Cancer of unknown primary: biological and clinical characteristics

PD-L1 expression and microsatellite instability (MSI) in cancer of unknown primary site

BACKGROUND

Cancer of unknown primary site (CUP) is a heterogeneous group of tumors for which the origin remains unknown. Clinical outcomes might be influenced by regulatory processes in its microenvironment. Microsatellite instability (MSI) is a predictive biomarker for cancer immunotherapy and its status, as well as co-occurrence with PD-L1 expression, is poorly evaluated. We aim to evaluate the expression of PD-L1 and the status of MSI in CUP and their possible associations with clinical-pathological features.

METHODS

The combined positive score (CPS) PD-L1 expression was evaluated by immunohistochemistry. MSI status was assessed using a hexa-plex marker panel by polymerase chain reaction followed by fragment analysis.

RESULTS

Among the 166 cases, MSI analysis was conclusive in 120, with two cases being MSI positive (1.6%). PD-L1 expression was positive in 18.3% of 109 feasible cases. PD-L1 expression was significantly associated with non-visceral metastasis and a dominance of nodal metastasis. The median overall survival (mOS) was 3.7 (95% CI 1.6-5.8) months and patients who expressed PD-L1 achieved a better mOS compared to those who did not express PD-L1 (18.7 versus 3.0 months, p-value: < .001). ECOG-PS equal to or more than two and PD-L1 expression were independent prognostic factors in multivariate analysis (2.37 and 0.42, respectively).

CONCLUSION

PD-L1 is expressed in a subset (1/5) of patients with CUP and associated with improved overall survival, while MSI is a rare event. There is a need to explore better the tumor microenvironment as well as the role of immunotherapy to change such a bad clinical outcome.

Pelvic metastatic squamous cell carcinoma of unknown primary site: A case report and brief literature review

RATIONALE

Cancer with unknown primary site is a kind of disease that is difficult to deal with clinically, accounting for 2% to 9% of all newly diagnosed cancer cases. Here, we report such a case with pelvic metastatic squamous cell carcinoma of an unknown primary site and review the relevant literature.

PATIENT CONCERNS DIAGNOSES

A 43-year-old Chinese female patient was referred to our hospital and initially diagnosed as "malignant tumor of right adnexal area?, obstruction of right ureter, secondary hydronephrosis".

INTERVENTIONS

Thereafter cytoreductive surgery was performed which included a total hysterectomy, left adnexectomy, partial omentum resection, pelvic lymph node dissection, and para-aortic lymph node dissection. The primary lesion could not be identified by supplementary examination and postoperative pathology. The patient was diagnosed as pelvic metastatic squamous cell carcinoma whose primary site was unknown. To prevent a recurrence, we administered adjuvant chemotherapy for the patient.

OUTCOMES

The patient was followed up after treatment, complete remission has been maintained for 72 months, and no recurrence or metastasis has been found.

LESSONS

Our case demonstrates that surgery combined with chemotherapy could be helpful for pelvic metastatic squamous cell carcinoma of unknown primary site.

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.

Microsatellite Instability-high-positive Cancer of Unknown Primary Origin with a Long-term Survival after Surgery Alone

An 80-year-old woman was referred to our hospital for a thorough examination of enlarged lymph nodes on the lesser curvature of the stomach. Upon suspicion of malignant lymphoma, the patient underwent open lymphadenectomy and was diagnosed with lymph node metastasis of poorly differentiated adenocarcinoma. The patient was subsequently diagnosed with microsatellite instability-high cancer of unknown primary origin. Surgical removal of the affected lymph nodes achieved full remission. Chemotherapy was considered in case of recurrence or identification of the primary site. Recurrence has not occurred in three years since the surgery. However, a long-term survival without chemotherapy is rare.

