Carcinoma of an unknown primary site: a chemotherapy strategy based on histological differentiation--results of a prospective study

Case Report: Metastatic succinate dehydrogenase-deficient gastrointestinal stromal tumor treated with chemotherapy and immune checkpoint inhibitor

We report a young adult with a recurrent metastatic succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumor (GIST) achieving a pathological complete response with a chemoimmunotherapy regimen. The patient underwent a gastroscopy, which revealed a large-ulcerated tumor on the greater gastric curvature. Histological analysis showed a poorly differentiated SDHB-deficient GIST with PDL1 expression at a 100% rate and a RET gene fusion. Rapid metastatic relapse after subtotal gastrectomy was resistant to imatinib. The patient received four cycles of cisplatin, etoposide, and pembrolizumab followed by pembrolizumab maintenance with a complete response. Late relapse 3 years later was treated with the same regimen and achieved complete pathological response. Two years later, an isolated focus was removed, showing the recurrent SDH-deficient GIST. Pembrolizumab is still in maintenance with no relapse to date. The role of chemoimmunotherapy as part of treatment in recurrent metastatic SDH-deficient, PDL1-positive GIST patients is worth further investigation.

Utility of UV Signature Mutations in the Diagnostic Assessment of Metastatic Head and Neck Carcinomas of Unknown Primary

BACKGROUND

Metastatic carcinoma of unknown primary origin to the head and neck lymph nodes (HNCUP) engenders unique diagnostic considerations. In many cases, the detection of a high-risk human papillomavirus (HR-HPV) unearths an occult oropharyngeal squamous cell carcinoma (SCC). In metastatic HR-HPV-independent carcinomas, other primary sites should be considered, including cutaneous malignancies that can mimic HR-HPV-associated SCC. In this context, ultraviolet (UV) signature mutations, defined as ≥ 60% C→T substitutions with ≥ 5% CC→TT substitutions at dipyrimidine sites, identified in tumors arising on sun exposed areas, are an attractive and underused tool in the setting of metastatic HNCUP.

METHODS

A retrospective review of institutional records focused on cases of HR-HPV negative HNCUP was conducted. All cases were subjected to next generation sequencing analysis to assess UV signature mutations.

RESULTS

We identified 14 HR-HPV negative metastatic HNCUP to either the cervical or parotid gland lymph nodes, of which, 11 (11/14, 79%) had UV signature mutations, including 4 (4/10, 40%) p16 positive cases. All UV signature mutation positive cases had at least one significant TP53 mutation and greater than 20 unique gene mutations.

CONCLUSION

The management of metastatic cutaneous carcinomas significantly differs from other HNCUP especially metastatic HR-HPV-associated SCC; therefore, the observation of a high percentage of C→T with CC →TT substitutions should be routinely incorporated in next generation sequencing reports of HNCUP. UV mutational signatures testing is a robust diagnostic tool that can be utilized in daily clinical practice.

Case Report: Combined pembrolizumab, 5-fluorouracil, and cisplatin therapy were remarkably effective in p16-positive squamous cell carcinoma of unknown primary

Background

Cancer of unknown primary (CUP) is a malignant tumor without a known primary lesion with a frequency of 3-5%. It can be divided into favorable and unfavorable prognosis subsets. While recommended treatments are available for the former group, there is no established treatment for the latter. Here, we report the effective treatment of a 32-year-old woman with p16-positive squamous cell CUP with pembrolizumab plus 5-fluorouracil and cisplatin therapy.

Case presentation

A 32-year-old woman presented with metastatic lesions in the liver, lung, bone, cervical region, abdominal region, and pelvic lymph nodes. She was diagnosed with p16-positive squamous cell carcinoma of unknown primary origin. The patient received pembrolizumab plus 5-fluorouracil and cisplatin therapy, which markedly reduced the metastasis and improved her Eastern Cooperative Oncology Group performance status after two courses.

Conclusion

This case report highlights the potential of pembrolizumab plus 5-fluorouracil and cisplatin therapy for treating CUP with an unfavorable prognosis. p16 positivity is worth examining for squamous cell carcinoma of unknown primary origin, and if present, this therapy should be considered a promising treatment option.

