Unknown primary tumours

Squamous Cell Carcinoma Metastatic to Cervical Lymph Nodes from an Unknown Primary Site: The Impact of Radiotherapy

Aims and background

Cervical lymph node metastases of squamous cell carcinoma from an unknown primary site constitute about 5% of the total head and neck cancer cases. The management of these patients is still a therapeutic challenge. The aim of the present study was to analyze the prognosis in a series of patients and, in particular, the impact of different radiotherapy techniques on the prognosis.

Methods and study design

Data from 60 patients with cervical lymph node metastases of squamous cell carcinoma from an unknown primary site were reviewed. Nine of 60 patients (15.0%) received excisional biopsy. Radiotherapy was delivered to the bilateral neck and pharyngeal mucosa (extensive field) in 11 patients (18.3%), to the bilateral neck in 24 patients (40.0%), and to the ipsilateral neck in 25 patients (41.7%). Fourteen patients (23.3%) also received chemotherapy.

Results

The 5-year overall survival rate of all patients was 68.5%. The overall survival of patients with N1, N2, and N3 stage was 100%, 68.0%, and 40.9%, respectively (P = 0.026). The overall survial of patients irradiated by ipsilateral neck, bilateral neck, and extensive field was 66.5%, 74.5%, and 54.6%, respectively (P = 0.5). At multivariate analysis, only N stage significantly affected overall survival (P = 0.032). The 5-year neck control rate of all patients was 65.6%. The neck control rate of patients with N1, N2, and N3 stage was 100%, 63.2%, and 34.6%, respectively (P = 0.064). The neck control rate of patients irradiated by ipsilateral neck, bilateral neck, and extensive field was 87.6%, 51.1%, and 72.7%, respectively (P = 0.279). Emergence of the occult primary was observed in 21.2% patients, and all of these occurred within the head and neck region. The primary tumor emerged in 23.3% of patients treated with ipsilateral and bilateral neck irradiation and in 12.5% of patients irradiated by extensive field (P = 0.469).

Conclusions

Patients with cervical lymph node metastases of squamous cell carcinoma from an unknown primary site have clinical features and a prognosis similar to those of other head and neck malignancies. Extensive irradiation results in a lower trend of emergence of the primary tumor than when patients are treated with ipsilateral and bilateral irradiation, but there is no significant difference in overall survival.

Pathological investigation of vertebral tumor metastasis from unknown primaries--a systematic analysis

BACKGROUND

This systematic analysis was conducted to investigate pathological diagnosis of vertebral tumor metastasis with unknown primaries.

METHODS

Clinical studies conducted to pathologically investigate vertebral tumor metastasis were identified using a predefined search strategy. Pooled diagnosis (PD) of each pathological confirmation was calculated.

RESULTS

For vertebral tumor metastasis, 5 clinical studies which included 762 patients were considered eligible for inclusion. Systematic analysis suggested that, for all patients with vertebral tumor metastasis, dominant PD was pathologically confirmed with lung cancer in 21.7% (165/762), with breast cancer in 26.6% (203/762) and with prostate cancer in 19.2% (146/762) . Other diagnosis that could be confirmed included lymphoma, multiple myeloma, renal cancer, for example, in this cohort of patients.

CONCLUSIONS

This systemic analysis suggested that breast, lung and prostate lesions could be the most common pathological types of cancer for vertebral tumor metastasis formunknown primaries, and other common diagnoses could include lymphoma, multiple myeloma, renal cancer.

Site-specific cancer deaths in cancer of unknown primary diagnosed with lymph node metastasis may reveal hidden primaries

