Time trends in survival from cancer of unknown primary: small steps forward

Cancers of unknown primary: Survival by histologic type, demographic features, and treatment in the U.S. Military Health System

BACKGROUND

Cancers of unknown primary (CUP), a group of heterogenous metastatic cancers lacking a known primary site, have poor prognosis. This study compared survival of CUP by histologic type, patient characteristics, and treatment in the U.S. Military Health System (MHS), which provides universal care to its members.

METHODS

Patients histologically diagnosed with CUP were identified from the U.S. Department of Defense (DoD)'s Automated Central Tumor Registry. Median survival with 95 % confidence intervals was calculated for demographic and treatment variables by histologic type. A multivariable accelerated failure time model estimated time ratios and 95 % confidence intervals.

RESULTS

The study included 3358 CUP patients. The most prevalent CUP in this study was well- and moderately-differentiated adenocarcinomas. Median survival varied by histologic type with squamous cell carcinoma having the longest at 25.1 months and poorly-differentiated carcinomas having the shortest at 3.0 months. For each histologic type, survival was generally similar by sex and active-duty status although women with well- and moderately-differentiated adenocarcinoma had longer survival than their male counterparts. Younger patients tended to have longer survival than those aged 65 years or older. Generally, there were no racial differences in survival except poorer survival for Black patients than White patients in the group of other histologic types. Patients with chemotherapy and radiation treatment generally had improved survival whereas patients with squamous cell carcinoma who received chemotherapy had shorter survival than those without.

CONCLUSION

Survival generally did not differ between racial groups, which may be related to equal healthcare access despite racial background. Further studies are warranted to better understand how survival in the MHS compares with that in the general U.S.

POPULATION

Clinicopathological, molecular and prognostic characteristics of cancer of unknown primary in China: An analysis of 1420 cases

BACKGROUND

Cancer of unknown primary (CUP) is defined the presence of metastatic disease without an identified primary site. An unidentifiable primary site of cancer creates significant challenges for treatment selection. We aimed to describe the clinicopathological, molecular, and prognostic characteristics of Chinese CUP patients.

METHODS

Patients with oncologist-confirmed CUP were identified at Fudan University Shanghai Cancer Center from 2019 to 2020. Information on patient characteristics, tumor presentation, treatment, and outcome were retrospectively collected from the inpatient database and pathological consultation database for descriptive analysis. A multivariable logistic regression model was established to identify factors associated with patient prognosis.

RESULTS

A total of 1420 CUP patients were enrolled in this study. The baseline characteristics of the entire cohort included the following: median age (59 years old), female sex (45.8%), adenocarcinoma (47.7%), and poorly differentiated or undifferentiated tumors (92.1%). For the inpatient cohort, the most common sites where cancer spread included the lymph nodes (41.8%), bone (22.0%), liver (20.1%), and peritoneum/retroperitoneum (16.0%). A total of 77.4% and 58.2% of patients were treated with local therapy and systemic therapy, respectively. Four prognostic factors, including liver metastasis, peritoneal/retroperitoneal metastasis, number of metastatic sites (N ≥ 2), and systemic treatment, were independently associated with overall survival. Additionally, 24.8% (79/318) of patients received molecular testing, including PD-L1, human papillomavirus, genetic variation, and 90-gene expression tests for diagnosis or therapy selection.

CONCLUSION

Cancer of unknown primary remains a difficult cancer to diagnose and manage. Our findings improve our understanding of Chinese CUP patient characteristics, leading to improved care and outcomes for CUP patients.

Feasibility of prognosis assessment for cancer of unknown primary origin using texture analysis of 18F-fluorodeoxyglucose PET/computed tomography images of largest metastatic lymph node

OBJECTIVE

Cancers of unknown primary origin cannot be staged using images, making the prognosis difficult. We attempted to predict prognosis of patients with unknown primary origin using tumour heterogeneity recently introduced in F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT).

METHODS

Overall, 30 patients with unknown primary origin who underwent whole-body F-FDG PET/CT scans were retrospectively enrolled for texture analysis. The volume of interest was placed in the largest metastatic lymph nodes and conventional parameters and grey-level co-occurrence matrix (GLCM) were calculated. Statistical analysis of image-based variables was performed using Cox regression analyses. Patients were stratified into two groups based on cutoff values of GLCMentropy obtained using receiver operating characteristics (ROCs). Patients were analyzed, and overall survival (OS) was compared using Kaplan-Meier analysis.

