Perceptions of cancer of unknown primary site: a national survey of Australian medical oncologists

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

BACKGROUND

Carcinoma of unknown primary (CUP) remains an important tumor entity and a disproportionate cause of cancer mortality. Little is known about the contemporary clinical characteristics, treatment patterns, and outcomes of CUP patients based on updated international classification guidelines. We evaluated a contemporary CUP cohort to provide insight into current clinical practice and the impact of tissue of origin assignment, site-specific and empirical therapy in a real-world setting.

METHODS

We conducted a retrospective cohort study of CUP patients, as defined by the updated European Society of Medical Oncology (ESMO) 2023 guidelines, across three tertiary referral centers in Australia between 2015 and 2022. We analyzed clinical characteristics, treatment patterns, and survival outcomes using the Kaplan-Meier method and Cox regression proportional hazard model between favorable and unfavorable risk groups.

RESULTS

We identified a total of 123 CUP patients (n = 86 unfavorable, n = 37 favorable risk as per the 2023 ESMO guidelines). Sixty-four patients (52%) were assigned a tissue of origin by the treating clinician. Median progression free survival (PFS) was 6.8 (95% confidence interval (CI) 5.1-12.1) months and overall survival (OS) 10.2 (95% CI 6.0-18.5) months. Unfavorable risk (hazard ratio [HR] 2.9, p = 0.006), poor performance status (HR 2.8, p < 0.001), and non-squamous histology (HR 2.5, p < 0.05) were associated with poor survival outcome. A total of 70 patients (57%) proceeded to systemic therapy. In patients with non-squamous histology and unfavorable risk, site-specific therapy compared to empirical chemotherapy did not improve outcome (median OS 8.2 vs. 11.8 months, p = 0.7).

CONCLUSIONS

In this real-world cohort, CUP presentations were heterogenous. Overall survival and rates of systemic treatment were poor. Poor performance status and unfavorable risk were associated with worse survival. For most patients, site-specific therapy did not improve survival outcome. Improved and timely access to diagnostic tests and therapeutics for this group of patients is urgently required.

A qualitative study of patients with Cancer of Unknown Primary: Perceptions of communication, understanding of diagnosis and genomic testing, and information needs

OBJECTIVE

Patients with Cancer of Unknown Primary (CUP) commonly report poor understanding of their illness and high levels of psychological distress. Despite the potential benefits to CUP patients, there is a paucity of research exploring the reasons behind poor understanding of a CUP diagnosis. The aim of this study was to understand patients' experiences of communication with doctors, their understanding of diagnosis and the role of genomic testing, as well as their information needs.

METHODS

Semi-structured interviews explored CUP patients' perceptions of communication with their doctors, understanding of their illness, and their needs regarding medical information. Qualitative inductive thematic analysis of transcribed audio-recordings was employed.

SETTING/PARTICIPANTS

Nineteen patients were recruited from within a prospective cohort study involving routine genomic testing of CUP patients.

RESULTS

CUP patients had varied perceptions of communication with doctors as well as different levels of need, readiness, and capacity for information. Some patients felt well understood and supported by their doctors while others did not. Many patients reported feeling overwhelmed and shocked when receiving their cancer diagnosis and emphasized the importance of family support in receiving and understanding medical information. While patients understood the implications of genomic testing for treatment and diagnosis, few had a detailed understanding of genomic testing.

CONCLUSIONS

Patients' experience of communication and understanding of CUP could be potentially improved by clinicians' assessment of the communication style preferred by each patient and their family and the development of online resources to meet their evolving information needs.

Healthcare Costs Before and After Diagnosis of Cancer of Unknown Primary Versus Ovarian Cancer in Australia

BACKGROUND

Little is known about the healthcare resource usage and costs for patients with cancer of unknown primary (CUP).

OBJECTIVE

The aim of this study was to describe and quantify healthcare resource use and costs in Australia, 6 months prior to and after a diagnosis of CUP, and compare to those of women with ovarian cancer.

METHODS

Individual-level data combining baseline surveys, clinical records and Medicare Benefits Schedule (MBS) claim records were analysed for 149 patients with CUP and 480 patients with ovarian cancer from two prospective cohort studies. MBS data were aggregated for the period 6 months prior to diagnosis date and 6 months after diagnosis. Data included doctor consultations, pathology, diagnostics, therapeutic procedures, imaging, allied health and medicines. Generalised linear models were used to evaluate the cost differences between CUP and ovarian cancer using gamma family and log link functions. Models were adjusted for age, employment, marital status, surgery, chemotherapy and number of comorbidities.