Cerebral meningioma associated with extensive calvarium osteolysis and presumed intratumoral carcinoma metastasis in a cat

Case summary

A 10-year-old male neutered domestic shorthair cat presented with a 3-month history of weight loss, dysorexia and lethargy. Neurological examination revealed decreased mentation, absent menace response bilaterally and proprioceptive deficits affecting all four limbs; these findings were consistent with a forebrain disorder. Brain CT revealed an extensive asymmetric permeative osteolysis destroying two-thirds of the circumference of the calvarium and involving the right frontal, parietal, temporal and occipital bones, as well as the left parietal bone. This extensive bone lysis was associated with a large ‘plaque-like’ extra-axial subdural/pachymeningeal lesion extending within the soft tissues surrounding the calvarium. The cat was humanely euthanased. Post-mortem MRI was performed, which revealed a T2-weighted (T2W) hypointense subdural lesion and a T2W hyperintense circumferential extracranial lesion lining the right calvarium and left parietal bone. Histopathological analysis on a post-mortem sample of the lesion revealed a fibroblastic subtype of meningioma. Epithelial neoplastic cells were observed scattered through the meningioma, calvarium and surrounding muscular tissues, corresponding with presumed metastatic carcinoma.

Relevance and novel information

To our knowledge, this is the first report of an intracranial meningioma associated with such an extensive and diffuse calvarial osteolysis in veterinary medicine. This is also the first description of presumed metastatic inclusions (adenocarcinoma in this case) inside an intracranial feline meningioma, which is a rare phenomenon known as tumour-to-tumour metastasis in human medicine.

Image-guided percutaneous needle biopsy for the diagnosis of cancer of unknown primary

AIM

This study aimed to assess the efficacy of image-guided percutaneous needle biopsy in patients with suspected cancer of unknown primary.

METHODS

We conducted a retrospective observational study. Among 291 patients with suspected cancer of unknown primary who were referred to our institution between April 2011 and March 2014, 89 who underwent image-guided percutaneous needle biopsy and 27 who underwent surgical biopsy were defined as the image-guided percutaneous needle biopsy group and the surgical group, respectively. Patient backgrounds, diagnostic yields, promptness of biopsy, general anesthesia rates, and severe complication rates were compared between the two groups.

RESULTS

There was no significant difference in the patient backgrounds of the two groups. The diagnostic yields were 98.9% (95% confidence interval, 93.9%-99.8%) in the image-guided percutaneous needle biopsy group and 100% (95% confidence interval, 87.5%-100%) in the surgical biopsy group (no significant difference; p = 1.0). The mean time to biopsy was significantly shorter (6.5 days vs. 21.3 days; p < .0001) and general anesthesia was used in significantly fewer patients (0% vs. 40.7%; p < .0001) in the image-guided percutaneous needle biopsy group. There was no significant difference in the rate of serious complications between the two groups (p = 1.0).

CONCLUSION

As a biopsy procedure for patients with suspected cancer of unknown primary, image-guided percutaneous needle biopsy is equally diagnostic and safe for surgical biopsy and might be preferable to surgical biopsy in terms of promptness and not requiring general anesthesia.

Cancer of unknown primary

Cancers of unknown primary (CUPs) are histologically confirmed, metastatic malignancies with a primary tumor site that is unidentifiable on the basis of standard evaluation and imaging studies. CUP comprises 2-5% of all diagnosed cancers worldwide and is characterized by early and aggressive metastasis. Current standard evaluation of CUP requires histopathologic evaluation and identification of favorable risk subtypes that can be more definitively treated or have superior outcomes. Current standard treatment of the unfavorable risk subtype requires assessment of prognosis and consideration of empiric chemotherapy. The use of molecular tissue of origin tests to identify the likely primary tumor site has been extensively studied, and here we review the rationale and the evidence for and against the use of such tests in the assessment of CUPs. The expanding use of next generation sequencing in advanced cancers offers the potential to identify a subgroup of patients who have actionable genomic aberrations and may allow for further personalization of therapy.

Overt Skeletal Metastases in a Patient of Occult (Microscopic) Follicular Thyroid Carcinoma: a Rare Case

Occult follicular thyroid carcinoma (FTC) presenting as distant metastases is a rare occurrence. However, despite being occult in majority of these cases, primary tumor can be detected on thyroid imaging or during surgery. Here, we present an extremely rare case of an occult FTC with overt skeletal metastases in which primary tumor was discernible only on microscopic examination.