RESULTS

Univariate Cox regression analysis showed significant differences in prognosis for parenchymal organ metastasis (P < 0.01), GLCM homogeneity (P = 0.01), GLCMcontrast (P < 0.01), GLCMentropy (P < 0.01) and GLCMdissimilarity (P < 0.01). Multivariate Cox regression analysis showed a significant difference in reduced prognosis for GLCMentropy positive (P < 0.01). Stratification was performed based on the GLCMentropy cutoff value, determined using ROCs analysis, with smaller groups showing better OS.

CONCLUSIONS

Despite previous difficulties in predicting prognosis in patients with unknown primary origin, F-FDG PET/CT texture features may enable stratification of prognosis. This could be useful for appropriate patient selection and management and help identify a subset of patients with favourable outcomes. These novel findings may be helpful for prognostication and improving patient care.

Descriptive epidemiology of cancer of unknown primary in South Korea, 1999-2017

BACKGROUND

Cancers of unknown primary (CUPs) are tumors found after metastasizing from unidentified primary sites; these tumors generally have unknown treatment strategies, expected treatment results, and prognosis. We assessed the epidemiological characteristics of CUPs in Korea.

METHODS

We extracted records for 1999 through 2017 from the Korea Central Cancer Registry using the International Statistical Classification of Diseases and Related Health Problems (10th revision) codes for CUP as defined by the International Agency for Research on Cancer. Age-standardized rates and relative survival rates were calculated.

RESULTS

The CUPs constituted 2.1 % of the total number of cancer registrations in 1999, declining to 0.7 % in 2017. The incidence rate decreased for both sexes (5.35 to 2.20 for men, 3.15 to 1.77 for women). Patients aged 80 years and older had the highest incidence rate at 40.2, and 86.3 % of CUPs occurred in those 50 years of age or older. The cases of retroperitoneum and peritoneum sites increased over time. Cases diagnosed by microscopic methods and death certification only were 62.3 % and 7.9 %, respectively. The malignant neoplasm of the retroperitoneum and peritoneum and unknown primary site had the highest and lowest survival rates, respectively. The 5-year relative survival rate increased over time from 14.2 % (1999-2002) to 27.3 % (2013-2017).

CONCLUSIONS

Our analysis of data from the Korea Central Cancer Registry found decreasing rates of CUP, although with consistent disparities by patient age and sex. Advancements in diagnostic technology may be decreasing the number of CUP diagnoses. Expanding the amount of information recorded in the registry may further improve diagnostic accuracy.

Carcinoma of Unknown Primary in a Patient With Lynch Syndrome

Lynch syndrome is the most common form of hereditary colorectal cancer and is associated with an increased incidence of endometrial cancer, small bowel cancer, and other malignancies. The advent of immune checkpoint blockade, next-generation sequencing, and precision medicine molecular tumor boards have revolutionized the current treatment landscape for many cancers and allowed for more creative approaches to treating patients. In addition, tissue agnostic approvals have also served as valid treatment options for patients with otherwise untreatable cancers. In this report, we discuss the case of a 70-year-old woman with Lynch syndrome found to have retroperitoneal lymphadenopathy with p16-negative squamous cell carcinoma, diagnosed as carcinoma of unknown primary (CUP). To our knowledge, this is the first report of Lynch syndrome-associated squamous cell CUP. More research is needed on newly emerging cancer presentations in Lynch syndrome patients as they achieve longer lifespans.

Advances in the management of brain metastases from cancer of unknown primary

Cancer of unknown primary accounts for 3-5% of all cancers for which an adequate investigation does not identify the primary tumor. The particular subset of brain metastasis in cancer of unknown primary (BMCUP) is a clinical challenge that lacks standardized diagnostic and therapeutic options. It is diagnosed predominantly in male patients in the sixth decade of age with complaints of headache, neurological dysfunction, cognitive and behavioral disturbances and seizures. The therapeutic approach to patients with BMCUP relies on local control and systemic treatment. Surgery or stereotactic radiosurgery and/or whole brain radiation therapy seems to be the cornerstone of the treatment approach to BMCUP. Systemic therapy remains essential as cancers of unknown primary are conceptually metastatic tumors. The benefits of chemotherapy were disappointing whereas those of targeted therapies and immune checkpoint inhibitors remain to be evaluated. In this Review, we address the advances in the diagnosis and treatment of BMCUP.