Cancer of unknown primary site (CUP) is a fatal cancer ranking among the five most common cancer deaths. CUP is diagnosed through metastases, which are limited to lymph nodes in some patients. Cause-specific survival data could guide the search for hidden primary tumors and help with therapeutic choices. The CUP patients were identified from the Swedish Cancer Registry between 1987 and 2008; 1,444 patients had only lymph node metastasis of defined histology (adenocarcinoma, squamous cell or undifferentiated). Site-specific cancer deaths were analyzed by lymph node location and histology. Kaplan-Meier survival curves were compared with metastatic primary cancer at related sites. Among the patients with metastasis to head and neck lymph nodes, 117 (59.1% of the specific cancer deaths) died of lung tumors. Patients with axillary lymph node metastasis died of lung and breast tumors in equal proportions (40.2% each). Also, squamous cell CUP in head and neck lymph nodes was mainly associated with lung tumor deaths (53.1%). With a few exceptions, survival of CUP patients with lymph node metastasis was indistinguishable from survival of patients with metastatic primary cancer originating from the organs drained by those nodes. The association between lymph node CUP metastases with cancer deaths in the drained organ and the superimposable survival kinetics suggests that drained organs host hidden primaries. Importantly, half of all site-specific cancer deaths (266/530) were due to lung tumors. Thus, an intense search should be mounted to find lung cancer in CUP patients with lymph node metastases.

Cancer of unknown primary (CUP): does cause of death and family history implicate hidden phenotypically changed primaries?

BACKGROUND

Cancer of unknown primary (CUP) is diagnosed at the metastatic stage. We aimed to identify hidden primary cancers in CUP patients by comparison with cancers in family members. We take use of the fact that the cause of death in CUP patients is often coded as the cancer in the organ of fatal metastasis.

PATIENTS AND METHODS

Forty-one thousand five hundred and twenty-three CUP patients were identified in the Swedish Family-Cancer Database, and relative risks (RRs) were calculated for cancer in offspring when family members were diagnosed with CUP and died of the cancer diagnosed in offspring.

RESULTS

The RR for lung cancer in offspring was 1.85 when a family member was diagnosed with CUP and died of lung cancer. Significant familial associations were found for seven other cancers. Many familial associations were also significant when offspring CUP patients died of the cancer diagnosed in family members.

CONCLUSIONS

The cause of death after CUP diagnosis frequently matched the cancer found in a family member, suggesting that the CUP had originated in that tissue. The metastasis had probably undergone a phenotypic change, complicating pathological tissue assignment. These novel data suggest that some CUP cases are phenotypically modified primary cancers rather than cancers of unknown primaries.

Biopsy of vertebral tumour metastasis for diagnosing unknown primaries

PURPOSE

To examine patients with vertebral tumour metastasis using transpedicular biopsy for diagnosing unknown primary tumours.

METHODS

13 men and 8 women aged 41 to 80 (mean, 61) years with vertebral tumour metastasis of unknown primary origin underwent transpedicular biopsy of the affected vertebra.

RESULTS

The origins of the primary tumours were lung cancer (n = 6), prostate cancer (n = 5), colorectal cancer (n = 5), kidney cancer (n = 4) and lymphoma (n = 1). All the specimens matched pathological characteristics of their corresponding primary tumours, except in one patient. This 42-year-old man had stage-4 colon cancer, in whom the pathologic findings could not enable differentiation between colon and prostate cancer.

CONCLUSION

Transpedicular biopsy of the vertebra is a cost-effective diagnostic tool for evaluating unknown primary tumours.

Cancer patients without a known primary: incidence and survival trends in Sweden 1960-2007

BACKGROUND

Metastatic cancer from an unknown primary tumour (CUP) is a common and heterogeneous clinical entity. In Sweden like in many other countries, the continuum of care for such patients remains to be established.

MATERIAL AND METHODS

Data on CUP cases reported to the Swedish Cancer Registry during 1960 through 2007 was used to assess time trends for incidence, survival, and histological tumour type.

RESULTS

There was an upward trend for the age-adjusted incidence until the late 1990s. This roughly paralleled the increase for all reported cancers during the same period. The increase of CUP mainly concerned patients aged above 50 years, and tumours classified as adenocarcinomas. The relative survival at 12 months after a diagnosis of CUP was estimated at 20%. However, after 12 months the relative survival levelled of and the 5-year estimate was 10-15% which suggests that a small proportion of CUP cases may be cured. Relative survival was highly dependent on age with substantially better outcome for young patients, particularly those aged below 30 years. We observed no time trend for survival.

