Cervical Cancer
Overview and Staging
Cervical cancer develops in the cervix, which is the lower, narrow end of the uterus leading to the vagina. It is often caused by human papillomavirus (HPV), a sexually transmitted virus. HPV is so common that it develops at some point in nearly all sexually active people, both women and men. Cervical cancer grows slowly and may not cause symptoms, but it can be detected with regular Pap tests and HPV testing.
Most cervical cancers (about 80 to 90 percent) are squamous cell carcinomas that start in the squamous cells covering the surface of the portion of the cervix closest to the vagina (known as the exocervix). The remaining cases are usually adenocarcinomas that arise from gland cells in the portion of the cervix closest to the uterus (known as the endocervix). The disease typically affects women younger than 50, but more than 15 percent of cases are in women older than 65.
Diagnosing and staging
An abnormal Pap test result is often the first step in diagnosing cervical cancer. After the abnormal Pap test result, you may have a colposcopy (an examination of your cervix during which a biopsy sample may be taken) or diagnostic imaging. A biopsy confirms the presence of cancer.
Staging a cancer is finding out the extent of the cancer, including the tumor size and if and how far it has spread. Determining the stage of cervical cancer is crucial in deciding which treatment options to pursue. Cervical cancer is clinically staged, which means your doctor classifies your cervical cancer based on your physical examination and diagnostic testing.
Cervical cancers are classified according to the tumor, node, metastasis (TNM) system developed by the American Joint Committee on Cancer. The tumor (T) is categorized according to its size and location, whether cancer cells are found in nearby lymph nodes (N), and whether cancer has metastasized (spread) (M) to other parts of the body. Once a cervical cancer has been classified, an overall stage is assigned (see Figures in Staging Illustrations).
Table 1. TNM Cervical Cancer Classifications
| Classification | Definition |
| Tumor (T) | |
| TX | Primary tumor cannot be assessed. |
| T0 | No evidence of primary tumor. |
| T1 | Cervical carcinoma confined to the uterus. |
| T1a | Invasive carcinoma diagnosed only by microscopy. Stromal invasion with a maximum depth of 5.0 mm measured from the base of the epithelium and a horizontal spread of 7.0 mm or less. |
| T1a1 | Measured stromal invasion of 3.0 mm or less in depth and 7.0 mm or less in horizontal spread. |
| T1a2 | Measured stromal invasion of more than 3.0 mm and not more than 5.0 mm, with a horizontal spread of 7.0 mm or less. |
| T1b | Clinically visible lesion confined to the cervix or microscopic lesion greater than T1a/IA2. Includes all macroscopically visible lesions, even those with superficial invasion. |
| T1b1 | Clinically visible lesion 4.0 cm or less in greatest dimension. |
| T1b2 | Clinically visible lesion more than 4.0 cm in greatest dimension. |
| T2 | Cervical carcinoma invading beyond the uterus but not to the pelvic wall or to lower third of the vagina. |
| T2a | Tumor without parametrial invasion. |
| T2a1 | Clinically visible lesion 4.0 cm or less in greatest dimension. |
| T2a2 | Clinically visible lesion more than 4.0 cm in greatest dimension. |
| T2b | Tumor with parametrial invasion. |
| T3 | Tumor extending to the pelvic sidewall and/or involving the lower third of the vagina and/or causing hydronephrosis or nonfunctioning kidney. |
| T3a | Tumor involving the lower third of the vagina but not extending to the pelvic wall. |
| T3b | Tumor extending to the pelvic wall and/or causing hydronephrosis or nonfunctioning kidney. |
| T4 | Tumor invading the mucosa of the bladder or rectum and/or extending beyond the true pelvis. |
| Node (N) | |
| Nx | Regional lymph nodes cannot be assessed. |
| N0 | No regional lymph node metastasis. |
| N0(i+) | Isolated tumor cells in regional lymph node(s) no greater than 0.2 mm. |
| N1 | Regional lymph node metastasis. |
| Metastasis (M) | |
| M0 | No distant metastasis. |
| M1 | Distant metastasis (including peritoneal spread or involvement of the supraclavicular, mediastinal or distant lymph nodes; lung; liver; or bone). |
Table 2. Stages of Cervical Cancer
| Stage | TNM Classification |
| I | T1, Any N, M0 |
| IA | T1a, Any N, M0 |
| IA1 | T1a1, Any N, M0 |
| IA2 | T1a2, Any N, M0 |
| IB | T1b, Any N, M0 |
| IB1 | T1b1, Any N, M0 |
| IB2 | T1b2, Any N, M0 |
| II | T2, Any N, M0 |
| IIA | T2a, Any N, M0 |
| IIA1 | T2a1, Any N, M0 |
| IIA2 | T2a2, Any N, M0 |
| IIB | T2b, Any N, M0 |
| III | T3, Any N, M0 |
| IIIA | T3a, Any N, M0 |
| IIIB | T3b, Any N, M0 |
| IVA | T4, Any N, M0 |
| IVB | Any T, Any N, M1 |
