Clinical validation of a 90-gene expression test for tumor tissue of origin diagnosis: a large-scale multicenter study of 1417 patients

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.

Site-specific therapy guided by a 90-gene expression assay versus empirical chemotherapy in patients with cancer of unknown primary (Fudan CUP-001): a randomised controlled trial

BACKGROUND

Empirical chemotherapy remains the standard of care in patients with unfavourable cancer of unknown primary (CUP). Gene-expression profiling assays have been developed to identify the tissue of origin in patients with CUP; however, their clinical benefit has not yet been demonstrated. We aimed to evaluate the efficacy and safety of site-specific therapy directed by a 90-gene expression assay compared with empirical chemotherapy in patients with CUP.

METHODS

This randomised controlled trial was conducted at Fudan University Shanghai Cancer Center (Shanghai, China). We enrolled patients aged 18-75 years, with previously untreated CUP (histologically confirmed metastatic adenocarcinoma, squamous cell carcinoma, poorly differentiated carcinoma, or poorly differentiated neoplasms) and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, who were not amenable to local radical treatment. Patients were randomly assigned (1:1) by the Pocock and Simon minimisation method to receive either site-specific therapy or empirical chemotherapy (taxane [175 mg/m2 by intravenous infusion on day 1] plus platinum [cisplatin 75 mg/m2 or carboplatin area under the curve 5 by intravenous infusion on day 1], or gemcitabine [1000 mg/m2 by intravenous infusion on days 1 and 8] plus platinum [same as above]). The minimisation factors were ECOG performance status and the extent of the disease. Clinicians and patients were not masked to interventions. The tumour origin in the site-specific therapy group was predicted by the 90-gene expression assay and treatments were administered accordingly. The primary endpoint was progression-free survival in the intention-to-treat population. The trial has been completed and the analysis is final. This study is registered with ClinicalTrials.gov (NCT03278600).

FINDINGS

Between Sept 18, 2017, and March 18, 2021, 182 patients (105 [58%] male, 77 [42%] female) were randomly assigned to receive site-specific therapy (n=91) or empirical chemotherapy (n=91). The five most commonly predicted tissues of origin in the site-specific therapy group were gastro-oesophagus (14 [15%]), lung (12 [13%]), ovary (11 [12%]), cervix (11 [12%]), and breast (nine [10%]). At the data cutoff date (April 30, 2023), median follow-up was 33·3 months (IQR 30·4-51·0) for the site-specific therapy group and 30·9 months (27·6-35·5) for the empirical chemotherapy group. Median progression-free survival was significantly longer with site-specific therapy than with empirical chemotherapy (9·6 months [95% CI 8·4-11·9] vs 6·6 months [5·5-7·9]; unadjusted hazard ratio 0·68 [95% CI 0·49-0·93]; p=0·017). Among the 167 patients who started planned treatment, 46 (56%) of 82 patients in the site-specific therapy group and 52 (61%) of 85 patients in the empirical chemotherapy group had grade 3 or worse treatment-related adverse events; the most frequent of these in the site-specific therapy and empirical chemotherapy groups were decreased neutrophil count (36 [44%] vs 42 [49%]), decreased white blood cell count (17 [21%] vs 26 [31%]), and anaemia (ten [12%] vs nine [11%]). Treatment-related serious adverse events were reported in five (6%) patients in the site-specific therapy group and two (2%) in the empirical chemotherapy group. No treatment-related deaths were observed.

INTERPRETATION

This single-centre randomised trial showed that site-specific therapy guided by the 90-gene expression assay could improve progression-free survival compared with empirical chemotherapy among patients with previously untreated CUP. Site-specific prediction by the 90-gene expression assay might provide more disease information and expand the therapeutic armamentarium in these patients.

