Cancer of unknown primary and the «seed and soil» hypothesis

The worldwide incidence rate of cancer of unknown primary (CUP) reaches 5% (Kang et al, 2021; Lee, Sanoff, 2020; Yang et al, 2022). CUP has an alarmingly high mortality rate, with 84% of patients succumbing within the first year following diagnosis (Registration and Service, 2018). Under normal circumstances, tumor cell metastasis follows the «seed and soil» hypothesis, displaying a tissue-specific pattern of cancer cell homing behavior based on the microenvironment composition of secondary organs. In this study, we questioned whether seed and soil concept applies to CUP, and whether the pattern of tumor and metastasis manifestations for cancer of known primary (CKP) can be used to inform diagnostic strategies for CUP. We compared data from metastatic and primary CUP foci to the metastasis patterns observed in CKP. Furthermore, we evaluated several techniques for identifying the tissue-of-origin (TOO) in CUP profiling, including DNA, RNA, and epigenetic TOO techniques.

Surgical resection of soft tissue metastasis in cancers: A single-center study of 77 cases over a 7-year period

INTRODUCTION

Soft tissue metastasis (STM) of cancers, encompassing skeletal muscle and subcutaneous tissue metastasis, is less common due to unique homeostatic conditions. With longer life expectancy and the advent of new imaging modalities, clinical physicians will increasingly encounter and manage such cases. This study retrospectively reviewed cases of STM in visceral cancers who underwent surgery at Fudan University Shanghai Cancer Center over a 7-year period.

METHODS

Data were collected through a comprehensive review of medical records, including demographic variables, primary tumor characteristics, surgical data, tumor pathology, and outcomes. Survival analysis was performed using Kaplan-Meier curves.

RESULTS

The study included 77 cases with a median follow-up period of 854 days. The most common primary tumor sites were the lung (11) and breast (10). The abdominal wall was the most frequent site of metastasis. The combination of visceral metastasis, age over 52 years, and a history of primary tumor correlates with a poorer prognosis. Surgical-related metastases are associated with a higher degree of differentiation. Additionally, we have identified a better prognosis for patients with cancer of unknown primary (CUP) exhibiting potential resectable soft tissue metastases.

CONCLUSION

The combination of visceral metastasis, age over 52 years, and a history of primary tumor suggest a poorer prognosis. While no significant impact on survival was observed for patients with lymph node metastasis. Surgical-related metastases are associated with a higher degree of differentiation. CUP patients with potentially resectable soft tissue metastases should be considered for surgical intervention.

Significance of Distinct Liquid Biopsy Compartments in Evaluating Somatic Mutations for Targeted Therapy Selection in Cancer of Unknown Primary

PURPOSE

Cancer of unknown primary (CUP) accounts for 2-5% of all cancer diagnoses, wherein standard investigations fail to reveal the original tumor site. Basket trials allocate targeted therapeutics based on actionable somatic mutations, independent of tumor entity. These trials, however, mostly rely on variants identified in tissue biopsies. Since liquid biopsies (LB) represent the overall tumor genomic landscape, they may provide an ideal diagnostic source in CUP patients. To identify the most informative liquid biopsy compartment, we compared the utility of genomic variant analysis for therapy stratification in two LB compartments (circulating cell-free (cf) and extracellular vesicle (ev) DNA).

METHODS

CfDNA and evDNA from 23 CUP patients were analyzed using a targeted gene panel covering 151 genes. Identified genetic variants were interpreted regarding diagnostic and therapeutic relevance using the MetaKB knowledgebase.

RESULTS

LB revealed a total of 22 somatic mutations in evDNA and/or cfDNA in 11/23 patients. Out of the 22 identified somatic variants, 14 are classified as Tier I druggable somatic variants. Comparison of variants identified in evDNA and cfDNA revealed an overlap of 58% of somatic variants in both LB compartments, whereas over 40% of variants were only found in one or the other compartment.

CONCLUSION

We observed substantial overlap between somatic variants identified in evDNA and cfDNA of CUP patients. Nonetheless, interrogation of both LB compartments can potentially increase the rate of druggable alterations, stressing the significance of liquid biopsies for possible primary-independent basket and umbrella trial inclusion.

Management and prognosis of patients with cancer of unknown primary: 20 years of experience

Background/aim

Cancer of unknown primary (CUP) is a difficult clinical entity to manage. The aim of the study was to investigate the sociodemographic and pathological characteristics, treatment options, and factors affecting overall survival (OS) in CUP patients whose primary tumor was not detected during follow-up.

Materials and methods

A total of 243 CUP patients whose primary tumors could not be detected during follow-up were included in the study. Their demographic characteristics, survival outcomes, and prognostic factors were investigated.