Anti-PD-1 Monoclonal Antibodies (mAbs) Are Superior to Anti-PD-L1 mAbs When Combined with Chemotherapy in First-Line Treatment for Metastatic Non-Small Cell Lung Cancer (mNSCLC): A Network Meta-Analysis

Platinum-based chemotherapy combined with anti-PD-1 or PD-L1 monoclonal antibodies (mAbs) is now standard first-line therapy for mNSCLC patients without sensitizing driver mutations. Anti-PD-1 and anti-PD-L1 mAbs are considered to be equivalent in efficacy. In the absence of head-to-head randomized control trials (RCTs), we utilized network meta-analysis (NWM) to provide an indirect comparison of their efficacy. A systematic literature review and NWM were performed using RCTs that investigated anti-PD-1 or PD-L1 mAbs ± chemotherapy in patients with mNSCLC in the first-line setting. The primary outcome was comparative overall survival (OS), while secondary outcomes were comparative progression-free survival (PFS), objective response rate (ORR), and rate of grade 3 and higher toxicities. We identified 24 RCTs. Patients treated with anti-PD-1 mAb + chemotherapy compared with anti-PD-L1 mAb + chemotherapy showed superior mOS, mPFS, and ORR with a similar rate of grade 3 and higher toxicities. This difference in mOS was most pronounced in the PD-L1 TPS 1-49% population. The two mAbs were equivalent as single agents. Anti-PD-1 mAb + chemotherapy improved mOS when compared to anti-PD-1 mAb monotherapy, whereas anti-PD-L1 mAbs + chemotherapy did not when compared to anti-PD-L1 mAb monotherapy. Head-to-head RCTs are warranted in the future.

Cervical: Lymphadenopathy

The neck region contains around 300 lymph nodes (LNs) out of 800 LNs in the whole body. The detailed study of LNs by Rouviere in 1932 [1] and the later illustration of metastatic predilection of head and neck malignancies to certain LN regions by Lindberg et al. [2] paved the road to a clinically sound classification. The American Academy of Otolaryngology and Head and Neck Surgery (AAO-HNS) and the American Joint Committee on Cancer (AJCC) developed the currently widely accepted levels classification of the cervical LNs (Table 8.1, Figs. 8.1 and 8.2).

Evaluation of survival benefits by platinums and taxanes for an unfavourable subset of carcinoma of unknown primary: a systematic review and meta-analysis

Background:

Although chemotherapeutic regimens containing a taxane or platinum agent have been widely recommended for unfavourable carcinoma of unknown primary (CUP), no evidence exists for the superiority of any administered regimens. To date, the efficacy has been mostly assessed in the limited setting of phase II trials, and few attempts have been made to synthesise all available data for survival outcomes.

Methods:

Electronic databases were searched from 1980 to 2011. Survival results were combined for each pre-specified category of regimens using a random-effects model, and meta-regression models were used to adjust for heterogeneity in some known prognostic factors.

Results:

A total of 32 studies were included for meta-analysis. Tendency towards better survival outcome by platinums or taxanes was indicated. After adjustment for important prognostic factors, however, the difference between the platinum-based and non-platinum regimens became no longer significant. Survival benefits by the taxane-based regimens remained significant, with a prolonged median survival time of 1.52 months (P=0.03) and a higher 1-year survival rate of 6.25% (P=0.05), but the benefit did not sustain for 2 years.

Conclusion:

Although no effective therapies have been established, this meta-analysis helps to fill an important gap of evidence. However, caution should still be taken because of the potential unmeasured confounding.

