor- or tissue-specific mutations and expression markers can be efficiently utilized for the diagnosis of cancers of unknown primary origin (CUPs). Systematic cataloging of tumor molecular portraits is likely to uncover a multitude of novel medically relevant DNA- and RNA-based markers.

Cancer of unknown primary-Epidemiological trends and relevance of comprehensive genomic profiling

Background

Cancer of unknown primary (CUP) is a distinct clinicopathological entity with poor prognosis, frequently resistant to chemotherapy. Comprehensive genomic profiling (CGP) by next‐generation sequencing potentially identifies novel treatment options for CUP patients. The objective of this study was to determine incidence and survival trends and to discuss the value of CGP in CUP patients.

Methods

Age‐standardized incidence rates (ASR) per 100 000 were calculated for 2935 CUP patients from 1981 to 2014 using cancer registry data of the canton of Zurich, Switzerland. Kaplan–Meier survival curves were estimated for sex, age, and histological groups. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (HR). A literature review was conducted to assess the current use of CGP in CUP patients.

Results

ASR of CUP increased from 10.3 to 17.6 between 1981 and 1997 and decreased to 5.8/100 000 in 2014. Mean overall survival remained stable. Mortality was significantly lower for patients with squamous cell carcinoma (HR 0.48 [95% CI, 0.41‐0.57]) and neuroendocrine carcinoma (0.75 [0.63‐0.88]) and higher for unclassified neoplasms (1.25 [1.13‐1.66]) compared to adenocarcinomas. The literature review identified 10 studies using CGP of CUP tissue. Clinically relevant mutations were identified in up to 85% of CUP patients, of which 13%‐64% may benefit from currently available drugs.

Conclusions

CUP incidence decreased probably due to improved diagnostics, but mortality did not improve over the last 34 years. CGP testing may help to identify molecular signatures in CUP patients and enable targeted treatment.

2018 consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary

Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2–9% of all cancer patients, mostly 60–75 years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

Metastatic diseases of the central nervous system - neuropathologic aspects

A large percentage of patients with cancer will develop brain metastases, and many of them will die within a few months following diagnosis of intracranial metastasis. Although the majority of the central nervous system metastases are derived from a well-known primary neoplasm, about 5-10% of brain metastases are from an unknown source, making the tissue diagnosis a first step in the search for a primary malignancy. The pathologist utilizes several immunohistochemical and molecular diagnostic tools for such investigation, helping the clinical oncologist to narrow down the clinical and radiologic exploration. Recently, analysis of actionable biomarkers for target therapy in brain metastasis has become significant due to reports of discrepancy of potential biomarkers between primary tumors and metastatic brain deposits.

SEOM clinical guideline on unknown primary cancer (2017)

Cancer of unknown primary site is a histologically confirmed cancer that manifests in advanced stage, with no identifiable primary site following standard diagnostic procedures. Patients are initially categorized based on the findings of the initial biopsy: adenocarcinoma, squamous-cell carcinoma, neuroendocrine carcinoma, and poorly differentiated carcinoma. Appropriate patient management requires understanding several clinical and pathological features that aid in identifying several subsets of patients with more responsive tumors.

Testicular Signet-Ring Cell Metastasis from a Carcinoma of Unknown Primary Site: A Case Report and Literature Review

Signet-ring cell carcinoma is a highly malignant adenocarcinoma consisting of cells characterized as cytoplasmic vacuoles filled with mucin. The most common primary location of this type of cancer is the stomach, but it may also be found in other organs such as prostate, testis, bladder, ovaries, or colon. To date, metastatic signet-ring cell carcinoma of unknown primary (CUP) site to the testis is an extremely rare entity in daily practice. Reviewing the literature, we have been able to detect only three cases of testicular metastases from CUP, two with histological diagnosis of a signet-ring cell carcinoma and one with an adenocarcinoma. In this short paper, we report a case of a 56-year-old man who presented to our Department with testicular mass and ascites. Following a standard diagnostic approach no primary tumor could be identified. CUP was the final clinical diagnosis, histologically characterized as poorly differentiated adenocarcinoma with signet-ring cells involving the peritoneum and the testicular structures.

Axillary node metastatic carcinoma without definitive primary: a case report

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Metastatic carcinoma is identified in an axillary node, without a breast lesion identified on mammogram.

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MRI nor PET identified a cancer primary in the breast, or elsewhere in the body, rendering this as carcinoma of unknown primary (CUP).

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Histochemical staining identified the nodal metastasis consistent with breast origin.

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Recommended treatment for isolated axillary CUP is mastectomy alone, or combination radiation plus chemotherapy.