Paclitaxel and Carboplatin-Induced Complete Remission in Peritoneal Carcinomatosis of Unknown Origin: A Report of Two Cases and Review of the Literature

Peritoneal carcinomatosis is a common evolution of digestive-tract cancer with a poor prognosis. However, a small subgroup unrelated to the digestive tract or any other primary cancer has a relatively better prognosis, especially in women. There are no published data to recommend a treatment regimen for this distinct group. Here we present two women with peritoneal carcinomatosis of unknown origin, who responded to chemotherapy with paclitaxel plus carboplatin. One underwent an exploratory laparotomy and was confirmed to have no residual tumor. The other had complete resolution of ascites and omentum lesions confirmed by radiological examination. From this experience we propose that paclitaxel plus carboplatin is an effective combination regimen for this unique subset of patients. Further prospective trials should be conducted to substantiate this proposal in a larger patient cohort.

Liver metastases from adenocarcinomas of unknown primary site: management and prognosis in 68 consecutive patients

BACKGROUND

In this retrospective study, we aimed to evaluate the clinicopathological characteristics of the patients presenting with liver metastases from unknown primary site besides survival rates, treatment outcomes, and prognostic factors.

METHODS

In all, 68 patients followed-up at our center with adenocarcinoma of unknown primary (ACUP) metastatic to the liver between 2005 and 2013 were enrolled. All of the liver metastases were proven by liver biopsy and all yielded diagnosis of adenocarcinoma.

RESULTS

Median age was 61 years (29-90) and most of the patients were male (male/female: 43/25). The liver was the only metastatic site in 2 (3%) patients whilst 66 patients (97%) had extrahepatic metastases. The most common extrahepatic metastatic sites were lymph nodes (89.7%), lungs (32.4%), bones (25%), peritoneum (11.8%), brain (4.4%), and adrenal glands (2.9%). Of all 68 patients, 39 (57.4%) were treated with chemotherapy. Median overall survival (OS) was significantly higher in ACUP patients treated with chemotherapy [12.5 months (95% CI 8.3-16.7) vs. 4 months (95% CI 1.2-6.8), (p = 0.026), respectively]. In multivariate analysis, ECOG (Eastern Cooperative Oncology Group) performance status (p = 0.009), chemotherapy (p = 0.024), serum albumin (p = 0.012), and serum CA 19-9 level (p = 0.026) at initial diagnosis were identified as independent prognostic factors influencing survival for the patients with liver metastases from ACUP.

CONCLUSION

Patients with liver metastases from ACUP have poor prognosis and chemotherapy improves survival. Decreased serum albumin level, increased CA 19-9 level and poor performance status are independent poor prognostic factors.

Indolent metastatic squamous cell carcinoma of unknown primary in the intrathoracic lymph node: a case report and review of the literatures

Metastatic squamous cell carcinoma from a cancer of unknown primary (CUP) affecting the intrathoracic lymph node is very rare. We reported a case of metastatic squamous cell carcinoma in the hilar and interlobar lymph node from a patient with CUP and reviewed the associated literature. Abnormal mass in the right hilar area was incidentally detected. A chest computed tomography scan showed a 2.5-cm diameter mass in the right hilum that had changed little in size for 3 years. The patient underwent a right pneumonectomy and mediastinal lymph node dissection. A metastatic squamous cell carcinoma in the hilar and interlobar lymph nodes without a primary lung or other lesion was diagnosed. The patient received adjuvant chemotherapy for a diagnosis of T0N1M0 lung cancer.

Massively-parallel sequencing assists the diagnosis and guided treatment of cancers of unknown primary

The clinical management of patients with cancer of unknown primary (CUP) is hampered by the absence of a definitive site of origin. We explored the utility of massively-parallel (next-generation) sequencing for the diagnosis of a primary site of origin and for the identification of novel treatment options. DNA enrichment by hybridization capture of 701 genes of clinical and/or biological importance, followed by massively-parallel sequencing, was performed on 16 CUP patients who had defied attempts to identify a likely site of origin. We obtained high quality data from both fresh-frozen and formalin-fixed, paraffin-embedded samples, demonstrating accessibility to routine diagnostic material. DNA copy-number obtained by massively-parallel sequencing was comparable to that obtained using oligonucleotide microarrays or quantitatively hybridized fluorescently tagged oligonucleotides. Sequencing to an average depth of 458-fold enabled detection of somatically acquired single nucleotide mutations, insertions, deletions and copy-number changes, and measurement of allelic frequency. Common cancer-causing mutations were found in all cancers. Mutation profiling revealed therapeutic gene targets and pathways in 12/16 cases, providing novel treatment options. The presence of driver mutations that are enriched in certain known tumour types, together with mutational signatures indicative of exposure to sunlight or smoking, added to clinical, pathological, and molecular indicators of likely tissue of origin. Massively-parallel DNA sequencing can therefore provide comprehensive mutation, DNA copy-number, and mutational signature data that are of significant clinical value for a majority of CUP patients, providing both cumulative evidence for the diagnosis of primary site and options for future treatment.