Clinical presentation of carcinoma of unknown primary: 14 years of experience

A carcinoma of unknown primary (CUP) is a histologically confirmed metastatic cancer without a definitive primary site after performing a detailed medical examination. The purpose of the study was to classify unfavorable CUPs into more reliable disease entities, which reflect the clinical course. We reviewed the medical records of patients diagnosed with a CUP between January 1995 and March 2008. Patients were classified into a conventional favorable-risk group and a newly proposed unfavorable-risk group according to the clinicopathologic features. Five hundred eighty-six patients were diagnosed with CUPs. Fifty-six (9.6%) patients were classified in the conventional favorable-risk group, and 486 (82.9%) patients were classified in the unfavorable-risk group. We further classified the 486 patients into six subgroups with an unfavorable risk, while excluding 29 patients (5.0%) who were not classifiable. The overall survival of the conventional favorable-risk group was 47.0 months (95% CI, 11.1~82.9 months), which was significantly longer than that of any subgroup of the newly proposed unfavorable-risk group (P < 0.001). Patients with squamous cell carcinoma in the abdominopelvic cavity showed similar overall survival with unfavorable-risk group (P = 0.484). Women with non-papillary malignant ascites had a survival in between the favorable and unfavorable groups (P <  0.001). The newly proposed unfavorable-risk group may assist in classifying CUP patients with an unfavorable risk in a clinically more meaningful way. Squamous cell carcinoma in the abdominopelvic cavity should be considered in the unfavorable-risk group and women with non-papillary malignant ascites in an intermediate-risk group. Further studies with molecular profiling would help in classifying and treating patients with CUPs and an unfavorable risk.

Challenges of utilizing immunostains to facilitate the diagnosis and management of metastatic adenocarcinoma

Women presenting with metastases from an unknown primary site represent a growing diagnostic challenge. Treatment is based upon the results of several diagnostic radiographic modalities that may locate the occult primary and determine the extent of metastatic tumor burden. Immunostaining represents another modality that can be used to facilitate identification and management of occult primary carcinoma. In patients who present with advanced disease, combining standard techniques with immunostaining can usually aid in determining the most effective regimen for optimal palliation and, in some cases, prolonged survival. We describe metastatic adenocarcinoma of unknown primary presenting as a pericardial effusion and coincident supraclavicular adenopathy. The patient completed the chemotherapy and had stable metastatic tumor burden with an acceptable quality of life. Two years after initial diagnosis, the patient expired because of disease progression. Although immunohistochemical staining initially suggested metastatic breast carcinoma, her clinical course confirmed a lung primary.

Large mass affecting retroperitoneal great vessels: a rare presentation of a cancer of unknown primary with diagnostic dilemma and challenged surgical intervention

INTRODUCTION

Cancers of unknown primary site (CUPs) consist of a clinical entity which accounts for 3-5% of all solid tumor patients. They are metastatic solid tumors whose fundamental characteristic is the absence of identifiable site of the primary tumor.

CASE REPORT

We report the case of a completely asymptomatic 34-year-old man with a palpated huge mass found incidentally in the left abdomen. All the investigations were normal. During the operation, a large mass was identified 2 cm below the left renal artery which was displacing and encompassing the great retroperitoneal vessels and the left ureter. A complete resection of the mass was performed while the histological examination revealed a solitary retroperitoneal lymph node categorized as metastatic adenocarcinoma of unknown primary site.

CONCLUSION

It is essential to assess the high incidence of patients with cancer who present with CUP. Early surgical excision of the metastatic lesion followed by adjuvant combination chemotherapy should be considered for patients with only a single site of malignancy.

Phase II trials in patients with carcinoma of unknown primary: a pooled data analysis

BACKGROUND

The management of carcinoma of unknown primary site remains debatable. The literature data consists of about 29 phase-II studies investigating 38 regimens, providing a broad range of response rates (RR).

METHODS

We performed a pooled published data analysis to identify the factors influencing RR in these 29 studies.

RESULTS

In front-line treatment, the overall RR was 31% (430/1,380). At least nine factors significantly influenced the reported RR, excluding drugs under investigation, such as the impact factor of the journal, single-centre study, some eligibility criteria, central radiological review, sample size calculation based on statistical hypothesis and stratification. Two drugs seem to improve RR: cisplatin and doxorubicin. Two drugs seem to be associated with a worse RR: irinotecan and carboplatin.

CONCLUSIONS

This pooled data analysis illustrates that in a phase II trial setting, it is impossible to attribute the variation in RR solely to the modification of drugs under investigation.