[2018 Consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary]

Cancer of unknown primary is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, cancer of unknown primary can account for 2-9% of all cancer patients, mostly 60-75 years old. This article reviews the main clinical, pathological and molecular studies conducted to analyse and determine the origin of cancer of unknown primary. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

Familial risks of second primary cancers and mortality in ovarian cancer patients

Background

With improving survival in ovarian cancer, second primary cancers (SPCs) and their etiological foundations are becoming an issue. The ways in which family history may influence the occurrence of SPCs and the related mortality are not well known.

Methods

Based on the Swedish Family-Cancer Database, we identified 11,300 ovarian cancer patients and followed them for diagnoses of SPCs until the end of 2015. Relative risks (RRs) of SPC in patients who had parents or siblings diagnosed with the same cancer (positive family history) were compared to those in patients without a family history (negative family history). Causes of death were compared between patients with and without SPC.

Results

A total of 1,111 (9.8%) ovarian cancer patients developed SPC with a median follow-up of 8 years. The impact of a family history of cancer on the risk of the same cancer as SPC was significant for colon (RR_{positive family history} [95% CI] vs RR_{negative family history} [95% CI]: 4.95 [3.03–8.09] vs 2.00 [1.63–2.47]), lung (3.32 [1.88–5.84] vs 1.45 [1.16–1.83]), and breast (2.08 [1.58–2.73] vs 1.01 [0.88–1.15]) cancers. With a family history of any cancer, the RR for non-ovarian SPCs was 1.66 (1.54–1.74), in contrast to 1.38 (1.24–1.54) for SPCs without any family history (P-trend <0.001). Accounting for 42.1% of all deaths, SPC was found to be the main cause of death for patients with SPC.

Conclusion

A family history of a particular cancer contributed to an increased risk of SPC at the same site. Therefore, considering family history at the time of diagnosis of ovarian cancer may alert physicians to a syndromic background, management of which may help the patient and her family members.

Prostate cancer survivors: Risk and mortality in second primary cancers

To assess etiological and clinical consequences of second primary cancers (SPCs) in prostate cancer (PC) patients, we followed newly diagnosed patients to identify men who were diagnosed with a SPC and recorded their causes of death. We used the Swedish Family‐Cancer Database to assess relative risks (RRs) and causes of death in SPCs until the year 2015 in patients with a PC diagnosis between 2001 and 2010. Among a total of 4.26 million men, 76 614 were diagnosed with PC at the median age of 71 years. Among them, 8659 (11.3%) received a subsequent diagnosis of SPC after a median follow‐up of 4 years. The most common SPCs were colorectal, skin, bladder, and lung cancers, melanoma, and non‐Hodgkin lymphoma. The ranking was almost identical with first cancers among elderly men in Sweden. The RR for SPCs in prostate‐specific antigen—detected PC was approximately equal to RR in other PC. Mortality patterns of PC patients were distinct depending on the presence or absence of SPC. Among patients with SPC, 47.8% died as a result of the corresponding SPC, followed by other causes (22.2%) and PC (18.1%). For patients without SPC, PC and non‐neoplastic causes almost matched each other as the main causes of death (48.5% and 47.8%). The results suggest that SPCs appear autonomous from primary PC and reflect incidence and mortality of first cancers in general. SPC was the most common cause of death in patients with SPC; close to half of the patients died due to SPC. For improved survival in PC patients, prevention and early detection of SPCs would be important, and the present results suggest that risk factors for SPC in PC are the same as those for first cancer in general.

Cancer of unknown primary-Epidemiological trends and relevance of comprehensive genomic profiling

Background

Cancer of unknown primary (CUP) is a distinct clinicopathological entity with poor prognosis, frequently resistant to chemotherapy. Comprehensive genomic profiling (CGP) by next‐generation sequencing potentially identifies novel treatment options for CUP patients. The objective of this study was to determine incidence and survival trends and to discuss the value of CGP in CUP patients.

Methods

Age‐standardized incidence rates (ASR) per 100 000 were calculated for 2935 CUP patients from 1981 to 2014 using cancer registry data of the canton of Zurich, Switzerland. Kaplan–Meier survival curves were estimated for sex, age, and histological groups. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (HR). A literature review was conducted to assess the current use of CGP in CUP patients.