Results

Of the 243 patients included in this study, 61.7% were male and 38.3% were female, and the median age was 61 (range: 19-90) years. The most common histological type was adenocarcinoma (79%). The median follow-up time of the patients was 30.3 months (95% CI: 11.4-49.3), the median OS time was 9.1 months (95% CI: 7.2-11.0), and 72.4% of the patients received at least 1 line of chemotherapy (CT). The difference in survival between the patients who did and did not receive CT was statistically significant (median OS: 10.1 vs. 4.2 months, p = 0.003). According to the multivariate analysis, the presence of cholestasis (HR: 0.48, 95% CI: 0.29-0.79, p = 0.004), lung metastasis (HR: 0.69, 95% CI: 0.51-0.95, p = 0.001), second-line chemotherapy (HR: 1.69, 95% CI: 1.14-2.49, p < 0.001), and Eastern Cooperative Oncology Group (ECOG) performance status (HR: 0.20, 95% CI: 0.10-0.40, p < 0.001) were independent prognostic factors influencing OS.

Conclusion

CUP patients who receive multiple lines of chemotherapy tend to have longer survival. This is the first study to report cholestasis as a prognostic factor in CUP patients. In addition, the presence of lung metastases, not receiving second-line chemotherapy, and ECOG performance status (≥2) were found to be independent poor prognostic factors.

Effect and outcomes analysis of anlotinib in non-small cell lung cancer patients with liver metastasis: results from the ALTER 0303 phase 3 randomized clinical trial

PURPOSE

Liver metastasis (LM) is common in non-small cell lung cancer (NSCLC), and always predicted worse outcomes with no effective therapy. We aimed to evaluate the effects and prognosis in LM patients treated with anlotinib.

METHODS

The present study is a post hoc analysis based on a multicenter, double-blind, phase 3 randomized clinical trial which designed to evaluate the efficacy and safety of anlotinib in patients with advanced NSCLC. A total of 437 patients were enrolled in present study, and 78 patients with LM.

RESULTS

Patients with LM showed a worse outcome compared to those without LM (PFS median, 2.6 vs 4.2 months), and OS (median, 5.6 vs 9.4 months, both P < 0.0001). The anlotinib was associated with longer PFS (median, 3.0 months) compared with placebo (median, 0.9 months), with a hazard ratio (HR) of 0.23 (95%CI, 0.12-0.42; P < 0.0001). Furthermore, OS was marginally significantly better in anlotinib group (median 6.6 months), compared with placebo (median 4.0 months), HR 0.61 (95%CI, 0.36-1.02; P = 0.055). Multivariate analysis confirmed normal peripheral blood LDH/TBiL level predicted better PFS and OS, lower ECOG score acted as independently prognostic factor for superior OS. Anlotinib was more associated with hand-foot syndrome (7.7% vs 0) and serum TSH level rise (7.7% vs 3.8%) and well tolerated, all AEs were no more than grade 3.

CONCLUSION

Patients with LM had a dismal prognosis, anlotinib could lead to a better PFS in pretreated NSCLC patients, which suggested anlotinib is a potential third-line or further therapy in these patients.

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.

Management of Pathologic Fractures around the Knee: Part 1-Distal Femur

Pathologic fractures secondary to metastatic disease are an increasingly prevalent problem. Such patients require multidisciplinary collaboration to optimize clinical outcomes. An established algorithm for clinical, laboratory, and radiographic work-up will ensure that each patient achieves the best outcome while avoiding catastrophic complications. Metastatic disease to the region of the knee is less commonly encountered than in other regions of the body, but it presents unique difficulties that merit discussion. Part one of this two-part article series will discuss the appropriate work-up of patients with suspected or impending pathologic fracture of the distal femur, highlight biopsy principles, address perioperative nonsurgical treatments that will optimize patient outcomes, and discuss available surgical treatment modalities.

OUP accepted manuscript

Background

Cancer of unknown primary (CUP) comprises a heterogeneous collection of malignancies that are typically associated with a poor prognosis and a lack of effective treatment options. We retrospectively evaluated the clinical utility of targeted next-generation sequencing (NGS) among CUP patients to assist with diagnosis and identify opportunities for molecularly guided therapy.

Patients and Methods

Patients with a CUP at Moffitt Cancer Center who underwent NGS between January 1, 2014 and December 31, 2019, were eligible for study inclusion. Next-generation sequencing results were assessed to determine the frequency of clinically actionable molecular alterations, and chart reviews were performed to ascertain the number of patients receiving molecularly guided therapy.

Results

Ninety-five CUP patients were identified for analysis. Next-generation sequencing testing identified options for molecularly guided therapy for 55% (n = 52) of patients. Among patients with molecularly guided therapy options, 33% (n = 17) were prescribed a molecularly guided therapy. The median overall survival for those receiving molecularly guided therapy was 23.6 months. Among the evaluable patients, the median duration of treatment for CUP patients (n = 7) receiving molecular-guided therapy as a first-line therapy was 39 weeks. The median duration of treatment for CUP patients (n = 8) treated with molecularly guided therapy in the second- or later-line setting was 13 weeks. Next-generation sequencing results were found to be suggestive of a likely primary tumor type for 15% (n = 14) of patients.

