Cancer of unknown primary (CUP) designates an enigmatic cancer entity with histologic confirmation of malignancy from a metastasis but no identifiable primary tumor in spite of a thorough diagnostic ...work-up. In this review, we discuss the validity of CUP as a distinct cancer entity as well as diagnostic pitfalls. As arguments against a distinct entity, the diagnosis of CUP is erroneous in some cases. Diagnostic pitfalls include incomplete diagnostics, uncertainty in classifying a lesion as either primary or metastasis and mistaking a relapse of an antecedent malignancy as CUP due to histologic and immunohistologic disparities. Given the high frequency of prior malignancies in CUP patients, relapse of an antecedent cancer should always be carefully excluded. Gene expression profiling-based classifier assays aim at aligning the molecular profile of CUP patients with established primary cancer patterns for highest congruency in order to identify the putative primary and treat accordingly. However, the spectrum of predicted putative primaries by molecular techniques is somewhat at odds with the primaries identified in autopsy series. Also, a first randomized clinical trial did not show superiority of primary-tailored therapy over unspecific platinum-based chemotherapy. CUP cases share an aggressive clinical course, atypical metastasis pattern, rapid progression of metastases, a generally poor response to chemotherapy and dismal outcome as distinct clinical features. Metastatic spread appears to take place in the early stages of tumor evolution, with CUP metastases subsequently undergoing genetic evolution toward a chromosomally highly complex and instable karyotype independent from the primary tumor. In clinical practice, the diagnosis of CUP is valid when no primary tumor is detectable. Treatment should ideally offer broad spectrum coverage across numerous malignancies and be well-established in CUP as is the case for carboplatin/paclitaxel and cisplatin / gemcitabine in particular, but it should also cover the most likely putative primary. The diligent diagnosis of CUP is warranted for clinical trials, making the eligibility process particularly laborious. In conclusion, we deem CUP a distinct cancer entity and the diagnosis accurate in most patient cases.
Background
Carcinoma of unknown primary origin (CUP) accounts for 2%–5% of newly diagnosed advanced malignancies, with chemotherapy as the standard of care. CUPISCO (NCT03498521) is an ongoing ...randomized trial using comprehensive genomic profiling (CGP) to assign patients with CUP to targeted or immunotherapy treatment arms based on genomic profiling. We performed a retrospective analysis of CUP cases referred for CGP to determine how many were potentially eligible for enrollment into an experimental CUPISCO arm.
Materials and Methods
Centrally reviewed adenocarcinoma and undifferentiated CUP specimens in the FoundationCore database were analyzed using the hybrid capture‐based FoundationOne CDx assay (mean coverage, >600×). Presence of genomic alterations, microsatellite instability (MSI), tumor mutational burden (TMB), genomic loss of heterozygosity (gLOH), and programmed death‐ligand 1 (PD‐L1) positivity were determined.
Results
A total of 96 of 303 patients (31.7%) could be matched to an experimental CUPISCO arm. Key genomic alterations included ERBB2 (7.3%), PIK3CA (6.3%), NF1 (5.6%), NF2 (4.6%), BRAF (4.3%), IDH1 (3.3%), PTEN, FGFR2, EGFR (3.6% each), MET (4.3%), CDK6 (3.0%), FBXW7, CDK4 (2.3% each), IDH2, RET, ROS1, NTRK (1.0% each), and ALK (0.7%). Median TMB was 3.75 mutations per megabase of DNA; 34 patients (11.6%) had a TMB ≥16 mutations per megabase. Three patients (1%) had high MSI, and 42 (14%) displayed high PD‐L1 expression (tumor proportion score ≥50%). gLOH could be assessed in 199 of 303 specimens; 19.6% had a score of >16%.
