If a woman is suspected to have cervical cancer, some investigations are required to confirm the diagnosis of the disease. Further, cervical cancer investigations can help in determining the extent of invasion and spread of disease to other body parts, which in turn help in choosing an appropriate treatment option.
Following are some commonly used diagnostic tools for cervical cancer:
- Colposcopy: It is a diagnostic technique which uses a colposcope – a device equipped with magnifying lenses, a light source, and some special instruments for biopsy or surgery.
This device enable doctors to closely examine the cervix surface to determine the presence of abnormal cells. Cervix surface is first treated with a 3% acetic acid solution that reacts with the HPV proteins, dehydrate the dysplastic cells (if any), and allow easy identification of any abnormal cells in the cervix.
Some other reagents like Lugol iodine may also be used to distinguish between low and high-grade lesions. Doctor can also collect biopsy samples with the help of a biopsy forceps if an abnormal area is observed during the procedure.
- Cervical Biopsy: Biopsy sample(s) from the cervix is generally collected in case an abnormal area(s) is observed during the colposcopy procedure.
It can provide very useful information about the cancer cells such as the type of cancer, the severity of cancerous changes involved (grade of cancer), and the presence of specific defective genes or proteins. Following are commonly techniques used for collecting biopsy sample from the cervix:
Endocervical curettage/scraping: This technique is used when the entire transformation zone could not be visualized via colposcope. A biopsy sample from the endocervical canal is obtained with the help of a curette scraping or sleeved endocervical brush. The biopsy sample is then tested in a laboratory for the presence of any abnormal/cancerous cells.
Cone biopsy: This is a type of excisional biopsy also known as conization as a cone-shaped biopsy sample is removed from the affected area (mostly from the transformation zone) in the cervix. This technique can be used as a treatment option for certain very early-stage cervical cancers that are limited to superficial cervical layer. This technique is employed for the diagnosis of cervical cancer, when:
-abnormal area extends up to the endocervical canal;
-high-grade cancerous lesion is suspected; or
-invasive carcinoma or adenocarcinoma in situ is suspected.
Following are procedures generally employed for cone biopsy:
-Loop Electrosurgical Excision Procedure (LEEP): In this procedure, a thin wire loop that can be heated with electricity is used to obtain cone biopsy from the transformation zone.
-Cold Knife technique: In this procedure, a surgical scalpel or a laser is used to excise the cervix tissue.
- Imaging Tests: These tests are generally employed after the establishment of the pathological diagnosis. They help to detect the spread of disease to distant body parts and assess the stage of the disease so that an appropriate treatment option can be selected. Alternatively, these tests are employed after treatment to evaluate the treatment efficacy and to detect disease response, progression, or recurrence.
Computed tomography (CT) scan: In this technique, detailed cross-sectional images of body organs are generated using x-rays, with or without a contrast medium. It can help diagnose the spread of disease to nearby/distant lymph nodes and other organs, and may also be used to guide a biopsy needle into the affected area.
Positron emission tomography (PET) scan: This technique uses a radioactive substance (e.g.fluorodeoxyglucose [FDG]) that is given intravenously prior to the procedure. Cancer cells absorb larger amounts of the radioactive substance than normal cells. The areas of higher radioactivity indicate cancerous tissue on the PET scan. Thus, this technique can diagnose spread of disease to distant body parts. It is usually combined with CT scan (PET/CT) .
Magnetic resonance imaging (MRI) scan: This technique provides detailed images of tissues inside the body using radio waves, strong magnetic field, and gadolinium contrast. It can accurately diagnose the extent of invasion and spread of disease to nearby/distant body parts.
Intravenous pyelogram (IVP): In this technique, various x-ray images are taken for the urinary system after injecting a contrast (dye) into patient’s vein. The dye is excreted in the urine by kidneys and outline the complete urinary system on the x-ray images. This helps the doctor to examine the complete urinary system for any abnormal areas. This test is rarely used now with the availability of more advanced imaging techniques like CT scan which can help in examining more body organs in one go.
Chest X-ray: This is relatively less-sensitive imaging technique that can reveal the spread of cancer to lungs or pleura. Spread to lungs or pleura may appear as nodul(s), pleural effusion, etc.