Updated Incidence, Treatment and Survival of a Nationwide Cohort of Patients with Peritoneal Metastases of Unknown Origin

The aim of this study was to investigate the incidence, treatment and survival of patients with peritoneal metastases (PM) of unknown origin. All Dutch patients diagnosed in 2017 and 2018 with PM of unknown origin (PM-CUP) were evaluated. Data were extracted from the Netherlands Cancer Registry (NCR). Patients with PM-CUP were categorized into the following histological subtypes: 1) adenocarcinoma, 2) mucinous adenocarcinoma, 3) carcinoid, 4) unspecified carcinoma and 5) other. Treatments were compared between the different histological subtypes in patients with PM-CUP. Overall survival (OS) was calculated using the Kaplan-Meier method for all patients with cancer of unknown origin and between histological subtypes in patients with PM-CUP. Significant differences in OS were assessed by using the log-rank test. In total, 3026 patients were diagnosed with cancer of unknown origin, 513 (17%) among them were diagnosed with PM-CUP. Most PM-CUP patients received best supportive care only (76%), whereas 22% received systemic treatment and 4% underwent metastasectomy. Median OS was 1.1 months for all patients with PM-CUP but varied from 0.6 months to 30.5 months depending on the underlying histology. In this study, PM-CUP were diagnosed in 17% of all patients with cancer of unknown primary and the reported survival in this cohort was extremely poor. Since survival differed among histological subtypes and recently more treatment options became available for a selected group of patients with peritoneal malignancies, it is of great importance to identify the histology of the metastases and whenever possible the primary tumor.

Brain metastases in adult patients with melanoma of unknown primary in the Netherlands (2011-2020)

BACKGROUND

Although patients with melanoma of unknown primary (MUP) have a better prognosis than similar-staged melanoma patients with known primary, the occurrence of brain metastases (BM) entails a serious complication. This study provides an overview of the incidence, treatment patterns, and overall survival (OS) of adult patients with BM-MUP in the Netherlands.

METHODS

BM-MUP cases were retrieved from the Netherlands Cancer Registry. Patient, disease and treatment-related characteristics were summarised using descriptive statistics. Overall survival (OS) was calculated by the Kaplan-Meier method, and the impact of prognostic factors on OS was assessed using Cox proportional hazard regression analyses.

RESULTS

Among 1779 MUP patients, 450 were identified as BM-MUP (25.3%). Of these patients, 381 (84.7%) presented with BM along with other metastases, while 69 (15.3%) had BM only. BM-MUP patients were predominantly male (68.2%), and had a median age of 64 years at diagnosis (interquartile range 54-71 years). Over time, the proportion of BM along other metastatic sites increased, and the occurrence of BM decreased (p = 0.01). 1-Year OS improved for the total population, from 30.0% (95% confidence interval (CI): 19.8-40.9%) in 2011-2012 to 43.6% (95%CI: 34.5-52.3%) in 2019-2020, and median OS more than doubled from 4.2 months (95%CI: 3.3-6.2 months) to 9.8 months (95%CI: 7.0-13.2 months). Patient's age, localisation of BM, presence of synchronous liver metastasis and treatment were identified as independent predictors of OS.

CONCLUSION

Notwithstanding the progress made in OS for patients with BM-MUP in the past decade, their overall prognosis remains poor, and further efforts are needed to improve outcomes.

Risk factors for cancer of unknown primary: a literature review

Cancer of Unknown Primary (CUP) is metastatic cancer with an unidentifiable primary tumour origin during life. It remains difficult to study the occurrence and aetiology of CUP. Hitherto, it is unclear whether risk factors are associated with CUP, yet identifying these factors could reveal whether CUP is a specific entity or a cluster of metastasised cancers from various primary tumour origins. Epidemiological studies on possible CUP risk factors were systematically searched in PubMed and Web of Science on February 1^st, 2022. Studies, published before 2022, were included if they were observational human-based, provided relative risk estimates, and investigated possible CUP risk factors. A total of 5 case-control and 14 cohort studies were included. There appears to be an increased risk for smoking in relation to CUP. However, limited suggestive evidence was found to link alcohol consumption, diabetes mellitus, and family history of cancer as increased risks for CUP. No conclusive associations could be made for anthropometry, food intake (animal or plant-based), immunity disorders, lifestyle (overall), physical activity, or socioeconomic status and CUP risk. No other CUP risk factors have been studied. This review highlights smoking, alcohol consumption, diabetes mellitus and family history of cancer as CUP risk factors. Yet, there remains insufficient epidemiological evidence to conclude that CUP has its own specific risk factor profile.

