The clinical value of tumour markers in the management of ovarian cancer

CA 15–3: A Prognostic Marker in Breast Cancer

CA 15–3 (also known as MUC1) is the most widely used serum marker in breast cancer. MUC1 is a large transmembrane glycoprotein which is frequently overexpressed and aberrantly glycosylated in cancer. Physiologically, MUC1 appears to play a role in cell adhesion and the high levels present in cancer may be causally involved in metastasis. At present the main uses of CA 15–3 are in preclinically detecting recurrent breast cancer and monitoring the treatment of patients with advanced breast cancer. In a prospective study of 368 patients we show that patients with high preoperative levels of CA 15–3 (>30.4 U/mL) had a worse outcome than patients with low levels of the marker. In multivariate analysis CA 15–3 as a prognostic marker was independent of both tumor size and nodal status. Furthermore, in multivariate analysis the prognostic impact of CA 15–3 was stronger than that of tumor size and at least as strong as nodal status. CA 15–3 may thus be the first independent prognostic serum marker in breast cancer.

Serum Tumor Markers: Past, State of the Art, and Future

Serum determinations of tumor markers are indispensable in the diagnosis and management of cancer, and therefore play an important role in clinical practice. After a short historical survey, we systematically review a number of contemporary aspects of serum tumor markers related to various organ systems, and briefly indicate possible future developments.

Tumor marker requests in a general teaching Turkish hospital

Serum tumor markers may be requested inappropriately by clinicians. In this retrospective study, we aimed to investigate the appropriateness of TM requests in our hospital. Patients in the study were identified from the TM requests for 3 months between June-August 2004, using the laboratory database. A total of 2249 patients (1351 men, 898 women) were included in the study and there were 6570 TM requests. The number of requests were 1050 (16%) for Carbohydrate Antigen 19-9, 993 (15.1%) for Cancer Antigen 125, 941 (14.3%) for Prostate Specific Antigen, 921 (14%) for free PSA, 925 (14.1%) for Cancer Antigen 15-3, 788 (12%) for Alphafetoprotein, 730 (11.1%) for Carcinoembryonic Antigen and 222 (3.4%) for AFP/Human Chorionic Gonadotrophin. Our findings support the idea that for the evidence-based use of TM requests the education of clinical staff is required. Clear clinical guidelines including recommendations about the appropriate use of TM can be useful for this education process. Careful audit studies are also useful to determine the impact of these guidelines on the practice of evidence-based laboratory medicine.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is <10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

The role of CA125 in clinical practice

BACKGROUND

CA125 is a high molecular weight glycoprotein, which is expressed by a large proportion of epithelial ovarian cancers. The sensitivity and specificity of CA125 are poor and there are no guidelines produced by the Royal College of Pathologists or the Association of Clinical Biochemists to aid clinicians and laboratories in its most appropriate use.

AIM

To identify the patient population having a CA125 measurement and to determine its contribution to individual patient management.

METHODS

A retrospective case note audit looking at patients who had a CA125 measurement performed between April 2000 and April 2002.

RESULTS

The study comprised 799 patients; 751 (94%) were female and 48 (6%) male; 221 (29%) females and 22 (46%) males had an abnormal result. CA125 was mainly used to investigate a wide range of signs and symptoms, and few tests were for follow up or screening of ovarian cancer. In female patients having a CA125 for suspicion of malignancy/ovarian cancer, only 39 (20%) of the abnormal results were caused by ovarian cancer. False positive results were largely caused by another malignancy (48 cases; 26%), benign ovarian disease (26 cases; 14%), and benign gynaecological conditions, particularly leiomyomas (18 cases; 9%). The specificity of CA125 for ovarian cancer increased with concentrations >1000 kU/litre.

CONCLUSIONS

These results confirm the high false positive rate and poor sensitivity and specificity associated with CA125. The substantial inappropriate usage of CA125 has led to results that are useless to the clinician, have cost implications, and add to patient anxiety and clinical uncertainty.

Towards evidence-based use of serum tumour marker requests: an audit of use in a tertiary hospital

BACKGROUND

Serum tumour markers (TM) are often measured in hospital patients. The reasons for their use and their benefits with regards to earlier cancer diagnosis and patient management are not known.

AIMS

To identify the patterns of TM use in a tertiary hospital and to determine the usefulness and appropriateness of requests in this setting.