Conclusions
Thirty‐two percent of patients would have been eligible for targeted therapy in CUPISCO. Future studies, including additional biomarkers such as PD‐L1 positivity and gLOH, may identify a greater proportion potentially benefiting from CGP‐informed treatment. Clinical trial identification number. NCT03498521
Implications for Practice
The findings of this retrospective analysis of carcinoma of unknown primary origin (CUP) cases validate the experimental treatment arms being used in the CUPISCO study (NCT03498521), an ongoing randomized trial using comprehensive genomic profiling to assign patients with CUP to targeted or immunotherapy treatment arms based on the presence of pathogenic genomic alterations. The findings also suggest that future studies including additional biomarkers and treatment arms, such as programmed death‐ligand 1 positivity and genomic loss of heterozygosity, may identify a greater proportion of patients with CUP potentially benefiting from comprehensive genomic profiling‐informed treatment.
This article focuses on the ability of comprehensive genomic profiling to identify potentially targetable genetic alterations in cancers of unknown primary, based on the inclusion criteria for the CUPISCO clinical trial and aiming for more effective therapeutic options for patients.
Centrosomes, the main microtubule-organizing centers in most animal cells, are of crucial importance for the assembly of a bipolar mitotic spindle and subsequent faithful segregation of chromosomes ...into two daughter cells. Centrosome abnormalities can be found in virtually all cancer types and have been linked to chromosomal instability (CIN) and tumorigenesis. Although our knowledge on centrosome structure, replication, and amplification has greatly increased within recent years, still only very little is known on nature, causes, and consequences of centrosome aberrations in primary tumor tissues. In this review, we summarize our current insights into the mechanistic link between centrosome aberrations, aneuploidy, CIN and tumorigenesis. Mechanisms of induction and cellular consequences of aneuploidy, tetraploidization and CIN, as well as origin and effects of supernumerary centrosomes will be discussed. In addition, animal models for both CIN and centrosome amplification will be outlined. Finally, we describe approaches to exploit centrosome amplification, aneuploidy and CIN for novel and specific anticancer treatment strategies based on the modulation of chromosome missegregation rates.
Abnormal karyotypes are common in cancer cells and frequently observed in acute myeloid leukemia (AML), in which complex karyotype aberrations are associated with poor prognosis. How exactly abnormal ...karyotypes arise and are propagated in AML is unclear. TP53 mutations and deletions are frequent in complex karyotype AML, suggesting a role of TP53 alterations in the development of chromosome abnormalities. Here, we generated isogenic TP53-knockout versions of the euploid AML cell line EEB to investigate the impact of TP53 on karyotype stability. We show that chromosome abnormalities spontaneously arise in TP53-deficient cells. Numerical aneuploidy could, to some extent, be propagated in a TP53-proficient setting, indicating that it does not necessarily trigger TP53 activation. In contrast, tolerance to structural chromosome aberrations was almost entirely restricted to TP53-knockout clones, all of which were able to continue proliferation in the presence of damaged DNA. Mechanistically, as a source of chromosome aberrations, limited numerical but not structural chromosomal instability was tolerated by TP53-wildtype cells. In contrast, structural instability was found only in TP53-knockout cells. Together, in myeloid cells TP53 loss allows for the development of complex karyotype aberrations and karyotype heterogeneity by perpetuation of chromosome segregation errors.
Old age and FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukaemia are associated with early relapse and poor survival. Quizartinib is an ...oral, highly potent, and selective next-generation FLT3 inhibitor with clinical antileukaemic activity in relapsed or refractory acute myeloid leukaemia. We aimed to assess the efficacy and safety of single-agent quizartinib in patients with relapsed or refractory acute myeloid leukaemia.