RESULTS

The mean healthcare costs in the 6 months prior to diagnosis of CUP were Australian (AU) $3903 versus AU$1327 for ovarian cancer (adjusted cost ratio 2.94, 95% confidence interval [CI] 2.08-4.15). Mean healthcare costs 6 months post-diagnosis were higher for patients with CUP versus ovarian cancer (AU$20,339 vs AU$13,819, adjusted cost ratio 1.47, 95% CI 1.13-1.92). Higher costs for patients with CUP were driven by imaging (AU$1937 vs AU$1387), procedures (AU$5403 vs AU$2702) and prescribed medicines for all conditions (AU$10,111 vs AU$6717).

CONCLUSIONS

Pre-diagnosis costs for patients with CUP are nearly triple those for ovarian cancer. Six months after diagnosis, healthcare costs for CUP remained higher than for ovarian cancer due to imaging, procedures and medicines.

Psychological distress, understanding of cancer and illness uncertainty in patients with Cancer of Unknown Primary

OBJECTIVE

Patients diagnosed with Cancer of Unknown Primary (CUP) experience high levels of psychological distress and report poor understanding of their cancer. We aimed to investigate: (1) if CUP patients with poorer understanding of their cancer diagnosis and testing experience more symptoms of psychological distress than those with better understanding; (2) if the relationship between patients' understanding of their cancer and psychological distress is mediated by illness uncertainty; and (3) explore whether patients' degree of understanding of their cancer can be predicted by clinical and socio-demographic factors.

METHODS

209 CUP patients completed a questionnaire measuring anxiety, depression, illness uncertainty, fatigue, pain, sleep and understanding of their cancer. Using an apriori theoretical framework, we employed structural equation modelling to investigate predictors of patient's understanding of their cancer and psychological distress and the relationships between understanding, illness uncertainty and distress.

RESULTS

The structural equation model displayed good fit indices and supported the hypothesised relationship of patient's understanding of their cancer and the extent of psychological distress, which was mediated via illness uncertainty. Physical symptoms were positively associated with psychological distress and illness uncertainty. Younger age was predictive of lower patient's understanding of their cancer and higher levels of psychological distress.

CONCLUSIONS

Patients with CUP, particularly those who are younger and experiencing more physical symptoms, report higher levels of psychological distress and may require additional mental health support. Our findings highlight a need to improve CUP patient's understanding about their illness, which could help reduce their illness uncertainty and alleviate psychological distress.

Development and Validation of a Novel Nomogram for Individualized Prediction of Survival in Cancer of Unknown Primary

PURPOSE

Prognostic uncertainty is a major challenge for cancer of unknown primary (CUP). Current models limit a meaningful patient-provider dialogue. We aimed to establish a nomogram for predicting overall survival (OS) in CUP based on robust clinicopathologic prognostic factors.

EXPERIMENTAL DESIGN

We evaluated 521 patients with CUP at MD Anderson Cancer Center (MDACC; Houston, TX; 2012-2016). Baseline variables were analyzed using Cox regression and nomogram developed using significant predictors. Predictive accuracy and discriminatory performance were assessed by calibration curves, concordance probability estimate (CPE ± SE), and concordance statistic (C-index). The model was subjected to bootstrapping and multi-institutional external validations using two independent CUP cohorts: V1 [MDACC (2017), N = 103] and V2 (BC Cancer, Vancouver, Canada and Sarah Cannon Cancer Center/Tennessee Oncology, Nashville, TN; N = 302).

RESULTS

Baseline characteristics of entire cohort (N = 926) included: median age (63 years), women (51%), Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1 (64%), adenocarcinomas (52%), ≥3 sites of metastases (30%), and median follow-up duration and OS of 40.1 and 14.7 months, respectively. Five independent prognostic factors were identified: gender, ECOG PS, histology, number of metastatic sites, and neutrophil-lymphocyte ratio. The resulting model predicted OS with CPE of 0.69 [SE: ± 0.01; C-index: 0.71 (95% confidence interval: 0.68-0.74)] outperforming Culine/Seve prognostic models (CPE: 0.59 ± 0.01). CPE for external validation cohorts V1 and V2 were 0.67 (± 0.02) and 0.70 (± 0.01), respectively. Calibration curves for 1-year OS showed strong agreement between nomogram prediction and actual observations in all cohorts.

CONCLUSIONS

Our user-friendly CUP nomogram integrating commonly available baseline factors provides robust personalized prognostication which can aid clinical decision making and selection/stratification for clinical trials.

Diagnostic and health service pathways to diagnosis of cancer-registry notified cancer of unknown primary site (CUP)

Background

Cancer of unknown primary (CUP) is a late-stage malignancy with poor prognosis, but we know little about what diagnostic tests and procedures people with CUP receive prior to diagnosis. The purpose of this study was to determine how health service utilisation prior to diagnosis for people with cancer-registry notified CUP differs from those notified with metastatic cancer of known primary.

Methods

We identified people with a cancer registry notification of CUP (n = 327) from the 45 and Up Study, a prospective cohort of 266,724 people ≥45 years in New South Wales, Australia, matched with up to three controls with a diagnosis of metastatic cancer of known primary (n = 977). Baseline questionnaire data were linked to population health data to identify all health service use, diagnostic tests, and procedures in the month of diagnosis and 3 months prior. We used conditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

Results

After adjusting for age and educational attainment, people with a cancer-registry notified CUP diagnosis were more likely to be an aged care resident (OR = 2.78, 95%CI 1.37–5.63), have an emergency department visit (OR = 1.65, 95%CI 1.23–2.21), serum tumor marker tests (OR = 1.51, 95%CI 1.12–2.04), or a cytology test without immunohistochemistry (OR = 2.01, 95%CI 1.47–2.76), and less likely to have a histopathology test without immunohistochemistry (OR = 0.43, 95%CI 0.31–0.59). Neither general practitioner, specialist, allied health practitioner or nurse consultations, hospitalisations, nor imaging procedures were associated with a CUP diagnosis.

Conclusions

The health service and diagnostic pathway to diagnosis differs markedly for people notified with CUP compared to those with metastatic cancer of known primary. While these differences may indicate missed opportunities for earlier detection and appropriate management, for some patients they may be clinically appropriate.

Differences in experiences of care between patients diagnosed with metastatic cancer of known and unknown primaries: mixed-method findings from the 2013 cancer patient experience survey in England

OBJECTIVES

To explore differences in experiences of care reported in the Cancer Patient Experience Survey (CPES) between patients with cancer of unknown primary (CUP) and those with metastatic disease of known primary (non-CUP); to determine insights pertaining to the experiences of care for CUP respondents from free-text comments.

DESIGN

Two separate, but related, studies, involving secondary analysis of existing data. Using frequency matching of CUP and non-CUP patients, statistical comparisons of responses to CPES questions were conducted. Free-text comments from CUP respondents were analysed thematically.

SETTING AND PARTICIPANTS

The CPES questionnaire comprises 63 closed questions measuring 8 areas that relate to experience of care and 3 free-text questions. Questionnaires were mailed to all adult patients (aged ≥16 years) in England with cancer admitted to hospital between 1 September 2013 and 30 November 2013.

RESULTS

Matched analysis of closed response items from 2992 patients found significant differences between CUP (n=1496) and non-CUP patients (n=1496): CUP patients were more likely to want more written information about their type of cancer and tests received, to receive their diagnosis from a general practitioner (GP) and have seen allied health professionals, but less likely to have understood explanations of their condition or had surgery. Freetext responses (n=3055) were coded into 17 categories and provided deeper insight regarding patient information and interactions with GPs. CPES data may include a preponderance of patients with favourable CUP subtypes and patients initially identified as CUP but whose primary was subsequently identified.

CONCLUSIONS

These are the first large-scale studies to explore the experiences of care of CUP patients. The significant differences identified between the experiences of CUP and non-CUP patients suggest CUP patients require more psychosocial support and specific interventions to manage diagnostic uncertainty and the multiple investigations many CUP patients face. Substantial limitations were identified with the CPES data, emphasising the need for prospective studies.

The undifferentiated carcinoma that became a melanoma: Re-biopsy of a cancer of an unknown primary site: a case report

BACKGROUND

Cancer of unknown primary site is still a demanding condition as it is per definition metastatic, with heterogeneous biological behavior, and it is often resistant to therapy. Cancer of unknown primary site accounts for approximately 1 to 5 % of all cancers, but is currently among the top six causes of cancer deaths in Western countries. To correctly identify the biological origin of the tumor, a large spectrum of differential diagnoses must be considered and scrutinized. At progression, re-biopsy might be necessary to reveal the true origin of the tumor or actionable targets.

CASE PRESENTATION

A 62-year-old Norwegian woman, with a fast growing lump in her left groin, was primarily diagnosed as having undifferentiated carcinoma that was BRAF V600 positive. There was complete response with paclitaxel-carboplatin and she was recurrence-free for 18 months. She had recurrence in both lungs and subcutaneously in her left groin and thigh; a re-biopsy revealed transformation to a malignant melanoma. She was resistant to BRAF inhibitors, then treated with ipilimumab and is currently a long-term survivor of 4 years and 4 months since the first diagnosis, with no clinical or radiological evidence of recurrence.

CONCLUSIONS

A biopsy from patients with metastasis of unknown primary should be analyzed thoroughly to identify organ of origin, molecular make-up, and possible molecular targets. Re-biopsy of cancer of unknown primary site at progression can reveal the true cellular origin of the tumor as well as provide novel therapeutic opportunities, including immunotherapy.