International consensus on the initial diagnostic workup of cancer of unknown primary

BACKGROUND

Although the incidence of Cancer of Unknown Primary (CUP) is estimated to be 1-2 % of all cancers worldwide, no international standards for diagnostic workup are yet established. Such an international guideline would facilitate international comparison, provide adequate incidence and survival rates, and ultimately improve care of patients with CUP.

METHODS

Participants for a four round modified Delphi study were selected via a CUP literature search in PubMed and an international network of cancer researchers. A total of 90 CUP experts were invited, and 34 experts from 15 countries over four continents completed all Delphi survey rounds.

FINDINGS

The Delphi procedure resulted in a multi-layer CUP classification for the diagnostic workup. Initial diagnostic workup should at least consist of history and physical examination, full blood count, analysis of serum markers, a biopsy of the most accessible lesion, a CT scan of chest/abdomen/pelvis, and immunohistochemical testing. Additionally, the expert panel agreed on the need of an ideal diagnostic lead time for CUP patients. There was no full consensus on the place in diagnostic workup of symptom-guided MRI or ultrasound, a PET/CT scan, targeted gene panels, immunohistochemical markers, and whole genome sequencing.

INTERPRETATION

Consensus was reached on the contents of the first diagnostic layer of a multi-layer CUP classification. This is a first step towards full consensus on CUP diagnostics, that should also include supplementary and advanced diagnostics.

Vegetable and fruit consumption and cancer of unknown primary risk: results from the Netherlands cohort study on diet and cancer

Background

Cancer of Unknown Primary (CUP) is a metastatic cancer for which the primary lesion remains unidentifiable during life and little is also known about the modifiable risk factors that contribute to its development. This study investigates whether vegetables and fruits are associated with CUP risk.

Methods

We used data from the prospective Netherlands Cohort Study on Diet and Cancer which includes 120,852 participants aged between 55 and 69 years in 1986. All participants completed a self-administered questionnaire on cancer risk factors at baseline. Cancer follow-up was established through record linkage to the Netherlands Cancer Registry and the Dutch Pathology Registry. As a result, 867 incident CUP cases and 4005 subcohort members were available for case-cohort analyses after 20.3 years of follow-up. Multivariable adjusted hazard ratios were calculated using proportional hazards models.

Results

We observed no associations between total vegetable and fruit consumption (combined or as separate groups) and CUP risk. However, there appeared to be an inverse association between the consumption of raw leafy vegetables and CUP. With respect to individual vegetable and fruit items, we found neither vegetable nor fruit items to be associated with CUP risk.

Conclusions

Overall, vegetable and fruit intake were not associated with CUP incidence within this cohort.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09502-7.

Adherence to the World Cancer Research Fund and the American Institute for Cancer Research lifestyle recommendations for cancer prevention and Cancer of Unknown Primary risk

BACKGROUND & AIMS

The World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) updated their cancer prevention recommendations in 2018. Adherence to these recommendations has been associated with lower cancer risk and mortality. However, adherence in relation to Cancer of Unknown Primary (CUP) risk has not been studied. This study investigates whether adherence to the WCRF/AICR recommendations is associated with CUP risk.

METHODS

Data from the prospective Netherlands Cohort Study on diet and cancer was used to measure adherence to the recommendations in relation to CUP risk. The cohort includes 120 852 participants (aged 55-69 years), who completed a self-administered questionnaire on cancer risk factors at baseline. Adherence was investigated with respect to body fatness, physical activity, plant foods, meat consumption and alcohol. Incident CUP cases were identified through record linkage to the Netherlands Cancer Registry and Dutch Pathology Registry. A follow-up of 20.3 years, resulted in 856 incident CUP cases and 3911 subcohort members with complete information available for case-cohort analyses. Multivariable adjusted hazard ratios were estimated using proportional hazards models and were adjusted for age at baseline, sex, cigarette smoking (status, frequency, and duration) and total energy intake.

RESULTS

Highest adherence appeared to be associated with decreased CUP risk in the age-sex adjusted model (HR: 0.76, 95% CI: 0.62-0.92). After additional adjustment for cigarette smoking (status, frequency, and duration), the association attenuated and was no longer statistically significant. No multiplicative interactions were observed between sex nor smoking status and overall adherence in relation to CUP.

CONCLUSION

Within this cohort, highest adherence to the WCRF/AICR recommendations is not statistically significantly associated with decreased CUP risk after multivariable adjustment.

