Visual Inspection
Visual inspection of the cervix, using acetic acid or Lugol’s iodine to highlight precancerous lesions so they can be viewed with the “naked eye”, shifts the identification of precancer from the laboratory to the clinic. Such procedures eliminate the need for laboratories and transport of specimens, require very little equipment and provide women with immediate test results.
A range of medical professionals—doctors, nurses, or professional midwives—can effectively perform the procedure, provided they receive adequate training and supervision. As a screening test, VIA performs equal to or better than cervical cytology in accurately identifying pre-cancerous lesions. This has been demonstrated in various studies where trained physicians and mid level providers correctly identified between 45% and 79% of women at high risk of developing cervical cancer. By comparison, the sensitivity of cytology has been shown to be between 47 and 62%.It should be noted, however, that cytology provides higher specificity than VIA. Like cytology, one of the limitations of VIA is that results are highly dependant on the accuracy of an individual’s interpretation. This means that initial training and on-going quality control are of paramount importance.
VIA can offer significant advantages over Pap in low-resource settings, particularly in terms of increased screening coverage, improved follow up care and overall program quality. Due to the need for fewer specialized personnel and less infrastructure, training, and equipment, with VIA public health systems can offer cervical cancer screening in more remote (and less equipped) health care settings and can achieve higher coverage. Furthermore, providers can share the results of VIA with patients immediately, making it possible to screen and treat women during the same visit. This helps ensure that follow up care can be provided on the spot and reduces the number of women who may miss out on treatment because they are not able to return to the clinic at another time. In a “screen and treat” project in Peru, for example, only 9% of women who screened positive failed to receive treatment in the single-visit approach, compared with 44% of women who were lost to treatment using a multi-visit model.
VIA has successfully been paired with cryotherapy, a relatively simple and inexpensive method of treating cervical lesions that can be performed by primary care physicians and mid-level providers.
Biopsy Procedures
While the pap smear is an effective screening test, confirmation of the diagnosis of cervical cancer or pre-cancer requires a biopsy of the cervix. This is often done through colposcopy, a magnified visual inspection of the cervix aided by using a dilute acetic acid (e.g. vinegar) solution to highlight abnormal cells on the surface of the cervix. Though squamous cell carcinoma is the cervical cancer with the most incidence, the incidence of adenocarcinoma of the cervix has been increasing in recent decades.
- squamous cell carcinoma (about 80-85%)
- adenocarcinoma (about 15% of cervical cancers in the UK)
- adenosquamous carcinoma
- small cell carcinoma
- neuroendocrine carcinoma
Non-carcinoma malignancies which can rarely occur in the cervix include
- melanoma
- lymphoma
Note that the FIGO stage does not incorporate lymph node involvement in contrast to the TNM staging for most other cancers.
For cases treated surgically, information obtained from the pathologist can be used in assigning a separate pathologic stage but is not to replace the original clinical stage.
For premalignant dysplastic changes, the CIN (cervical intraepithelial neoplasia) grading is used.
Staging
Cervical cancer is staged by the International Federation of Gynecology and Obstetrics (FIGO) staging system, which is based on clinical examination, rather than surgical findings. It allows only the following diagnostic tests to be used in determining the stage: palpation, inspection, colposcopy, endocervical curettage, hysteroscopy, cystoscopy, proctoscopy, intravenous urography, and X-ray examination of the lungs and skeleton, and cervical conization.
The TNM staging system for cervical cancer is analogous to the FIGO stage.
- Stage 0 - full-thickness involvement of the epithelium without invasion into the stroma (carcinoma in situ)
- Stage I - limited to the cervix
- IA - diagnosed only by microscopy; no visible lesions
- IA1 - stromal invasion less than 3 mm in depth and 7 mm or less in horizontal spread
- IA2 - stromal invasion between 3 and 5 mm with horizontal spread of 7 mm or less
- IB - visible lesion or a microscopic lesion with more than 5 mm of depth or horizontal spread of more than 7 mm
- IB1 - visible lesion 4 cm or less in greatest dimension
- IB2 - visible lesion more than 4 cm
- Stage II - invades beyond cervix
- IIA - without parametrial invasion, but involve upper 2/3 of vagina
- IIB - with parametrial invasion
- Stage III - extends to pelvic wall or lower third of the vagina
- IIIA - involves lower third of vagina
- IIIB - extends to pelvic wall and/or causes hydronephrosis or non-functioning kidney
- IVA - invades mucosa of bladder or rectum and/or extends beyond true pelvis
- IVB - distant metastasis
