Molecularly guided therapy versus chemotherapy after disease control in unfavourable cancer of unknown primary (CUPISCO): an open-label, randomised, phase 2 study.

BACKGROUND: Patients with unfavourable subset cancer of unknown primary (CUP) have a poor prognosis when treated with standard platinum-based chemotherapy. Whether first-line treatment guided by comprehensive genomic profiling (CGP) can improve outcomes is unknown. The CUPISCO trial was designed to inform a molecularly guided treatment strategy to improve outcomes over standard platinum-based chemotherapy in patients with newly diagnosed, unfavourable, non-squamous CUP. The aim of the trial was to compare the efficacy and safety of molecularly guided therapy (MGT) versus standard platinum-based chemotherapy in these patients. This was to determine whether the inclusion of CGP in the initial diagnostic work-up leads to improved outcomes over the current standard of care. We herein report the primary analysis. METHODS: CUPISCO was a phase 2, prospective, randomised, open-label, active-controlled, multicentre trial done at 159 sites in 34 countries outside the USA. Patients with central eligibility review-confirmed disease (acceptable histologies included adenocarcinoma and poorly differentiated carcinoma) and an Eastern Cooperative Oncology Group performance status of 0 or 1, evaluated by CGP, who reached disease control after three cycles of standard first-line platinum-based chemotherapy were randomly assigned 3:1 via a block-stratified randomisation procedure to MGT versus chemotherapy continuation for at least three further cycles. The primary endpoint was investigator-assessed progression-free survival in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03498521, and follow-up is ongoing. FINDINGS: From July 10, 2018, to Dec 9, 2022, 636 (42%) of 1505 screened patients were enrolled. Median follow-up in the treatment period was 24·1 months (IQR 11·6-35·6). Of 438 patients who reached disease control after induction chemotherapy, 436 were randomly assigned: 326 (75%) to the MGT group and 110 (25%) to the chemotherapy group. Median progression-free survival in the intention-to-treat population was 6·1 months (95% CI 4·7-6·5) in the MGT group versus 4·4 months (4·1-5·6) in the chemotherapy group (hazard ratio 0·72 [95% CI 0·56-0·92]; p=0·0079). Related adverse event rates per 100-patient-years at risk were generally similar or lower with MGT versus chemotherapy. INTERPRETATION: In patients with previously untreated, unfavourable, non-squamous CUP who reached disease control after induction chemotherapy, CGP with subsequent MGTs resulted in longer progression-free survival than standard platinum-based chemotherapy. On the basis of these results, we recommend that CGP is performed at initial diagnosis in patients with unfavourable CUP. FUNDING: F Hoffmann-La Roche.

Frequency and Prognostic Value of Circulating Tumor Cells in Cancer of Unknown Primary.

BACKGROUND: Cancer of unknown primary (CUP) is defined as a primary metastatic malignancy, in which the primary tumor remains elusive in spite of a comprehensive diagnostic workup. The frequency and prognostic value of circulating tumor cells (CTCs), which are considered to be the source of metastasis, has not yet been systematically evaluated in CUP. METHODS: A total of 110 patients with a confirmed diagnosis of CUP according to the European Society for Medical Oncology (ESMO) guidelines, who presented to our clinic between July 2021 and May 2023, provided blood samples for CTC quantification using CellSearch methodology. CTC counts were correlated with demographic, clinical, and molecular data generated by comprehensive genomic profiling of tumor tissue. RESULTS: CTCs were detected in 26% of all patients at initial presentation to our department. The highest CTC frequency was observed among patients with unfavorable CUP (35.5%), while patients with single-site/oligometastatic CUP harbored the lowest CTC frequency (11.4%). No statistically significant association between CTC positivity and the number of affected organs (P = 0.478) or disease burden (P = 0.120) was found. High CTC levels (≥5 CTCs/7.5 mL; 12/95 analyzed patients) predicted for adverse overall survival compared to negative or low CTC counts (6-months overall survival rate 90% vs 32%, log-rank P < 0.001; HR 5.43; 95% CI 2.23-13.2). CTC dynamics were also prognostic for overall survival by landmark analysis (log-rank P < 0.001, HR 10.2, 95% CI 1.95-52.9). CONCLUSIONS: CTC frequency is a strong, independent predictor of survival in patients with CUP. CTC quantification provides a useful prognostic tool in the management of these patients.