DISCUSSION

Cases diagnosed as CUP includes patients with metastatic spread from a wide variety of tumours although certain tumour types probably are overrepresented, for example, cancers in sites that are difficult to examine clinically. Incidence trends probably represent the sum of trends for these cancers as well as diagnostic trends. The decreased incidence observed during the last decade might thus be explained in terms of a combination of improved diagnostic methods to detect primary tumours and decreasing incidence for e.g. pancreatic cancer and lung cancer among males. There is a need of evidence-based programs that define the continuum of care for CUP patients. Such a program is currently being developed through collaboration between all health care regions in Sweden.

Incidental detection of an occult oral malignancy with autofluorescence imaging: a case report

Background

Autofluorescence imaging is used widely for diagnostic evaluation of various epithelial malignancies. Cancerous lesions display loss of autofluorescence due to malignant changes in epithelium and subepithelial stroma. Carcinoma of unknown primary site presents with lymph node or distant metastasis, for which the site of primary tumour is not detectable. We describe here the use of autofluorescence imaging for detecting a clinically innocuous appearing occult malignancy of the palate which upon pathological examination was consistent with a metastatic squamous cell carcinoma.

Case Description

A submucosal nodule was noted on the right posterior hard palate of a 59-year-old white female during clinical examination. Examination of this lesion using a multispectral oral cancer screening device revealed loss of autofluorescence at 405 nm illumination. An excisional biopsy of this nodule, confirmed the presence of a metastatic squamous cell carcinoma. Four years ago, this patient was diagnosed with metastatic squamous cell carcinoma of the right mid-jugular lymph node of unknown primary. She was treated with external beam irradiation and remained disease free until current presentation.

Conclusion

This case illustrates the important role played by autofluorescence tissue imaging in diagnosing a metastatic palatal tumour that appeared clinically innocuous and otherwise would not have been biopsied.

Gene Expression Profiling to Identify the Histogenetic Origin of Metastatic Adenocarcinomas of Unknown Primary

Purpose

Patients with adenocarcinoma of unknown primary origin (ACUP) constitute approximately 4% of all malignancies. For effective treatment of these patients, it is considered optimal to identify the primary tumor origins. Currently, the success rate of the diagnostic work-up is only 20% to 30%. Our goal was to evaluate the contribution of gene expression profiling for routine clinical practice in patients with ACUP.

Patients and Methods

Formalin-fixed, paraffin-embedded (FFPE) samples were obtained from 84 patients with a known primary adenocarcinoma and from 38 patients with ACUP. An extensive immunohistochemical panel classified 16 of the patients with ACUP, whereas 22 patients remained unclassified for their histogenetic origin. Information about staging procedures and clinical follow-up were available in all patient cases. The expression data were analyzed in relation to clinicopathologic variables and immunohistochemical results.

Results

The gene expression–based assay classified the primary site correctly in 70 (83%) of 84 patient cases of primary and metastatic tumors of known origin, with good sensitivity for the majority of the tumor classes and relatively poor sensitivity for primary lung adenocarcinoma. Gene expression profiling identified 15 (94%) of 16 patients with initial ACUP who were classified by immunohistochemistry, and it made a valuable contribution to a potential site of origin in 14 of the 22 patients with ACUP.

Conclusion

The gene expression platform can classify correctly from FFPE samples the majority of tumors classes both in patients with known primary and in patients with ACUP. Therefore, gene expression profiling represents an additional analytic approach to assist with the histogenetic diagnosis of patients with ACUP.

[Metastases of unknown origin--principles of diagnosis and treatment]

DEFINITION

Cancer of unknown primary (CUP) origin refers to patients who present with histologicaly confirmed metastatic cancer in whom a detailed medical history, complete physical examination, including pelvic and rectal examination, full blood count and biochemistry, urinalysis and stool occult blood testing, hisinpathological review oJ biopsy speimens with the use of immunohistochemistry, chest radiography, computed tomography of the abdomen and pelvis, and in certain cases mammography, fail to identify the primary site.

EPIDEMIOLOGY OF CUP

The cancer of unknown primary accounts for 3%-5% of all human cancers.

