Cervical Cancer: Symptoms, Causes, Types & PET-CT as a Diagnostic Tool

Cervical cancer is a tumor of the lower region of the uterus (cervix) that connects with the vagina. It takes a while to develop, and it can, at first, be mistaken for abnormal changes in the cells of the cervix, which then go on to develop without being diagnosed and treated. There are no early signs or symptoms of cervical cancer, and early screening and medical evaluation are very important.

If symptoms do occur, they are irregular periods, unusual (abnormal) bleeding, and pelvic pain. Doctors use other tests when there is a suspicion of, or a diagnosis of, cervical cancer to better understand the cancer and whether it has spread. In some patients, a PET-CT modality is useful as an important imaging modality, especially to look at the spread of cancer and for staging purposes.

What Is Cervical Cancer?

The cervix has various types of cells, and cervical cancer occurs when irregular cells start to multiply out of control. The most frequent location of cervical cancer is where the two cell types of glands and squamous cells come into contact in the endocervix and ectocervix of the cervix. It takes years before cervical cancer becomes serious, and cell changes that eventually lead to cancer occur before the cancer develops. Such changes are more common in women who have been screened for cervical cancer and often are treated without affecting their ability to develop into cancer.

Cervical Cancer Symptoms

Early cervical cancer may not cause any obvious symptoms. When symptoms occur, they can include:

• Vaginal bleeding after sexual intercourse
• Bleeding between periods
• Periods that are heavier or longer than usual
• Vaginal bleeding after menopause
• Watery, foul-smelling, or blood-stained vaginal discharge
• Pelvic pain
• Pain during sexual intercourse

As the cancer gets worse, it produces other symptoms as well, including difficulty or pain when urinating or passing stool, blood in the urine or stool, back pain, abdominal pain, leg swelling, and constant tiredness. Other than cancer, these symptoms also happen due to various other causes. Symptoms that are unusual or do not go away are not to be ignored, though. Your healthcare provider is able to identify the cause of the condition and order proper testing.

Cervical Cancer Causes

Persistent infection with high-risk types of human papillomavirus (HPV) is the main cause of cervical cancer. Indeed, almost all cervical cancers are caused by the result of prolonged infection with high-risk types of HPV. HPV 16 and HPV 18 lead to many cervical cancers in the world. HPV infections are not cancerous and get resolved naturally by the body's immune system in the majority. 

A high-risk HPV infection, however, leads to abnormal changes in the cervical cells if the infection is longstanding and lasts for several years. These are precancerous and, if left untreated, turn into cervical cancer. Some things make it more likely to get HPV that does not go away, or cervical cancer. These include a compromised immune system, smoking or secondhand smoke, and certain reproductive factors. The prevention of cervical cancer includes regular screening and HPV vaccination.

Types of Cervical Cancer

The main cervical cancer types are classified according to the cells in which the cancer begins.

Squamous Cell Carcinoma

Squamous cell carcinoma develops from the thin, flat squamous cells lining the ectocervix. It is the most common type of cervical cancer and accounts for the majority of cases.

Adenocarcinoma

Adenocarcinoma develops from the glandular cells found in the endocervix. It is another major type of cervical cancer. Some less common forms, such as clear cell adenocarcinoma, are also classified under this group.

Adenosquamous Carcinoma

There are cases of cervical cancers showing characteristics of both squamous cell carcinoma and adenocarcinoma. These are called adenosquamous or mixed carcinomas. Other, rare kinds of cervical cancer are also possible. It is important to comprehend what type of cervical cancer is involved since the stage and type of the cancer and other clinical findings have an impact on treatment.

How Is Cervical Cancer Diagnosed?

There are no accurate tests available to detect all cancers. A doctor conducts a physical exam and reviews symptoms and medical history, as well as test results, to determine if the patient has cervical cancer. Tests such as an HPV test, Pap smear test, pelvic exam, colposcopy, and biopsy are used, depending on the circumstances. To get a small piece of tissue from the cervix to study further under the microscope is a procedure known as a biopsy. This is to help find out whether or not there is cancer. Imaging tests are then ordered when necessary to learn the size of the cancer and if the cancer has spread to other parts of the body.

Cervical Cancer and PET-CT

PET-CT scans are a combination of two imaging techniques: Positron Emission Tomography (PET) and Computed Tomography (CT). PET gives data on the metabolic activity of tissues; CT gives detailed images of tissue anatomy. Usefully, the two types of information provide physicians with a more complete picture of regions that are affected by cancer.

A small quantity of a radioactive substance (usually a radioactive glucose called FDG) is given. The increased glucose uptake in many cancer cells compared with the cells in normal organs makes increased signal uptake on PET images more prominent to indicate the sites of abnormal glucose uptake. The CT is able to give detailed structural information about the body.

Role of PET-CT in Cervical Cancer

PET-CT may be recommended in selected patients with cervical cancer to help evaluate the extent of disease. It can provide information about the primary tumour and may help identify involvement of lymph nodes or disease in other parts of the body. This information can be useful when determining the stage of cancer and planning treatment. PET-CT may also be considered when doctors need a broader assessment of the body, particularly when there is concern that the cancer may have spread beyond the cervix.

However, PET-CT does not replace biopsy when tissue confirmation is required. PET-CT findings also need to be interpreted along with clinical information and other investigations because increased tracer uptake can occur in some non-cancerous conditions as well.

What Happens During a PET-CT Scan?

Before the scan, the patient may receive specific preparation instructions, including dietary restrictions and guidance regarding blood glucose levels. A radioactive tracer is administered through a vein, followed by a waiting period that allows the tracer to distribute through the body. During imaging, the patient lies on a scanning table while the PET and CT images are acquired. It is important to remain still during the scan so that the images can be properly evaluated. The complete process can take several hours because preparation, tracer administration, the uptake period, and scanning are all part of the examination.

Molecular Diagnostics and Therapy for PET-CT Imaging

At Molecular Diagnostics and Therapy, PET-CT imaging is performed using modern nuclear medicine and imaging technology. The PET-CT evaluation can help provide metabolic and anatomical information when such imaging is clinically indicated. The need for a PET-CT scan depends on the patient's diagnosis, symptoms, previous test results, and treatment plan. A doctor or oncology team can determine whether PET-CT is appropriate and how its findings should be interpreted alongside other investigations.

Conclusion

There may not be any signs or symptoms of cervical cancer in the early stages, so it is important to have regular screening and be ready to make a medical diagnosis. Persistent infection with high-risk HPV is the primary cause, and there are two major types in particular: squamous cell and adenocarcinoma. Depending on the suspicion or diagnosis of cervical cancer, other tests are employed to diagnose and stage the cancer. Performing a biopsy is essential to establishing a cancer diagnosis, and imaging is essential to learning about how much disease has spread. 

PET-CT is useful in some patients for providing metabolic and anatomical information, and some argue that PET-CT is a crucial tool for assessing lymph node and spread evaluation in selected patients. Molecular Diagnostics and Therapy performs PET-CT scans as part of a full diagnostic work-up for a patient, as recommended by their treating physician.