Chemotherapy in carcinomas of unknown primary site: a high-dose intensity policy

[Structured diagnostics and therapy of the CUP syndrome]

BACKGROUND

In the majority of cases, patients with cancer of unknown primary (CUP) have a poor prognosis with no prospect of being cured. Hence, a reasonable focus of diagnostics on its essential targets seems appropriate.

PATIENTS

Particularly important is the identification of all patients who can be assigned to subgroups with a favorable prognosis and who might benefit from a specific therapy. For all other patients, platinum-based combination therapy is the standard cytostatic therapy.

THERAPY

In addition to platinum derivatives, taxanes, gemcitabine and irinotecan can also be used. Promising innovative approaches include targeted therapies, in particular bevacizumab and erlotinib, and identification of the tissue origin with micro-RNA or gene expression analyses which can help identify the most suitable organ-specific therapy for individual patients.

PERSPECTIVES

It would be desirable if the group of patients treated with unspecific therapy could be reduced by improved diagnostics so that these patients could be treated with organ-specific therapy or with molecularly targeted approaches. Micro-RNA and gene expression analyses appear to be interesting for this purpose. Another complementary approach is to improve the treatment results of patients receiving an unspecific standard combination therapy by additional administration of new targeted substances.

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.

Metastases in the Absence of a Primary Tumor: Advances in the Diagnosis and Treatment of CUP Syndrome

INTRODUCTION

The term cancer of unknown primary site (CUP) syndrome is used to describe malignancies in which a complete diagnostic work-up detects metastases in the absence of an identifiable primary tumor.

METHODS

Based on a selective literature review, national and international guidelines, and the experience of the "Arbeitskreis CUP-Syndrom der Arbeitsgemeinschaft Internistische Onkologie der Deutschen Krebsgesellschaft" (CUP Syndrome Committee of the Medical Oncology Joint Working Group of the German Cancer Society), developments in the diagnosis and treatment of CUP syndrome are reported.

RESULTS

Most patients diagnosed with CUP have an unfavorable prognosis, with a life expectancy of less than 12 months. Nevertheless, it is important to identify subsets of patients in whom specific treatment offers the chance of long-term survival or even full recovery.

DISCUSSION

Only rigorous further development of diagnostic tools and treatment protocols will enable an improvement of the poor prognosis of patients with CUP syndrome. Specific molecular treatment strategies have shown promising results.

Forty years experience of treating cancer of unknown primary

Cancer of unknown primary site (CUP) is not a rare tumour. It accounts as the seventh to eighth most frequently diagnosed cancer in a general medical oncology service. Since CUP is not a homogeneous disease and it consists of different favourable and unfavourable sub-sets, treatment of each clinicopathological entity requires a unique approach. The spectrum of therapeutic management includes both locoregional and systemic therapy and should intend to offer optimal benefit to favourable CUP patients and palliative care to unfavourable cases. This review article provides both a historical outline of CUP treatment as well as a helpful therapeutic guide to every oncologist who treats CUP patients.

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.

Les carcinomes de primitif inconnu

PURPOSE

Carcinoma of unknown primary site is a common clinical syndrome, accounting for 2% of cancer patients. Diagnosis is a recurrent challenge for internists. Treatment is difficult and prognosis is still poor. This review presents one synthesis of diagnosis strategies and therapeutic trials. It envisages the interest of new molecular biology methods as well as therapeutic perspectives.

CURRENT KNOWLEDGE AND KEY POINTS

Pathologic examination completed with immunohistochemical tests, and, depending on cases, with electron microscopy, cytogenetics, and molecular biology is a key-point for diagnosis. Diagnosis work-up, based on histological type and on individualization of some clinical presentation, proceeds in three steps. Positron emission tomography is recommended when a curative treatment is planed, particularly in cases of isolated metastasis. Functional status analysed using the performance status and simple biologic parameters (serum lactate dehydrogenase, serum alkaline phosphatase) permit us to assess prognosis. Chemotherapy is offered for patients with a good general health status.

FUTURE PROSPECTS AND PROJECTS

Further evaluation of positron emission tomography, as well as cost-benefit analyses, is warranted. Further randomised trials are necessary to determine the optimal chemotherapy regimen in good-risk patients and the interest of chemotherapy in patients with poor-risk disease. Gene expression profiling and proteomic evaluation, as well as pharmacogenomic offer new investigation fields.

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.

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.

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.

Alternative bimonthly cycles of doxorubicin, cyclophosphamide, and etoposide, cisplatin with hematopoietic growth factor support in patients with carcinoma of unknown primary site

BACKGROUND

Because carcinomas of unknown primary origin are highly malignant tumors with a bad prognosis (median survival, 6-12 months) and no current optimal therapy, the authors designed a prospective dose-dense chemotherapy regimen with the objective of improving the results observed in patients who receive conventional treatment.

METHODS

Eighty-two patients received alternative bimonthly cycles of doxorubicin 50 mg/m(2) with cyclophosphamide 1000 mg/m(2) (AC) and etoposide 300 mg/m(2) with cisplatin 100 mg/m(2) (EP). Cycles were given at 2-week intervals with granulocyte-macrophage-stimulating factor support (5 microg/kg per day) from Day 4 to Day 10. Patients without measurable lesions were included, because the major end point was survival.