Treatment for patients with unknown primary cancer and favorable prognostic factors

Patients with carcinoma of unknown primary site are heterogeneous with respect to clinical and pathologic features. Within this diverse group, specific clinical and/or pathologic features can be used to define several subsets with favorable prognoses. Specific subsets include women with peritoneal carcinomatosis, women with isolated axillary lymph node metastases, adenocarcinoma presenting as a single metastatic lesion, young men with features of extragonadal germ cell tumor, squamous carcinoma involving cervical or inguinal lymph nodes, and neuroendocrine carcinoma. Prospective identification of patients in these favorable subgroups allows the most effective treatment to be selected. This review summarizes current recommendations for the evaluation and treatment of patients in each of these favorable prognostic subsets.

Irinotecan plus carboplatin for patients with carcinoma of unknown primary site

Carcinoma of unknown primary site (CUP) is rarely encountered in clinical practice and optimal chemotherapy has not yet been established. This phase II study was conducted to evaluate the efficacy and toxicity of combined irinotecan+carboplatin therapy in chemotherapy-naive patients with CUP. Irinotecan was administered at 60 mg m(-2) as a 90-min intravenous infusion on days 1, 8 and 15. Carboplatin was administered at an area-under-the curve of 5 mg ml(-1) min as a 60-min intravenous infusion on day 1. This cycle was repeated every 28 days for up to six cycles. Forty-five patients were enrolled in the study. An intent-to-treat analysis revealed an objective response rate to the treatment of 41.9% (95% confidence interval, 27.0-57.9%). The median time to progression was 4.8 months and the median survival was 12.2 months. The 1- and 2-year survival rates were 44 and 27%, respectively. The most frequent grade 3 or more severe adverse events were leukopaenia (21%), neutropaenia (33%), anaemia (25%) and thrombocytopaenia (20%). Thus, the combination of irinotecan plus carboplatin was found to be active in patients with CUP. Therefore, the regimen may be one of the potentially available chemotherapeutic options for community standard of care in patients with a good performance status.

[The role of the pathologist in the diagnosis of metastases from urological malignancies]

Metastases are sometimes the first revelation of urologic cancers. The role of the pathologist in case metastatic disease of unknown origin is to affirm the malignant character of the lesion; provide histological information for possible origins; and to give histological therapeutic arguments. In most of the cases the histological analysis based on cellular morphology is sufficient to suspect a particular origin. In case of poor differentiated carcinoma in addition to the histological analysis, the immunohistochemical study allows the detection of various specific antigens. In this review we approach the various morphological criteria and the interest of the various antibodies to confirm the urologic origin of a metastasis.

Carcinoma of unknown primary site: development in a single institution of a prognostic model based on clinical and serum variables

PURPOSE

To identify clinical and biologic variables with significant impact on survival in patients with carcinomas of an unknown primary site (CUP) and to develop a simple prognostic model.

PATIENTS AND METHODS

In this retrospective study, univariate and multivariate prognostic factors analyses were conducted in a population of 100 patients with CUP. Patients with features requiring well defined treatments had previously been excluded.

RESULTS

Overall survival (OS) was significantly related to the following pretreatment adverse prognostic clinical factors: a poor performance status (2 or 3), weight loss more than 10% in the last six months, the presence of liver metastases and more than two metastatic sites. Two biological parameters predicted a significantly shorter survival: elevated serum levels of alkaline phosphatase and of lactate dehydrogenase. In the multivariate analysis, only two independent adverse prognostic parameters were retained: a poor performance status and the presence of liver metastases. We developed a prognostic model for OS based on the following subgroups: good prognosis (PS 0 or 1 and absence of liver metastases), intermediate prognosis (PS> or =2 or presence of liver metastases) and poor prognosis (PS> or =2 or presence of liver metastases). Median OS for the three groups was 10.8, 4 and 1.9 months respectively, p<0.0001.

CONCLUSION

A simple prognostic model using performance status and presence of liver metastases was developed. It allowed the assignment of patients into three subgroups with different outcomes. Treatment strategies could be adapted for each subgroup. We think that this prognostic model could be useful and should be validated in other patient series.