Conclusion

Next-generation sequencing results enabled the identification of treatment options in a majority of patients and assisted with the identification of a likely primary tumor type in a clinically meaningful subset of patients.

Factors Affecting Life Expectancy After Bone Metastasis in Adults - Results of a 5-year Prospective Study

There is a scarcity of literature available regarding the factors affecting life expectancy in bone metastasis (BM). Our objective is to evaluate the factors affecting life expectancy in adult patients with BM. In this prospective cohort study for over 5 years, 111 adults with BM were included in the analysis. The life expectancy was calculated from the time of diagnosis of BM to death. Statistical analysis was done using the SPSS statistical program. The Pearson chi-square test was used to analyze the significance and life expectancy was represented on the Kaplan Meier curve. The overall median survival time was 9 months. The patients with a primary malignancy detected along with BM had a median survival of 9 months. Those without a known primary at the time of diagnosis survived for a median period of 8 months and those with known primary for 14 months (P-value 0.01). The median survival of patients with BM from the lung, breast, and prostate was 6, 14, and 24 months, respectively (P-value 0.001). Only 22% of patients with extraskeletal metastasis in addition to BM survived more than 6 months (P-value 0.013). Patients with neurological deficits had a median survival of 2 months (P-value 0.0001). There was no statistically significant association between gender and the mode of treatment and survival. There was a significant association between life expectancy and mode of presentation, the primary site of origin, presence of extraskeletal secondary, BM with unknown primary, and symptoms on presentation in patients with BM.

Defining a Distinct Immunotherapy Eligible Subset of Patients with Cancer of Unknown Primary Using Gene Expression Profiling with the 92-Gene Assay

Background

Although recent advances in immunotherapy have transformed the treatment landscape for many anatomically defined cancers, these therapies are currently not approved for patients diagnosed with cancer of unknown primary (CUP). Molecular cancer classification using gene expression profiling (GEP) assays has the potential to identify tumor type and putative primary cancers and thereby may allow consideration of immune checkpoint inhibitor (ICI) therapy options for a subset of patients with CUP. Herein, we evaluated and characterized the ability of a 92‐gene assay (CancerTYPE ID) to provide a molecular diagnosis and identify putative tumor types that are known to be sensitive to ICI therapies in patients with CUP or uncertain diagnosis.

Findings

A total of 24,426 cases from a large‐scale research database of 92‐gene assay clinical cases were classified, of which 9,350 (38%) were predicted to have an ICI‐eligible tumor type. All ICIs with approved indications as of March 2020 were included in the analysis. Non‐small cell lung cancer (NSCLC) was the most frequent molecular diagnosis and accounted for 33% of the ICI‐eligible tumor types identified and 13% of the overall reportable results. In addition to NSCLC, the assay also frequently identified urothelial carcinomas, gastric cancer, and head and neck squamous cell carcinoma. The distributions of identified tumor types with indications for ICI therapy were similar across age and gender.

Conclusions

Results suggest that molecular profiling with the 92‐gene assay identifies a subset of ICI‐eligible putative primary cancers in patients with CUP. We propose a treatment strategy based on available tests, including clinicopathologic features, GEP, and ICI biomarkers of response.

Regulatory approval of immune checkpoint inhibitors (ICI) is restricted to anatomically defined cancers with a known primary. This article reports cases submitted for 92‐gene assay testing with an unknown or uncertain diagnosis for which the subsequent post‐test report included a tumor type linked to an FDA‐approved ICI therapy, with the goal of identifying characteristics of cancers of unknown primary tumors that might benefit from immunotherapy.

Sentinel node theory helps tracking of primary lesions of cancers of unknown primary

Background

Sentinel lymph node is the first stop of lymphatic spreading of cancer with known primary. The lymph node metastasis pattern of cancer of unknown primary (CUP) is unclear and has been presumed to follow the same pathway. To test this hypothesis, data of all 716 patients clinically diagnosed as CUP in our center were collected.

Methods

Diagnoses of lymph node metastasis were established by ¹⁸F-FDG PET-CT and/or biopsy pathology. Three hundred and forty-seven cases meeting the criteria were divided into three groups: pathology-confirmed primary with invasive biopsy or surgery of the suspicious lesion (group A, n = 64), primary still unknown even with invasive biopsy or surgery of the suspicious lesion (group B, n = 204), and others with no suspicious lesion or lesions who had not been sampled due to medical or other reasons (group C, n = 79). We assessed the clinicopathological features between these groups, and the relationship between lymph node metastasis pattern and confirmed primary site.