RESULTS

The median number of alternative cycles of AC and EP was 4 cycles (range, 1-12 cycles). An objective response was observed in 24 of 62 patients (39%; 95% confidence interval, 30-48%) with measurable lesions, including 6 patients who achieved a complete response. Among 20 patients with nonmeasurable disease, 9 patients (45%) had no evidence of progressive disease at the end of chemotherapy. The overall median survival of 82 patients was 10 months, with 5 patients surviving clinically disease free at 17 months, 29 months, 45 months, 64 months, and 70 months after the end of treatment. Myelosuppression was the most common toxicity. Two toxic deaths occurred.

CONCLUSIONS

Using these doses and schedules, a dose-dense chemotherapy regimen did not appear to improve the outcome of patients with carcinoma of unknown primary site. Alternative studies dealing with news drugs will be required.

Prognostic stratification in UPC: a role for assessing the value of conventional-dose and high-dose chemotherapy for unknown primary carcinoma

High-dose chemotherapy has been advocated by some investigators as a means to circumvent drug resistance, thereby improving treatment results in patients with solid tumors. For patients with unknown primary tumors, this hypothesis has only recently undergone limited testing. Two groups (one from the USA and one from Europe) have published their experience with higher doses of chemotherapy in the treatment of UPC. The results are not superior to those reported by other investigators using more standard doses of chemotherapy. Most importantly, chemotherapy trials for UPC are usually conducted in small populations made up of heterogeneous patient subsets with varying sensitivity to chemotherapy. It seems likely that progress in the management of patients with unknown primary cancers will occur as a result of efforts to improve the understanding of the natural history of this disease coupled with the assessment of novel agents targeted against specific biochemical abnormalities that will be demonstrated to be important in the development and maintenance of these malignancies.

Treatable subsets in cancer of unknown primary origin

The purpose of this study was to investigate the treatable subsets in cancer of unknown primary origin (CUP). Fifty patients (27 males and 23 females; median age, 53 years) with CUP diagnosed between April 1992 and June 1999 were analyzed retrospectively. Of the 50 patients, 39 received chemotherapy: platinum-based in 31, non-platinum-based in 4, and clinical trials of new agents in 4. Of the 39 patients, 13 (33.3%; 95% confidence interval: 19.1 - 50.2%) showed objective responses, with 4 complete responders. Patients with poorly differentiated carcinomas in whom beta-subunit of human chorionic gonadotropin (beta-HCG) was elevated more than 10 mIU / ml and female patients with peritoneal adenocarcinomatosis achieved high response rates (83.3% and 80%, respectively) with platinum-based chemotherapy, as compared with only a 15.3% response rate in the remaining patients. Platinum-based chemotherapy provided promising results in patients with poorly differentiated carcinomas and in female patients with peritoneal adenocarcinomatosis. Significantly elevated serum levels of beta-HCG in patients with poorly differentiated carcinoma might predict a better response to platinum-based chemotherapy. However, the investigation of novel chemotherapeutic approaches is warranted for other groups of patients with CUP.

Carboplatin plus paclitaxel in unknown primary carcinoma: a phase II Hellenic Cooperative Oncology Group Study

PURPOSE

To evaluate the efficacy of the carboplatin/paclitaxel combination in patients with carcinoma of unknown primary site (CUP).

PATIENTS AND METHODS

Seventy-seven consecutive CUP patients (45 women and 32 men; median age, 60 years) were treated with carboplatin at target area under the curve 6 mg/mL/min followed by paclitaxel 200 mg/m(2) as a 3-hour infusion and granulocyte colony-stimulating factor from days 5 to 12. Treatment courses were repeated every 3 weeks to a maximum of eight cycles. Forty-seven patients had adenocarcinomas, 27 had undifferentiated carcinomas, and three had squamous cell carcinomas. Thirty-three patients presented with liver, bone, or multiple organ metastases, 23 with predominantly nodal/pleural disease, and 19 (16 women) with peritoneal carcinomatosis.

RESULTS

The overall response rate by intent-to-treat analysis was 38.7% (95% confidence interval, 27.5% to 49.9%). There were no differences in response between adenocarcinomas and undifferentiated carcinomas, but efficacy varied among clinical subsets. The response rates and median survival times in the three clinically defined subsets were 47.8% and 13 months, respectively, for patients with predominantly nodal/pleural disease, 68.4% and 15 months, respectively, in women with peritoneal carcinomatosis, and 15.1% and 10 months, respectively, in patients with visceral or disseminated metastases. Chemotherapy was well-tolerated.

CONCLUSION

Carboplatin plus paclitaxel combination chemotherapy is effective in patients with predominantly nodal/pleural metastases of unknown primary carcinoma and in women with peritoneal carcinomatosis. However, in patients with liver, bone, or multiple organ involvement, the combination offers limited benefit. The investigation of novel treatment approaches is highly warranted for this group of patients.