A Clinical Review of the Investigation and Management of Carcinoma of Unknown Primary in a Single Cancer Network

AIMS

Carcinoma of unknown primary (CUP) is a common encounter in oncological practice and represents 2.0-6.0% of all invasive malignancies. Evidence to support particular therapeutic strategies in this patient population is scarce, and empirical therapies are frequently derived from research on patients where the primary tumour site is known.

MATERIALS AND METHODS

This retrospective study reviewed the management of all patients recorded to have a diagnosis of CUP in a single cancer centre over a period of 12 months. Health records were reviewed documenting the CUP subtype, the investigations carried out both in the referring cancer unit and subsequently at the cancer centre and the recommended treatment (type and regimen), together with survival. The outcomes were examined in respect to a number of prognostic factors. Statistical tests were considered significant at P < 0.05.

RESULTS

One hundred and sixty-six patients were recorded to have a diagnosis of CUP, representing 3.7% of all referrals to the cancer centre. The median age of patients was 68 years (range 32-94 years), and 52.0% were women. The three most common CUP subgroups were CUP-liver/multiple sites (25.0%), CUP-bone (21.0%) and CUP-brain (16.0%). The remaining subgroups occurred at frequencies of less than 10% each. Histological confirmation was only obtained in 55.0% of cases. Even within a single subtype, 41 patients with CUP-liver/multiple sites underwent a total of 19 different investigations before any treatment being given. Forty-seven (28.0%) patients received radiotherapy, 30 (18.0%) received chemotherapy and 58 (35.0%) received supportive care alone. Nine different 5-fluorouracil-containing regimens were used in 11 patients treated with chemotherapy for CUP-liver. The overall median survival for all patients was 4.0 months. Survival was better in patients with a good performance status (0-1) and absent liver metastases (median survival 15.0 months; 95% confidence interval 8.0-22.1) and those who received chemotherapy (median survival 13.0 months; 95% confidence interval 7.4-18.6). Multivariate analysis confirmed female gender (P = 0.006), a good performance status (0/1) (P < 0.0001) and absent liver metastases (P = 0.002) as favourable prognostic indicators.

CONCLUSIONS

The appropriate management of patients with CUP is unclear and this study revealed a high degree of variation in clinical practice. This area is in urgent need of clinical research to ensure that the treatment of CUP is evidence based. Until such time, clinical recommendations are suggested for the investigation and treatment of such patients. Therapeutic progress will be facilitated by designating a clinical lead for CUP in each clinical network.

A patient with pulmonary lymphangitic carcinomatosis successfully treated with TS-1 and cisplatin

A 37-year-old man was referred to our hospital with complaints of dyspnea and general fatigue. Chest radiograph and CT scan revealed thickness of bronchovascular bundles in both lungs. In spite of various examinations, the primary lesion was not identified. He received chemotherapy containing TS-1 and cisplatin. Pulmonary lymphangitic carcinomatosis disappeared and the patient achieved a good partial response. He survived for 14 months after the chemotherapy. We believe the combination of TS-1 and cisplatin is one of the attractive options for patients with cancer of unknown primary site.

Identification of Clinical Prognostic Factors in Patients with Unknown Primary Tumors Treated with a Platinum-Based Combination

OBJECTIVE

The aim of this study was to evaluate patient and tumor characteristics in 102 patients with unknown primary tumors (UPT) prospectively treated with a combination of carboplatin, doxorubicin, and etoposide, to identify clinical variables predictive of response and survival.

PATIENTS AND METHODS

The association between clinical characteristics and outcome was evaluated by univariate and multivariate analysis: chi(2) test and logistic regression analysis were used to study variables predictive of response, and survival analysis, comparison of survival curves and Cox multiple regression analysis to study variables predictive of survival.

RESULTS

We obtained 26.5% objective responses (95% confidence interval: 18.2-36.1%) and a median survival of 9 months (95% confidence interval: 7-11 months). Several variables were associated with response to treatment and survival at univariate analysis. At multivariate analysis the number of tumor sites, bone/visceral involvement and epithelial tumor markers were significantly predictive of response; presence of pain, serum alkaline phosphatase, carboplatin AUC and response to treatment were significantly associated with survival.

