Phase II trial of cisplatin for adenocarcinoma of unknown primary site. IKZ/IKO Clinical Research Group

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.

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.

[Metastatic cáncer presentation. Validation of a diagnostic algorithm with 221 consecutive patients]

BACKGROUND

The use of a diagnostic algorithm for metastatic cancer presentation (MCP) might enhance the diagnosis of primary tumors amenable to treatment with considerable savings both in time and diagnostic examinations.

MATERIALS AND METHODS

From January 1992 to April 1997, all patients admitted with the diagnosis of MCP were prospectively studied. From each patient, a basic study consisting in a clinical interview, complete physical examination, standard blood testing with tumoral markers and chest X-ray were obtained. Patients with a negative basic study were classified as having a metastatic cancer of unknown origin (MUO); in these patients, a protocolized study (abdominal CT scan and mammography among women) were performed. Patients who after the application of the basic and protocolized studies had no primary tumor detected underwent an exhaustive investigation in order to validate the efficiency of the diagnostic algorithm.

RESULTS

Two hundred twenty-one patients were included in the study. The mean age of patients was 63 years (range: 23-82). The main symptom was of bone (30%), neurological (24%), thoracic (16%) and abdominal (16%) origin. The basic study was positive for 138 patients (62.4%), with chest X-ray and physical examination yielding the highest number of diagnoses among these patients. The histology of metastases contributed to the definite diagnosis in 31 patients. Only PSA had a high sensitivity and specificity. Eighty-three patients were classified as MUO. The protocolized study diagnosed the primary tumor in 24 patients (30%), 20 by abdominal CT scan and four by mammography; eight of these patients were deemed to be amenable to treatment. The remaining 59 patients underwent an exhaustive study, and a diagnosis was made in 13; nevertheless, none of them was considered candidate for a specific treatment. Finally, 47 patients (21%) remained undiagnosed. The predominant primary tumors included sites at the lung (42%), prostate (6%) and breast (6%). The most common metastatic locations included bone (42%), central nervous system and liver (24%), and the most common histological types were adenocarcinoma (61%) and undifferentiated carcinoma (15%).

CONCLUSIONS

Lung cancer and MUO represented 62% of MCP. The basic study oriented in two thirds of cases, and the physical examination and chest X-ray showed the highest diagnostic yield. The histology of metastases and PSA had a key, diagnostic relevance. A protocolized study based on abdominal CT scan and mammography (females) can identify the remaining treatable tumors.

A phase II study of mitomycin C, cisplatin and continuous infusion 5-fluorouracil (MCF) in the treatment of patients with carcinoma of unknown primary site

Carcinoma of unknown primary site remains a common clinical diagnosis, accounting for between 5 and 10% of all cancer patients. Numerous combination chemotherapy regimens have been used in the management of carcinoma of unknown primary site, resulting in response rates of 0-48%. We present the results of a single centre phase II study of the use of the combination of mitomycin C (7 mg m(-2) on day 1 of cycles 1, 3 and 5) cisplatin (60 mg m(-2) on day 1) and continuous infusion 5-fluorouracil (300 mg m(-2) daily), MCF, delivered as a 21-day cycle, in patients with carcinoma of unknown primary site. Thirty-one patients with a diagnosis of carcinoma of unknown primary site were treated in Aberdeen Royal Infirmary between 1997 and 2001 with MCF. In total, 136 cycles of MCF were delivered (median of 5 cycles per patient). Toxicity was acceptable, with 19% grade 3 or 4 neutropenia, 16% grade 3 or 4 thrombocytopenia and 13% grade 3 or 4 nausea and vomiting. No cases of neutropenic sepsis were seen and there were no treatment-related deaths, however, six patients developed thrombotic complications. The overall response rate was 27% (CR 3%; PR 23%). Median time to progression was 3.4 months (95% CI 1.1-5.6 months) and median overall survival was 7.7 months (95% CI 5.7-9.8 months). Survival at 1 year was 28%, and at 2 years, 10%. MCF is a tolerable regimen with comparable toxicity, response rates and survival data to most platinum-based combination chemotherapy regimens in use for this devastating disease.

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.