Family history of cancer in first degree relatives and risk of cancer of unknown primary

Objective

Cancer of Unknown Primary (CUP) refers to the presence of metastatic lesions, with no identifiable primary site during the patient's lifetime. Poor survival and lack of available treatment highlight the need to identify potential CUP risk factors. We investigated whether a family history of cancer is associated with increased CUP risk.

Methods

We performed a case cohort analysis using data from the Netherlands Cohort Study, which included a total of 963 CUP cases and 4,288 subcohort members. A Cox Proportional Hazards Regression was used to compare CUP risk in participants who reported to have a family member with cancer to those who did not, whilst adjusting for confounders.

Results

In general, we observed no increased CUP risk in those who reported a family history of cancer. CUP risk appeared slightly increased in those who reported cancer in a sibling (HR: 1.16, 95% CI: 0.97–1.38), especially in those with a sister with cancer compared with those without (HR: 1.23, 95% CI: 0.99–1.53), although these findings are not statistically significant.

Conclusion

Having a family history of cancer is not an independent risk factor of CUP.

Abstract LB088: Meat consumption and Cancer of Unknown Primary (CUP) risk: results from the Netherlands Cohort Study on diet and cancer

Meat consumption and Cancer of Unknown Primary (CUP) risk: results from the Netherlands Cohort Study on diet and cancer

Purpose: Cancer of Unknown Primary (CUP) is a metastasized cancer for which the primary tumor origin remains unidentifiable during a patient's lifetime. CUP prognosis is highly unfavorable with a median survival of 1.7 months. Research into CUP etiology with respect to dietary factors is particularly scarce. This study investigates whether meat consumption is associated with CUP risk, and whether there is multiplicative interaction between sex or cigarette smoking status and the relationship of meat consumption and CUP risk. Methods: Data was utilized from the prospective Netherlands Cohort Study (NLCS) that includes 120,852 participants aged 55-69 years from 204 Dutch municipalities. All participants completed a self-administered questionnaire on diet and other cancer risk factors at baseline. Habitual meat consumption was measured with respect to red meat (overall), beef, pork, minced meat, liver, processed meat, poultry and fish. The food-frequency questionnaire had been validated against a 9-day diet record and was tested for reproducibility. Cancer follow-up was established through record linkage to the Netherlands Cancer Registry and the Dutch Pathology Registry. As a result, a total of 899 CUP cases and 4,111 subcohort members with complete and consistent dietary data were available for case-cohort analyses after 20.3 years of follow-up. Multivariable adjusted hazard ratios (HRs) were calculated using proportional hazards models, and were adjusted for age, sex, alcohol consumption, cigarette smoking variables (status, frequency, duration), and total energy intake. Results: In general, we observed no association between red meat (overall) consumption and CUP risk (multivariable adjusted HR for Q4 vs. Q1: 1.04, 95% CI: 0.83-1.30, Ptrend = 0.31). An increased risk was observed between beef consumption and CUP, for which a statistically significant trend was found (HR for Q4 vs. Q1: 1.22, 95% CI: 0.99-1.52, Ptrend = 0.02). The effect of beef consumption on CUP risk appeared to be stronger in women (HR Q4 vs. Q1: 1.47, 95% CI: 1.04-2.07, Ptrend = 0.004). A statistically significant association was also observed between processed meat consumption and CUP risk (HR for Q4 vs. Q1: 1.40, 95% CI: 1.12-1.75, Ptrend = 0.006). Our sex-stratified analysis indicated that the effect of processed meat consumption on CUP risk was more pronounced in women (HR for Q4 vs. Q1: 1.53, 95% CI: 1.08-2.16, Ptrend = 0.001), than in men (HR Q4 vs. Q1: 1.33, 95% CI: 0.99-1.79, Ptrend = 0.15). In contrast, no associations were observed between poultry or fish consumption and CUP risk (HR for C4 vs. C1: 0.97, 95% CI: 0.79-1.21, Ptrend = 0.28 & HR for Q4 vs. Q1: 1.25, 95% CI: 0.99-1.57, Ptrend = 0.29, respectively). We found no multiplicative interaction between cigarette smoking status and meat consumption and CUP risk. Conclusion: Beef and processed meat consumption appear to be associated with increased CUP risk in women. In men, there appeared to be a non-significant positive association between processed meat consumption and CUP risk.

Citation Format: Karlijn Hermans, Piet Van den Brandt, Caroline Loef, Rob Jansen, Leo Schouten. Meat consumption and Cancer of Unknown Primary (CUP) risk: results from the Netherlands Cohort Study on diet and cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB088.

