**7.4. Truscan or polarprobe**

This is a portable electronic device designed by Polartechnics, Crystalaid microelectronics in Australia, which allows a non-invasive screening for cervical cancer. Its modality of operation involves emission of low voltage electrical impulses when put in contact with the cervix generate real time images of the cervix which is compared with a data base of thousands of colposcopic and cervical biopsy pictures to give a final diagnosis of the optical image gener‐ ated. This is associated with less pain, removes the challenges encountered in the third world in terms of performance of the conventional Pap smear and is noted to improve compliance to screening in women(Quek et al 1998)

#### **7.5. Ovarian carcinoma screening**

Ovarian cancers are the 4th commonest cause of deaths in women in the USA and the Britain with an overall survival of 35% with about 75% of the women universally presenting in advanced stages. This is largely because of none specificity of presentations, absence of a known precursor, and the absence of specific screening test for ovarian cancers. How fre‐ quently should patients be screened for ovarian cancers is not specific the NIH in 1994 recommended that all women with a family history of hereditary cancer syndrome should have a yearly screening for ovarian cancer using the available screening methods.

#### **7.6. Biochemical markers for ovarian cancer screening**

#### *7.6.1. CA125*

CA 125 is one of the biochemical tumor markers known as cancer antigen or carbohydrate Antigen 125. This high molecular glycoprotein was identified using monoclonal antibody OC 125 was discovered by Bast et al in 1980.This modality of screening is nonspecific, which is elevated in 80% of patients with epithelial cancers and about 50% in the stage 1 cancers. It is expressed by all tissues of mullerian origin but not produced by normal ovarian epithelium This has sufficient sensitivity in post menopausal patients since other conditions that will result in a rise in the value of the CA125 such as missed miscarriages, endometriosis, pelvic inflam‐ matory disease and benign molar pregnancy are absent in postmenopausal women with ovarian cancer.

A value of greater than 35umg/ml is considered significant for further evaluation to be done. The specificity of the screening method is about 99.9% with a poor positive predictive value of 26%. The predictive value can however be increased with serial annual CA125 as against a single value.A clinical programme by Skates et al 2003, confirmed that women with serial annual rising level of CA125 are more at risk of developing ovarian cancers than women with steady level (risk of ovarian cancer Algorithm-ROCA).If the risk is greater than 1% the patient will need evaluation using transvaginal ultrasound to determine whelter further evaluation is necessary.

#### *7.6.2. Other tumor markers useful in the screening of ovarian malignancies*

**Urinary gonadotropin peptides** are peptides with sequence similar to B subunit of human chorionic gonadotropin and present in 70% of women with epithelial tumours. The presence of an identifiable ovarian tumour by ultrasound, an elevated CA125 and normal urinary gonadotropin peptide are most likely a benign tumor. **Carbohydrate Antigen 19-9 i**s increased in patients' mucinous ovarian tumours but not in epithelial tumours

**Carcinoembryonic Antigen (CEA):** This is a high molecular weight glycoprotein, which is a good tumour marker for the detection of mucinous ovarian tumours and noted in 90% of mucinous tumours. **Alpha feto protein-**Albumin like protein, which is increased in patients with germ cell tumours except dysgerminonas and teratomas.

**Human placentae alkaline phosphatase:** This is a glycoprotein molecule which has two sub units and is useful in differentiating germ cell tumours from other ovarian tumors but has the draw back of being expressed by other mullerian structures hence is not specific

**Human chorionic gonadotropin:** This is elevated in non-gestational choriocarcinoma, embryonal and polyembryomas.

In order to improve the sensitivity and specificity of tumour markers use of multimarkers blood test like oviplex which has the incorporation of five tumour markers (CA125,C reactive protein, serum amyloid A(SAA), interleutin 6 and 8 have been shown to improve the sensitivity y 94% and 91% specificity especially when it concerns early ovarian cancer detection(Edgell et al, 2010).

Following diagnosis and treatment tumor markers like macrophage colony stimulating factor (MCSF) can be used in the follow up of patients which has a high predictive value for persistent disease and is raised in 68% of patients with ovarian cancer.

#### **7.7. Genetic screening**

women above the age of 30years can be prolonged to 5years if HPV testing is added to

This is a portable electronic device designed by Polartechnics, Crystalaid microelectronics in Australia, which allows a non-invasive screening for cervical cancer. Its modality of operation involves emission of low voltage electrical impulses when put in contact with the cervix generate real time images of the cervix which is compared with a data base of thousands of colposcopic and cervical biopsy pictures to give a final diagnosis of the optical image gener‐ ated. This is associated with less pain, removes the challenges encountered in the third world in terms of performance of the conventional Pap smear and is noted to improve compliance

Ovarian cancers are the 4th commonest cause of deaths in women in the USA and the Britain with an overall survival of 35% with about 75% of the women universally presenting in advanced stages. This is largely because of none specificity of presentations, absence of a known precursor, and the absence of specific screening test for ovarian cancers. How fre‐ quently should patients be screened for ovarian cancers is not specific the NIH in 1994 recommended that all women with a family history of hereditary cancer syndrome should

CA 125 is one of the biochemical tumor markers known as cancer antigen or carbohydrate Antigen 125. This high molecular glycoprotein was identified using monoclonal antibody OC 125 was discovered by Bast et al in 1980.This modality of screening is nonspecific, which is elevated in 80% of patients with epithelial cancers and about 50% in the stage 1 cancers. It is expressed by all tissues of mullerian origin but not produced by normal ovarian epithelium This has sufficient sensitivity in post menopausal patients since other conditions that will result in a rise in the value of the CA125 such as missed miscarriages, endometriosis, pelvic inflam‐ matory disease and benign molar pregnancy are absent in postmenopausal women with

A value of greater than 35umg/ml is considered significant for further evaluation to be done. The specificity of the screening method is about 99.9% with a poor positive predictive value of 26%. The predictive value can however be increased with serial annual CA125 as against a single value.A clinical programme by Skates et al 2003, confirmed that women with serial annual rising level of CA125 are more at risk of developing ovarian cancers than women with steady level (risk of ovarian cancer Algorithm-ROCA).If the risk is greater than 1% the patient

have a yearly screening for ovarian cancer using the available screening methods.

**7.6. Biochemical markers for ovarian cancer screening**

conventional screening (Grade A recommendation)

**7.4. Truscan or polarprobe**

134 Contemporary Gynecologic Practice

to screening in women(Quek et al 1998)

**7.5. Ovarian carcinoma screening**

*7.6.1. CA125*

ovarian cancer.

This is based on the background information that 5-10% of women have hereditary genetic predisposition and more than 90% of inherited ovarian tumours occur as a result of genetic mutations in the BRCA1 and BRCA2 genes resulting in chromosomal structure dysfunction and increased risk of malignant transformation. The presence of BRCA 1 and 2 confers 16-90% risk of development of ovarian cancers by the age of 70years as against the 1.7% in the general population ((Brose MS et al 2002,Struewing JP et al 1997). In addition Lancaster et al 2007 also estimated that germline mutation of the above mentioned genes confers a 85% lifetime risk of breast cancer and 46% risk of ovarian cancers. Also mutations in the gene mismatch repair gene MLH, MSH or MSH6 associated with lynch /hereditary non polyposis colorectal cancer have a 9-12% of ovarian cancer and advised in favor of genetic risk assessment which will enable the physician to develop strategies prevent these genetically enabled tumour, provide counseling advice, chemoprevention and prophylactic surgeries for the benefit of the patient.