Results

ASR of CUP increased from 10.3 to 17.6 between 1981 and 1997 and decreased to 5.8/100 000 in 2014. Mean overall survival remained stable. Mortality was significantly lower for patients with squamous cell carcinoma (HR 0.48 [95% CI, 0.41‐0.57]) and neuroendocrine carcinoma (0.75 [0.63‐0.88]) and higher for unclassified neoplasms (1.25 [1.13‐1.66]) compared to adenocarcinomas. The literature review identified 10 studies using CGP of CUP tissue. Clinically relevant mutations were identified in up to 85% of CUP patients, of which 13%‐64% may benefit from currently available drugs.

Conclusions

CUP incidence decreased probably due to improved diagnostics, but mortality did not improve over the last 34 years. CGP testing may help to identify molecular signatures in CUP patients and enable targeted treatment.

2018 consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary

Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2–9% of all cancer patients, mostly 60–75 years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

Are we ready for routine precision medicine? Highlights from the Milan Summit on Precision Medicine, Milan, Italy, 8-9 February 2018

On 8 and 9 February 2018, the IFOM-IEO campus in Milan hosted the Milan summit on Precision Medicine, which gathered clinical and translational research experts from academia, industry and regulatory bodies to discuss the state of the art of precision medicine in Europe. The meeting was pervaded by a generalised feeling of excitement for a field that is perceived to be technologically mature for the transition into clinical routine but still hampered by numerous obstacles of a methodological, ethical, regulatory and possibly cultural nature. Through lively discussions, the attendees tried to identify realistic ways to implement a technology-rich precision approach to cancer patients.

Precision medicine based on epigenomics: the paradigm of carcinoma of unknown primary

Epigenetic alterations are a common hallmark of human cancer. Single epigenetic markers are starting to be incorporated into clinical practice; however, the translational use of these biomarkers has not been validated at the 'omics' level. The identification of the tissue of origin in patients with cancer of unknown primary (CUP) is an example of how epigenomics can be incorporated in clinical settings, addressing an unmet need in the diagnostic and clinical management of these patients. Despite the great diagnostic advances made in the past decade, the use of traditional diagnostic procedures only enables the tissue of origin to be determined in ∼30% of patients with CUP. Thus, development of molecularly guided diagnostic strategies has emerged to complement traditional procedures, thereby improving the clinical management of patients with CUP. In this Review, we present the latest data on strategies using epigenetics and other molecular biomarkers to guide therapeutic decisions involving patients with CUP, and we highlight areas warranting further research to engage the medical community in this unmet need.

Molecular analysis of ovarian mucinous carcinoma reveals different cell of origins

It is believed that a subset of primary ovarian mucinous tumors is derived from mature teratomas [1–5]. To confirm this, we performed microsatellite genotyping using a variety of short tandem repeat makers and analyzed allelotypes of 8 mucinous tumors (4 mucinous carcinomas, 3 atypical proliferative mucinous tumors and 1 mucinous cystadenoma) associated with a teratoma to determine whether they were clonally related. 7 of the 8 mucinous tumors showed complete or a high degree of homozygosity. Among the 6 pairs of tumors with teratoma tissue available for comparison, 5 of 6 showed a high or complete degree of allelotypes matching, which differed from the somatic allelotypes of the normal control tissue. A discrepancy was detected between carcinoma and teratoma in one pair at several loci, with different X-chromosome inactivation patterns revealed by the HUMARA clonality assay. We also investigated the allelotypes of 16 ovarian mucinous carcinomas without a teratoma in young patients (range 13–30) and in 6 older patients (range 40–67) using the same method. None of these tumors showed pure homozygosity. The number of homozygous loci in this cohort was significantly lower than that in the first. Our results suggest first, that most mucinous tumors associated with a teratoma are derived from the teratoma but occasionally they could be collision tumors and second that the majority of pure mucinous tumors in young women in whom a teratoma is not present are not derived from a teratoma.