We did an open-label, multicentre, single-arm, phase 2 trial at 76 hospitals and cancer centres in the USA, Europe, and Canada. We enrolled patients with morphologically documented primary acute myeloid leukaemia or acute myeloid leukaemia secondary to myelodysplastic syndromes and an Eastern Cooperative Oncology Group (ECOG) performance status of 0–2 into two predefined, independent cohorts: patients who were aged 60 years or older with relapsed or refractory acute myeloid leukaemia within 1 year after first-line therapy (cohort 1), and those who were 18 years or older with relapsed or refractory disease following salvage chemotherapy or haemopoietic stem cell transplantation (cohort 2). Patients with an FLT3-ITD allelic frequency of more than 10% were considered as FLT3-ITD positive, whereas all other patients were considered as FLT3-ITD negative. Patients received quizartinib once daily as an oral solution; the initial 17 patients received 200 mg per day but the QTcF interval was prolonged for more than 60 ms above baseline in some of these patients. Subsequently, doses were amended for all patients to 135 mg per day for men and 90 mg per day for women. The co-primary endpoints were the proportion of patients who achieved a composite complete remission (defined as complete remission + complete remission with incomplete platelet recovery + complete remission with incomplete haematological recovery) and the proportion of patients who achieved a complete remission. Efficacy and safety analyses included all patients who received at least one dose of quizartinib (ie, the intention-to-treat population). Patients with a locally assessed post-treatment bone marrow aspirate or biopsy were included in efficacy analyses by response; all other patients were considered to have an unknown response. This study is registered with ClinicalTrials.gov, number NCT00989261, and with the European Clinical Trials Database, EudraCT 2009-013093-41, and is completed.
Between Nov 19, 2009, and Oct 31, 2011, a total of 333 patients were enrolled (157 in cohort 1 and 176 in cohort 2). In cohort 1, 63 (56%) of 112 FLT3-ITD-positive patients and 16 (36%) of 44 FLT3-ITD-negative patients achieved composite complete remission, with three (3%) FLT3-ITD-positive patients and two (5%) FLT3-ITD-negative patients achieving complete remission. In cohort 2, 62 (46%) of 136 FLT3-ITD-positive patients achieved composite complete remission with five (4%) achieving complete remission, whereas 12 (30%) of 40 FLT3-ITD-negative patients achieved composite complete remission with one (3%) achieving complete remission. Across both cohorts (ie, the intention-to-treat population of 333 patients), grade 3 or worse treatment-related treatment-emergent adverse events in 5% or more of patients were febrile neutropenia (76 23% of 333), anaemia (75 23%), thrombocytopenia (39 12%), QT interval corrected using Fridericia's formula (QTcF) prolongation (33 10%), neutropenia (31 9%), leucopenia (22 7%), decreased platelet count (20 6%), and pneumonia (17 5%). Serious adverse events occurring in 5% or more of patients were febrile neutropenia (126 38% of 333; 76 treatment related), acute myeloid leukaemia progression (73 22%), pneumonia (40 12%; 14 treatment related), QTcF prolongation (33 10%; 32 treatment related), sepsis (25 8%; eight treatment related), and pyrexia (18 5%; nine treatment related). Notable serious adverse events occurring in less than 5% of patients were torsades de pointes (one <1%) and hepatic failure (two 1%). In total, 125 (38%) of 333 patients died within the study treatment period, including the 30-day follow-up. 18 (5%) patients died because of an adverse event considered by the investigator to be treatment related (ten 6% of 157 patients in cohort 1 and eight 5% of 176 in cohort 2.
Single-agent quizartinib was shown to be highly active and generally well tolerated in patients with relapsed or refractory acute myeloid leukaemia, particularly those with FLT3-ITD mutations. These findings confirm that targeting the FLT3-ITD driver mutation with a highly potent and selective FLT3 inhibitor is a promising clinical strategy to help improve clinical outcomes in patients with very few options. Phase 3 studies (NCT02039726; NCT02668653) will examine quizartinib at lower starting doses.
Ambit Biosciences/Daiichi Sankyo.
The prognosis of elderly patients with acute myeloid leukemia (AML) is still dismal even with intensive chemotherapy. In this trial, we compared the antileukemic activity of standard induction and ...consolidation therapy with or without the addition of the kinase inhibitor sorafenib in elderly patients with AML.
