Advances in the clinical laboratory detection of gestational trophoblastic disease

Does Postevacuation β -Human Chorionic Gonadotropin Level Predict the Persistent Gestational Trophoblastic Neoplasia?

β -human chorionic gonadotropin (HCG) level is not a reliable marker for early identification of persistent gestational trophoblastic neoplasia (GTN) after evacuation of hydatidiform mole. Thus, this study was conducted to evaluate β -HCG regression after evacuation as a predictive factor of malignant GTN in complete molar pregnancy. Methods. In this cross-sectional study, we evaluated a total of 260 patients with complete molar pregnancy. Sixteen of the 260 patients were excluded. Serum levels of HCG were measured in all patients before treatment and after evacuation. HCG level was measured weekly until it reached a level lower than 5 mIU/mL. Results. The only predictors of persistent GTN are HCG levels one and two weeks after evacuation. The cut-off point for the preevacuation HCG level was 6000 mIU/mL (area under the curve, AUC, 0.58; sensitivity, 38.53%; specificity, 77.4%), whereas cut-off points for HCG levels one and two weeks after evacuation were 6288 mIU/mL (AUC, 0.63; sensitivity, 50.46%; specificity, 77.0%) and 801 mIU/mL (AUC, 0.80; sensitivity, 79.82%; specificity, 71.64%), respectively. Conclusion. The rate of decrease of HCG level at two weeks after surgical evacuation is the most reliable and strongest predictive factor for the progression of molar pregnancies to persistent GTN.

Normal Production of Human Chorionic Gonadotropin in Perimenopausal and Menopausal Women and After Oophorectomy

Background:

The normal pituitary production of human chorionic gonadotropin (hCG) alongside luteinizing hormone, and its presence in women after bilateral oophorectomy, during perimenopause and menopause, as measured in serum and urine, has been known for 30 years and is described in numerous publications. Last year our group discussed this finding in a correspondence to the editor in the March 15th issue of New England Journal of Medicine, yet the misinterpretation of low-level hCG in these women seems to have increased in magnitude.

Methods:

This is an outcomes study of 36 cases of menopausal hCG referred to the USA hCG Reference Service over a 1-year period, from March 2007 to March 2008.

Results:

Eight cases occurred in women after oophorectomy, 28 were women in menopause/perimenopause. Surgery was postponed in 5 (14%) of 36 cases, and in 3 cases (8%), chemotherapy was unnecessarily administered. In 2 cases, computed tomography scans were cancelled. The average hCG detected was 10 ± 7.2 IU/L in cases receiving an oophorectomy and 9.8 ± 6.7 in perimenopause and 11 ± 6.2 IU/L in menopause cases.

Conclusions:

Low-level hCG production in woman in physiologic perimenopause, in menopause, or in women with prior bilateral oophorectomy is a normal biologic and biochemical phenomenon. Management protocols in all fields need to be changed to accept pituitary hCG as normal and recognize the clinical maneuvers that will secure the diagnosis. Understanding this physiology will avoid needless delays in necessary therapies such as organ transplant procedures and will limit the misadventure of prescribing unnecessary cancer treatments.

Detection of perimenopause or postmenopause human chorionic gonadotropin: an unnecessary source of alarm

OBJECTIVE

The normal pituitary production of human chorionic gonadotropin alongside luteinizing hormone, measurable in menopausal serum and urine was initially reported over 3 decades ago and has been described in numerous subsequent publications. Unfortunately, delays or cancellations of important medical procedures and use of needless chemotherapy still occurs because of the finding of human chorionic gonadotropin in perimenopausal and postmenopausal woman. We describe the problem and a concise approach to this management dilemma in menopausal women.

STUDY DESIGN

This is an outcomes study of 36 cases of perimenopausal and postmenopausal human chorionic gonadotropin evaluated in cases referred to the USA hCG Reference Service.

RESULTS

By report of the provided records, in 6 of 36 cases, unneeded chemotherapy was given for assumed recurrent gestational trophoblastic disease. In 9 cases, surgery was cancelled or postponed and in 3 cases renal transplantation was cancelled at the time of locating a matched donor kidney. In all cases the measured human chorionic gonadotropin was due to menopausal production of pituitary human chorionic gonadotropin. The average human chorionic gonadotropin detected in perimenopausal cases was 6.4 +/- 3.2 IU/L, and in postmenopausal cases was 11.6 +/- 7.0 IU/L or significantly higher. In 24 cases, therapeutic doses of high-estrogen birth control pill were used to confirm pituitary origin with 23 cases demonstrating successful human chorionic gonadotropin suppression.

CONCLUSION

Low levels of human chorionic gonadotropin production in the perimenopausal and postmenopausal state is a normal physiologic phenomenon. Provider education is warranted and management protocols are suggested in all health-related fields to clarify the normality of low level pituitary human chorionic gonadotropin production. Understanding this physiology will avoid delays in necessary therapies such as organ transplants, and will limit the misadventure of prescribing unnecessary treatments for presumed gestational malignancy.

Role of tumor markers in patients with solid cancers: A critical review

The measurement of tumor markers is currently one of the most rapidly growing areas in laboratory medicine. Lack of sensitivity and specificity preclude the use of most existing markers for the early detection of malignancy. For patients with diagnosed malignancy, however, markers are potentially useful in determining prognosis, predicting therapeutic response, maintaining surveillance following curative surgery and monitoring therapy in advanced disease. Clinically useful markers include CEA in the surveillance of patients with diagnosed colorectal cancer, AFP and HCG in the management of patients with non-seminomatous germ cell tumors, HCG in the management of patients with trophoblastic disease, CA 125 for monitoring therapy in patients with ovarian cancer, estrogen receptors for predicting response to hormone therapy in breast cancer and HER-2 for the identification of women with breast cancer likely to respond to trastuzumab (Herceptin). Although widely used, the impact of PSA screening in reducing mortality from prostate cancer remains to be shown.

The classification, functions and clinical use of different isoforms of HCG

HCG is composed of two subunits, HCGalpha and HCGbeta. During early pregnancy, HCG stimulates progesterone production in the corpus luteum, and injection of HCG is widely used to induce ovulation in assisted reproduction treatment (ART). Under experimental conditions, the free subunits have been shown to exert functions other than those of HCG, but the relevance of these remains to be determined. Intact HCG, free subunits and degraded forms of these occur in biological fluids, and determinations of these are important for diagnosis and monitoring of pregnancy, pregnancy-related disorders and several types of cancer. Development of optimal methods for the various forms has been hampered by lack of appropriate standards and expression of the concentrations of the various forms in units that are not comparable. Furthermore, the nomenclature for HCG assays is confusing and in some cases misleading. These problems can now be solved; a uniform nomenclature has been established, and new standards are available for HCG, its subunits HCGalpha and HCGbeta, the partially degraded or nicked forms of HCG and HCGbeta, and the beta-core fragment. This review describes the biochemical and biological background for the clinical use of determinations of various forms of HCG. The clinical use of HCG and studies on HCG vaccines are briefly reviewed.