METHODS

A cross-sectional, retrospective study of TM ordered over a 3-month period was conducted. Data were obtained from patient records. CA-125, CA 15-3, CA 19-9, carcinoembryonic antigen (CEA), and alpha-fetoprotein (AFP) were studied. Prostate specific antigen was not separately investigated. The reasons for ordering, usefulness and appropriateness of use were defined prior to analysis.

RESULTS

A total of 476 TM was ordered in 373 patients. One hundred and six (22%) of all results were abnormal by laboratory criteria. AFP was the most popular test ordered. Forty-seven per cent of patients had no cancer diagnosis. Oncological units (ONC) ordered 27% of tests. The most popular reasons for TM ordering were for screening (36%) followed by diagnostic aid (19%). ONC units ordered TM mainly for monitoring disease status, as opposed to non-ONC units who ordered TM usually for diagnostic aid. TM were deemed appropriately ordered in 69% of cases. Twenty-nine per cent of TM were helpful in patient management. Only four results (<1%) aided in diagnosis.

CONCLUSIONS

The reasons and appropriateness of TM use varied depending on the specialization of the requesting clinician. The current serum TM are most useful as aids in cancer patients, rather than for diagnosis (P <0.0001). Apart from AFP, these TM seem to have limited use in the general medical, non-oncological patients. Guidelines for their use in this setting are needed.

[Gastric metastasis from ovarian carcinoma revealed by a gastro-splenic perforation]

Metastatic disease involving the stomach is unusual. We report the case of a gastric metastasis from ovarian cancer revealed by gastro-splenic perforation. The gastric metastasis was diagnosed 17 years after the diagnosis of primary cancer.

Clinical uses of tumor markers: a critical review

Tumor markers are molecules that indicate the presence of malignancy. They are potentially useful in cancer screening, aiding diagnosis, assessing prognosis, predicting in advance a likely response to therapy, and monitoring patients with diagnosed disease. Because of the low prevalence of most cancers in the general population and the limited sensitivity and specificity of available markers, these tests alone are generally of little value in screening for cancer in healthy subjects. Currently, however, PSA in combination with digital rectal examination and CA 125 together with ultrasound are undergoing evaluation as screening modalities for prostate and ovarian cancer, respectively. Again, because of a lack of sensitivity and specificity, markers are rarely of use in the early diagnosis of cancer. As prognostic indicators, markers may provide information that is independent of traditionally used factors or within subgroups defined by traditional criteria, for example, urokinase plasminogen activator in node-negative breast cancer. At present, the best available marker for predicting response to therapy is the estrogen receptor for selecting hormone-sensitive breast cancers. Many different markers can be used in the surveillance of patients with diagnosed malignancies, the most useful of these being HCG in trophoblastic disease and both AFP and HCG for nonseminomatous testicular germ cell tumors. In general, the currently available tumor markers lack sensitivity for early cancer and specificity for malignancy. The goal of future research should be to develop more sensitive and specific markers, especially for the common cancers.

Effect of topotecan on serum CA-125 in patients with advanced epithelial ovarian cancer

The effect of topotecan on CA-125 serum levels was evaluated in 30 patients with advanced epithelial ovarian cancer. All patients had progressive disease and were relapsing during (11 patients) or after (19 patients) chemotherapy containing paclitaxel and platinum. Topotecan (1.0 mg/m(2)/day) was administered intravenously on Days 1-5 every 3 weeks. The patients had received a median of 2 (1-5) prior regimens. Four patients had increased CA-125 only, and 26 had both measurable disease and increased CA-125. Two patients (7%) achieved a clinical partial response with durations of 5 and 10+ months, respectively. Eighteen other patients (60%) exhibited no clinical change with a median duration of 5+ months (range: 2-11+ months). Among these patients 9 (30%) had a biochemical response. The rate of change in CA-125 (s, slope of the exponential regression curve) during treatment with topotecan was compared with s over a period before treatment. A decrease in s was observed in 20 patients (74%). Comparing the mean values of s before and during topotecan, a significant (P = 0.005) decrease was seen in the CA-125 serum levels. The mean doubling times before and during treatment were 59 and 1421 days, respectively. Toxicity was mainly hematologic. Neutropenia grades III and IV were seen in 16 and 10 patients, respectively. No patients died due to side effects. Generally the side effects were mild to moderate. In conclusion, at the given dose intensity topotecan shows activity in advanced paclitaxel- and platinum-resistant ovarian cancer based on CA-125 measurements.