Results

In group A, the primary sites of 61 cases were compatible with sentinel node theory, resulting in a positive predictive value of 95%. No significant differences in age, sex, bone metastasis, or visceral metastasis observed between group A and group B, except that group A had a higher ratio of differentiated carcinoma (94% vs. 77%, P = 0.003).

Conclusion

To our knowledge, this is the first evidence indicating that the majority of clinical CUP cases follow the sentinel node theory to spread in lymph nodes, which helps tracking the primary, especially for differentiated carcinoma.

Imaging features and prognostic value of 18F-FDG PET/CT detection of soft-tissue metastasis from lung cancer: a retrospective study

BACKGROUND

Soft-tissue metastasis (STM) is a relatively rare, but not exceptional, manifestation of lung cancer. The purpose of this study was to evaluate the imaging features of STM from lung cancer using fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), and assess the impact of STM detected at baseline PET/CT on patient survival.

METHODS

Out of 4543 patients with lung cancer who underwent ¹⁸F-FDG PET/CT in our hospital between January 2013 and September 2018, 85 were diagnosed with STM (78 at baseline PET/CT and 7 at restaging PET/CT) and included in the imaging study. We conducted a comparative survival analysis between patients with stage 4 lung cancer with and without STM at baseline PET/CT (n = 78 in each group) and performed univariate and multivariate analyses to investigate the factors affecting the prognosis of lung cancer.

RESULTS

A total of 219 lesions were identified by ¹⁸F-FDG PET/CT: 215 were detected by PET and 139 by CT. Muscle STM were primarily found in the hip and upper limb muscle, whereas subcutaneous STM were mainly distributed in the chest, abdomen, and back. In 68 patients, STM were found incidentally during routine ¹⁸F-FDG PET/CT staging. Isolated STM were detected in 6 patients, whose tumor staging and treatment were affected by PET/CT findings. There were no significant differences in the 1-, 3-, and 5-year survival rates between patients with and without STM at baseline PET/CT. Brain and adrenal metastases, but not STM, were associated with poor prognosis of stage 4 lung cancer.

CONCLUSIONS

We described the PET/CT imaging characteristics of STM from lung cancer, and confirmed that PET/CT can detect unsuspected STM to change the staging and treatment of some patients. Our analysis indicates that STM is not a useful prognostic indicator for patients with advanced lung cancer, while brain and adrenal metastases portend a poor prognosis.

Role of 18F-FDG PET/CT in the detection of primary malignancy in patients with bone metastasis of unknown origin

OBJECTIVE

The present study investigates the role of ¹⁸F-FDG PET/CT in the detection of primary malignancy in patients with bone metastasis of unknown primary origin (BMUO).

MATERIAL AND METHODS

This retrospective study considered histopathological examination findings or clinical follow-up data as the standard reference in the diagnosis of primary tumors, and results were compared with results of PET/CT scans.

RESULTS

The study included 100 patients with BMUO (74 males, 26 females, mean age 61 years). The primary origin was identified in 92 of the 100 patients. Adenocarcinoma was the most common histopathological subtype in patients in whom the primary origin of tumor was detected (65.2%). The most common primary tumor was lung carcinoma (n=52) followed by prostate (n=13), breast (n=7), colon (n=4), gastric (n=3), ovarian (n=2), renal cell (n=2), adrenal (n=1), thyroid (n=1), endometrial (n=1) and parotid (n=1) carcinoma, hepatobiliary cancers (n=2), leiomyosarcoma (n=2) and maxillary sinus tumor (n=1). The numbers of patients in whom PET/CT showed true positive, true negative, false positive (FP) and false negative (FN) results were 72, 7, 8 and 13, respectively. The sensitivity, specificity, accuracy and detection rate of PET/CT in detecting the primary tumor were 84.7%, 46%, 79% and 72%, respectively. The overall survival was significantly lower in lung cancer group when compared to non-lung cancer group, whereas it was significantly higher in prostate cancer group than in non-prostate cancer group.

CONCLUSIONS

PET/CT, as a non-invasive method, can be preferred as the first choice in the detection of primary tumor in patients with BMUO.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

Skeletal metastases of unknown primary (SMUP) represent a clinical challenge in dealing with patients diagnosed with bone metastases. Management of these patients has improved significantly in the past few years. however, it is fraught with a lack of evidence. While some patients have achieved impressive gains, a more systematic and tailored treatment is required. Nevertheless, in real-life practice, the outlook at the beginning of treatment for SMUP is decidedly somber. An incomplete translational relevance of pathological and clinical data on the mortality and morbidity rate has had unsatisfactory consequences for SMUP patients and their physicians. We examined several approaches to confront the available evidence; three key points emerged. The characterization of the SMUP biological profile is essential to driving clinical decisions by integrating genetic and molecular profiles into a multi-step diagnostic work-up. Nonetheless, a pragmatic investigation plan and therapy of SMUP cannot follow a single template; it must be adapted to different pathophysiological dynamics and coordinated with efforts of a systematic algorithm and high-quality data derived from statistically powered clinical trials. The discussion in this review points out that greater efforts are required to face the unmet needs present in SMUP patients in oncology.