Age-Dependent Metastatic Spread and Survival: Cancer of Unknown Primary as a Model

In order to describe a novel approach for the clinical study of metastases, we provide here age-specific incidence and survival data for cancer of unknown primary (CUP). Metastases in various organs are found at CUP diagnosis, which have implications for prognosis, and we hypothesize similar prognostic implications for metastases found at diagnosis of primary cancers. We identified 33,224 CUP patients from the Swedish Cancer Registry and calculated incidence rates (IRs) for CUP development. Cox proportional hazards regression models were performed to estimate hazard ratios (HRs) for relative survival in CUP patients compared to the general population. In age-group specific analyses, a maximal IR was reached at age 85-89 years, followed by a marked decline to age 90+ (7-fold in men and 3-fold in women). The overall HR for relative survival declined systematically by age. CUP may be applied as an epidemiological age-incidence model for cancer metastases providing evidence in line with autopsy data that the metastatic potential, as shown by the incidence of CUP, appears to weaken markedly at age 85 years, depending on metastatic locations. The relative death rates were highest among young patients, which was probably entirely due to the low death rates in young background population.

Location of metastases in cancer of unknown primary are not random and signal familial clustering

Cancer of unknown primary (CUP) is a fatal disease diagnosed through metastases. It shows intriguing familial clustering with certain defined primary cancers. Here we examine whether metastatic location in CUP patients is related to primary non-CUP cancers in relatives based on the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for CUP patients defined by metastatic location depending on cancer in their first degree relatives. SIRs for CUP were high in association with liver (3.94), ovarian (3.41), lung (2.43) and colorectal cancers (1.83) in relatives. The SIR was 1.63 for CUP with metastases in the abdomen when a relative was diagnosed with ovarian cancer. CUP with liver metastases associated with liver (1.44) cancer in relatives. CUP with head and neck region metastases associated with relatives’ esophageal (2.87) cancer. CUP metastases in the thorax associated with a relative’s cancers in the upper aerodigestive tract (2.14) and lung (1.74). The findings, matching metastatic location in CUP and primary cancer in relatives, could be reconciled if these cases of CUP constitute a phenotypically modified primary lacking tissue identification, resulting from epitope immunoediting. Alternatively, CUP metastases arise in a genetically favored tissue environment (soil) promoting growth of both primary cancers and metastases (seeds).

A case of occult intrahepatic cholangiocarcinoma diagnosed by autopsy

Cancer of unknown primary is associated with unknown biology and dismal prognosis. The most common primary sites of cancer of unknown primary were usually the lungs in autopsy studies, and intrahepatic cholangiocarcinoma is rare. We describe the case of a 57-year-old male patient with systemic lymph node metastasis. Imaging examination failed to reveal primary cancer; however, immunostaining of cytokeratins 7, 19, and 20 of a metastatic axillary lymph node suggested a pancreaticobiliary cancer as a primary lesion. He died of liver abscess and sepsis, and then, autopsy indicated occult intrahepatic cholangiocarcinoma. We discuss the clinical course of this rare cholangiocarcinoma including the diagnostic procedure and also present a review of the English literature regarding patients with cancer of unknown primary.

GyneScan: an improved online paradigm for screening of ovarian cancer via tissue characterization

Ovarian cancer is the fifth highest cause of cancer in women and the leading cause of death from gynecological cancers. Accurate diagnosis of ovarian cancer from acquired images is dependent on the expertise and experience of ultrasonographers or physicians, and is therefore, associated with inter observer variabilities. Computer Aided Diagnostic (CAD) techniques use a number of different data mining techniques to automatically predict the presence or absence of cancer, and therefore, are more reliable and accurate. A review of published literature in the field of CAD based ovarian cancer detection indicates that many studies use ultrasound images as the base for analysis. The key objective of this work is to propose an effective adjunct CAD technique called GyneScan for ovarian tumor detection in ultrasound images. In our proposed data mining framework, we extract several texture features based on first order statistics, Gray Level Co-occurrence Matrix and run length matrix. The significant features selected using t-test are then used to train and test several supervised learning based classifiers such as Probabilistic Neural Networks (PNN), Support Vector Machine (SVM), Decision Tree (DT), k-Nearest Neighbor (KNN), and Naive Bayes (NB). We evaluated the developed framework using 1300 benign and 1300 malignant images. Using 11 significant features in KNN/PNN classifiers, we were able to achieve 100% classification accuracy, sensitivity, specificity, and positive predictive value in detecting ovarian tumor. Even though more validation using larger databases would better establish the robustness of our technique, the preliminary results are promising. This technique could be used as a reliable adjunct method to existing imaging modalities to provide a more confident second opinion on the presence/absence of ovarian tumor.