The Role of 18 FDG PET-CT in Evaluation of Unknown Primary Tumours

An unknown primary tumor (UPT) is defined as a biopsy-proven malignancy whose anatomic origin remains unidentified after diagnostic evaluation. The estimated incidence of unknown primary tumors is 2 %-7 % of all malignancies. In 15-25 % of cases, the primary site cannot be identified even on postmortem examination. The management of these patients remains a clinical challenge. The aim of this study was to determine the role of 18FDG-PET CT in evaluation of primary tumor and its influence on therapeutic management. Fifty patients with histologically-proven metastases of UPT were included. For all patients, the conventional diagnostic work-up was unsuccessful in localizing the primary site. Whole-body PET/CT images were obtained approximately 60 min after intravenous injection of 350-425 MBq of (18) F-FDG. PET/(CT) depicted histologically verified primary tumors in 21of 46 patients (P > .05), achieving detection rates of approx. 61 % in patients presenting with cervical lymph node metastases from unknown primary tumors, and 40 % in those with extra cervical disease presentation. A positive predictive value of 72 % to 92 % was seen for all patients, depending on category of clinical presentation. In this study, PET/CT detection of additional metastases in 14.2 % (3 cases out of 21 true positives) influenced change in management plan. Considering recent studies and the results of this study, whole body FDG-PET/CT has to be considered a useful tool in evaluating metastases from an UPT, allowing an identification of primary tumors in 42 %, and modifying the stage of the disease and oncological treatment in about 50 % of cases. These results suggest the use of PET/CT with FDG in an early phase of the diagnostic evaluation to optimize the management of these patients.

Complete biologic response to taxane based chemotherapy confirmed by [F]FDG PET/CT and surgery in a cancer of unknown primary site

Cancers of an unknown primary site are heterogenous with respect to their clinical and pathologic features. They are generally very aggressive, but specific favorable subsets have a better prognosis. For these favorable subsets, taxane based chemotherapy is very effective for a subset of woman with papillary serous peritoneal adenocarcinoma. A 52 year-old woman underwent [(18)F]-FDG PET/CT for routine health screening. On PET/CT, multiple hypermetabolic lymph nodes were detected in the paraaortic spaces, and there were no other hypermetabolic abnormalities. The patient was diagnosed with an unknown primary cancer that probably originated from the ovary or peritoneum, according to clinical studies and biopsy results. This was not a typical case of a favorable subset of cancer of an unknown primary site, but the tumor showed complete biologic response to taxane based chemotherapy as revealed by PET/CT, and necrotic tumor cells were confirmed by surgery.

Subsequent cancers in patients diagnosed with cancer of unknown primary (CUP): etiological insights?

BACKGROUND

Patterns of subsequent malignancies in patients with cancer of unknown primary (CUP) may provide etiological insight into the primary tumor. The objective of the present study is to quantify risks of the subsequent cancers in CUP patients since such studies are lacking.

PATIENTS AND METHODS

A population-based cohort of CUP was identified from the Swedish Family-Cancer Database of year 2008. Standardized incidence ratios (SIRs) were calculated for developing the following malignancies in 31,357 CUP patients from 1975 to 2008.

RESULTS

A total of 755 CUP patients developed subsequent cancers, showing a significantly increased overall SIR of 1.69 (95% confidence interval 1.57-1.81). Among the most common 32 malignancies, increased SIRs were noted for 16 sites. Over 10-fold increases were observed for squamous cell carcinoma at four sites, possibly as a result of uncontrolled human papillomavirus infection due to faltering immune surveillance. The highest SIRs were observed among CUP patients diagnosed at a younger age and during the first follow-up year.

CONCLUSIONS

Swedish CUP survivors had a higher risk of developing many subsequent cancers. Different patterns of risk excess may be suggestive of possible roles for disease- and therapy-related immunosuppression, reappearance of hidden primary tumors, or genetic predisposition.