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.

Prognostic and risk factors in patients with metastatic bone disease of an upper extremity

Background

The aim of this study was to evaluate survival of metastatic bone disease of an upper extremity, and to identify the prognostic factors that influence survival.

Methods

Patients with metastatic bone disease of an upper extremity between 2008 and 2015 were reviewed from the database of a tertiary university hospital.

Results

Of 102 patients, 48 males and 54 females with a median age of 61 (range, 28–82 years), the humerus (64.7%), clavicle (13.7%), and scapula (12.7%) were the common sites for bone metastasis of an upper extremity. Fifty-nine (57.8%) presented with pathologic fracture. No history of cancer was found in 76.5% of patients. The mean onset of metastatic bone disease after the first diagnosis of primary cancer was 4.74 ± 14.07 months (range, 0–84 months). Lung (31.4%) was the most common primary cancer followed by liver (14.7%), breast (12.7%), thyroid (7.8%), and renal (3.9%). Eighty-two cases (80.39%) died from the disease such that the median survival was 4.08 months (95% CI 2.57–6.17). The significant risk factors were the type of primary tumor (P < 0.001, HR = 4.44; 95% CI, 1.99–9.90) and ECOG performance status (P = 0.021, HR = 2.11, 95% CI 1.12–3.99).

Conclusions

Patients with metastatic bone disease of an upper extremity have a limited life expectancy. The type of primary tumor and ECOG performance status were the important prognostic factors that influenced overall survival. Our data help in the management of patients, families, and doctors, so as to avoid over- or under-treatment.

Impact of family history of cancer on risk and mortality of second cancers in patients with prostate cancer

BACKGROUND

Survival rates are increasing in patients with prostate cancer, and second primary cancers (SPCs) are becoming more common in these patients. However, the etiology and clinical consequences of SPCs are not well-known. We define the impact of family history on SPC and causes of mortality in these patients.

PATIENTS AND METHODS

A nation-wide cohort study based on the Swedish Family-Cancer Database covering 4.4 million men and 80,449 prostate cancers diagnosed between 1990 and 2015. Relative risks (RRs) and cumulative incidence for SPCs and for familial SPC were calculated for prostate cancer patients.

RESULTS

SPC was diagnosed in 6,396 men and more than a third of these patients had a first-degree family history of any cancer; the familial risk was 1.37 (95% CI: 1.27-1.40), compared to 1.10 (1.08-1.16), without a family history. Cumulative incidence by the age of 83 years reached 21% for prostate cancer alone, 28% in those with SPC, and 35% in patients with SPC and family history. Family history was associated with the risk of seven specific SPCs, including colorectal, lung, kidney, bladder and skin (both melanoma and squamous cell) cancers, and leukemia. Colorectal and lung cancers were common SPCs, and family history doubled the risk of these SPCs. In patients with SPC, half of all causes of death were due to SPC and only 12.77% were due to prostate cancer. Most deaths in SPC were caused by lung and colorectal cancers.

CONCLUSIONS

SPCs were an important cause of death in patients with prostate cancer and family history was an important risk factor for SPCs. Prevention of SPC should be essential when prostate cancer survival rates are being improved and this could start by conducting a thorough assessment of family history at the time of prostate cancer diagnosis.

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.

Primary Recurrence in the Lung is Related to Favorable Prognosis in Patients with Pancreatic Cancer and Postoperative Recurrence

BACKGROUND

The pattern of recurrence affects the clinical outcome in tumor patients. However, the clinical significance of lung metastasis as the primary recurrence site after resection in patients with pancreatic cancer remains unclear. This study aimed to clarify the clinical significance of the primary recurrence site in patients with pancreatic cancer, in terms of prognosis and clinicopathological features.

METHODS

This retrospective cohort study included 220 patients with postoperative recurrence after pancreatectomy for pancreatic cancer and classified by primary site of recurrence. We focused on patients with lung metastasis as the primary recurrence and investigated its correlation with prognosis and clinicopathological factors.

RESULTS

Twenty-four (11%) patients had lung metastasis as the primary recurrence. This recurrence pattern had the best prognosis among all recurrence patterns, including liver metastasis and local recurrence. Patients with lung metastasis as the primary recurrence had favorable overall survival and survival from the date of recurrence compared with patients with other primary recurrence sites in both univariate (P = 0.0008 and P = 0.0005) and multivariate analyses (P = 0.0051 and P = 0.0068). In terms of clinicopathological features of resected pancreatic tumors, lung metastasis as the primary recurrence was associated with lower tumor stage and histologic grade, and less vascular invasion and residual tumor volume than liver metastasis.

