Cancer-of-Unknown-Primary-Origin: A SEER–Medicare Study of Patterns of Care and Outcomes among Elderly Patients in Clinical Practice

Abstract

Knowledge of contemporary patterns of cancer-of-unknown-primary-origin (CUP) diagnostic work-up, treatment, and outcomes in routine healthcare is limited. Thus, we examined data from elderly patients diagnosed with CUP in real-world US clinical practice. From the Surveillance, Epidemiology, and End Results–Medicare-linked database, we included patients ≥ 66 years old with CUP diagnosed between 1 January 2013 and 31 December 2015. We analyzed baseline demographics, clinical characteristics, methods of diagnostic work-up (biopsy, immunohistochemistry, imaging), treatment-related factors, and survival. CUP diagnosis was histologically confirmed in 2813/4562 patients (61.7%). Overall, 621/4562 (13.6%) patients received anticancer pharmacotherapy; among these, 97.3% had a histologically confirmed tumor and 83.1% received all three procedures. Among those with a histologically confirmed tumor, increasing age, increasing comorbidity score, not receiving all three diagnostic measures, and having a not-further specified histologic finding of only ‘malignant neoplasm’ were all negatively associated with receipt of anticancer pharmacotherapy. Median overall survival was 1.2 months for all patients. Median time between CUP diagnosis and treatment initiation was 41 days. Limited diagnostic work-up was common and most patients did not receive anticancer pharmacotherapy. The poor outcomes highlight a substantial unmet need for further research into improving diagnostic work-up and treatment effectiveness in CUP.

Retrospective analysis of clinical characteristics and outcomes of patients with carcinoma of unknown primary from three tertiary centers in Australia

“…In this study, 62% of patients underwent genomic profiling and 83% of patients received systemic therapy, with a median OS of 23.7 months in favorable risk patients compared to 10.9 months in unfavorable risk patients 16 . Patients in our study also had similar survival outcomes compared to other contemporary cohorts which have reported median OS ranging from 1.2–4 months for patients who did not receive treatment and 9.5–12 months for patients who did receive treatment 18–20 . Historical literature has reported a range of OS with palliative platinum‐based chemotherapy from 2.7 to 11 months in unfavorable risk patients 9,11–13 .…”

“…Only 57% of patients within our cohort received systemic therapy. This is higher than reported literature rates where less than 50% of CUP patients proceed to systemic treatment 18,20,23 . The higher rates of systemic therapy in this study in part reflect our specific study inclusion criteria which necessitated a complete diagnostic workup, including tissue biopsy, to confirm the diagnosis of CUP.…”

“…This is higher than reported literature rates where less than 50% of CUP patients proceed to systemic treatment. 18,20,23 The higher rates of systemic therapy in this study in part reflect our specific study inclusion criteria which necessitated a complete diagnostic workup, including tissue biopsy, to confirm the diagnosis of CUP. Many previous studies, especially those that have relied on registry databases, have also included the population of frail patients with a clinical CUP diagnosis only, who are not fit for systemic treatment.…”

Utilizing Electronic Health Records (EHR) and Tumor Panel Sequencing to Demystify Prognosis of Cancer of Unknown Primary (CUP) patients

“…Conventional IHC-based pathology reviews are often unable to identify a primary diagnosis for advanced metastatic tumor samples [2,5], particularly in community clinics where resources are limited. And in many cases, patients do not receive the complete diagnostic work-up that is recommended for CUPs [45]. As a result, oncologists resort to empiric treatment regimens to treat many patients with CUP [18] even when targeted therapies would otherwise be the standard of care for a corresponding known primary.…”

Utilizing Electronic Health Records (EHR) and Tumor Panel Sequencing to Demystify Prognosis of Cancer of Unknown Primary (CUP) patients

“…Conventional IHC-based pathology reviews are often unable to identify a primary diagnosis for advanced metastatic tumor samples [3,6], particularly in community clinics where resources are limited. And in many cases, patients do not receive the complete diagnostic work-up that is recommended for CUPs [54]. As a result, oncologists resort to empiric treatment regimens to treat many patients with CUP [18] even when targeted therapies would otherwise be the standard of care for a corresponding known primary.…”