DIAGNOSIS OF CUP

The standard diagnostic procedure for the majority of patients includes histopathologic review of biopsy specimens with the use of immunoltistochemistry, chest radiography, computed tomography of the abdomen and pelvis, and in certain cases mamography, fail to identify the abdomen and pelvis. The four common histologic diagnoses are: adenocarcinoma (70%), poorly differentiated carcinoma (20%), squamous carcinoma (10%), and poorly differentiated neoplasms (5%).

PROGNOSIS OF CUP

The prognosis for most patients with unknown primary tumors is poor, with survival often less than 6 months from diagnosis.

THERAPY OF CUP

Based on clinical and pathologic features, approximately 40% of patients can be categorized within subsets for which specific treatment has been defined. Empiric therapy is an option for the remaining 60% of patients.

CONCLUSION

Metastatic tumors of unknown origin have a unique clinical presentation due to a specific biology. Insight into the molecular biology of unknown primary tumors will be essential for the development of more effective treatments.

Impact of PET-FDG in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary

We carried out a study to evaluate the contribution of positron emission tomography with (18)F-fluorodeoxyglucose (PET-FDG) in the diagnosis and therapeutic care of patients presenting with metastases of unknown primary. PET-FDG was prospectively performed in 51 patients. The PET-FDG data were confirmed histologically or by a follow-up on average at 13 months. PET-FDG identified the primary in 24 percent of cases, and detected the presence of additional metastases in 41 percent of cases. PET-FDG led to a therapeutic modification for 12 patients (24 percent). Furthermore, the therapeutic impact seems more marked in localized forms than in the multifocal. This broad exploratory study confirms the important role of PET-FDG in the diagnosis and therapeutic management of patients with metastases of unknown primary.

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.

Immunocytochemical identification of carcinomas of unknown primary in serous effusions

Metastases from carcinomas of unknown primary site (CUP) in serous effusion are a common clinical problem. Immunocytochemistry was applied as an adjunct to the cytological diagnosis of metastatic carcinomas in serous effusions. Subjects of this study were 118 pleural, 53 peritoneal, and 9 pericardial effusions from 180 patients routinely investigated in the Institute of Cytopathology. Specimens were primarily stained according to Papanicolaou (Pap). The avidin-biotin-complex method (ABC) was secondarily applied for the visualization of immunologic reactions. We have used a panel of six monoclonal antibodies (CK 5/6, CK 7, CK 20, CA 125, TTF-1, and cdx 2) so as to identify the primary tumor site of metastatic carcinoma cells in serous effusions. Applying an algorithm of immunocytochemical marker constellations, we were able to correctly diagnose primary tumor sites in 86 of 101 (85.1%) patients with CUP syndromes. The best result was achieved for the identification of metastatic carcinomas of the ovaries (94.7%) and the lungs (88.1%). We established an algorithm comprising six immunocytochemical markers that enabled a correct diagnosis of primary tumor sites in 85.1%. The panel studied could be useful in diagnostic routine for the identification of primary tumors of unknown origin metastatic to the serous membranes.

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.

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.

Combination of cisplatin-doxorubicin-cyclophosphamide in adenocarcinoma of unknown primary site: a phase II trial