CONCLUSIONS

Pancreatic cancer patients with lung metastasis as the primary recurrence after pancreatectomy have a better prognosis than those with other recurrence patterns.

Risk factors for local recurrence after total en bloc spondylectomy for metastatic spinal tumors: A retrospective study

BACKGROUND

The aim of this study was to evaluate local recurrence and survival outcomes after frozen autograft total en bloc spondylectomy for metastatic spinal tumors.

METHODS

We retrospectively analyzed data from 91 patients with metastatic spinal tumors who underwent frozen autograft total en bloc spondylectomy at our institution between May 2010 and April 2015. We assessed the incidence, primary cancer type, and sites of local recurrence. Risk factors for local recurrence were also examined through the statistical analysis of 17 items, including clinico-pathological characteristics, treatment history, and preoperative or surgical complications. Survival outcomes were evaluated with particular attention paid to the presence of local recurrence.

RESULTS

The median follow-up duration was 27.4 months (range, 4-66 months). Local recurrence was diagnosed in 10 of 91 patients (11.0%). The sites of recurrence were intradural in 4 cases, epidural in 3 cases, in a vertebral body adjacent to the resected vertebral body in 2 cases, and in the paraspinal muscle in 3 cases. None of the patients had recurrence from the liquid nitrogen-treated tumor-bearing autograft. There were no local recurrences of renal cell carcinoma, thyroid cancer, or lung cancer. Multivariate analysis indicated that radiotherapy history was the only risk factor for local recurrence (odds ratio, 6.26; 95% confidence interval, 1.21-45.62; p = 0.04). The 2-year survival rate was significantly lower for the recurrence group than for the non-recurrence group (p < 0.05).

CONCLUSIONS

A history of radiation was the only risk factor for local recurrence. Patients with recurrence had a significantly worse prognosis than those without recurrence.

Long-term survival with transarterial chemoembolization and radioembolization in a patient with cancers of unknown primary

Cancers of unknown primary (CUP) are histologically proven metastatic malignant tumors without an identified primary site before treatment. The common characteristics are early dissemination, lower response to chemotherapy and poor prognosis with short life expectancy. Treatment was directed according to the presence of localized or disseminated disease. The most frequent site of metastasis is the liver, which is a suitable target organ for arterial-directed therapies. We report a case of 53-year-old woman who was diagnosed with CUP and suspected with intracellular cholangiocellular carcinoma (ICC), presented with a very large, unresectable, chemotherapy-refractory hepatic mass and treated with transarterial chemoembolization and transarterial radioembolization and surprisingly followed for 48 months with minimally progressive and stable disease. Arterial-directed therapies, an important therapeutic option in unresectable liver tumors, can provide survival benefit even for ICC and CUP which are very large in size.

Axillary lymph node metastases from unknown primary: A French multicentre study

PURPOSE

The aim of the study was to investigate the management and prognosis of axillary cancers from unknown primaries (CUPax).

METHODS

We included all patients with lesions described as axillary nodal metastases from an unknown primary referred to four French tertiary breast cancer centres between January 1988 and December 2012. The inclusion criteria comprised: no sign of primary breast cancer on clinical examination nor on imaging (mammography, ultrasonography and breast MRI) and no primary tumour identified elsewhere.

RESULTS

CUPax represented 1.8% of all metastatic axillary lymphadenopathies in our institutions. The overall survival rate was 71%, and 16.7% of patients had secondary inflammatory breast cancer signalling a posteriori that CUPax originated from the breast. Factors that favourably affected survival according to univariate analysis were: histological type of non specific adenocarcinoma (versus other types, p = 0.02), only one lymph node involved (versus several, p = 0.04), a normal CA153 serum-level (p = 0.02), no distant metastasis at initial assessment (p = 0.02), no secondary distant metastasis (p = 0.005) and radiotherapy to the ipsilateral breast/chest wall/lymph nodes (p = 0.04). On multivariate analysis including these factors, a histological type of non-specific adenocarcinoma (p = 0.03) and distant metastases (p = 0.03) were identified as independent factors affecting survival.

CONCLUSION

We believe that these results will shed light on current investigations and treatment of this rare entity.

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.

Identification and survival outcomes of a cohort of patients with cancer of unknown primary in Ontario, Canada

BACKGROUND

Cancer of unknown primary origin (CUP) is defined by the presence of pathologically identified metastatic disease without clinical or radiological evidence of a primary tumour. Our objective was to identify incident cases of CUP in Ontario, Canada, and determine the influence of histology and sites of metastases on overall survival (OS).