Cancer of unknown primary (CUP) is the finding of a metastatic cancerous lesion without an established primary source localized within the body. CUP can be of any cancer cell type, however, adenocarcinoma is most often identified by histology. Up to 5% of all malignant diagnoses are classified as CUP. PET is an imaging modality often utilized to distinguish a primary source in the setting of CUP, yet often a primary is never identified. CUP can be further stratified using specific qualifiers as favorable and unfavorable, indicating the potential therapeutic response to treatment regimens. Treatment approach to CUP relies heavily on the cell type identified by histology, the location of the lesion, and the amount of spread within the body. In the typical setting and presentation, per current literature, CUP arises in the 7th decade of life in patients with multiple comorbidities, and often has a poor prognostic value. This case report identifies an atypical presentation of CUP, a 38-year-old Caucasian female with an axillary mobile mass, and no associated systemic symptoms. Biopsy of the node and immunohistochemical staining showed histology consistent with metastatic carcinoma. Mammography, MRI, and PET scan found no evidence of tumor primary or distant metastasis. Further staining confirmed metastatic carcinoma consistent with breast origin, without an established breast primary. As in this case, CUP may present in an atypical manner, warranting a thorough investigation aiming to identify the tumor primary to aid in identification of a proper treatment regimen and approach.

Unusual Presentation of an Adenocarcinoma of the Lung Metastasizing to the Mandible, Including Molecular Analysis and a Review of the Literature

Lung cancer is the most frequent cause of cancer-related death worldwide. Metastases of non-small cell lung carcinoma to the oral and maxillofacial region are rare. Thus, the diagnosis of a metastatic lesion in the oral cavity is challenging to the clinician and to the pathologist. This report presents a case of a 72-year-old man with metastatic lung adenocarcinoma located in the posterior mandibular region. Next-generation sequencing analysis showed no important mutations in the relevant genes except in the TP53 tumor suppressor gene.

Future microfluidic and nanofluidic modular platforms for nucleic acid liquid biopsy in precision medicine

Nucleic acid biomarkers have enormous potential in non-invasive diagnostics and disease management. In medical research and in the near future in the clinics, there is a great demand for accurate miRNA, mRNA, and ctDNA identification and profiling. They may lead to screening of early stage cancer that is not detectable by tissue biopsy or imaging. Moreover, because their cost is low and they are non-invasive, they can become a regular screening test during annual checkups or allow a dynamic treatment program that adjusts its drug and dosage frequently. We briefly review a few existing viral and endogenous RNA assays that have been approved by the Federal Drug Administration. These tests are based on the main nucleic acid detection technologies, namely, quantitative reverse transcription polymerase chain reaction (PCR), microarrays, and next-generation sequencing. Several of the challenges that these three technologies still face regarding the quantitative measurement of a panel of nucleic acids are outlined. Finally, we review a cluster of microfluidic technologies from our group with potential for point-of-care nucleic acid quantification without nucleic acid amplification, designed to overcome specific limitations of current technologies. We suggest that integration of these technologies in a modular design can offer a low-cost, robust, and yet sensitive/selective platform for a variety of precision medicine applications.

Location of metastases in cancer of unknown primary are not random and signal familial clustering

Cancer of unknown primary (CUP) is a fatal disease diagnosed through metastases. It shows intriguing familial clustering with certain defined primary cancers. Here we examine whether metastatic location in CUP patients is related to primary non-CUP cancers in relatives based on the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for CUP patients defined by metastatic location depending on cancer in their first degree relatives. SIRs for CUP were high in association with liver (3.94), ovarian (3.41), lung (2.43) and colorectal cancers (1.83) in relatives. The SIR was 1.63 for CUP with metastases in the abdomen when a relative was diagnosed with ovarian cancer. CUP with liver metastases associated with liver (1.44) cancer in relatives. CUP with head and neck region metastases associated with relatives’ esophageal (2.87) cancer. CUP metastases in the thorax associated with a relative’s cancers in the upper aerodigestive tract (2.14) and lung (1.74). The findings, matching metastatic location in CUP and primary cancer in relatives, could be reconciled if these cases of CUP constitute a phenotypically modified primary lacking tissue identification, resulting from epitope immunoediting. Alternatively, CUP metastases arise in a genetically favored tissue environment (soil) promoting growth of both primary cancers and metastases (seeds).

The possibility of clinical sequencing in the management of cancer

Comprehensive genomic profiling using next-generation sequencing technologies provides insights into understanding the genomic architecture of human cancer. This new understanding of the cancer genome allows us to identify many more genomic alterations occurring within tumors than before, some of which could be potential therapeutic targets through molecular targeted agents. Currently, a large number of molecular targeted agents are being developed, and consequently, cancer treatment is rapidly shifting from empiric therapy employing cytotoxic anticancer drugs to genotype-directed therapy using molecular targeted agents. In current daily clinical practice, hotspot-based single-gene assays that detect RAS mutations in colorectal cancer or EGFR mutations in non-small cell lung cancer are widely used to identify variants. However, it is becoming evident that more comprehensive genomic analysis is crucial in identifying the patient population that may benefit from molecular targeted therapy and the accelerated development of novel drugs for early clinical trials. For these purposes, an increasing number of gene panel-based targeted sequencing is commercially available in clinical practice from sequencing companies. Despite several challenges in implementing this approach, comprehensive genomic profiling and identification of actionable mutations is likely to become one of the standard options in the management of cancer in the near future. The use of clinical sequencing has the potential to usher a new era in precision medicine for cancer diagnosis and treatment. In this review, we discuss the application of comprehensive genomic profiling using next-generation sequencing technologies in clinical oncology and address the current challenges for its implementation.