The purpose of this report is to evaluate toxicity, response, and survival of the cyclophosphamide-doxorubicin-cisplatin (CAP) chemotherapy regimen in patients with adenocarcinoma of unknown primary site (ACUP). Twenty-two patients with ACUP were eligible for this study between June 1992 and April 1999. There were 13 men (59%) and 9 women (41%) with a median age of 53.5 years (range: 29--78 years). Lung (seven), liver (six), vertebral bone site (six), and abdominal nodes (six) were the most common metastatic sites. Treatment consisted of doxorubicin 50 mg/m(2), cyclophosphamide 1,000 mg/m(2), and cisplatin 100 mg/m(2) (CAP), administered every 3 weeks; a total of six courses were planned. Twenty-two patients were assessable for toxicity and 20 patients were assessable for response. Grade III to IV neutropenia was observed in 14 patients (64%); febrile neutropenia occurred in 6 patients (27%) and in 10 cycles (12.5%). Grade III to IV anemia and thrombocytopenia were found in 12 (54.5%) and 9 patients (41%), respectively. Grade III to IV nausea and vomiting was observed in 9 patients (41%). Ten patients, 50% of the assessable population, obtained an objective response, including 3 complete (15%) and 7 partial (35%) responses. The median response duration was 3.9 months (range: 0.5--13.3 months). One patient (5%) had stable disease and 5 patients (25%) had progressive disease. The median overall survival and the median time to progression were 10.7 months (range: 0.4--56.9 months) and 8.8 months (range: 6.6--16.5 months), respectively. The CAP regimen in patients with ACUP had significant activity. This chemotherapy regimen induced a high level of grade III to IV toxicities and could not be considered as a treatment of reference. However, the emergence of long-term survivors among responder patients highlighted the need to search for an active treatment for patients with ACUP.

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

BACKGROUND

To evaluate the efficacy and toxicity of a chemotherapy strategy based on histological differentiation, for patients with carcinoma of unknown primary site.

PATIENTS AND METHODS

Forty-eight patients were prospectively included in the trial. Thirty patients with poorly-differentiated carcinoma or poorly-differentiated adenocarcinoma (group A) received a combination of cisplatin and etoposide. Patients with a responsive or stable disease after two cycles received the same regimen plus bleomycin, ifosfamide and G-CSF. Eighteen patients with well- or moderately-differentiated carcinoma (group B) received cisplatin, continuous infusion 5-fluorouracil (5-FU) and alpha-interferon. Treatment was maintained in case of response or stable disease for up to six cycles.

RESULTS

The overall response rate (RR) for the entire group is 43% (95% confidence interval (CI): 35.9%-50.1%): seven CR and five PR in group A (RR = 40%) and six CR and two PR in group B (RR = 44%). Grade 4 leucopenia was observed in 22 (46%) patients and sepsis in 3 (6%). Median survival is 9.4 months (range 5-13.7 months) and 16.1 months (range 11.8 20.3 months), respectively.

CONCLUSIONS

This chemotherapy strategy is one way to achieve high response rates, particularly for patients with well- or moderately-differentiated adenocarcinoma usually considered poorly chemosensitive.

Unknown primary tumours

Unknown primary tumours (UPTs) are defined by the absence of a primary tumour in biopsy proved metastatic cancer. These tumours have a specific biology with clinical characteristics of rapid progression and random atypical metastases. Cytogenetic abnormalities have been demonstrated, particularly deletion of chromosome 1p. Diagnostic evaluation that includes pathology review, physical examination, chest radiography, computed tomography of the abdomen, and mammography is directed at the identification of treatable subsets. Based on clinicopathological criteria, therapy responsive subsets of patients with UPTs can be defined. These subsets have a better prognosis than the average median survival time of four months in patients with UPTs.

Hyperthermia and radiotherapy for inoperable squamous cell carcinoma metastatic to cervical lymph nodes from an unknown primary site

INTRODUCTION

Neck node metastases from an unknown primary carcinoma represent an infrequent but challenging problem for oncologists. The management of such patients is controversial, but radiotherapy alone or as part of a multimodal approach is often indicated. Patients with inoperable lesions usually receive radiotherapy alone at palliative doses. In an attempt to increase local control in patients with locally advanced neck disease from an unknown primary carcinoma, local hyperthermia was combined with definitive radiotherapy.

MATERIAL AND METHODS

Between 1982 and 1993, radiotherapy and local microwave hyperthermia were used to treat 15 patients with metastatic neck nodes from an unknown primary site. The patients had previously undergone only biopsy or fine needle biopsy, and showed no signs of metastases beyond the clavicle. Radiation to the nodes and the potentially primary sites in the head and neck was delivered by a 6 MV linear accelerator or a Cobalt 60 unit, to a total dose of 57.50-74.40 Gy (median 70 Gy). Hyperthermia was added using a BSD 1000 unit at an operating frequency of 280-300 MHz for 2-7 sessions (mean 3.1; median 2) at a desired minimum temperature of 42.5 degrees C. Two patients also received i.v. cisplatin 20 mg/m2/week as a radiosensitizer.