MATERIAL AND METHODS

We used the Ontario Cancer Registry (OCR) and the Same-Day Surgery and Discharge Abstract Database (SDS/DAD) to identify patients diagnosed with CUP in Ontario between 1 January 2000, and 31 December 2005. Patient diagnostic information, including histology and survival data, was obtained from the OCR. We cross-validated CUP diagnosis and obtained additional information about metastasis through data linkage with the SDS/DAD database. OS was assessed using Cox regression models adjusting for histology and sites of metastases.

RESULTS

We identified 3564 patients diagnosed with CUP. Patients without histologically confirmed disease (n = 1821) had a one-year OS of 10.9%, whereas patients with confirmed histology (n = 1743) had a one-year OS of 15.6%. The most common metastatic sites were in the respiratory or digestive systems (n = 1603), and the most common histology was adenocarcinoma (n = 939). Three-year survival rates were 3.5%, 5.3%, 41.6% and 3.6% among adenocarcinoma, unspecified carcinoma, squamous cell carcinoma and undifferentiated histology, respectively. Three-year survival rates were 40%, 2.4%, 8.0% and 4.6% among patients with metastases localised to lymph nodes, the respiratory or digestive systems, other specified sites, and unspecified sites, respectively.

CONCLUSION

CUP patients in Ontario have a poor prognosis. Some subgroups may have better survival rates, such as patients with metastases localised to lymph nodes and patients with squamous cell histology.

A Simple Risk Model to Predict Survival in Patients With Carcinoma of Unknown Primary Origin

Carcinoma of unknown primary origin (CUP) is characterized by diverse histological subtypes and clinical presentations, ranging from clinically indolent to frankly aggressive behaviors. This study aimed to identify prognostic factors of CUP and to develop a simple risk model to predict survival in a cohort of Asian patients.We retrospectively reviewed 190 patients diagnosed with CUP between 2007 and 2012 at a single medical center in Taiwan. The clinicopathological parameters and outcomes of our cohort were analyzed. A risk model was developed using multivariate logistic regression and a prognostic score was generated.The prognostic score was calculated based on 3 independent prognostic variables: the Eastern Cooperative Oncology Group (ECOG) scale (0 points if the score was 1, 2 points if it was 2-4), visceral organ involvement (0 points if no involvement, 1 point if involved), and the neutrophil-to-lymphocyte ratio (0 points if ≤3, 1 point if >3). Patients were stratified into good (score 0), intermediate (score 1-2), and poor (score 3-4) prognostic groups based on the risk model. The median survival (95% confidence interval) was 1086 days (500-1617, n = 42), 305 days (237-372, n = 75), and 64 days (44-84, n = 73) for the good, intermediate, and poor prognostic groups, respectively. The c-statistics using the risk model and ECOG scale for the outcome of 1-year mortality were 0.80 and 0.70 (P = 0.038), respectively.In this study, we developed a simple risk model that accurately predicted survival in patients with CUP. This scoring system may be used to help patients and clinicians determine appropriate treatments.

Bone metastases of unknown origin: epidemiology and principles of management

Metastases are the most common malignancies involving bone; breast, prostate, lung and thyroid are the main sites of primary cancer. However, up to 30 % of patients present with bone metastases of unknown origin, where the site of the primary neoplasm cannot be identified at the time of diagnosis despite a thorough history, physical examination, appropriate laboratory testing and modern imaging technology (CT, MRI, PET). Sometimes only extensive histopathological investigations on bone specimens from biopsy can suggest the primary malignancy. At other times, a bone lesion can have such a highly undifferentiated histological appearance that a precise pathological classification on routine hematoxylin-eosin-stained section is not possible. The authors reviewed the relevant literature in an attempt to investigate the epidemiology of the histological primaries finally identified in patients with bone metastases from occult cancer, and a strategy of management and treatment of bone metastases from occult carcinomas is suggested. Lung, liver, pancreas and gastrointestinal tract are common sites for primary occult tumors. Adenocarcinoma is the main histological type, accounting for 70 % of all cases, while undifferentiated cancer accounts for 20 %. Over the past 30 years, lung cancer is the main causative occult primary for bone metastases and has a poor prognosis with an average survival of 4-8 months. Most relevant literature focuses on the need for standardized diagnostic workup, as surgery for bone lesions should be aggressive only when they are solitary and/or the occult primaries have a good prognosis; in these cases, identification of the primary tumor may be important and warrants special diagnostic efforts. However, in most cases, the primary site remains unknown, even after autopsy. Thus, orthopedic surgery has a mainly palliative role in preventing or stabilizing pathological fractures, relieving pain and facilitating the care of the patient in an attempt to provide the most appropriate therapy for the primary tumor as soon as possible.

LEVEL OF EVIDENCE

5.