All patients received standard cytarabine and daunorubicin induction (7+3 regimen) and up to two cycles of intermediate-dose cytarabine consolidation. Two hundred one patients were equally randomly assigned to receive either sorafenib or placebo between the chemotherapy cycles and subsequently for up to 1 year after the beginning of therapy. The primary objective was to test for an improvement in event-free survival (EFS). Overall survival (OS), complete remission (CR) rate, tolerability, and several predefined subgroup analyses were among the secondary objectives.
Age, sex, CR and early death (ED) probability, and prognostic factors were balanced between both study arms. Treatment in the sorafenib arm did not result in significant improvement in EFS or OS. This was also true for subgroup analyses, including the subgroup positive for FLT3 internal tandem duplications. Results of induction therapy were worse in the sorafenib arm, with higher treatment-related mortality and lower CR rates. More adverse effects occurred during induction therapy in the sorafenib arm, and patients in this arm received less consolidation chemotherapy as a result of higher induction toxicity.
In conclusion, combination of standard induction and consolidation therapy with sorafenib in the schedule investigated in our trial is not beneficial for elderly patients with AML.
A major drawback of cancer chemotherapy is the lack of tumor-specific targets which would allow for the selective eradication of malignant cells without affecting healthy tissues. In contrast with ...normal cells, most tumor cells contain multiple centrosomes, associated with the formation of multipolar mitotic spindles and chromosome segregation defects. Many tumor cells regain mitotic stability after clonal selection by the coalescence of multiple centrosomes into two functional spindle poles. To overcome the limitations of current cancer treatments, we have developed a cell-based screening strategy to identify small molecules that inhibit centrosomal clustering and thus force tumor cells with supernumerary centrosomes to undergo multipolar mitoses, and subsequently, apoptosis. Using a chemotaxonomic selection of fungi from a large culture collection, a relatively small but diverse natural product extract library was generated. Screening of this compound library led to the identification of griseofulvin, which induced multipolar spindles by inhibition of centrosome coalescence, mitotic arrest, and subsequent cell death in tumor cell lines but not in diploid fibroblasts and keratinocytes with a normal centrosome content. The inhibition of centrosome clustering by griseofulvin was not restricted to mitotic cells but did occur during interphase as well. Whereas the formation of multipolar spindles was dynein-independent, depolymerization of interphase microtubules seemed to be mechanistically involved in centrosomal declustering. In summary, by taking advantage of the tumor-specific phenotype of centrosomal clustering, we have developed a screening strategy that might lead to the identification of drugs which selectively target tumor cells and spare healthy tissues.
The mutant IDH1 (mIDH1) inhibitor BAY1436032 demonstrated robust activity in preclinical AML models, supporting clinical evaluation. In the current dose-escalation study, BAY1436032 was orally ...administered to 27 mIDH1 AML subjects across 4 doses ranging from 300 to 1500 mg twice-daily. BAY1436032 exhibited a relatively short half-life and apparent non-linear pharmacokinetics after continuous dosing. Most subjects experienced only partial target inhibition as indicated by plasma R-2HG levels. BAY1436032 was safe and a maximum tolerated dose was not identified. The median treatment duration for all subjects was 3.0 months (0.49-8.5). The overall response rate was 15% (4/27; 1 CRp, 1 PR, 2 MLFS), with responding subjects experiencing a median treatment duration of 6.0 months (3.9-8.5) and robust R-2HG decreases. Thirty percent (8/27) achieved SD, with a median treatment duration of 5.5 months (3.1-7.0). Degree of R-2HG inhibition and clinical benefit did not correlate with dose. Although BAY1436032 was safe and modestly effective as monotherapy, the low overall response rate and incomplete target inhibition achieved at even the highest dose tested do not support further clinical development of this investigational agent in AML.
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