RESULTS

Nine patients achieved a complete, and four a partial response for an overall response rate of 86.5%. Acute and late toxicity was mild: four patients experienced pain during hyperthermia, two moist cutaneous desquamation, and one cutaneous necrosis. The actuarial probability of maintaining local control at 5 years is 64.5% and the actuarial overall survival 29%. Five patients developed distant metastases and died of disease, two experienced nodal recurrence and two died of other unrelated causes.

CONCLUSION

The addition of local microwave hyperthermia to radiotherapy in the treatment of metastatic squamous cell carcinoma of the neck in patients with an unknown primary site leads to good local control with moderate toxicity. No definite conclusions are possible because of the small number of patients involved in this phase II trial.

18F-FDG whole body positron emission tomography (PET) in patients with unknown primary tumours (UPT)

The management of patients with unknown primary tumours (UPT) often includes a large number of radiographical studies and invasive procedures, but the occult primary tumour is detected in less than 25%. In this prospective study we explored whether non-invasive whole body PET scans using FDG (18-F-fluorodeoxyglucose) are of clinical value in detection of UPT. Whole-body FDG-PET scans were performed in 20 patients following standard staging procedures according to histology. PET results were verified either histologically or by the clinical course of the disease. 11 patients had neck metastases (5 squamous cell, 5 adenocarcinomas and 1 poorly differentiated carcinoma). The remaining patients had metastases located in bone (3), bone marrow (1), brain (1), pericardium (1), skin (1), pleura (1) and chest wall (1). All metastatic lesions were visible with PET. In 13 patients PET suggested the site for the primary tumour and this was verified in 9 (45%), either histologically or by the clinical course of disease. 8 of these had primary lung cancer and 1 had carcinoma at the basis of the tongue. In most patients PET had no treatment related implications. 3 patients with non-small cell lung cancer (NSCLC) received chemotherapy prompted by the PET result. The rest received either radical radiotherapy to the head and neck region (7), palliative radiotherapy to the metastatic lesion (8), chemotherapy based on signet ring cell carcinoma in bone marrow (1) or no therapy (1). These results indicates that PET is useful in UPT preceding expensive and invasive diagnostic procedures and can result in a faster diagnosis in approximately one third of the patients who then avoid unnecessary extensive procedures. Furthermore, a larger proportion of patients will receive treatment aimed at the correct diagnosis. A prospective cost-effectiveness analysis of PET in this setting is warranted.

Improving survival in metastatic carcinoma of unknown origin

Metastatic carcinoma from an unknown primary site accounts for 3% to 5% of all newly diagnosed malignant lesions. Although 85% of patients who receive this diagnosis are dead within a year, 5% to 10% may be long-term survivors. Close cooperation between an experienced pathologist and the referring physician is essential in the management of these patients. One important task for the physician is to recognize those subgroups of patients who may have a better prognosis and thus may be treated in a different fashion. A second challenge is not to overinvestigate or overtreat patients who fall into the poor prognosis category. Empirical chemotherapy should not be given simply for the sake of doing something. Rather, proper emphasis should be placed on regional therapy, symptomatic treatment, and the best palliative care. Patients may be confused and frustrated when confronted with the news that the source of their tumor is not apparent. They should be reassured that this lack does not preclude development of a rational treatment plan and that those cancers for which highly effective systemic therapy exists have been excluded. A caring, informed physician may help empower the patient to make educated and informed choices.

[Carcinoma of unknown primary site. Apropos of 100 patients treated at the Montpellier regional center of cancer prevention]

PURPOSE

Carcinomas of unknown primary site are frequent neoplasms which raise diagnostic and therapeutic problems in clinical practice.

METHODS

Clinical records of 100 patients with carcinoma of unknown primary site whose clinical management took place at the Centre Regional de Lutte Contre le Cancer de Montpellier were retrospectively reviewed. Initial clinical and biological characteristics, pre-treatment evaluation, therapies and outcome were recorded.