Carcinomas of an unknown primary origin--diagnosis and treatment

Carcinomas of an unknown primary origin (CUP) account for 3-5% of all malignancies and are thus among the ten most-frequent cancers worldwide. Having a specific and unique phenotype of early and usually aggressive metastatic dissemination with no identifiable primary tumor, CUP are a challenge for physicians. The diagnostic workup of patients with CUP includes a careful clinical and extensive histopathological examination, as well as the use of imaging techniques. CUP can be divided into favorable and unfavorable subsets. Patients with unfavorable CUP subsets have a poor prognosis with a median survival of approximately 8 months; the optimal chemotherapy regimen for these patients remains to be determined. Although studies have focused on the introduction of new cytotoxic agents with broad-spectrum clinical activity (such as gemcitabine, irinotecan, and taxanes), no randomized trial has provided clear evidence of a survival benefit. Molecular targeted therapies that are approved for other solid tumors are now considered for the treatment of patients with CUP. Molecular diagnostic tools, such as DNA microarray analysis, could help in the search for 'lost' CUP origins. In this Review, we describe the clinical evaluation of patients with CUP, and discuss treatment strategies and outcomes of patients with various CUP subsets.

Cancer microRNAs: from subtype profiling to predictors of response to therapy

MicroRNAs (miRNAs) are key regulators of gene expression that regulate important oncogenes and tumor suppressors. Many miRNAs can also act as oncogenes or tumor suppressors, and thus the altered expression of miRNAs is a hallmark of many cancer types. Dysregulated miRNAs provide a potentially powerful new tool that could be used to enable the characterization of tumor environments and identify novel and important oncogenic pathways. More recently, there has been growing interest in the field of miRNAs as biomarkers of cancer risk, diagnosis and response to therapy. Understanding the associations between miRNA expression and cancer phenotypes, and the potential of miRNA profiling in clinical applications, promises to be highly rewarding in the field of cancer research.

A case of long-term recurrence-free poorly differentiated neuroendocrine carcinoma of lymph nodes treated by surgical resection without any chemotherapy

A 77-year-old man presented with a 2-month history of an enlarged right inguinal lymph node. Diagnostic excisional biopsy of the inguinal lymph node proved it to be a poorly differentiated neuroendocrine carcinoma by histological and immunohistological analyses. We diagnosed a poorly differentiated neuroendocrine carcinoma by histological examination and immunohistological analysis of the resected inguinal lymph node. We performed computed tomographic examination and positron emission tomography, which identified lymph node involvement without any signs of other tumors. Because these tumors had grown expandingly and had been encapsulated locally, we performed an operation to dissect all of the involved lymph nodes. Direct invasion to the right external iliac artery was not detected, and two of the enlarged lymph nodes were successfully resected without any complications. Pathologically, the resected specimen was diagnosed as a neuroendocrine carcinoma with a negative surgical margin and it was similar to the histology of the inguinal lymph node previously resected. The patient had no recurrence for 3 years without receiving any adjuvant treatment. There have been no reports describing a case of poorly differentiated neuroendocrine carcinoma, of unknown origin, which metastasized to other lymph nodes. Although further studies are required, complete resection of the involved lymph nodes should be considered as a choice for localized, expanding growth-pattern disease even if it is undifferentiated type.

[Pathohistology and molecular genetic diagnostics in CUP syndrome]

Patients with cancers of unknown primary (CUP syndrome) represent a relatively large group of cancer patients (5-10%) in whom the histomorphological diagnosis is made from tissue from the metastasis, and the site of the primary tumour remains unclear. The incidence is variable, depending on the definition used and the intensity of the search for a primary tumour. From a biological and prognostic point of view, it is helpful to distinguish eight clinical entities of the CUP syndrome; four of these entities can be subdivided histologically. Histopathologic diagnosis should be performed using a diagnostic algorithm based on the HE morphology and supplemented by immunohistochemistry. With the use of a broad spectrum of immunohistochemical markers, many tumour entities can be diagnosed, so in most cases molecular genetic investigations are not necessary.

New prognostic index to predict survival in patients with cancer of unknown primary site with unfavourable prognosis

AIMS

To identify independent prognostic factors in patients with cancer of unknown primary site (CUP) who do not belong to prognostically favourable subsets, and to develop a prognostic index for predicting survival in these patients.