FUNDING

Clinical Research Plan of Shanghai Hospital Development Center, Program for Shanghai Outstanding Academic Leader, and Shanghai Anticancer Association SOAR PROJECT.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

New techniques to identify the tissue of origin for cancer of unknown primary in the era of precision medicine: progress and challenges

Despite a standardized diagnostic examination, cancer of unknown primary (CUP) is a rare metastatic malignancy with an unidentified tissue of origin (TOO). Patients diagnosed with CUP are typically treated with empiric chemotherapy, although their prognosis is worse than those with metastatic cancer of a known origin. TOO identification of CUP has been employed in precision medicine, and subsequent site-specific therapy is clinically helpful. For example, molecular profiling, including genomic profiling, gene expression profiling, epigenetics and proteins, has facilitated TOO identification. Moreover, machine learning has improved identification accuracy, and non-invasive methods, such as liquid biopsy and image omics, are gaining momentum. However, the heterogeneity in prediction accuracy, sample requirements and technical fundamentals among the various techniques is noteworthy. Accordingly, we systematically reviewed the development and limitations of novel TOO identification methods, compared their pros and cons and assessed their potential clinical usefulness. Our study may help patients shift from empirical to customized care and improve their prognoses.

Multiple approaches revealed MGc80-3 as a somatic hybrid with HeLa cells rather than a gastric cancer cell line

The short-tandem-repeats (STR) profiles of MGc80-3 and HeLa partially overlap, raising suspicion of contamination in the MGc80-3 cell line. However, there has not been any relevant study demonstrating whether MGc80-3 was fully replaced by HeLa cells, just mixed with HeLa cells (co-existing), or was a somatic hybrid with HeLa cells. In addition to STR profiling, various approaches, including single nucleotide polymorphisms genotyping, polymerase chain reaction, screening for human papillomaviruses type 18 (HPV-18) fragment, chromosome karyotyping, pathological examination of xenografts, tissue-specific-90-gene expression signature and high-throughput RNA sequencing were used to determine the nature of MGc80-3. Our study found that the abnormal STR profile, partially overlapping with that of HeLa cells (64.62% to 71.64%), could not verify MGc80-3 as a HeLa cell line. However, the STR 13.3 repeat allele in the D13S317 locus that seemed to be unique to HeLa cells was detected in MGc80-3. Almost all the MGc80-3 cells exhibited HPV-18 fragments in the genome as well as certain HeLa marker chromosomes, such as M7 and M12. The molecular assay of the 90-gene expression signature still considered MGc80-3 as a stomach cancer using an algorithmic analysis. The expression pattern of multiple genes in MGc80-3 was quite different from that in HeLa cells, which showed that certain characteristics belonged to gastric cancer cell lines. High throughput RNA sequencing showed the distinct patterns of gene expression in MGc80-3. In conclusion, MGc80-3 cell line is a somatic hybrid with HeLa cells rather than a pure gastric cancer cell line.

Comprehensive analysis of cancer of unknown primary and recommendation of a histological and immunohistochemical diagnostic strategy from China

BACKGROUND

Previous studies on cancer of unknown primary (CUP) mainly focus on treatment and prognosis in western populations and lacked clinical evaluation of different IHC markers, so this study aimed to evaluate characteristics of CUP and recommend a diagnostic strategy from a single center in China.

METHODS AND RESULTS

Data of 625 patients with CUP were retrospectively collected and reviewed. The patients ranged in age from 20 to 91 years, with a female-to-male ratio of 1.3:1. The predominant histological type was poor or undifferentiated adenocarcinomas (308; 49.3%). The results of Canhelp-Origin molecular testing for the identification of the tissue of origin in 262 of 369 patients (71.0%) were considered predictable (similarity score > 45), with the most common predicted primary tumor site being the breast (57, 21.8%). Unpredictable molecular results correlated with more aggressive clinical parameters and poor survival. Thee positivity rates of several targeted antibodies (GATA3, GCDFP15, TTF1, Napsin A, and PAX8), based on the clinically predicted site, were lower than those reported for the corresponding primary tumors. Nonetheless, TRPS1 and INSM1 were reliable markers of predicted breast carcinoma (75.0%) and neuroendocrine tumors (83.3%), respectively. P16 expression, as well as HPV and EBER testing contributed significantly to the diagnosis of squamous cell carcinomas. Survival analysis revealed that older ages (> 57), ≥ 3 metastatic sites, non-squamous cell carcinomas, bone/liver/lung metastases, unpredictable molecular results, and palliative treatment correlated with poor overall survival.

CONCLUSIONS

We recommend a CUP diagnostic strategy involving the use of targeted antibody panels as per histological findings that is potentially applicable in clinical practice. The markers TRPS1, INSM1, and P16 expression, as well as HPV and EBER testing are particularly valuable in this aspect. Molecular testing is also predictive of survival rates.