CONCLUSIONS

The identification of variables that can predict prognosis and response to treatment in patients with UPT may be useful to offer aggressive treatment to sensitive subsets of patients and provide therapeutic alternatives to those with a low probability of benefiting from standard treatment. In our patients the use of carboplatin AUC higher than 6 and response to treatment were the most important factors associated with prognosis, together with presence of pain and serum alkaline phosphatase. However, larger series and identification of new disease markers are necessary to better define predictive and prognostic variables in UPT patients.

Carboplatin, doxorubicin and etoposide in the treatment of tumours of unknown primary site

The aim of this study was to assess the activity and toxicity of a platinum-based treatment on a group of patients with unknown primary tumours (UPTs). Patients with a diagnosis of UPT underwent a standard diagnostic procedure. Treatment was started within 2 weeks from diagnosis and consisted of carboplatin 400 mg m(-2) day 1, doxorubicin 50 mg m(-2) day 1, etoposide 100 mg m(-2) days 1-3, every 21 days. Response was evaluated after three courses and treatment continued in case of objective response (OR) or symptom control. A total of 102 patients were eligible. The median age was 59 years, sex male/female 54/48, histology was mainly adenocarcinoma or poorly differentiated carcinoma. Nodes, bone, liver and lung were the most frequently involved sites. In all, 79 patients received at least three courses of treatment; 26 patients received six courses or more. Six complete responses and 21 partial responses were observed, for a total of 27 of 102 ORs or 26.5% (95% confidence interval 18.2-36.1%). The median survival was 9 months and median progression-free survival was 4 months. Toxicity was moderate to severe, with 57.8% of patients experiencing grade III-IV haematological toxicity, mainly leucopenia. The regimen employed has shown activity in tumours of unknown primary site, but was associated with significant toxicity. Such toxicity may be considered unjustified, given the large proportion of patients with tumours not likely to respond. Efforts should therefore be addressed to identify predictors of response to chemotherapy, thus limiting aggressive treatment to those patients who could benefit from it.

Cervical lymph node metastases of squamous cell carcinoma from an unknown primary

Cervical lymph node metastases of squamous cell carcinoma from occult primary constitute about 2-5% of all patients with carcinoma of unknown primary site (CUP). Metastases in the upper and middle neck are generally attributed to head and neck cancers, whereas the lower neck (supraclavicular area) involvement is often associated with primary malignancies below the clavicles. The diagnostic procedures include physical examination with thorough evaluation of the head and neck mucosa using fiber-optic endoscopy, biopsies from all suspicious sites or blindly from the sites of possible origin of the primary, computer tomography and/or magnetic resonance. A systematic tonsillectomy in the absence of suspicious lesions is often recommended since up to 25% of primary tumors can be detected in this site. The thoracic primary (tracheal, bronchial, lung, esophagus) has to be excluded, especially in the case of lower neck involvement. Positron emission tomography (PET) with fluoro-2-deoxy-D-glucose allows detection of primary tumor in about 25% of cases, but this procedure is still considered investigational. Therapeutic approaches include surgery (lymph node excision or neck dissection), with or without postoperative radiotherapy, radiotherapy alone and radiotherapy followed by surgery. In early stages (N1), neck dissection and radiotherapy seem to have similar efficacy, whereas more advanced cases (N2, N3) necessitate combined approaches. The extent of radiotherapy (irradiation of bilateral neck and mucosa versus ipsilateral neck radiotherapy) remains debatable. A potential benefit from extensive radiotherapy should be weighted against its acute and late morbidity and difficulties in re-irradiation in the case of subsequent primary emergence. The role of other methods, such as chemotherapy and hyperthermia, remains to be determined.