MATERIALS AND METHODS

In this prospective study, univariate and multivariate analyses of prognostic factors were conducted in a population of 145 patients with CUP in two clinical institutions. Subsets of patients with favourable prognostic features and those requiring well-defined treatment were excluded.

RESULTS

The 1-year overall survival rate for all patients was 42% and the median overall survival was 330 days. Overall survival was significantly related to the following pre-treatment prognostic factors: poor Eastern Cooperative Oncology Group performance status (ECOG PS)>or=2, presence of liver metastasis, elevated serum lactate dehydrogenase (LDH), high white blood cell count, anaemia, age>or=63 years, and prolonged QTc interval in electrocardiography (ECG). In multivariate analysis, four independent adverse prognostic parameters were retained: elevated LDH (hazard ratio 2.21; 95% confidence interval 1.41-3.47; P=0.001), prolonged QTc interval (hazard ratio 2.10; 95% confidence interval 1.28-3.44; P=0.003), liver metastasis (hazard ratio 1.77; 95% confidence interval 1.11-2.81; P=0.016) and ECOG PS>or=2 (hazard ratio 1.69; 95% confidence interval 1.05-2.73; P=0.03). We developed a prognostic index for overall survival based on the following subgroups: good prognosis (no or one adverse factor), intermediate prognosis (two adverse factors) and poor prognosis (three or four adverse factors). The median overall survival for the three subgroups was 420, 152 and 60 days, respectively, P<0.0001.

CONCLUSIONS

This study validated previously identified important prognostic factors for survival in patients with CUP. Prolonged QTc was additionally identified as a strong adverse prognostic factor. We developed a simple prognostic index using performance status, LDH, presence of liver metastasis and QTc interval in ECG, which allowed assignment of patients into three subgroups with divergent outcome.

The role of L1-CAM immunohistochemial staining in the diagnosis of abdominal-pelvic cancer of uncertain primary site in women

OBJECTIVE

The L1 adhesion molecule (L1-CAM,CD171) is over expressed in ovarian and endometrial carcinomas and other tumors derived from the Mullerian tract. Here we evaluated whether L1-CAM could serve as a novel tumor marker for the diagnosis of metastatic abdominal-pelvic cancers of uncertain origin in women.

PATIENTS AND METHODS

During a 6-year period we investigated 28 patients with metastatic abdominal or pelvic cancer with uncertain primary-origin. In all these cases a thorough clinical, surgical, pathologic and immunohistochemistry evaluation was performed and correlated to the L1-CAM expression as determined by immunohistochemical staining.

RESULTS

In 20 patients where the differential diagnosis was primary ovarian or endometrial cancer and primary or recurrent colon cancer, L1 immunohistochemistry staining allowed or supported the correct diagnosis. In four cases L1 staining allowed the correct diagnosis between breast and ovarian cancer. In two cases vaginal metastases of unknown origin were positive to L1 immunohistochemistry staining implying their mullerian origin and one case each of inguinal lymph node metastases and abdominal wall cancer that were positive for L1-CAM, allowed the correct diagnosis of primary ovarian cancer. In a whole, L1-CAM was of crucial role of delinating the final diagnosis in 17 of the 28 cases described.

CONCLUSIONS

L1-CAM, a new tumor marker, was found to be specific for metastatic cancer originating from mullerian origin. Its incorporation into the conventional immunohistochemistry analysis in cases of cancer of unknown primary in women, allows a correct diagnosis and subsequent treatment in the majority of cases with abdominal-pelvic carcinomatosis.

Long-Term Remission in a Patient with Carcinoma of Unknown Primary Site

BACKGROUND

Cancer of unknown primary site also designated as CUP syndrome usually presents as metastatic disease with a poor prognosis and low remission as well as survival rates.

CASE

We report a 46-year-old male with para-aortal and left-sided cervical lymph node metastases. Histological examination of a cervical lymph node revealed papillary carcinoma. Despite thorough investigation, no primary tumor was found. The patient was empirically treated with six courses of the FACP regimen (5-fluorouracil, Adriamycin, cyclophosphamide and cisplatin) combined with radiotherapy (40 Gy) and has remained in complete remission for 124 months.

CONCLUSION

This case indicates that treatment of a patient with cancer of unknown primary site may be rewarded by a benign course. However, complete cure remains a very rare event in CUP. Remission can be achieved with a platinum-containing regimen combined with radiotherapy.