Liver metastasis predicts poorer prognosis in stage IV lung adenocarcinoma patients receiving first-line gefitinib

OBJECTIVES

Gefitinib is currently used as a first-line therapy in patients of advanced non-small cell lung cancer (NSCLC) with susceptible epidermal growth factor receptor (EGFR) mutations. However, treatment outcomes of these patients vary. This study was conducted to evaluate the impact of specific metastatic sites on treatment outcomes of patients with stage IV lung adenocarcinoma with susceptible EGFR mutations receiving first-line gefitinib, focusing on the impact of liver metastasis.

MATERIALS AND METHODS

Between October 2009 and April 2014, patients of stage IV lung adenocarcinoma harboring EGFR mutation in exon 19 or 21, who received first-line gefitinib treatment, were enrolled in two hospitals and followed until December 22, 2014. The impacts of various clinical features, including sex, age, smoking history, performance status, EGFR mutation site, metastatic sites, etc., on progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 148 patients were eligible for analysis. Patients with liver metastasis on initial diagnosis (n=19) had shorter PFS and OS than those without liver metastasis did (median of PFS, 6.7 vs. 11.2 months, p<0.0001; median of OS, 9.2 vs. 17.5 months, p<0.0001). Multivariable Cox regression analysis showed liver metastasis was an independent poor prognostic factor for PFS (HR=2.939 [95% CI: 1.729-4.997], p<0.0001) and OS (HR=3.300 [95% CI: 1.708-6.373], p=0.0004).

CONCLUSION

Liver metastasis predicts poorer PFS and OS in stage IV lung adenocarcinoma patients with susceptible gene mutations receiving first-line gefitinib. Further study is warranted to elucidate the underlying mechanisms and find treatment modalities to improve prognosis of these patients.

Causes of death in patients with extranodal cancer of unknown primary: searching for the primary site

BACKGROUND

Cancer of unknown primary (CUP) is a fatal cancer, accounting for 3-5% of all diagnosed cancers. Finding the primary site is important for therapeutic choices and we believe that the organ which is designated as the cause of death may give clues about the primary site.

METHODS

A total of 20,570 patients with CUP were identified from the Swedish Family-Cancer Database. Causes of death--as reported in the death certificate--were investigated, analyzing reported metastatic sites and histological subtypes separately. Survival was compared with metastatic cancer with a known primary tumor.

RESULTS

An organ-specific cancer could be identified as a cause of death in approximately 60% of all CUP patients with adenocarcinoma or undifferentiated histology. In adenocarcinoma, lung cancer was the most frequent cause of death (20%), followed by pancreatic cancer (14%), and ovarian cancer (11%). Lung cancer was the most common cause of death in patients with CUP metastases diagnosed in the nervous system (69%), respiratory system (53%), and bone (47%), whereas ovarian cancer was the most common cause of death when CUP was diagnosed in the pelvis (47%) or the peritoneum (32%). In CUP diagnosed in the liver, liver and pancreatic cancers accounted for 26% and 22% of deaths, respectively. Also in squamous cell CUP, lung cancer was the most common cause of death (45%).

CONCLUSIONS

According to the causes of death, the primary site appeared frequently to be either the organ where CUP metastases were diagnosed or an organ which may be traced through the known metastatic patterns of different cancer types.

Surfactant protein A compared to thyroid transcription factor-1 in identifying metastatic tumors of lung origin in cytopathology

INTRODUCTION

Differentiating primary tumors and metastases of lung origin from other neoplasms often cannot be done on cytomorphology alone. Immunocytochemistry using markers such as thyroid transcription factor-1 (TTF-1) is employed for this purpose. Surfactant protein A (SPA) is a glycoprotein with multiple functions in the lung. There have been limited immunohistochemical studies investigating the diagnostic role of SPA. This study aimed to determine the diagnostic utility of SPA compared with that of TTF-1 in identifying tumors of lung origin in cytology samples.

MATERIALS AND METHODS

A total of 155 consecutive cytology specimens procured outside of the lung were analyzed, in which SPA immunohistochemistry was reported. Cases were reviewed to document final diagnoses, immunostain results (including TTF-1), and histopathology follow-up when available.

RESULTS

Cytoplasmic SPA immunoreactivity was identified primarily in metastatic lung adenocarcinomas (ADC). SPA was also positive in 3 carcinomas of gynecologic/breast origin. SPA and TTF-1 specificity and positive predictive value were high (>90%) with relatively low sensitivity and negative predictive value for identifying metastatic ADC of lung origin. A panel of SPA and TTF-1 correctly identified most (79.7%) lung metastatic adenocarcinomas.

CONCLUSIONS

SPA is a useful cytoplasmic marker to confirm lung origin in metastatic nonmucinous ADC. However, SPA is limited by having low sensitivity and being negative in up to 35% of metastatic ADCs of lung origin, whereas TTF-1 exhibited better sensitivity. SPA may rarely demonstrate false immunoreactivity in a subset of gynecologic/breast carcinomas. Employing a panel of SPA and TTF-1 has better diagnostic utility than either stain alone.