Cancer of unknown primary: clinicopathologic correlations

Cancer of unknown primary origin (CUP) accounts for 5-10% of all malignant tumors at presentation and remains the death certificate diagnosis in 0.5-5% of patients. We investigated CUP patients whose primary site remained unknown throughout the entire clinical course. We reviewed 9,436 consecutive autopsies performed between 1984 and 1999 at the Mayo Clinic, matched with 177,167 cancer patients treated in the same time period. Sixty-four patients who died of CUP underwent postmortem examination. Antemortem pathologic diagnoses were obtained in 57 patients, agreed with postmortem diagnoses in 98%, and included adenocarcinoma (n=44), undifferentiated carcinoma (n=7), squamous cell carcinoma (n=3), and others (n=3). Autopsy located the primary site in 35 patients (55%). Common primary sites were lung (n=8), the pancreaticobiliary (n=13) and GI tracts (n=9). Of 43 patients evaluated for tumor-specific therapy, only six received no further oncologic treatment and untreated patients survived a median of 57 (range 10-280) days, compared with 225 (range 19-1,129) days for patients treated with chemotherapy and/or radiotherapy (n=37). Our findings show that (1) autopsy studies provide a valuable tool for quality control in the setting of CUP, and (2) treated patients have a small but significant survival benefit.

Diagnostic and therapeutic management of cancer of an unknown primary

Metastatic Cancer of Unknown Primary Site (CUP) accounts for approximately 3% of all malignant neoplasms and is therefore one of the 10 most frequent cancer diagnoses in man. Patients with CUP present with metastatic disease for which the site of origin cannot be identified at the time of diagnosis. It is now accepted that CUP represents a heterogeneous group of malignancies that share a unique clinical behaviour and, presumably, unique biology. The following clinicopathological entities have been recognised: (i) metastatic CUP primarily to the liver or to multiple sites, (ii) metastatic CUP to lymph nodes including the sub-sets involving primarily the mediastinal-retroperitoneal, the axillary, the cervical or the inguinal nodes, (iii) metastatic CUP of peritoneal cavity including the peritoneal papillary serous carcinomatosis in females and the peritoneal non-papillary carcinomatosis in males or females, (iv) metastatic CUP to the lungs with parenchymal metastases or isolated malignant pleural effusion, (v) metastatic CUP to the bones, (vi) metastatic CUP to the brain, (vii) metastatic neuroendocrine carcinomas and (viii) metastatic melanoma of an unknown primary. Extensive work-up with specific pathology investigations (immunohistochemistry, electron microscopy, molecular diagnosis) and modern imaging technology (computed tomography (CT), mammography, Positron Emission Tomography (PET) scan) have resulted in some improvements in diagnosis; however, the primary site remains unknown in most patients, even on autopsy. The most frequently detected primaries are carcinomas hidden in the lung or pancreas. Several favourable sub-sets of CUP have been identified, which are responsive to systemic chemotherapy and/or locoregional treatment. Identification and treatment of these patients is of paramount importance. The considered responsive sub-sets to platinum-based chemotherapy are the poorly differentiated carcinomas involving the mediastinal-retroperitoneal nodes, the peritoneal papillary serous adenocarcinomatosis in females and the poorly differentiated neuroendocrine carcinomas. Other tumours successfully managed by locoregional treatment with surgery and/or irradiation are the metastatic adenocarcinoma of isolated axillary nodes, metastatic squamous cell carcinoma of cervical nodes, or any other single metastatic site. Empirical chemotherapy benefits some of the patients who do not fit into any favourable sub-set, and should be considered in patients with a good performance status.

A randomised study of protracted venous infusion of 5-fluorouracil (5-FU) with or without bolus mitomycin C (MMC) in patients with carcinoma of unknown primary

No standard regimen has been identified for patients with a carcinoma of unknown primary (CUP). This study compared protracted venous infusion 5-fluorouracil (PVI 5-FU) with or without mitomycin C (MMC) in patients with CUP in a multicentre, prospectively randomised study. 88 patients were randomised to PVI 5-FU (300 mg/m(2)/day for a maximum of 24 weeks) +/-MMC (7 mg/m(2) 6 weekly for four courses). The overall response rate was 11.6% for PVI 5-FU alone compared with 20.0% for PVI 5-FU plus MMC (P=0.29). Median failure-free survival (FFS) was 4.1 months for PVI 5-FU and 3.6 months for PVI 5-FU plus MMC (P=0.78) with an equivalent overall survival (OS) (6.6 versus 4.7 months, P=0.60). Symptomatic benefit was observed in most patients in each arm. PVI 5-FU is a well tolerated outpatient treatment regimen for patients with CUP, although the addition of MMC provides little extra benefit. PVI 5-FU may be a potential reference regimen in randomised trials with newer chemotherapy agents in patients with CUP.