A Systematic Review of Diagnostic and Prognostic Biomarkers for Head and Neck Cancer of Unknown Primary: An Unmet Clinical Need

Head and neck cancer of unknown primary (HNCUP) is defined as cervical lymph node metastases without a detectable primary tumor. The management of these patients presents a challenge to clinicians since guidelines in the diagnosis and treatment of HNCUP remain controversial. An accurate diagnostic workup is fundamental for the search for the hidden primary tumor to allow the best adequate treatment strategy. The purpose of this systematic review is to present the currently available data about the diagnostic and prognostic molecular biomarkers for HNCUP. Systematic research in an electronic database was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and identified 704 articles, of which 23 studies were selected and included in the analysis. Fourteen studies investigated HNCUP diagnostic biomarkers and focused on the human papilloma virus (HPV) and the Epstein-Barr virus (EBV) due to the strong associations with oropharyngeal cancer and nasopharyngeal cancer, respectively. HPV status was shown to possess prognostic value, correlating with longer disease-free survival and overall survival. HPV and EBV are the only available HNCUP biomarkers, and they are already used in clinical practice. A better characterization of the molecular profiling and the development of tissue-of-origin classifiers are necessary to improve the diagnosis, staging, and therapeutic management of patients with HNCUP.

Utility of RNA Expression to Determine the Tissue of Origin of Malignancies with an Inconclusive Histopathology

We present 2 cases of cancer of unknown origin in which RNA-based cancer classification testing provided vital insight and directed treatment management. The tissue of origin could not be determined in both of these patients utilizing morphology and immunohistochemical analysis of the tissue samples. Next-generation sequencing and tumor-of-origin testing using an RNA-based molecular cancer classifier were performed to elucidate the possible tissue of origin. A 61-year-old male with a history of localized basal cell carcinoma presented with a 4.4-cm axillary lymph node in addition to upper extremity edema and supraclavicular lymphadenopathy. RNA-based tumor origin testing revealed skin basal or squamous cell carcinoma as the likely tissue of origin, with a probability of 97%. He received vismodegib, a hedgehog inhibitor, after progression on cemiplimab and experienced a partial response by RECIST criteria, which is currently ongoing for over a year. A 74-year-old female patient with a remote history of ovarian cancer for which she underwent resection and adjuvant chemotherapy presented 15 years later with abdominal pain. The diagnostic workup revealed a 2-cm pancreatic mass and enlarged peritoneal lymph nodes. RNA sequencing revealed a 99% likelihood of the tissue of origin being serous ovarian carcinoma. Subsequently, she underwent surgery and adjuvant chemotherapy and is currently in remission with letrozole maintenance. Genomic data already plays a crucial role in therapeutic decision-making for individuals with cancer. These cases highlight the complementary role of genomic data in the diagnostic workup of cancer, leading to favorable patient outcomes.

Identification of functional pathways and molecular signatures in neuroendocrine neoplasms by multi-omics analysis

BACKGROUND

Neuroendocrine neoplasms (NENs) represent a heterogeneous class of rare tumors with increasing incidence. They are characterized by the ability to secrete peptide hormones and biogenic amines but other reliable biomarkers are lacking, making diagnosis and identification of the primary site very challenging. While in some NENs, such as the pancreatic ones, next generation sequencing technologies allowed the identification of new molecular hallmarks, our knowledge of the molecular profile of NENs from other anatomical sites is still poor.

METHODS

Starting from the concept that NENs from different organs may be clinically and genetically correlated, we applied a multi-omics approach by combining multigene panel testing, CGH-array, transcriptome and miRNome profiling and computational analyses, with the aim to highlight common molecular and functional signatures of gastroenteropancreatic (GEP)-NENs and medullary thyroid carcinomas (MTCs) that could aid diagnosis, prognosis and therapy.

RESULTS

By comparing genomic and transcriptional profiles, ATM-dependent signaling emerged among the most significant pathways at multiple levels, involving gene variations and miRNA-mediated regulation, thus representing a novel putative druggable pathway in these cancer types. Moreover, a set of circulating miRNAs was also selected as possible diagnostic/prognostic biomarkers useful for clinical management of NENs.

CONCLUSIONS

These findings depict a complex molecular and functional landscape of NENs, shedding light on novel therapeutic targets and disease biomarkers to be exploited.