RESULTS

Three main histological types were observed: adenocarcinoma (66 patients), poorly differentiated carcinoma (19 patients), epidermoid carcinoma (11 patients). Bone, lung, lymph nodes and liver were the most frequently involved metastatic sites. Analysis of the investigations aimed at identifying the primary site (none of which being positive) showed 68 different combinations in 100 patients. Anemia (< 100 g/L) was observed in 10 patients, while serum alkaline phosphatase was increased in 42 patients. Seven patients died before any therapy. Chemotherapy or radiotherapy was advocated in 70 and 59 patients, respectively. Thirty-six patients had concomitant chemoradiotherapy. Chemotherapy included a platinum derivative in 53 patients. The median number of cycles was four. Nine objective responses were observed, six of which occurred in patients who were receiving platinum-based chemotherapy. Ninety-six deaths were encountered, 95 due to the disease progress and one due to an intercurrent cause. The median survival was 9 months. Univariate analysis identified two prognostic factors: the number of metastatic sites and the serum alkaline phosphatase.

CONCLUSIONS

This retrospective study confirms the difficulties in the management of patients with carcinomas of unknown primary site. A literature review suggests limited diagnostic investigations in clinical practice with the aim of identifying tumors of potential prognostic (breast and ovary) or therapeutic (prostate) value. Apart from specific subgroups of patients for whom specific therapy is recommended, there is no current standard chemotherapy.

A multicentre phase II study of carboplatin and prolonged oral etoposide in the treatment of cancer of unknown primary site (CUPS)

Cisplatin-based combination chemotherapy is frequently used to treat patients with carcinoma of unknown primary site (CUPS). Response rates in the literature range from 12% to 26% and median survival from 5 to 7 months. The goal of this study was to evaluate the combination of carboplatin and prolonged oral etoposide in patients with CUPS, with the hope of minimizing toxicity but improving efficacy and convenience. Treatment consisted of carboplatin, 300 mg m(-2) on day 1, and oral etoposide 50 mg on days 1-20, every 4 weeks for up to nine cycles. A total of 33 patients were treated and all were evaluable for toxicity. Non-haematological toxicity was mild to moderate, with the exception of one case of grade 4 stomatitis. Grade 4 leucopenia was observed in eight (24%) patients and sepsis in four (12%), with two and possibly three treatment-related deaths. For the 26 patients evaluable for response, the response rate was 23% with responses lasting a median of 11 months (range 7-13 months), with one patient still responding at 12 months. An additional nine patients (35%) had stable disease. Median survival for all patients was 5.6 months (range 2 weeks to 33 months). The combination of carboplatin with prolonged oral etoposide has moderate activity similar to that of other platinum-based regimens and is a well tolerated, convenient, outpatient regimen. Dosing according to estimated creatinine clearance to achieve a carboplatin AUC of 6.0 mg ml(-1) min might have decreased the incidence of severe myelotoxicity without compromising the regimen's efficacy.

Use of immunocytochemistry in the diagnosis of metastatic carcinoma

Metastasis of unknown primary site is a common clinical problem. Immunohistochemistry has been shown to be a useful tool in the identification of the primary site. The availability of new antibodies specific for a wide range of antigens and working on routinely fixed, paraffin-imbedded material will ensure that this technique will continue to offer useful information in the search for an elusive primary tumour.

Metastases of unknown primary site

Despite the fact that effective therapy does not currently exist for the majority of patients presenting with metastases of unknown primary site, the last decade has witnessed significant advances in the approach to this heterogeneous disease. The use of modern pathologic techniques that frequently provide better diagnostic precision and the recognition of specific subgroups with a favorable prognosis and responsiveness to treatment has improved the outcome for some patients. Currently the diagnostic strategy should emphasize the rapid identification of patients likely to benefit from available therapy, whereas clinical research should focus on the development of more effective treatments for those patients with unresponsive tumors. In the future, continued improvements in the molecular characterization of these tumors will likely enhance understanding of the metastatic process, allow for more specific definitions of cell lineage, and provide insights for better therapy.