Development and validation of a prognostic model to predict the length of survival in patients with carcinomas of an unknown primary site

PURPOSE

To identify clinical and biologic variables with significant impact on survival in patients with carcinomas of an unknown primary site and to develop a simple prognostic model for the selection of patients in prospective clinical trials.

PATIENTS AND METHODS

Univariate and multivariate prognostic factor analyses were conducted in a population of 150 unselected patients and led to the construction of two successive classification schemes. An external data set of 116 patients enrolled onto two prospective trials was used for validation.

RESULTS

When studying clinical variables only, poor performance status (2 or 3) and presence of liver metastases were retained in the multivariate analysis. The first classification scheme consisted of three subgroups of patients with median survivals of 10.8, 6.0, and 2.4 months, according to the number of adverse prognostic factors. With the introduction of serum lactate dehydrogenase (LDH) levels in a further step, liver metastases were no longer significant. The second classification scheme therefore included poor performance status (relative risk [RR], 2.1) and elevated serum LDH level (RR, 2.1). Good-risk and poor-risk patients were identified, with median survivals of 11.7 months and 3.9 months, respectively (P <.0001). The 1-year survival rates were 45% and 11%, respectively. This second classification scheme was validated in an external data set: the median survival rates of patients assigned to the good-risk group and the poor-risk group were 12 months and 7 months, respectively (P =.0089). The 1-year survival rates were 53% and 23%, respectively.

CONCLUSION

A simple prognostic model using performance status and serum LDH levels was developed and validated. It allows the assignment of patients into two subgroups with divergent outcome. Further prospective trials will be designed using this prognostic model.

Hepatic metastases from an unknown primary neoplasm (UPN): survival, prognostic indicators and value of extensive investigations

AIM

The objectives of this study were to identify prognostic features for patients with hepatic metastases and unknown primary neoplasms (UPN), determine the common primary tumours, assess the value of diagnostic tests in finding these tumours, and evaluate the impact of therapy and knowledge of the primary tumour on patient survival.

MATERIALS AND METHODS

Eighty-eight patients with UPN and liver biopsy proven hepatic metastases over a 10-year period were reviewed (M:F, 58:30; age range 27-91 years, median 64.5 years). Histopathology, diagnostic investigations and success at identifying the primary neoplasm were recorded. In addition, in 70 patients with adenocarcinoma histology (M:F, 48:22; age range 27-91 years, median 65 years), treatment and survival data from the date of biopsy were recorded.

RESULTS

The histological spectrum included adenocarcinoma in 70, neuroendocrine in four, squamous cell carcinoma in four, small cell carcinoma in four, carcinoid in two, hepatoma in one and three others. Extensive investigation identified a primary neoplasm in 16/88 patients (18%) including colorectal in six, gastric in two, lung in four, oesophageal in two, prostate in one and carcinoid in one. In the adenocarcinoma group survival data were available for 62/70 patients. Sixteen of 62 patients received active treatment with either surgery, chemotherapy, radiotherapy or a combination protocol. Forty-six of 62 patients received palliative care alone. Median survival for the adenocarcinoma group overall was 49 days. The median survival for treated patients (49 days) versus untreated patients (52 days) was not significantly different (P=0.128). Patients <65 years were more likely to receive active treatment than those >65 years (P=0.006). Age with a hazard ratio (HR) of 1.01 (P=0.178), active treatment (HR=0.65;P=0.194), knowledge of the primary neoplasm (HR=0.60;P=0.213) and male gender (HR=0.88;P=0.642) had no significant effect on survival.

CONCLUSION

Although hepatic metastases are associated with poor prognosis, it is essential that a liver biopsy be performed to obtain a histological diagnosis. Adenocarcinoma metastases carry a dismal prognosis, and no prognostic factors, including knowledge of the primary tumour, are significant for patient survival. Extensive investigation is not warranted in patients with adenocarcinoma liver metastases.