Meat consumption and cancer of unknown primary (CUP) risk: results from The Netherlands cohort study on diet and cancer

Purpose

Cancer of unknown primary (CUP) is a metastasised cancer for which no primary lesion could be identified during life. Research into CUP aetiology with respect to dietary factors is particularly scarce. This study investigates whether meat consumption is associated with CUP risk.

Methods

Data was utilised from the prospective Netherlands cohort study that includes 1,20,852 participants aged 55–69 years. All participants completed a self-administered questionnaire on diet and other cancer risk factors at baseline. Cancer follow-up was established through record linkage to the Netherlands Cancer Registry and the Dutch Pathology Registry. A total of 899 CUP cases and 4111 subcohort members with complete and consistent dietary data were available for case–cohort analyses after 20.3 years of follow-up. Multivariable adjusted hazard ratios (HRs) were calculated using proportional hazards models.

Results

We found a statistically significant positive association with beef and processed meat consumption and CUP risk in women (multivariable adjusted HR Q4 vs. Q1 1.47, 95% CI 1.04–2.07, P_trend = 0.004 and Q4 vs. Q1 1.53, 95% CI 1.08–2.16, P_trend = 0.001, respectively), and a non-significant positive association with processed meat consumption and CUP risk in men (multivariable adjusted HR Q4 vs. Q1 1.33, 95% CI 0.99–1.79, P_trend = 0.15). No associations were observed between red meat (overall), poultry or fish consumption and CUP risk.

Conclusion

In this cohort, beef and processed meat consumption were positively associated with increased CUP risk in women, whereas a non-significant positive association was observed between processed meat consumption and CUP risk in men.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02600-5.

Alcohol consumption, cigarette smoking and cancer of unknown primary risk: Results from the Netherlands Cohort Study

Cancer of unknown primary (CUP) is a metastasised malignancy with no identifiable primary tumour origin. Despite the frequent occurrence and bleak prognosis of CUP, research into its aetiology is scarce. Our study investigates alcohol consumption, tobacco smoking and CUP risk. We used data from the Netherlands Cohort Study, a cohort that includes 120 852 participants aged 55 to 69 years, who completed a self‐administered questionnaire on cancer risk factors at baseline. Cancer follow‐up was established through record linkage to the Netherlands Cancer Registry and Dutch Pathology Registry. After 20.3 years of follow‐up, 963 CUP cases and 4288 subcohort members were available for case‐cohort analyses. Multivariable‐adjusted hazard ratios (HRs) were calculated using proportional hazard models. In general, CUP risk increased with higher levels of alcohol intake (P_trend = .02). The association was more pronounced in participants who drank ≥30 g of ethanol per day (HR: 1.57, 95% confidence interval [CI]: 1.20‐2.05) compared to abstainers. Current smokers were at an increased CUP risk (HR: 1.59, 95% CI: 1.29‐1.97) compared to never smokers. We observed that the more the cigarettes or the longer a participant smoked, the higher the CUP risk was (P_trend = .003 and P_trend = .02, respectively). Interaction on additive scale was found for participants with the highest exposure categories of alcohol consumption and cigarette smoking frequency and CUP risk. Our findings demonstrate that alcohol consumption and cigarette smoking are associated with increased CUP risk. Lifestyle recommendations for cancer prevention regarding not drinking alcohol and avoiding exposure to smoking are therefore also valid for CUP.

What's new?

Little is known about factors that raise the risk of cancer of unknown primary (CUP), in which metastases have no identifiable primary tumor origin. This prospective study examined possible associations between CUP and alcohol consumption and cigarette smoking, using sex‐stratified analyses and assessing variables such as smoking frequency and duration. Analyses show that higher alcohol consumption, current cigarette smoking, more cigarettes smoked, and longer smoking duration are associated with increased CUP risk. The data highlight the significance of lifestyle factors in CUP risk and suggest that lifestyle recommendations regarding alcohol intake and smoking are relevant to CUP prevention.

ELVIRA HSV, a yield reduction assay for rapid herpes simplex virus susceptibility testing

A colorimetric yield reduction assay, ELVIRA (enzyme-linked virus inhibitor reporter assay) HSV, was developed to determine the antiviral drug susceptibilities of herpes simplex virus (HSV). It uses an HSV-inducible reporter cell line. This simple and rapid assay has an objective readout, low inoculum size, and good reproducibility. The results correlate well with those of the plaque reduction assay.