Cancer of unknown primary (CUP) through the lens of precision oncology: a single institution perspective

PURPOSE

For patients with cancer of unknown primary (CUP), treatment options are limited. Precision oncology, the interplay of comprehensive genomic profiling (CGP) and targeted therapies, aims to offer additional treatment options to patients with advanced and hard-to-treat cancers. We aimed to highlight the use of a molecular tumor board (MTB) in the therapeutic management of CUP patients.

METHODS

In this single-center observational study, CUP patients, presented to the MTB of the Comprehensive Cancer Center Munich LMU, a tertiary care center, were analyzed retrospectively. Descriptive statistics were applied to describe relevant findings.

RESULTS

Between June 2016 and February 2022, 61 patients with unfavorable CUP were presented to the MTB, detected clinically relevant variants in 74% (45/61) of patients, of which 64% (29/45) led to therapeutic recommendation. In four out of 29 patients (14%), the treatment recommendations were implemented, unfortunately without resulting in clinical benefit. Reasons for not following the therapeutic recommendation were mainly caused by the physicians' choice of another therapy (9/25, 36%), especially in the context of worsening of general condition, lost to follow-up (7/25, 28%) and death (6/25, 24%).

CONCLUSION

CGP and subsequent presentation to a molecular tumor board led to a high rate of therapeutic recommendations in patients with CUP. Recommendations were only implemented at a low rate; however, late GCP diagnostic and, respectively, MTB referral were found more frequent for the patients with implemented treatment. This contrast underscores the need for early implementation of CGP into the management of CUP patients.

Factors Influencing the Outcome of Head and Neck Cancer of Unknown Primary (HNCUP)

Background: This study on patients with head and neck cancer of unknown primary (HNCUP) assesses the impact of surgical and non-surgical treatment modalities and the tumour biology on the oncological outcome. Methods: A total of 80 patients with HNCUP (UICC I−IV) were treated with simultaneous neck dissection followed by adjuvant therapy, between 1 January 2007 and 31 March 2020. As the primary objective, the influence of treatment modalities on the overall survival (OS), the disease-specific survival (DSS) and the progression-free survival (PFS) were analysed in terms of cox regression and recursive partitioning. The tumour biology served as secondary objectives. Results: The 5-year OS for the entire cohort was 67.7%, (95% CI: 54.2−81.2%), the 5-year DSS was 82.3% (72.1−92.5%) and the 5-year PFS was 72.8% (61.8−83.8%). Cox regression revealed that patients undergoing adjuvant radiotherapy only had a four times higher risk to die compared to patients receiving chemoradiation therapy (HR = 4.45 (1.40; 14.17), p = 0.012). The development of distant metastases had a significantly negative impact on OS (HR = 8.24 (3.21−21.15), p < 0.001) and DSS (HR = 23.79 (6.32−89.56), p < 0.001). Recursive portioning underlined the negative influence of distant metastases on OS (3.2-fold increase in death probability) and DSS (4.3-fold increase in death probability), while an UICC stage of IVb increased the risk for further progression of the disease by a factor of 2. Conclusions: The presence of distant metastases as well as adjuvant treatment with radiation without concomitant chemotherapy, were among others, significant predictors for the overall survival of HNCUP patients, with distant metastases being the most significant predictor.

Axillary Nodal Metastases from Carcinoma of Unknown Primary (CUPAx): Role of Contrast-Enhanced Spectral Mammography (CESM) in Detecting Occult Breast Cancer

Axillary lymph node metastases of occult breast cancer (CUPAx) is an unusual condition that represents both a diagnostic and therapeutic challenge. The first steps in the diagnostic work-up of patients with CUPAx are the histological analysis of the lymph node metastasis and the execution of basic breast diagnostic imaging (mammography and ultrasound). In the case of occult breast cancer, breast Magnetic Resonance (MR) must be performed. Breast MR identifies a suspicious lesion in many patients and second-look ultrasound detects a corresponding ultrasound alteration in about half of cases, allowing the performance of a US-guided biopsy. In the case of an MR-only lesion, MR-guided biopsy is mandatory. We present a case of CUPAx in which contrast-enhanced spectral mammography (CESM) is used to help the detection of occult breast cancer and to guide stereotactic vacuum breast biopsy (VABB). CESM is a new breast imaging technique that is proving to have good performance in breast cancer detection and that is showing potential in the identification of occult breast cancer in a CUPAx setting. The use of an innovative and personalized breast imaging approach in breast cancer patients improves diagnostic possibilities and promises to become the focus in decision strategies.

[Lymphedema as initial manifestation of malignancy]

Lymphedema may result from various benign or malignant causes. In particular rapidly progressing central or unilateral lymphedema (even in case of only discrete clinical findings) should initiate an extensive diagnostic workup to detect underlying malignancies in order to enable early therapy.

Metastases in the Absence of a Primary Tumor: Advances in the Diagnosis and Treatment of CUP Syndrome

INTRODUCTION

The term cancer of unknown primary site (CUP) syndrome is used to describe malignancies in which a complete diagnostic work-up detects metastases in the absence of an identifiable primary tumor.

METHODS

Based on a selective literature review, national and international guidelines, and the experience of the "Arbeitskreis CUP-Syndrom der Arbeitsgemeinschaft Internistische Onkologie der Deutschen Krebsgesellschaft" (CUP Syndrome Committee of the Medical Oncology Joint Working Group of the German Cancer Society), developments in the diagnosis and treatment of CUP syndrome are reported.

RESULTS

Most patients diagnosed with CUP have an unfavorable prognosis, with a life expectancy of less than 12 months. Nevertheless, it is important to identify subsets of patients in whom specific treatment offers the chance of long-term survival or even full recovery.

DISCUSSION

Only rigorous further development of diagnostic tools and treatment protocols will enable an improvement of the poor prognosis of patients with CUP syndrome. Specific molecular treatment strategies have shown promising results.