Clinical staging of gynecological cancers

Clinical staging is used to determine the extent and spread of cancer within the body before treatment starts. The location from where the cancer originates is called the ‘primary site’. The extent to which the tumor has spread at the time of diagnosis is called ‘clinical stage’ in medical lexicon. At the time of diagnosis, the cancer may be localized to the primary site, may have spread locally, or may have spread to involve distant sites and organs. The staging system provides information for planning treatment and predict the prognosis. Another purpose of clinical staging is to provide means of sharing clinical experience using an internationally accepted language, and standardizing treatment so that evidence-based, comprehensive cancer care plan can be offered to an individual patient.

For cancers of the female genital tract, two systems of clinical staging are used frequently, the TNM staging system, suggested by the American Joint Committee on Cancer, and the FIGO staging system, suggested by the International Federation of Gynecology and Obstetrics.

Both systems classify the extent of tumor into four main clinical stages; stage I to stage IV. Frequently a question is asked. In which stage is the tumor? ‘1^st stage’ or the ‘2^nd /3^rd stage’ or the ‘4^th stage’. There is no such thing as the ‘4^th stage’ when it comes to clinical staging. Clinical stage means extent of tumor at the time of diagnosis!

For the patient, the staging process involves clinical assessment of the anatomical site, radiological imaging, blood tests, endoscopy, and sometimes even surgical exploration. The stage of cancer is determined by factors including, the size of the tumor, its location within the organ, the depth of invasion, the presence of regional lymph nodes, and presence or absence of disease in distant sites.

Besides clinical examination, radiological imaging plays a crucial role in the staging of gynecological malignancies. It can also be used to monitor treatment response and detect recurrence of the cancer.

Generally speaking there ae two types of imaging techniques. Ultrasound, CT scan and MRI scan provide information about the primary site, size, extent of local spread, and presence or absence of disease in organs, such as, lungs or the liver. These scans delineate the structure accurately and with precision. On the other hand, PET scan and other radio-isotope scans inform us whether the cancer is active or dormant. Occasionally, these scans can also identify small volume of disease in distant sites. It is for this reason, that sometimes both a MRI scan and a PET scan need to be performed.

The most commonly used imaging modalities for gynecological cancers include:

Ultrasound: Ultrasound is a non-invasive imaging technique that uses high-frequency sound waves to create images of the internal organs. It is often used to evaluate pelvic masses and to guide biopsies or other procedures.

Computed Tomography (CT) scan: CT scan uses X-rays and computer technology to create detailed images of the body. It can provide information about the size, location, and extent of the cancer, as well as the presence of any metastases.

Magnetic Resonance Imaging (MRI): MRI uses a powerful magnetic field and radio waves to create detailed images of the body. It is a valuable tool for the staging of gynecological malignancies because it can provide detailed images of the female reproductive system and surrounding structures. It is particularly useful for evaluating the extent of local invasion of the tumor and the involvement of nearby structures such as the bladder, rectum, or lymph nodes.

Positron Emission Tomography (PET) scan: PET scan is a specialized imaging test that uses a radioactive tracer to identify areas of increased metabolic activity in the body. It can help identify areas of cancer spread, even in areas that cannot be seen on other imaging tests.

A diagram of the female genital tract is shown below, followed by description of the clinical staging for the common gynecological malignancies: